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1 aqua Journal of Ichthyology and Aquatic Biology Vol. 6 (2), November 2002 Aquapress ISSN

2 aqua - Journal of Ichthyology and Aquatic Biology Managing Editor: Heiko Bleher Via G. Falcone 11, Miradolo Terme (PV), Italy Tel.: /08 - Fax: heiko@pmp.it Scientific Editor: Dr. Walter Ivantsoff Senior Research Fellow, Department of Biological Sciences, Macquarie University, N.S.W. 2109, Australia Tel Fax wivantso@rna.bio.mq.edu.au Editorial Board: Gerald R. Allen, I Dreyer Road Roleystone, W. A. Australia 6111 George W. Barlow, Department of Integrative Biology, University of California, Berkeley, CA , U.S.A. Henri J. Dumont, Rijksuniversiteit Gent, Laboratorium voor Ecologie der Dieren, Zoogeografie en Natuur - behoud, K. L. Ledeganckstraat, 9000 Gent, Belgium Jacques Géry, Chemin du Plantier, Sarlat, France Frank Kirschbaum, Institut für Gewässerökologie und Binnenfischerei, Abt. 4 Forschungsverbund Berlin e. V. Müggelseedamm 310, Berlin, Germany Friedhelm Krupp, Forschungsinstitut Senckenberg, Senckenberganlage 25, Frankfurt am Main, Germany Christian Lévêque, CNRS - Programme Environnement Vie et Sociétès, 1 Place Aristide Briand, Paris Cédex, France Volker Mahnert, Muséum d Histoire Naturelle, Route de Malagnou 1, 1211 Genève 6, Switzerland Robert R. Miller, University of Michigan, Museum of Zoology, Ann Arbor, Michigan 48109, U.S.A. Paolo Parenti, Department of Enviromental Sciences, University of Milan-Bicocca, Piazza della Scienza 1, I Milan, Italy John E. Randall, Bishop Museum, 1525 Bernice Street, P.O. Box A, Honolulu, Hawaii, U.S.A. Wolfgang Schneider, Hessisches Landesmuseum, Darmstadt, Friedensplatz 1, Darmstadt, Germany Lothar Seegers, Grenzstraße 47b, Dinslaken, Germany Wolfgang Villwock, Universität Hamburg, Zoologisches Institut und Zoologisches Museum, Martin-Luther-King- Platz 3, Hamburg, Germany Chem Yi-yu, Institute of Hydrobiology, Academia Sinica, Wuhan Hubei, P. R. China Scope and aims aqua is an international journal which publishes original scientific articles in the fields of systematics, taxonomy, bio geography, ethology, ecology, and general biology of fishes, amphibians, aquatic invertebrates, and plants. Papers on freshwater, brackish, and marine organisms will be considered. aqua is fully refereed and aims at publishing manuscripts within 2-4 months of acceptance. With the pub li cation of aqua we are pursuing a new concept: In view of the importance of colour patterns in species identi fication and animal ethology, authors are encouraged to submit colour illustrations as well as descriptions of coloration. It is our aim to provide the international scientific community with an efficiently published series meeting high scientific and technical standards. Call for papers The editors welcome the submission of original manuscripts which should be sent directly to the scientific editor. Full length research papers and short notes will be considered for publication. There are no page charges and colour illustrations will be published free of charge. Authors will receive 50 free reprints of each paper. Subscription Notice A volume (4 issues) of aqua will be published each year, each issue comprising 48 pages (includ ing cover). The annual subscription rate is US$ plus postage US$ / Euro 26,00 plus postage Euro 10,50 (priority postage US$ 16.00/Euro 17,00). Subscription enquires should be sent to the address given below or our aquapress@pmp.it ISSN Publisher: Aquapress, Redazione aqua, I Miradolo Terme (Pavia), Italy Printer: Grafiche Dessí s.r.l., (Torino) Italy Typesetting: Rossella Bulla 2002 aqua, Journal of Ichthyology and Aquatic Biology

3 Zusammenfassung Anhand von Exemplaren, die im Januar 2002 während einer Conservation International Korallenriffstudie gesammelten wurden, werden zwei neue Pomacentriden aus dem nordwestlichen Madagaskar beschrieben. Pomacentrus atriaxillaris wird anhand von drei Exemplaren (25,4 bis 64,0 mm SL), die in Tiefen von 10 bis 27 m über einem Sand-Schuttboden gefangen wurden, beschrieben. Sie ist mit P. reidi Fowler & Bean aus den Philippinen, dem östlichen Indonesien, Papua-Neuguinea, Palau, Solomon Inseln, Vanuatu sowie vom nördlichen Großen Barrierenriff (Australien), verwandt. P. atriaxillaris ist leicht an dem relativ großen schwarzen Punkt an der oberen Brustflossenbasis, besonders aber an der Schwarzfärbung der Brustaqua, Journal of Ichthyology and Aquatic Biology Descriptions of two new species of damselfishes (Pomacentridae: Pomacentrus) from Madagascar Gerald R. Allen Department of Aquatic Zoology, Western Australian Museum, Francis Street, Perth, Western Australia 6000 and Conservation International, 1919 M. Street N.W. Suite 600, Washington, DC 20036, U.S.A. Accepted: Keywords Taxonomy, marine fishes, Madagascar, Pomacentridae, Pomacentrus, new species Abstract Two new species of pomacentrid fishes are described from north-western Madagascar, based on specimens collected during a Conservation International coral reef survey in January Pomacentrus atriaxillaris is described from three specimens mm SL, collected in areas where the bottom is sand-rubble, at depths of m. It is related to P. reidi Fowler & Bean from the Philippines, eastern Indonesia, Papua New Guinea, Palau, Solomon Islands, Vanuatu, and the northern Great Barrier Reef, Australia. P. atriaxillaris is readily distinguished by the relatively large black spot at the upper pectoral fin base and particularly by the black coloration of the pectoral fin axil, as well as having a more angular posterior dorsal and anal fin profile. Pomacentrus caeruleopunctatus is described from four specimens, mm SL, collected in areas of mixed live coral and rubble at depths of between 7-10 m. It is most similar to P. caeruleus Quoy & Gaimard, which is widely distributed in the western Indian Ocean. The two species differ in colour pattern details, body depth (P. caeruleus is more slender), and the greater maximum size of P. caeruleopunctatus. flossenaxel, zu erkennen. Diese Art hat auch ein mehr winkelförmiges Rückenflossen- und Afterflossenprofil. Pomacentrus caeruleopunctatus wird anhand von vier Exemplaren (62,0 bis 72,9 mm SL) beschrieben, die in einem Gebiet mit lebenden Korallen und Bodenschutt in Tiefen zwischen 7 und 10 m gefangen wurden. Diese Art ist P. caeruleus Quoy & Gaimard, die im westlichen Indischen Ozean weit verbreitet ist, sehr ähnlich. Die zwei Arten unterscheiden sich in Einzelheiten des Farbmusters, Körperhöhe (P. caeruleus ist viel schlanker) und in der Maximalgröße von P. caeruleopunctatus. Résumé Deux nouvelles espèces de Pomacentridés sont décrites du nord-ouest de Madagascar, sur base de spécimens collectés lors d'une étude des récifs coralliens de la Conservation International, en janvier Pomacentrus atriaxillaris est décrit à partir de trois spécimens de 25,4-64,0 mm LS, collectés à des endroits où le fond est formé de gravats sableux, à des profondeurs de m. L'espèce est proche de P. reidi Fowler & Bean des Philippines, de l'est indonésien, de Papouasie Nouvelle-Guinée, Palau, les îles Salomon, Vanuatu et le nord de la Grande Barrière de corail australienne. P. atriaxillaris se distingue facilement par une tache noire relativement grande à la base supérieure de la pectorale et, surtout, par la couleur noire de l'aisselle de la pectorale, ainsi que par le profil plus anguleux de la dorsale postérieure et de l'anale. P. caeruleopunctatus est décrit sur base de quatre spécimens, de 62,0-72,9 mm LS, collectés à des endroits de coraux vivants variés et de gravats, à des profondeurs de 7-10 m. Il se rapproche le plus de P. caeruleus Quoy & Gaimard, largement distribué à l'ouest de l'océan Indien. Les deux autres espèces se distinguent par des détails du patron de coloration, la hauteur du corps (P. caeruleus est plus élancé), et la plus grande taille maximale de P. caeruleopunctatus. Sommario Sono descritte due nuove specie di pomacentridi sulla base di esemplari raccolti da una spedizione di Conservation International effettuata nel gennaio aqua vol. 6 no

4 Descriptions of two new species of damselfishes (Pomacentridae: Pomacentrus) from Madagascar presso la barriera corallina del Madagascar nordoccidentale. La descrizione di Pomacentrus atriaxillaris si basa su tre esemplari di mm SL, raccolti in aree dai fondali misti di sabbia e pietrisco e a profondità di m. Si tratta di una specie vicina a P. reidi Fowler & Bean diffusa nella Filippine, Indonesia orientale, Papua Nuova Guinea, Palau, Isole Solomone, Vanuatu e la parte settentrionale della Grande Barriera Corallina Australiana. P. atriaxillaris si contraddistingue per la presenza di una grande macchia scura alla base superiore della pinna pettorale e soprattutto per la colorazione nera all ascella della pettorale, come pure per avere un più acuto profilo posteriore della pinna dorsale e di quella anale. Pomacentrus caeruleopunctatus viene descritto sulla base di quattro esemplari di mm SL, raccolti in aree sassose miste a corallo vivo a profondità di 7-10 m. È una specie simile a P. caeruleus Quoy & Gaimard, largamente diffuso nell Oceano Indiano occidentale. Le due specie differiscono nei dettagli della colorazione, nell altezza del corpo (P. caeruleus è più allungato) e per le maggiori dimensioni massime riscontrate in P. caeruleopunctatus. Introduction Damselfishes of the family Pomacentridae are among the most common inhabitants of tropical coral reefs and sub-tropical rocky reefs. Allen (1991) recorded 321 species in 28 genera, but since then approximately 25 additional species have been described or resurrected from synonymy (see Allen & Adrim, 2000). The two largest genera, Chromis Cuvier and Pomacentrus Lacépède, have accounted for a large percentage of new discoveries over the past three decades. In combination, they contain 140 species or about 40 percent of all pomacentrids. The present paper describes two new species of Pomacentrus collected by the author during a coral reef survey by Conservation International in January They were the only new fishes procured during the 16-day expedition. Methods The methods of counting and measuring are the same as those described by Allen (1975) except the length of the dorsal and anal spines are measured proximally at the base of the spine rather than the point where the spine emerges from the scaly sheath. The last dorsal and anal soft rays are split at the base and are counted as a single element in each case. The decimal figure.5 appearing in the scale count above the lateral line refers to a small truncated scale at the base of the dorsal fin. All fish lengths are expressed as standard length (SL), unless stated otherwise. Head length is abbreviated as HL. Counts and proportions appearing in parentheses apply to the range for the paratypes. Due to the damaged condition of the smaller paratype, only the holotype and largest paratype were used for measurements and most counts of Pomacentrus atriaxillaris. Proportional measurements expressed as percentage of the standard length are provided in Table I. Type specimens are deposited at the Western Australian Museum, Perth (WAM). Pomacentrus atriaxillaris n. sp. (Figs. 1-2; Table I) Holotype: WAM P , 64.0 mm SL, Marie Bank, Mitsio Islands, northwestern Madagascar ( S, E), 12 m, spear, G. R. Allen, 12 January Paratypes: WAM P , 2 specimens, mm SL, Andavakalovo Island, near Nosy Hara, north-western Madagascar ( S, E), 27 m, spear, G. R. Allen, 17 January Diagnosis Dorsal rays XIV,14; anal rays II,14-15; pectoral rays 18-19; tubed lateral line scales 18-20; gill rakers (total 21-24); body depth in SL; colour pale grey, slightly darker on upper part of head and back, with dark grey scale outlines (most conspicuous on back and nape); dorsal, anal, and caudal fins dark charcoal grey, a pale grey submarginal stripe on dorsal fin; pectoral fins translucent with blackish spot at upper base and covering most of fin axil; pelvic fins white. Description Dorsal rays XIV,14; anal rays II,15 (II,14); all dorsal and anal soft rays branched, the last to base; pectoral rays 19 (18-19), the upper and lowermost pairs unbranched; pelvic rays I,5; principal caudal rays 15, the median 13 branched; upper and lower procurrent caudal rays 4, the posteriormost segmented; scales in longitudinal series 28; tubed lateral line scales of holotype 18 on left side and 20 on right, those of paratypes damaged; posterior midlateral scales with a pore or deep pit (in continuous series) 8; scales above lateral line to origin of dorsal fin 3.5; scales above lateral line to base of middle dorsal spine 1.5; scales below lateral line to origin of anal fin 8.5; gill rakers ( ), total rakers 24 (21-22). Body ovate, the depth 1.9 (2.1) in SL, and compressed, the width 2.5 (2.8) in body depth; HL 3.2 in SL; dorsal profile of head evenly-rounded from dorsal fin origin to snout; snout shorter than orbit, its length 3.9 (5.1) in HL; orbit diameter 2.9 (3.0) in HL; interorbital space convex, its width 3.5 (4.3) in HL; caudal peduncle depth 2.2 (2.3) in HL; caudal peduncle length 2.5 in HL. Mouth terminal, small, and oblique, forming an angle of about 37 to horizontal axis of head and body; maxilla nearly reaching a vertical at anterior edge of pupil, the upper jaw length 3.3 (3.1) in HL; teeth mainly uniserial except for a few slender buttress teeth in spaces between main row of teeth at front of jaws; teeth incisiaqua vol. 6 no

5 Gerald R. Allen Fig. 1. Pomacentrus atriaxillaris, holotype, 64.0 mm SL, north-western Madagascar. Photo by G. R. Allen. form to conical in shape, about 40 (38) in each jaw (excluding buttress teeth). Tongue pointed, set far back in mouth. Gill rakers long and slender, the longest on lower limb near angle about two-thirds length of longest gill filaments. Anterior nostril round with slightly raised rim, directly anterior to middle of eye and about midway between anterior edge of eye and upper lip; posterior nostril inconspicuous, barely larger than cephalic sensory pores, situated above and behind anterior nostril and close to anterior edge of orbit. Opercle ending posteriorly in a flat spine, the tip acute but short, barely projecting from beneath a large scale; margin of preopercle with 26 serrae on left side of holotype (11 plus several low crenulations in juvenile paratype); preorbital with 1-2 blunt serrae posteriorly and separated by a notch from suborbital series; lower edge of suborbital with 6-7 serrae (none on juvenile paratypes). Scales finely ctenoid; head scaled except lips, tip of snout, preorbital, and suborbital; a scaly sheath at base of dorsal and anal fins, averaging about one-half pupil width at base of spinous portion of dorsal fin and slightly less at base of anal fin; a column of scales on each membrane of dorsal and anal fins, narrowing distally, those on spinous portion of dorsal fin progressively longer, reaching at least two-thirds distance to spine tips on posterior membranes, then gradually shorter on soft portion; small scales on caudal fin extending about two-thirds distance to posterior margin; small scales on basal one-fifth of pectoral fins; a cluster of several scales forming median process, extending posteriorly from between base of pelvic fins, its length nearly half that of pelvic spine; axillary scale above base of pelvic spine about one-third length of pelvic fin. Origin of dorsal fin over first lateral line scale, the predorsal distance 2.6 (2.9) in SL; base of soft portion of dorsal fin contained about 2.6 times in base of spinous portion; dorsal fin spines gradually increasing in length to about sixth or seventh spine, remaining spines subequal; first dorsal spine 4.2 (4.5) in HL; seventh dorsal spine 2.2 (1.9) in HL; last dorsal spine 2.2 Fig. 2. Pomacentrus atriaxillaris, juvenile, about 40.0 mm SL, north-western Madagascar. Photo by G. R. Allen. 47 aqua vol. 6 no

6 Descriptions of two new species of damselfishes (Pomacentridae: Pomacentrus) from Madagascar Table I. Proportional measurements of selected type specimens of Pomacentrus atriaxillaris and P. caeruleopunctatus as percentages of the standard length. P. atriaxillaris P. caeruleopunctatus Holotype Paratype Holotype Paratype Paratype Paratype WAM WAM WAM WAM WAM WAM P P P P P P Standard length (mm) Body depth Body width Head length Snout length Orbit diameter Interorbital width Upper jaw length Caudal peduncle depth Caudal peduncle length Predorsal length Preanal length Prepelvic length Length dorsal fin base Length anal fin base Length pectoral fin Length pelvic fin Length pelvic fin spine Length first dorsal spine Length seventh dorsal spine Length last dorsal spine Length longest dorsal ray Length first anal spine Length second anal spine Length longest anal ray Length caudal fin Fig. 3. Pomacentrus reidi, about 70.0 mm SL, Rabaul, New Britain. Photo by G. R. Allen. aqua vol. 6 no

7 Gerald R. Allen (2.1) in HL; membranes of spinous portion of dorsal fin slightly incised; eighth dorsal soft ray longest, 1.2 (1.0) in SL; first anal spine 5.8 (5.1) in HL; second anal spine 2.3 (2.1) in HL; longest (tenth) anal soft ray 1.4 (1.3) in HL; caudal fin emarginate with angular lobes, its length 0.9 (0.8) in HL; fourth pectoral ray longest, 1.1 (1.0) in HL; pelvic spine 2.0 (1.9) in HL; first soft ray of pelvic fin forming short filament, 1.1 (0.9) in HL. Colour when fresh or alive (from underwater photographs and field notes): freshly collected holotype generally pale grey, slightly darker on upper part of head and back with darker grey scale outlines, most conspicuous on back and nape; dorsal, anal, and caudal fins dark charcoal grey, a pale grey submarginal stripe on dorsal fin; pectoral fins translucent with blackish spot at upper base and covering most of axil; pelvic fins white. The two juvenile paratypes are similar, but the cheek and snout are light blue and there are faint blue spots on the rear part of the caudal peduncle. There is also a fine blue margin on the dorsal and anal fins. Colour in alcohol: holotype generally tan, except dusky light brown on upper part of head and back; dorsal, anal, and caudal fins dusky brownish, a whitish submarginal stripe on dorsal fin; pectoral and pelvic fins translucent with dark brown spot at upper pectoral-fin base and covering most of pectoral-fin axil. The two juvenile paratypes are generally lighter than the holotype, basically light tan with dusky brown dorsal, anal, and caudal fins. Although they possess the characteristic dark spot on the upper pectoral fin base, the dark marking on the axil of the fin is less vivid than on the holotype. Etymology This species is named Pomacentrus atriaxillaris from the Latin ater (black) and axillaris (of an angle) in reference to the characteristic black pectoral fin axil. Distribution and habitat Pomacentrus atriaxillaris is currently known only from north-western Madagascar and appears to be relatively scarce. A group of about 10 adults was observed at the type locality at a depth of m. The habitat consisted of mainly rubble bottom at the base of a gently-sloping reef. In addition, several juveniles were encountered on sand-rubble bottoms in m depth. Adult fish appeared to feed on plankton, while swimming up to 2-3 m above the bottom. Juveniles were generally shy and remained close to rocky shelter. Comparisons Pomacentrus atriaxillaris is most closely related to P. reidi Fowler and Bean, 1928 (Fig. 3) from the Philippines, eastern Indonesia (Sulawesi and Molucca Islands to New Guinea), Papua New Guinea, Palau, Solomon Islands, Vanuatu, and the northern Great Barrier Reef of Australia (Allen, 1991). The two species are very similar in general appearance, most meristic features (including 14 dorsal spines, a count found in a minority of Pomacentrus), and coloration. However, P. atriaxillaris is readily separated by the relatively large black spot at the upper pectoral fin base and particularly by the black coloration of the pectoral fin axil. In contrast, P. reidi has a tiny pectoral spot, which does not invade the axil. Moreover, there is rarely any evidence of the pectoral spot in preserved specimens of P. reidi. Another difference involves the shape of the posterior profile of the dorsal and anal fins. The angle at the rear part of these fins is relatively acute in P. atriaxillaris compared to the more rounded profile of P. reidi. There also appears to be a difference in the number of tubed lateral line scales and a possible modal difference in pectoral ray counts, although additional specimens of P. atriaxillaris would be desirable before making a definitive decision. P. reidi generally possesses tubed lateral line scales and pectoral rays. In contrast, P. atriaxillaris has lateral line scales (holotype with 18 tubed scales on the left side and 20 on the right (no counts possible for paratypes due to damaged condition) and 18 (1 specimen) or 19 (2 specimens) pectoral rays. Comparative material examined at WAM consisted of 25 specimens of P. reidi, mm SL, from Indonesia (Moluccas), Papua New Guinea (Madang, Manus, New Britain, and Bougainville), Vanuatu, and Australia (northern Great Barrier Reef and Ashmore Reef). Pomacentrus caeruleopunctatus n. sp. (Figs. 4-6; Table I) Holotype: WAM P , 72.9 mm SL, Marie Bank, Mitsio Islands, north-western Madagascar ( S, E), 7-10 m, spear, G. R. Allen, 12 January Paratypes: WAM P , 3 specimens, mm SL, collected with holotype. Fig. 4. Pomacentrus caeruleopunctatus, holotype, 72.9 mm SL, north-western Madagascar. Photo by G. R. Allen. 49 aqua vol. 6 no

8 Descriptions of two new species of damselfishes (Pomacentridae: Pomacentrus) from Madagascar Diagnosis Dorsal rays XIII,13; anal rays II,15; pectoral rays 18; tubed lateral line scales 17-19; gill rakers (total, 20-22); body depth in SL; mainly blue with dark grey scale margins; most of body scales with 2-3 intense blue, horizontally-elongate spots; narrow blackish bar on rear margin of preopercle, and slightly wider blackish bar on rear upper margin of opercle; dorsal, anal, and caudal fins generally charcoal grey to blackish with fine blue margins and pair of submarginal blue stripes; sheath scales at base of dorsal and anal fins and interradial scales of dorsal, anal, and caudal fins bright blue, also blue Fig. 5. Pomacentrus caeruleopunctatus, adult, about 75 mm SL, north-western Madagascar. Photo by G. R. Allen. Fig. 6. Juveniles of Pomacentrus caeruleus (left) and Pomacentrus caeruleopunctatus, about 40 mm SL, north-western Madagascar. Photo by G. R. Allen. aqua vol. 6 no

9 Gerald R. Allen streaks on posterior edge of dorsal and anal fins; pectoral fins pale yellow with blackish bar across base; pelvic fins pale yellow with blue anterior edge. Description Dorsal rays XIII,13; anal rays II,15; all dorsal and anal soft rays branched, the last to base; pectoral rays 18, the upper 2 and lowermost unbranched; pelvic rays I,5; principal caudal rays 15, the median 13 branched; upper and lower procurrent caudal rays 5 or 6, the posterior 1-2 segmented; scales in longitudinal series 28; tubed lateral line scales 18 (17-19); posterior midlateral scales with a pore or deep pit (in continuous series) 8 (5-9); scales above lateral line to origin of dorsal fin 3.5; scales above lateral line to base of middle dorsal spine 1.5; scales below lateral line to origin of anal fin 8.5; gill rakers ( ). Body ovate, relatively elongate for the genus, the depth 2.3 ( ) in SL, and compressed, the width 2.4 ( ) in body depth; HL 3.4 ( ) in SL; dorsal profile of head more or less strait from dorsal fin origin to front of eye, except for slight concavity just behind eye in large (> 66 mm SL) adults; snout shorter than orbit, its length 4.5 ( ) in HL; orbit diameter 3.2 ( ) in HL; interorbital space convex, its width 4.3 ( ) in HL; caudal peduncle depth 2.0 ( ) in HL; caudal peduncle length 2.4 ( ) in HL. Mouth terminal, small, and oblique, forming an angle of about 38 to 42 to horizontal axis of head and body; maxilla reaching a vertical about midway between anterior edge of orbit and anterior edge of pupil, the upper jaw length 3.4 ( ) in HL; teeth biserial with outer primary row of incisiform to conical teeth and inner row of slender buttress teeth in spaces between main row of teeth; about 38 (35-39) teeth in each jaw (excluding buttress teeth). Tongue pointed, set far back in mouth. Gill rakers long and slender, the longest on lower limb near angle about two-thirds length of longest gill filaments. Anterior nostril round with slightly raised rim, directly anterior to middle of eye and about midway between anterior edge of eye and upper lip; posterior nostril inconspicuous, difficult to differentiate from surrounding cephalic sensory pores, situated above and behind anterior nostril and close to anterior edge of orbit. Opercle ending posteriorly in a flat spine, the tip acute but short, barely projecting from beneath a large scale; margin of preopercle with 22 serrae on left side of holotype (19-24); preorbital with single blunt serra; suborbital with 4 (2-4) serrae along lower edge. Scales finely ctenoid; head scaled except lips, tip of snout, preorbital, and suborbital; a scaly sheath at base of dorsal and anal fins, averaging about one-half pupil width at base of dorsal and anal fins; a column of scales on each membrane of dorsal and anal fins, narrowing distally and becoming progressively longer to about middle of soft portion of fin, then gradually shorter on remaining soft portion of fins; small scales covering nearly entire caudal fin, except outer margin; small scales on basal one-fifth of pectoral fins; a triangular cluster of several scales forming median process, extending posteriorly from between base of pelvic fins, its length more than half that of pelvic spine; axillary scale above base of pelvic spine slightly less than one-third length of pelvic fin. Origin of dorsal fin over second lateral-line scale, the predorsal distance 3.1 ( ) in SL; base of soft portion of dorsal fin contained about 2.0 ( ) times in base of spinous portion; dorsal fin spines gradually increasing in length to last spine; first dorsal spine 4.4 ( ) in HL; seventh dorsal spine 2.3 ( ) in HL; last dorsal spine 1.8 ( ) in HL; membranes of spinous portion of dorsal fin slightly incised; eighth dorsal soft ray longest, 1.3 ( ) in SL; first anal spine 4.8 ( ) in HL; second anal spine 2.0 ( ) in HL; longest (tenth) anal soft ray 1.3 ( ) in HL; caudal fin emarginate with angular lobes, its length 1.0 ( ) in HL; fourth pectoral ray longest, 1.1 ( ) in HL; pelvic spine 1.8 ( ) in HL; first soft ray of pelvic fin forming short filament, 1.0 ( ) in HL. Colour in life (from underwater photos): most of head and body blue with dark grey scale margins, except nape charcoal grey; most of body scales with 2-3 intense blue, horizontally-elongate spots; narrow blackish bar on rear margin of preopercle, and slightly wider blackish bar on rear upper margin of opercle; dorsal, anal, and caudal fins generally charcoal grey to blackish with fine blue margins and pair of submarginal blue stripes; sheath scales at base of dorsal and anal fins and inter-radial scales of dorsal, anal, and caudal fins bright blue, also blue streaks on posterior edge of dorsal and anal fins; pectoral fins pale yellow with blackish bar across base; pelvic fins pale yellow with blue anterior edge. A juvenile fish that was photographed (estimated 40 mm SL) was similar in colour to adults, except the pelvic fins were brighter yellow, the dark bar on the upper edge of the opercle was intense blue, and there was a blackish spot on the upper pectoral fin base rather than a narrow bar across the entire fin base. Colour in alcohol: holotype medium brown with narrow, dark brown scale margins; a narrow brown bar on rear margin of preopercle, and slightly wider brown bar on rear upper margin of opercle; dorsal, anal, and caudal fins generally dark brown with trio of submarginal, pale grey stripes on soft dorsal fin; pectoral fins translucent whitish with brown bar across base, pectoral fin axil whitish; pelvic fins mainly light grey except dusky brown along anterior edge. Two paratypes are very similar in colour, but the third paratype (64.0 mm SL) has a considerably darker body (about the same colour as the dorsal, anal, and caudal fins). 51 aqua vol. 6 no

10 Descriptions of two new species of damselfishes (Pomacentridae: Pomacentrus) from Madagascar Etymology This species is named Pomacentrus caeruleopunctatus, from the Latin caeruleus for sky-blue and punctum for little dot, in reference to the characteristic blue spots on the body scales. Allen, G. R. & M. Adrim Amblypomacentrus clarus, a new species of damselfish (Pomacentridae) from the Banggai Islands, Indonesia. Records of the Western Australian Museum, 20: Distribution and habitat Pomacentrus caeruleopunctatus is currently known only from north-western Madagascar, where it was common in areas of mixed live coral and rubble at depths between about 5 and 15 m. It apparently feeds on planktonic items as individuals were usually seen in groups, well above the bottom. Comparisons Pomacentrus caeruleopunctatus appears to be most similar to P. caeruleus Quoy and Gaimard 1825, which ranges widely in the western Indian Ocean from East Africa to the Maldives. Both species are primarily blue with yellow pelvic fins, relatively elongate for the family, and exhibit similar meristic features. Moreover, they both possess horizontally elongate blue marks on the scales. These marks are most evident on the posterior part of the body of P. caeruleus and there is usually a single mark on each scale. In contrast, P. caeruleopunctatus, usually has 2-3 marks per scale and they are found over the entire body. Other colour differences are evident in juveniles (Fig. 6). The most noticeable of these involve the posterior part of the body and adjoining fins, which are yellow in P. caeruleus and dark blue in P. caeruleopunctatus. The body depth of P. caeruleopunctatus is generally greater than that of P. caeruleus ( versus ). There is also a substantial difference in maximum size. The holotype of P. caeruleopunctatus is 72.9 mm SL compared to a maximum size of 56 mm SL reported by Winter - bottom et al. (1989) for 305 specimens of P. caeruleus reported (as P. coelestis) from the Seychelles. Comparative material examined at WAM consisted of 26 specimens of P. coelestis, mm SL, from Kenya and the Seychelles. Acknowledgements Thanks are due to Conservation International for providing the opportunity to visit Madagascar. Fieldwork was assisted by Jean Maharavo, Sheila McKenna, Mike Piling, Bemahafaly Randriamanantsoa, Rémi Ratsimbazafy, Emre Turak, Charlie Veron, and Fred Wells. Sue Morrison of WAM provided curatorial assistance. References Allen, G. R The Anemonefishes, their Classification and Biology. Second edition. T.F.H. Publications, Inc., Neptune City, New Jersey, 352 pp. Allen G. R Damselfishes of the World. Mergus, Melle, Germany, 271 pp. aqua vol. 6 no

11 aqua, Journal of Ichthyology and Aquatic Biology Agonistic and predatory behaviour of the lizardfish Synodus saurus (Linnaeus, 1758) (Actinopterygii: Synodontidae) from the Azores Marta S. C. Soares 1, João Pedro Barreiros 1*, Luis Sousa 1 & Ricardo S. Santos 2 1) Departamento de Ciências Agrárias, Universidade dos Açores, Angra do Heroísmo, Portugal. 2) Departamento de Oceanografia e Pescas, Universidade dos Açores, Horta, Portugal. s: 1*) jpedro@angra.uac.pt (corresponding author) Accepted: Keywords Predation strategies, prey, NE Atlantic, Synodontidae, inter- intraspecific interactions Abstract The behaviour of the lizardfish Synodus saurus, a common demersal predator in Azorean waters, is described. A total of 25 hours qualitative diurnal underwater observations were carried out between July 2000 and January Behavioural aspects are presented, illustrated with diagrams based on in situ observations. S. saurus is a cryptic predator that feeds mainly of small pelagic, gregarious fish; it is primarily associated with soft bottom substrate. Besides remaining camouflaged buried beneath the sand, S. saurus is a highly mobile predator capable of rapidly swimming more than five meters to capture its prey. S. saurus maintains a territory through agonistic interactions, and also interacts non-agonistically with hetero specifics such as Bothus podas maderensis. Zusammenfassung Das Verhalten des Eidechsenfisches Synodus saurus, ein häufiger, am Boden lebender Raubfisch in den Gewässern der Azoren, wird beschrieben. Zwi - schen Juli 2000 und Januar 2001 wurden insgesamt 25 Stunden qualitativer Unterwasserbeobachtungen bei Tageslicht ausgeführt. Die Verhaltensaspekte werden angegeben und anhand von in-situ Beobachtungen grafisch unterstützt. S. saurus ist ein kryptischer Räuber, der hautsächlich kleine, pelagische, gesellig lebende Fische frisst. Diese Art kommt in erster Linie auf einem weichen Bodengrund vor. Obwohl sich sie sich meistens im Sand versteckt hält, so ist S. saurus aber auch ein recht mobiler Räuber, der sehr schnell über eine Distanz von mehr als 5 Metern schwimmen kann um sein Opfer zu fangen. S. saurus unterhält ein Territorium durch agonistische Interaktionen, lebt aber auch non-agonistisch mit anderen Bodenfischarten, wie Bothus podas maderensis, zusammen. Résumé On décrit ici le comportement du Poisson-lézard Synodus saurus, un prédateur démersal commun aux Açores. Un total de 25 heures d'observations subaquatiques diurnes de qualité y fut consacré, entre juillet 2000 et janvier On présente des phases du comportement, illustrées par des diagrammes, basées sur des observations in situ. S. saurus est un prédateur cryptique qui se nourrit surtout de petits poissons pélagiques grégaires; il occupe surtout les zones à substrat doux. Outre le fait de se camoufler en s'enterrant sous le sable, S. saurus est un prédateur très mobile, capable de nager vite sur plus de cinq mètres pour capturer sa proie. S. saurus défend un territoire par interactions agressives et vit pacifiquement avec d'autres espèces comme Bothus podas maderensis. Sommario Il comportamento del pesce lucertola Synodus saurus, un comune predatore di fondo delle acque delle Azzorre viene descritto in dettaglio. Rappresenta il risultato di 25 ore di osservazioni subacquee diurne compiute tra luglio 2000 e gennaio Gli aspetti comportamentali sono illustrati con diagrammi ottenuti da osservazioni in situ. S. saurus è un predatore criptico che si nutre principalmente di piccoli pesci gregari pelagici; abita soprattutto fondali fangosi e arenosi. Sebbene sia ben camuffato sotto la sabbia, S. saurus è un predatore molto mobile capace di spostarsi rapidamente per oltre cinque metri per catturare la preda. S. saurus mantiene il proprio territorio attraverso interazioni agonistiche, ma interagisce non agonisticamente con altre specie come Bothus podas maderensis. Introduction Fish behavioural ecology is a recent, well-recognised discipline (Cury, 1998). Underwater observation to gain insight into fish behaviour is an important research tool (Longhurst, 1981; Sazima, 1986). The lizardfish Synodus saurus is a common, but little-known coastal predator. Golani (1993), who worked on this species in Israel, presented limited information on its feeding behaviour based on the examination of stomach contents. There is no record of any qualitative or quantitative field observations of 53 aqua vol. 6 no

12 Agonistic and predatory behaviour of the lizardfish Synodus saurus from the Azores the behaviour of the species. However, Sweatman (1984) has studied the predatory behaviour of the congeneric S. englemani. Synodus saurus lives mostly on sandy bottoms in island waters (Sulak, 1986). It is abundant in Azorean waters, and commonly found at less than 20 m, although reported once at 400 m (Sulak, 1986; Santos et al. 1997). Synodus saurus has a small head, eyes of moderate size, and is effectively camouflaged by the dorsal color pattern of fine spotting and vermiculation. The pattern differs on rocky and sandy bottoms. This species exhibits no sexual dimorphism, and reaches 43 cm in total length (TL). This study concerns aspects of the social and nonsocial (particularly predatory) behaviour of the lizardfish. Material and methods Locality All observations were made at Terceira Island (Azores - NE Atlantic). The chosen study sites were off the south-east coast and round to the north coast of the island. Observation sites were all shallower than 15 m, generally with sandy bottom substrate or mixed sand and rocks. Behavioural observations Observations were carried out between July 2000 and January 2001, but interrupted during December due to bad weather. A total of 25 hours of qualitative diurnal observations were made while snorkeling and scuba diving. Notes were made on a plastic slate and photographs taken. Behavioural sequence diagrams were created from in situ observations. Observations were made from far enough away to avoid disturbance. Underwater visibility was good: the fish were easy to see and observe. Once located, an individual was followed for as long as possible. Any changes in position were considered moves, including changes in orientation on the same spot. Because the attacks and agonistic movements were faster, they were easy to distinguish from ordinary changes of position. Results Non-social behaviour Immobile postures on the bottom i. The individual remains stationary, resting on its pelvic fins with the head inclined upward, which gives it a relatively curved posture. The head and the anterior pelvic zone are not in full contact with the bottom. Tail and dorsal fins are kept retracted. The dorsal body colour pattern mimics the bottom. In rocky environments, the dorsal bands are wider and brownish, while the dorsal area maintains a less greenish tone. ii. The head and ventral zone stay in close contact with the bottom. The animal rests its head on the crest of a sand ripple (on a sandy bottom) or on top of a rock. Immobile postures ambush The individual remains stationary and camouflaged on the substrate. It may remain partly buried, with most of the body or just the torso visible. Locomotion i. Swimming: Swimming is of anguilliform type using the caudal fin and body undulations. Movement is cyclical: two to three undulations of the tail fin (extension of the caudal rays) are followed by an interruption (retraction of the caudal rays). Movement is usually in a straight line and about half a meter or less from the bottom. The pectoral fins remain extended. The dorsal rays are raised at the beginning of the swimming movement and again with every change in direction. ii. Lift-off: Before swimming, an individual lifts itself off the bottom using coordinated movements of the pelvic fins and caudal fin propulsion. The pectoral and dorsal fin rays are extended at the same time. iii. Landing: When the fish stops swimming, it begins to sink. As it nears the bottom, the dorsal fin rays are extended, then immediately retracted. The fish settles with its rear half on the bottom, and its front half raised on the pelvic fins. The pectoral fins remain retracted. Camouflage movements Individuals are able to blend in with the surrounding habitat by partly burying the body. The fish opens and closes its mouth continuously, and uses the operculum to dig into the sand, while rapidly moving the pelvic and caudal fins. Lizardfish are able to stay almost completely buried. Threat When disturbed, the fish opens and closes its mouth frequently. The dorsal fin rays are extended and the anterior part of the body may be raised slightly. When the threat continues, the animal quickly leaves its position. Predatory behaviour Forty-eight predatory episodes were observed, all involving attracks on schools of small fishes. These can be classified as follows: a) Rapid, straight movement from a stationary position on the bottom (Fig. 1); b) Rapid movement from a stationary position in mid-water (Fig. 2 and 3); c) Stalking. Movement a) - motionless, and with its body straight, the lizardfish watches a school of fish swimming near the surface. The predator may change position or direction to keep the moving school in sight. Having focused on a specific individual or group of prey, fish, it darts swiftly from the bottom, straight at the school. This type of attack occurred during all observation periods. Several lizardfish may attack at the same time or in succession. aqua vol. 6 no

13 Marta S. C. Soares, João Pedro Barreiros *, Luis Sousa & Ricardo S. Santos Fig. 1. Predatory movement (type a). Fig. 2. Predatory movement (type b) with no change of direction. 55 aqua vol. 6 no

14 Agonistic and predatory behaviour of the lizardfish Synodus saurus from the Azores Movement b) - begins in a similar way. In this case, however, the predator abandons its initial position on the bottom for a second position closer to its potential prey. From here, the attack may or may not proceed. If it does, the predator focuses on the school, changes direction if necessary and moves swiftly and obliquely towards the prey. These movements are very fast. Movement c) - is also aimed at several prey. The predator leaves its ambush position and, swimming slowly and stealthily, approaches and joins the school. It then strikes from a position inside the school. Usually, the predator returns to the initial place of ambush. It seldom moves away from this original position. The failure rate of attacks is high (about 70%). The same predator may charge the same school of prey several times (N = 1.7 on average, for each passing school). The attacks were preceded by body movements which make attack behaviour quite predictable. On one occasion, we observed a simultaneous attack by two lizardfish. Both individuals swam swiftly to the school, then one of them stopped mid-water. This fish remained stationary while the second made its strike. Both lizardfish then returned to the bottom at the same time. Thus some targeting movements are not completed. The lizardfish moves from the bottom to mid-water, swims or even stops briefly under the school, then returns to its original position on the bottom. We observed four incomplete movements of this kind. Some of the predators just swim under the school of prey without attacking. The passing of the school appears to induce them to search for more suitable ambush locations while keeping in visual contact. That is, they follow the school s movement or direction. When hunting, individuals travel as far as 5 m between the bottom and the school of prey near the surface. While on the bottom, lizardfish may make some short stalking moves. These include searching for prey, rotating, changing direction or, if motionless, maintaining a posture that enables them to scan the surroundings. Lizardfish tend to gather near the passing school of prey. At these times, few lizardfish remain buried. Social behaviour Agonistic behaviour - intraspecific interactions This kind of interaction was observed 9 times. These confrontations may result in close contacts or even aggression. i. Situation 1 (Fig. 4 a, b and c): Two individuals (A and B), separated by a few metres, remain motionless on the bottom. B whirls and changes direction to face A. They both display by erecting the dorsal fin, then charge rapidly towards each other. The winner, B, occupies its opponent s previous resting place, and A swims away. A few seconds later, B moves towards its opponent s new position. Watching carefully from a distance, A reacts instantly by swimming straight at B. They confront each other again and, as before, A is defeated. The winner sees its opponent off, patrols its territory energetically and finally returns to its initial position. ii. Situation 2 (Fig. 5 a, b and c): One fish (A) swims swiftly towards another (B) that is stationary and attacks it. As they whirl about close to the sea floor, B offers some resistance but then quickly escapes. The winner, A, occupies its opponent s former position. This type of behaviour is frequent when schools of prey pass by. The predators are competing for the most suitable place to launch an attack. iii. Situation 3: In this case, a juvenile S. saurus, which was stalking a school, was attacked by (as in Movement a) by an older and bigger conspecific. Non-agonistic behaviour - intraspecific relations i. Posture at the sea bottom: Pairs of individuals (N = 15) were observed lying close together on the bottom, parallel, head to tail and motionless, with their pectoral and caudal fins extended. This behaviour may be connected with sexual activity. However, since this species does not show sexual dimorphism, it was impossible to determine whether such pairs were male and female. Paired postures were only seen in August. ii. Pursuit: Also only seen in August. We recorded three instances of non-aggressive pursuit, in which one individual closely followed another (Figure 6 a, b and c). Non-agonistic behaviour - interspecific relations On four occasions we observed, S. saurus closely following a wide-eyed flounder Bothus podas maderensis (Pleuronectiformes: Bothidae). In three instances, the lizardfish kept cm behind the flounder, stopping and starting with it. On one occasion there was close contact, with the lizardfish stopping directly over the flounder for a few moments (Figure 7 a and b). Discussion Immobile and camouflaged postures are frequently cited as characterizing the behaviour of species of Synodontidae. Their unique ability to camouflage themselves and catch their prey has often been described in the literature (Keenleyside, 1979; Sulak, 1986; Golani, 1993; Wirtz, 1994; Saldanha, 1997; Kagiwara & Abilhôa, 2000). However, their attack behaviour is more complex than previous reports suggest (Sweatman, 1984). Close-range ambush from a stationary position may be a lizardfish tactic, although we never saw it. None of the predatory movements we observed began from a buried ambush position, although some authors have reported such behaviour: i) An extremely rapid attack by S. saurus on an iapterichthus caecus from an immobile ambush posaqua vol. 6 no

15 Marta S. C. Soares, João Pedro Barreiros *, Luis Sousa & Ricardo S. Santos Fig. 3. Predatory movement (type b) with change of direction. Fig. 4. Intraspecific attack (Situation 1). 57 aqua vol. 6 no

16 Agonistic and predatory behaviour of the lizardfish Synodus saurus from the Azores Fig. 5. Intraspecific attack (Situation 2). ture, biting it then slowly swallowing it head first [P. Afonso - pers. com.]. ii) A similar situation observed by M. Gonçalves [pers. com.], in which a S. saurus remained in an ambush position, face to face, and close to a specimen of Scorpaena maderensis for several minutes. There was a sudden attack, and the S. made - rensis was ingested head-first. The fact that all attacks were directed toward schools of prey may indicate that these are more frequent, and probably more effective. These schools are very abundant in Azorean waters, and mostly composed of juvenile Sardina pilchardus. Synodus saurus may stalk their prey for a long time in order to make a catch. They may also remain motionless for several minutes before striking. This suggests that the moment chosen for attack is critical. Whether targeting species of pelagic, gregarious or benthic species, the speed of strike is crucial to success. If the attack is unsuccessful, the sequence of moving and scanning begins again immediately (Sweatman, 1984). From a particular pre-strike change of posture, whether on the bottom or in mid-water, we were able to tell when an attack was about to take place. Predation on S. saurus is almost unknown. Its capacity for camouflage may be an anti-predation mechanism. In the Azores, Barreiros & Santos (1998) mention S. saurus as a prey of Epinephelus marginatus (Serranidae). Synodus saurus lives most of its life alone (Keenleyside, 1979), keeping a good distance from other lizardfish. Our observations lead us to believe that they inhabit a preferential area (possibly residential), to which they return after an attack. These preferential areas justify their intraspecific agonistic mechanisms. Larger individuals dominate. They may change to a more promising location where there is less competition from their fellows (Farnsworth & Beecham, 1997). This may be the distribution model of these predators, in relation to prey and predator density or distribution. Agonistic behaviour, between members of the same species, may be a segregational mechanism targeting small individuals that venture into the preferred areas of larger and older individuals (Du Buit, 1996). Agonistic intraspecific interactions, and observed cannibalism (Soares, 2001), are usually referred to as mechanisms regulating the composition of the community (Persson & Diehl, 1990). The non-agonistic behaviour reported in this study, either intra- (non-aggressive pursuits) or interspecific (with B. p. maderensis), may represent a follower pursuit situation with feeding advantages for the follower. The lizardfish watches closely as others dig in the sand and disturb benthic organisms, then it moves in and feeds on the disturbed prey (Keenleyside, 1979). Since this species displays no obvious sexual dimoraqua vol. 6 no

17 Marta S. C. Soares, João Pedro Barreiros *, Luis Sousa & Ricardo S. Santos Fig. 6. S. saurus pursues another individual of its own species. Fig. 7. Direct contact between S. saurus and B. podas maderensis. 59 aqua vol. 6 no

18 Agonistic and predatory behaviour of the lizardfish Synodus saurus from the Azores phism (Sulak, 1986; Saldanha, 1997), the reason for posturing in pairs remains a mystery. Sousa (2001) states that the females generally attain larger size (males rarely reach more than 30 cm). In the pairs we observed, one fish (possibly a female) was always substantially larger; thus the pairing may have a sexual function. Acknowledgements We are grateful to Maria Fujaco for invaluable assistance during fieldwork. We also thank Pedro Ré from the University of Lisbon. This work was made possible by the support of the University of the Azores (Department of Agricultural Sciences and Department of Oceanography and Fisheries) and the University of Lisbon (Faculty of Sciences). Thanks are due to the two anonymous referees who helped to significantly improve this paper. References Barreiros, J. P. & R. S. Santos Notes on the food habits and predatory behaviour of the dusky grouper, Epinephelus marginatus (Lowe, 1834) (Pisces: Serranidae) in the Azores. Arquipélago. Life and Marines Sciences, 16A: Cury, P Dynamics of Pelagic Fish Distribution and Behaviour. In: Effects on Fisheries and Stock Assessment (Ed. P. Fréon & O. A. Misund). Blackwell Scientific Publications, Oxford. Du Buit, M. H Diet of hake (Merluccius merluccius) in the Celtic Sea. Fisheries Research, 28: Farnsworth, K. D. & J. A. Beecham Beyond the ideal free distribution: more general models of predator distribution. Journal of Theoretical Biology, 187: Golani, D The biology of the Red Sea migrant, Saurida undosquamis in the Mediterraneam and comparison with the indigenous confamilial Synodus saurus (Teleostei: Synodontidae). Hydrobiologia, 271: Kagiwara, F. & V. Abilhôa A alimentação do peixe-lagarto Synodus foetens (Linnaeus, 1766) em um banco areno-lodoso da Ilha do Mel, Paraná, Brasil. Arquivo de Ciências Veterinárias e Zoologia da UNIPAR, 3 (1): Keenleyside, M. H. A Diversity and Adaptation in Fish Behaviour. Springer-Verlag, Berlin, 208pp. Longhurst, A. R Analysis of Marine Ecosystems. Academic Press, Bedford Institute of Oceanography, Dartmouth, Nova Scotia. Persson, L. & S. Diehl Mechanistic individual based approaches in the population/community ecology of fish. Annales Zoologici Fennici, 27: Saldanha, L Fauna Submarina Atlântica. Terceira edição, Publicações Europa-América Lda. Lisboa, Portugal. 364pp. Santos, R. S., Porteiro, F. M. & J. P. Barreiros Marine Fishes of the Azores. Annotated Checklist and Bibliography. Arquipélago. Life and Marine Sciences Supplement 1, xxi + 225pp. Sazima, I Similarities in feeding behaviour between some marine and freshwater fishes in two tropical communities. Journal of Fish Biology, 29: Soares, M Ecologia Alimentar e Aspectos Comportamentais de Synodus saurus (Linnaeus, 1758) (Actinopterygii: Synodontidae) dos Açores. Tese de licenciatura em Biologia Aplicada aos Recursos Animais Variante Marinhos, Faculdade de Ciências, Universidade de Lisboa. vii + 54pp. Sousa, L Estudo da reprodução do peixelagarto Synodus saurus (Linnaeus, 1758) (Actinopterygii: Synodontidae) nos Açores. Tese de licenciatura em Ciências do Meio Aquático, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto. 52pp. Sulak, K. J Synodontidae. In: Fishes of the North-east Atlantic and the Mediterranean (Ed. P. J. P. Whitehead, M. L. Bauchôt, J. C. Hureau, J. Nielsen & E. Tortonese): Vol I., , UNESCO. Paris. Sweatman, H. P.A A field study of the predatory behavior and feeding rate of a piscivorous coral reef fish, the lizardfish Synodus englemani. Copeia, 1984(1): Wirtz, P Underwater Guide. Madeira Fish, Canary Islands and Azores. Verlag S. N., Stuttgart. 159 pp. aqua vol. 6 no

19 aqua, Journal of Ichthyology and Aquatic Biology Juvenile grunt (Haemulidae) mimicking a venomous leatherjacket (Carangidae), with a summary of Batesian mimicry in marine fishes Ivan Sazima Departamento de Zoologia and Museu de História Natural, Caixa Postal 6109, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil. isazima@unicamp.br - Fax: +55 (19) Accepted: Keywords Protective resemblance, mimicry, Oligoplites palometa, Pomadasys ramosus, venomous model, juveniles, tidal streams, western Atlantic Abstract A presumed example of facultative Batesian mimicry between a grunt and a leatherjacket is described from tidal streams and mangrove zones in south-eastern Brazil. While moving over open areas or when threatened, juvenile Pomadasys ramosus (Haemulidae) closely resemble, and behave like, their presumed venomous model, juvenile Oligoplites palometa (Carangidae), a species with venom glands in its dorsal and anal spines. A summary of 24 published examples of Batesian mimicry in marine fishes shows that most species (83.3%) mimic venomous models, three species (12.5%) imitate poisonous models and only one species (4.1%) mimics a model which is neither venomous nor poisonous. Resumo Um presumível exemplo de mimetismo Batesiano facultativo, entre uma espécie de corcoroca e uma espécie de guaivira, é descrito de manguezais no sudeste do Brasil. O juvenil de Pomadasys ramosus (Haemulidae), quando se desloca por áreas abertas ou quando ameaçado, apresenta grande semelhança de colorido e comportamento com o seu presumido modelo peçonhento, o juvenil de Oligoplites palometa (Carangidae), uma espécie com glândulas de peçonha em seus acúleos dorsais e anais. Um sumário de 24 casos publicados sobre mimetismo Batesiano entre peixes marinhos mostra que a maioria das espécies (83.3%) imita modelos peçonhentos, três espécies (12.5%) imitam modelos venenosos e apenas uma espécie (4.1%) imita um modelo que não é peçonhento nem venenoso. Zusammenfassung Hier wird ein mutmaßliches Beispiel von fakultativer, Betesscher Mimikry beschrieben, zwischen einem Grunzer und einer Stachelmakrele, in einem Gehzeitenfluss sowie in Mangrovenzonen, im südöstlichen Brasilien. Beim Durchschwimmen offener Gebiete verhalten sich junge Pomadasys ramosus (Haemulidae), genau so wie das mutmaßliche Model, junge Oligoplites palometa (Carangidae), eine Art mit Giftdrüsen in der Rücken- und Afterflosse, und sie ähneln diesem auch sehr. Eine Zusammenfassung von 24 veröffentlichten Beispielen Betesscher Mimikry unter Meeresfischen zeigt an, dass die meisten Arten (83,3 %) giftige Modelle, drei Arten (12,5 %) toxische Modelle, und ein Modell dass weder giftig noch toxisch ist, nachahmen. Résumé Est décrit un exemple présumé de mimétisme batésien facultatif entre un Grogneur et un Carange originaires de fleuves soumis aux marées et de zones de mangrove au sud-est du Brésil. Lorsqu'ils se meuvent en zones découvertes ou qu'ils sont menacés, les Pomadasys ramosus (Haemulidae) juvéniles ressemblent fort à et se comportent comme leur modèle venimeux présumé, l'oligoplites palometa (Carangidae) juvénile, une espèce à glandes vénéneuses dans ses épines dorsales et anales. Un résumé de 24 exemples publiés de mimétisme batésien chez les poissons de mer montre que la plupart des espèces (83,3%) imitent des modèles venimeux, trois espèces (12,5%) s'inspirent de modèles toxiques et une seule espèce (4,1%) imite un modèle qui n'est ni venimeux ni toxique. Sommario Viene descritto un esempio di presunto mimetismo facoltativo batesiano tra un grugnitore e un carangide, osservato presso le correnti di marea e le zone a mangrovie del Brasile sudorientale. Quando si muovono in aree aperte oppure si sentono minacciati, i giovani di Pomadasys ramosus (Haemulidae) prendono le sembianze e il comportamento del loro presunto modello velenoso rappresentato dall individuo giovane di Oligoplites palometa (Carangidae), una specie provvista di ghiandole velenifere nei raggi spinosi dorsali e anali. Esaminando 24 esempi di mimetismo batesiano in pesci marini si osserva che la maggior parte delle specie (83.3%) ha come modello specie velenose per 61 aqua vol. 6 no

20 Juvenile grunt mimicking a venomous leatherjacket, with a summary of Batesian mimicry in marine fishes contatto, mentre tre (12.5%) imitano specie che sono velenose per ingestione e solo una (4.1%) imita un modello non velenoso. Introduction Batesian mimicry involves a harmless species, the mimic, which resembles a harmful or unpalatable one, the model (Wickler, 1968; Edmunds, 1974). Several cases of presumed protective mimicry between marine fishes have been proposed, some of them disputed and others generally accepted (summaries in Randall & Randall, 1960; Randall & Kuyter, 1989; Smith-Vaniz et al., 2001). Perhaps one of the bestknown examples is the blenny Ecsenius bicolor (Day, 1888), which mimics Meiacanthus atrodorsalis (Günther, 1877) a fangblenny able to deliver a toxic bite (Losey, 1972; Springer & Smith-Vaniz, 1972; Smith- Vaniz et al., 2001). Toxic (venomous or poisonous) models include species in fish families as diverse as the Blenniidae, Scorpaenidae, Trachinidae, and Tetraodontidae (Randall & Randall 1960; Randall & Kuiter, 1989). Among jacks (Carangidae), species of leatherjackets of the genera Scomberoides Lacepède, 1801 and Oligoplites Gill, 1863 have dorsal and anal spines with venomous glands and are able to inflict a painful wound (Halstead et al., 1972; Sazima & Uieda, 1979; pers. obs.). However, no species of leatherjacket has hitherto been proposed as a venomous model in any case of protective resemblance. During studies on the natural history of mangrove-dwelling fishes in southeastern Brazil, I came upon what I regard as an example of facultative Batesian mimicry involving the grunt Pomadasys ramosus (Poey, 1860) as the mimic and the leatherjacket Oligoplites palometa (Cuvier, 1832) as the model. The morphological and behavioural similarities between the two species are described herein. In addition, a summary of Batesian mimicry in marine fishes is provided, with comments. Methods Juvenile grunts (P. ramosus) and leatherjackets (O. palometa) were opportunistically recorded from February to December 2001 in several tidal streams and mangrove zones in the region of Ubatuba ( 'S), São Paulo, south-eastern Brazil. The behaviour of the fishes was recorded during daylight in the course of 11 surface and 3 underwater snorkelling session (Sazima 1986), using local animal and all occurrences samplings (Lehner 1979): a total of about 13 hours of field observations. Observations were focused on particular behaviours (e.g., foraging, flight) and associated colour changes related to the bottom type and potentially camouflaging background. In one tidal stream I counted the numbers of individuals of both species on two occasions by slowly wading for one hour through clear, shallow water at ebb tide, covering approximately 300 m during each count. In addition, I seined a stretch of about 100 m in another stream. Voucher specimens of both species were deposited in the fish collection of the Museu de História Natural, Universidade Estadual de Campinas (ZUEC). Colour transparencies taken both in the habitat and in field aquaria were scanned and deposited in the ZUEC fish photo file (numbers as for specimens). Measurements used throughout are total length (TL) for both species, standard length (SL) for the grunt, and fork length (FL) for the leatherjacket. Microscopic sections of anal and dorsal spines of Oligoplites were prepared using routine histological methods, and stained with haematoxylin/eosin to demarcate the venom glands (Halstead et al., 1972; Sazima & Uieda, 1979). The summary of recorded cases of Batesian mimicry is drawn from the literature, with one additional example based on field observations. Species names follow Eschmeyer (1998, updated 2000 in Froese & Pauly, 2001). Fig. 1. Pomadasys ramosus juveniles: above, an individual about 15 mm TL drifting slowly close to the bottom in its mangrove habitat; below, a larger juvenile (22.4 mm SL, ZUEC 5537) showing the dark, camouflaged, colour pattern while hovering close to plant debris (photographed in field aquarium). Photos by I. Sazima. aqua vol. 6 no

21 Ivan Sazima Results Juvenile grunts, Pomadasys ramosus, bear a close resemblance to juvenile leatherjackets, Oligoplites palometa, both in colour pattern and behaviour, and were found together in tidal streams and mangrove zones. The two counts produced similar proportions of models to mimics: three leatherjackets and two grunts in one count and three leatherjackets and one grunt in the other. The seine catch yielded five leatherjackets and two grunts. Both fish species may hover in a head-down, oblique and curved posture (Fig. 1), although the leatherjacket was observed to hover both close to the bottom and to the water s surface, whereas the grunt hovered close to the bottom only. This difference appears related to foraging tactics, as the grunt feeds mainly on bottomdwelling invertebrates, whereas the leatherjacket preys on both benthic and pelagic invertebrates, besides picking scales from other fishes (Sazima & Uieda, 1980; pers. obs.). From this hovering posture, both fishes occasionally darted at prey, which they engulfed before resuming their hovering. While close to decaying plant fragments and other dark debris, both species often adopted a dark colour pattern, which camouflaged them against the background (Fig. 1, see Sazima & Uieda, 1979 for a figure of O. palometa). When camouflaged in this dark attire, both species moved slowly close to the bottom and their swimming resembled the movement of waterlogged plant debris drifting in the water current. However, while moving over open, detritus-free, lightcoloured sandy bottom, both the leatherjacket and the grunt promptly adopted a contrasting, bicoloured (yellowish and dark) pattern (Figs. 2-3). While in this bicoloured attire, both species no longer behaved like waterlogged debris and swam in a normal fish-like manner instead (see also Sazima & Uieda, 1979). The bicoloured pattern was also adopted when the fishes were chased or otherwise threatened, regardless of the bottom type and the presence of dark debris. Fig. 2. Oligoplites palometa juvenile and venom glands: above, an individual 14.4 mm FL (ZUEC 5197) showing the contrasting bicoloured pattern (photographed in field aquarium); below, cross-section of the dorsal spine of a juvenile 26 mm FL showing venom cells (dark red) packed in the anterior grooves. Photos by I. Sazima (upper) and V. S. Uieda (lower). Fig. 3. Mimetic pair: above, Oligoplites palometa juvenile 22.1 mm FL (ZUEC unnumbered); below, Pomadasys ramosus juvenile 22.4 mm SL (ZUEC 5537) while moving over an area of open, light-coloured sandy bottom in their tidal stream habitat. Photos by I. Sazima. 63 aqua vol. 6 no

22 Juvenile grunt mimicking a venomous leatherjacket, with a summary of Batesian mimicry in marine fishes Table I. Species of fishes reported as Batesian mimics and their putative models, with the type of noxiousness of each model species, and sources. The sequence of families for mimics follows Nelson (1994); genera and species are in alphabetical order. Mimics Models Noxiousness Sources Cheilodipterus nigrotaeniatus (Apogonidae) Meiacanthus grammistes (Blenniidae) venomous Smith-Vaniz et al. (2001) Cheilodipterus parazonatus (Apogonidae) Meiacanthus vittatus (Blenniidae) venomous Allen et al. (1975), Smith-Vaniz et al. (2001) Cheilodipterus zonatus (Apogonidae) Meiacanthus geminatus, M. vittatus venomous Gon, 1993, (Blenniidae) Smith-Vaniz et al. (2001) Fowleria vaiulae (Apogonidae) Scorpaenodes guamensis venomous Goren & Karplus (1983) (Scorpaenidae) Fowleria sp. (?= F. variegata) (Apogonidae) Scorpaenodes guamensis venomous Siegel & Adamson (1983) (Scorpaenidae) Plectropomus laevis (Serranidae) - juvenile Canthigaster valentini poisonous Randall & Hoese (1986) (Tetraodontidae) Calloplesiops altivelis (Plesiopidae) Gymnothorax meleagris powerful bite McCosker (1977) (Muraenidae) Centrogenys vaigiensis (Centrogeniidae) Scorpaena picta (Scorpaenidae) venomous Whitley (1935) Pomadasys ramosus (Haemulidae) - juvenile Oligoplites palometa (Carangidae) venomous This paper juvenile Pentapodus trivittatus (Nemipteridae) Meiacanthus crinitus (Blenniidae) venomous Smith-Vaniz et al. (2001) juvenile Scolopsis bilineatus (Nemipteridae) Meiacanthus atrodorsalis venomous Russell et al. (1976), juvenile M. lineatus, M. smithi (Blenniidae) Smith-Vaniz et al. (2001) Scolopsis margaritifer (Nemipteridae) Meiacanthus geminatus, venomous Russell et al. (1976), juvenile M. lineatus, M. vittatus (Blenniidae) Smith-Vaniz et al. (2001) Ecsenius bicolor (Blenniidae) Meiacanthus atrodorsalis (Blenniidae) venomous Losey (1972), Smith-Vaniz et al. (2001) Ecsenius gravieri (Blenniidae) Meiacanthus nigrolineatus, venomous Smith-Vaniz et al. (2001) (Blenniidae) Petroscirtes breviceps (Blenniidae) Meiacanthus grammistes, venomous Springer & M. kamoharai, M. vittatus Smith-Vaniz (1972), (Blenniidae) Smith-Vaniz et al. (2001) Petroscirtes fallax (Blenniidae) Meiacanthus lineatus (Blenniidae) venomous Russell et al. (1976), Lieske & Myers (1994) Plagiotremus laudandus (Blenniidae) Meiacanthus atrodorsalis (Blenniidae) venomous Losey (1972), Smith-Vaniz et al. (2001) Plagiotremus phenax (Blenniidae) Meiacanthus smithi (Blenniidae) venomous Springer & Smith-Vaniz (1972), Smith-Vaniz et al. (2001) Plagiotremus townsendi (Blenniidae) Meiacanthus nigrolineatus (Blenniidae) venomous Lieske & Myers (1994), Smith-Vaniz et al. (2001) Amblygobius linki (Gobiidae) Meiacanthus anema (Blenniidae) venomous Springer & Smith-Vaniz (1972) Valenciennea helsdingenii (Gobiidae) Meiacanthus anema (Blenniidae) venomous Springer & Smith-Vaniz (1972) Solea solea (Soleidae) Echiichthys vipera, Trachinus draco venomous Masterman (1908) (Trachinidae) Paraluteres arqat (Monacanthidae) Canthigaster margaritata poisonous Randall & Randall (1960) (Tetraodontidae) Paraluteres prionurus (Monacanthidae) Canthigaster valentini (Tetraodontidae) poisonous Tyler (1966) aqua vol. 6 no

23 Ivan Sazima Both species change their colours and habits when they reach about mm TL. The grunt changes to dusky yellow above (with sinuous darker lines on the flanks) shading to whitish below, adopts a demersal lifestyle, and no longer swims in a head-down or curved posture. The leatherjacket changes to dusky green above, shading to silvery white below, and adopts a pelagic lifestyle similar to that recorded for two other sympatric leatherjacket species, Oligoplites saurus and O. saliens (Sazima & Uieda, 1980; Randall, 1996; Carvalho-Filho, 1999). The venom glands of O. palometa are retained throughout life, albeit the venom cells (Fig. 2) occupy much less space (up to about 50%, pers. obs.) in the spine grooves of adults than in those of juveniles. Published records of 24 examples of Batesian mimics in marine fishes are summarised here (Table I), together with their presumed models and their type of noxiousness. For reference, the scientific names of the species concerned (except for the four already detailed in the text), including author and date, are listed here in alphabetical order: Amblygobius linki Herre, 1927; Calloplesiops altivelis (Steindachner, 1903); Canthigaster margaritata (Rüppell, 1829); Canthigaster valentini (Bleeker, 1853); Centrogenys vaigiensis (Quoy & Gaimard, 1824); Cheilodipterus nigrotaeniatus Smith & Radcliffe, 1912; Cheilodipterus zonatus Smith & Radcliffe, 1912; Echiichthys vipera (Cuvier, 1829); Ecsenius gravieri (Pellegrin, 1906); Fowleria vaiulae (Jordan & Seale, 1906); Fowleria variegata (Valenciennes, 1832); Gymnothorax meleagris (Shaw, 1795); Meiacanthus anema (Bleeker, 1852); Meiacanthus crinitus Smith-Vaniz, 1987; Meiacanthus geminatus Smith-Vaniz, 1976; Meiacanthus grammistes (Valenciennes, 1836); Meiacanthus kamoharai Tomiyama, 1956; Meiacanthus lineatus (De Vis, 1884); Meiacanthus nigrolineatus Smith-Vaniz, 1969; Meiacanthus oualanensis (Günther, 1880); Meiacanthus smithi Klausewitz, 1962; Meiacanthus vittatus Smith-Vaniz, 1976; Paraluteres arqat Clark & Gohar, 1953; Paraluteres prionurus (Bleeker, 1851); Pentapodus trivittatus (Bloch, 1791); Petroscirtes breviceps (Valenciennes, 1836); Petroscirtes fallax Smith-Vaniz, 1976; Plagiotremus laudandus (Whitley, 1961); Plagiotremus phenax Smith-Vaniz, 1976; Plagiotremus townsendi (Regan, 1905); Scolopsis bilineatus (Bloch, 1793); Scolopsis margaritifer (Cuvier, 1830); Scorpaena picta Cuvier, 1829; Scorpaenodes guamensis (Quoy & Gaimard, 1824); Solea solea (Linnaeus, 1758); Trachinus draco Linnaeus, 1758, Valenciennea heldingenii (Bleeker, 1858). Discussion The contrasting colours of O. palometa may be regarded as an example of a warning pattern, since the combination of black and yellow or white is one of the most widespread colour patterns among animals which advertise their noxious properties (e.g. Cott, 1966; Wickler, 1968; Edmunds, 1974). Although leatherjackets are venomous throughout life, small individuals are presumably more vulnerable to predation than larger ones, due not only to their smaller size but also to their solitary habits larger individuals school (pers. obs.). Hence more effective defensive tactics are to be expected among juveniles, and this is indeed the case for a number of marine fish species, be this camouflage, Batesian mimicry, or association with larger and/or dangerous organisms (e.g. Randall & Randall, 1970; Heck & Weinstein, 1978; Mansuetti, 1963). The combination of well-developed venom glands on dorsal and anal spines (Fig. 2, see also Sazima & Uieda, 1979) and a warning colour pattern renders the juvenile O. palometa a suitable Batesian model. The colour pattern adopted by P. ramosus is remarkably similar to that of its presumed model O. palometa, as both fishes may change their colour according to the bottom type (with or without dark debris) and circumstances such as flight and fright reaction. While the dark pattern is an example of camouflage (Sazima & Uieda, 1979), the contrasting pattern may best be viewed as an example of Batesian mimicry, in which the bicoloured P. ramosus juvenile is a mimic of O. palometa, a well-armed model (Sazima & Uieda, 1979). I regard this as an example of facultative mimicry, not only because it is adopted in the juvenile phase only (Russell et al., 1976), but also because the grunt is already afforded some degree of protection by its dark camouflaging pattern while close to dark debris. The mimetic, bicoloured pattern is adopted while the fish is particularly exposed (moving over open areas), or when chased or otherwise frightened. The fact that both species rely on camouflage as a first-line defence, and on warning coloration (and mimicry) as a second-line defence, is noteworthy, and probably related to the small size and solitary habits of the juveniles. It may be argued that P. ramosus and O. palometa together represent a case of defensive convergence in which both species use a dark attire while close to dark debris and a bicoloured one while over open sandy bottom (contrasting colours may be regarded as a disruptive pattern, see below). However, when in the open, both species could instead simply adopt plain, pale attire, which, in principle, would be more difficult for a visually-guided predator, foraging over a sandy background, to perceive. Juveniles of Trachinotus falcatus (Linnaeus, 1758), also a carangid, adopt a curved posture and a dark pattern (Randall & Randall, 1960) while among decaying vegetation, and change to pale greyish or yellowish and silvery while over an open sandy bottom (pers. obs.). Pale colours without any obviously visible markings are widespread among fishes dwelling over sandy areas (e.g. Hobson & Chess, 1986; Humann & DeLoach, 2000; pers obs.). Contrasting colours are often found among reef 65 aqua vol. 6 no

24 Juvenile grunt mimicking a venomous leatherjacket, with a summary of Batesian mimicry in marine fishes fishes and may sometimes be regarded as disruptive camouflaging patterns, in addition to their generally accepted functions of warning, territorial, and sexual signalling (e.g. Wickler, 1968; Lowe-McConnell, 1987). Among fishes dwelling over sandy or muddy bottoms, contrasting colours are generally related to social signals or sexual displays (certainly not the case in a solitary juvenile) or to warning colours plus Batesian mimicry (e.g. the pairs Trachinus draco- Solea solea or Meiacanthus anema-amblygobius linki). Moreover, contrasting colours employed as a disruptive pattern are generally found over complex types of background (e.g. coral reef, forest floor), not over plain backgrounds such as sand or mud (Cott, 1966; Edmunds, 1974; Wickler, 1968). Thus, it seems more plausible (and parsimonious) to follow the working hypothesis that the bicoloured, contrasting pattern of the leatherjacket is a warning signal and that the resemblance of the grunt involves a Batesian mimetic relationship, albeit facultative and restricted to particular situations. In both the counts and the seine catch the leatherjacket model outnumbered (albeit only slightly) its presumed grunt mimic, one of the postulated requirements for Batesian mimicry (e.g. Wickler 1968; Losey 1972; Edmunds, 1974; Russell et al., 1976). However, even if the leatherjacket did not outnumber its mimic, Batesian mimicry cannot be disregarded since the mimic would still enjoy some degree of protection (Springer & Smith-Vaniz, 1972; Edmunds, 1974). A glance at Table I reveals that most mimics (83.3%) imitate venomous models, three species (12.5%) mimic poisonous models, and only one mimic (4.1%) imitates a model which is neither venomous nor poisonous. In more than half (62.5%) of the cases the venomous models are fangblennies of the genus Meiacanthus, a model involved in several mimicry complexes (Springer & Smith-Vaniz, 1972), including a few cases of aggressive mimicry (Russell et al,. 1976). For instance, the blenny Plagiotremus laudandus, a Batesian mimic of M. atrodorsalis (Losey, 1972), is an aggressive mimic of both the latter and the blenny Ecsenius bicolor (see Sazima, 2002 for a summary of aggressive mimicry in fishes). Blenniids dominate the cases of Batesian mimicry (Table I), and are similar to serranids in numbers of aggressive mimicry examples (Sazima, 2002). This richness of mimicry examples among blenniids is probably due both to the large number of species within the family (Nelson, 1994), and to the fact that the nemophine fangblennies are very suitable as noxious models for mimicry complexes due to their efficient venom-delivering apparatus plus the warning colours in some species (see recent review in Smith-Vaniz et al., 2001). The few reported poisonous Batesian models among marine fishes are puffers of the genus Canthigaster, and the only case of a model that is neither venomous nor poisonous is a moray, a fish able to inflict a painful and dangerous bite (Halstead, 1970). Five species (20.8%) of the mimics, including the grunt P. ramosus, resemble their presumed models only as juveniles. Four of these cases involve juveniles of species that outgrow their model, and thus the protective resemblance is lost as the mimic grows (the only example in which both the mimic and the model lose their similarity as they grow is the pair P. ramosus and O. palometa). Fish species which act as mimics only as juveniles are classified as facultative mimics, whereas the remaining examples summarised here are regarded as obligatory mimics (Russell et al., 1976). Except for the pairs Amblygobius linki-meiacanthus anema and Pomadasys ramosus-o. palometa, both of which occur in tidal streams, mangrove zones, and estuaries (Springer & Smith-Vaniz, 1972; Sazima & Uieda, 1979; Menezes & Figueiredo, 1980), the remaining mimetic associates come mostly from coral reefs, the most species-rich marine habitat, especially in the Indo-Pacific (e.g. Thresher, 1991). I suspect that examples of mimicry among brackish water fishes, besides being less numerous than those on coral reefs, are also less likely to be detected due to factors such as poorer visibility (compared to coral reef waters), and also to a scarcity of underwater or other studies of live fishes (i.e. in their habitual colours) in mangrove zones and estuaries. Moreover, these latter environments harbour fewer fish species and are less stable than the rich tropical coral reefs (e.g. Sale, 1991; Moyle, 1995) and thus possibly offer fewer opportunities for the development of evolutionarily complex processes such as mimicry. These factors notwithstanding, examples of aggressive mimicry among fish species dwelling in brackish water have been reported recently (Sazima, 2002). Given the large number of known venomous, poisonous, or otherwise noxious fish species (Halstead, 1970) which might act as models, the number of reported Batesian mimics is surprisingly low and based on few models. One possible explanation is that the focus on protective mimicry in marine fishes is scarce and/or inadequate (see comments above on brackish waters) or, more probably, that these fishes rely mostly on defensive tactics other than mimicry (e.g. schooling, sheltering, camouflage). It should be noted that defence types other than mimicry may be simpler and perhaps less costly from an evolutionary viewpoint (e.g. Wickler, 1968; Edmunds, 1974). Although mimicry in marine fishes is sometimes a controversial issue (e.g. Domeier, 1994), the cases summarised here may be taken as at least good working hypotheses. There are examples in which the mimics display habits strikingly divergent from most other species within a given family, as in the case of three diurnal Cheilodipterus species (Apogonidae) in an otherwise nocturnal family (Smith-Vaniz et al., 2001). In such and other similar cases, mimicry still represents the most plausible (and parsimonious) aqua vol. 6 no

25 Ivan Sazima explanation until better interpretations are presented. Limited but nevertheless convincing demonstrations of the value of Batesian mimicry among blennies have been presented and commented upon by Losey (1972), Springer & Smith-Vaniz (1972), and Smith- Vaniz et al. (2001). Acknowledgements I thank Marlies Sazima, Virgínia S. Uieda, and Wilson Uieda for helping during the field work (MS also helped with field and aquarium photographs); José L. Figueiredo for checking the identity of the mimic; Jansen S. Zuanon for critically reading the manuscript; John E. Randall and William F. Smith-Vaniz for providing copies of their inspiring papers; the Instituto Florestal (Núcleo Picinguaba) for logistical support on the northern tip of the São Paulo coast; the IBAMA for permits to study and collect fishes along the Brazilian coast; the CNPq, FAEP-Unicamp, and FAPESP for essential financial support. This paper is dedicated to John E. Randall, William F. Smith-Vaniz, and Barry C. Russell, for their inspiring insights on mimicry in marine fishes. References Allen, G. R., Russell, B. C., Carlson, B. A., & W. A. Starck, II Mimicry in marine fishes. Tropical Fish Hobbyist, 24 (1): Carvalho-Filho, A Peixes: costa brasileira. 3rd ed. Ed. Melro, São Paulo, 320 pp. Cott, H. B Adaptive coloration in animals. Methuen, London, 508 pp. Domeier, M. L Speciation in the serranid fish Hypoplectrus. Bulletin of Marine Science, 54 (1): Edmunds, M Defence in animals: a survey of anti-predator defences. Longman, Harlow, 357 pp. Eschmeyer, W. N. (ed.) Catalog of fishes. California Academy of Sciences, San Francisco. Froese, R. & D. Pauly., (Eds.) FishBase. World Wide Web electronic publication. Gon, O., Revision of the cardinalfish genus Cheilodipterus (Perciformes: Apogonidae), with description of five new species. Indo-Pacific Fishes, 22: Goren, M. & I. Karplus Preliminary observations on the scorpion fish Scorpaenodes guamensis and its possible mimic the cardinal fish Fowleria abocellata. Development in Ecology and Environmental Quality, 2: Halstead, B. W Poisonous and venomous marine animals of the world. Vol. 3. U.S. Government Printing Office, Washington, D.C., 1006 pp. Halstead, B. W., D. D. Danielson, W. J. Baldwin & P. C. Engen Morphology of the venom apparatus of the leatherback fish Scomberoides sanctipetri (Cuvier). Toxicon, 10: Heck, K. L., Jr. & M. P. Weinstein Mimetic relationships between tropical burrfishes and opistobranchs. Biotropica, 10 (1): Hobson, E. S. & J. R. Chess Relationships among fishes and their prey in a nearshore community of southern California. Environmental Biology of Fishes, 17 (3): Humann, P. & N. DeLoach Reef fish identification: Florida, Caribbean, Bahamas. 3rd ed. New World Publications, Jacksonville, 481 pp. Lehner, P. N Handbook of ethological methods. Garland STPM Press, New York. Losey, G. S Predation protection in the poison-fang blenny, Meiacanthus atrodorsalis, and its mimics, Ecsenius bicolor and Runula laudandus (Blenniidae). Pacific Science, 26 (2): Lowe-McConnell, R. H Ecological studies in tropical communities. Cambridge University Press, Cambridge, 382 pp. Mansuetti, R Symbiotic behavior between small fishes and jellyfishes, with new data on that between the stromateid, Peprilus alepidotus, and the scyphomedusa, Chrysaora quinquecirrha. Copeia, 1963 (1): Masterman, A. T On a possible case of mimicry in the common sole. Journal of the Linnaean Society (Zoology), 30: McCosker, J. E Fright posture of the plesiopid fish Calloplesiops altivelis: an example of Batesian mimicry. Science, 197: Menezes, N. A. & J. L. Figueiredo Manual de peixes marinhos do sudeste do Brasil. IV. Teleostei (3). Museu de Zoologia Universidade de São Paulo, São Paulo, 105 pp. Moyle, P. B. Fish: an enthusiast s guide. University of California Press, Berkeley, 272 pp. Nelson, J. S Fishes of the world. 3rd ed. John Wiley & Sons, New York, 600 pp. Randall, J. E Caribbean reef fishes. T. F. H. Publications, Neptune City, 386 pp. Randall, J. E. & D. F. Hoese, Revision of the groupers of the Indo-Pacific genus Plectropomus (Perciformes: Serranidae). Indo-Pacific Fishes, 13: Randall, J. E. & R. H. Kuiter The juvenile Indo- Pacific grouper Anyperodon leucogrammicus, a mimic of the wrasse Halichoeres purpurescens and allied species, with a review of the recent literature on mimicry in fishes. Revue Française d Aquariologie, 16 (2): Randall, J. E. & H. A. Randall Examples of mimicry and protective resemblance in tropical marine fishes. Bulletin of Marine Sciences Gulf & Caribbean 10 (4): Russell, B. C., Allen G. R. & H. R. Lubbock New cases of mimicry in marine fishes. Journal of Zoology, London. 180: Sale, P. F. (Ed.) The ecology of fishes on coral reefs. Academic Press, San Diego. 754 pp. Sazima, I Similarities in feeding behaviour 67 aqua vol. 6 no

26 Juvenile grunt mimicking a venomous leatherjacket, with a summary of Batesian mimicry in marine fishes between some marine and freshwater fishes in two tropical communities. Journal of Fish Biology, 29 (1): Sazima, I Juvenile snooks (Centropomidae) as mimics of mojarras (Gerreidae), with a review of aggressive mimicry in fishes. Environmental Biology of Fishes, 65 (1): Sazima, I. & V. S. Uieda Adaptações defensivas em jovens de Oligoplites palometa (Pisces, Carangidae). Revista Brasileira de Biologia, 39 (3): Sazima, I. & V. S. Uieda Comportamento lepidofágico de Oligoplites saurus e registro de lepidofagia em O. palometa e O. saliens (Pisces, Carangidae). Revista Brasileira de Biologia, 40 (4): Seigel, J. A. & T. A. Adamson Batesian mimicry between a cardinalfish (Apogonidae) and a venomous scorpionfish (Scorpaenidae) from the Philippine Islands. Pacific Science, 37 (1): Smith-Vaniz, W. F., Satapoomin, U. & G. R. Allen Meiacanthus urostigma, with discussion and examples of mimicry in species of Meiacanthus (Teleostei: Blenniidae: Nemophini). aqua, Journal of Ichthyology and Aquatic Biology, 5 (1): Springer, V. G. & W. F. Smith-Vaniz Mimetic relationships involving fishes of the family Blenniidae. Smithsonian Contributions in Zoology, 112: Thresher, R. E Geographic variability in the ecology of coral reef fishes: evidence, evolution, and possible implications. In: The ecology of fishes on coral reefs. (Ed. P. F. Sale): Academic Press, New York. Tyler, J. C Mimicry between the plectognath fishes Canthigaster valentini (Canthigasteridae) and Paraluteres prionurus (Aluteridae). Notulae Naturae, 386: Whitley, G. P Fishes from Princess Charlotte Bay, North Queensland. Records of the South Australian Museum, 5 (3): Wickler, W Mimicry in plants and animals. McGraw-Hill, New York, 255 pp. aqua vol. 6 no

27 aqua, Journal of Ichthyology and Aquatic Biology A new species of Bryconamericus (Characiformes: Characidae) from the Cuña-Pirú creek in north-eastern Argentina, with comments on accompanying fishes Amalia M. Miquelarena 1(*), Lucila C. Protogino 1, Ramiro Filiberto 1, and Hugo L. López 1,2 1) Instituto de Limnología Dr. Raúl A. Ringuelet y División Zoología Vertebrados, Casilla Correo 712, Paseo del Bosque s/n, 1900 La Plata, Argentina. (*) miquelar@museo.fcnym.unlp.edu.ar 2) Comisión de Investigaciones Científicas y Técnicas de la Provincia de Buenos Aires (CIC) Accepted: Keywords Bryconamericus, conservation, biodiversity, upper Paraná basin, Argentina Abstract A new species of the characid genus Bryconamericus is described from a tributary of the upper Paraná River, in the province of Misiones, Argentina. The new species can be distinguished from all other species of the genus by the presence of an irregular series of tricuspid teeth on the outer premaxillary row; branched anal fin rays 16-19; perforated scales on lateral line 37-40; a different coloration pattern, with a wide, silvery lateral band and a vertically-elongated humeral spot; very weak sexual dimorphism and the absence of bony hooks on fins in males. A list of fish incidentally collected with the new species is also included. Resúmen Una nueva especie de Characidae del género Bryconamericus es descripta para un tributario del río Paraná superior, en la provincia de Misiones, Argentina. La nueva especie puede distinguirse de todas las otras especies del género, por presentar una serie irregular de dientes tricúspides en la hilera externa del premaxilar; radios ramificados de la aleta anal 16-19; escamas perforadas de la línea lateral 37-40; diferente patrón de coloración, con una ancha banda lateral plateada y una mancha humeral alargada verticalmente; dimorfismo sexual muy débil, ausencia en los machos de espinas óseas en las aletas. Una lista de peces, incidentalmente colectados con la nueva especie, es también incluida. Zusammenfassung Eine neue Art der Characiden-Gattung Bryconame - ricus wird aus einem Nebenfluß des oberes Paranàs, in der Provinz Misiones (Argentinien), beschrieben. Die neue Art unterscheidet sich von allen anderen Arten der Gattung durch die Anwesenheit einer unregelmäßigen Serie dreispitziger Zähne in der äußeren, maxillaren Reihe; verzweigte Afterflossenstrahlen 16-19; gelöcherte Schuppen in der Seitenlinie 37-40; ein unterschiedliches Farbmuster mit einem breiten, silbernen Seitenband und einem vertikalen, länglichen Schulterfleck; sehr schwacher geschlechtlicher Dimorphismus und die Abwesenheit von knöcherigen Hacken an den Flossen der Männchen. Eine Liste der zufällig, zusammen mit der neuen Art, gefangenen Fische ist ebenfalls bei gefügt. Résumé Une nouvelle espèce du genre Bryconamericus est décrite d'un tributaire du Paraná supérieur, dans la province de Misiones, Argentine. L'espèce nouvelle se distingue de toutes les autres espèces du genre par la présence d'une série irrégulière de dents tricuspides sur la rangée prémaxillaire externe, les rayons de la nageoire anale ramifiés, les écailles perforées sur la ligne latérale, un patron de coloration différent avec une large bande latérale argentée et une tache humérale allongée verticalement, un dimorphisme sexuel très ténu et l'absence de crochets osseux sur les nageoires des mâles. Une liste de poissons collectés avec l'espèce nouvelle est ajoutée. Sommario Si descrive una nuova specie di caracide del genere Bryconamericus proveniente da un tributario del Paraná superiore nella provincia di Misiones, Argen - tina. La nuova specie può essere distinta da tutte le altre dello stesso genere per la presenza di una serie irregolare di denti tricuspidali sulla fila esterna prem ascellare; raggi anali ramificati; squame perforate lungo la linea laterale; una diversa co lo - razione, composta di un ampia, argentea banda la terale e una macchia allungata verticalmente in prossimità del cinto pettorale; dimorfismo sessuale scarsamente accen tuato e assenza di uncini ossei sulle pinne dei maschi. Si include una lista completa di specie di pesci raccolte contestualmente a questa nuova specie. 69 aqua vol. 6 no

28 A new species of Bryconamericus from the Cuña-Pirú creek in north-eastern Argentina, with comments on accompanying fishes Introduction The province of Misiones is one of the most biodiverse areas in Argentina. It possesses three main collector rivers with headwaters in the Brazilian territory - the Paraná, the Uruguay, the Iguazú - and a number of streams and smaller rivers with headwaters in the Misiones Sierra, the range separating the east and west watersheds of this province. An account of ichthyological research in the province has been given by Gómez and Chébez (1996) with subsequent contributions by Miquelarena & Protogino (1996), Miquelarena et al. (1997), Braga (1998), and Casciotta et al. (2000). The Cuñá-Pirú creek (27 10 S, W) is a small stream that marks the boundary between the General San Martín and Cainguás Departments. It runs along the Cuñá-Pirú valley designated an area of outstanding biological diversity, and located in a pristine rainforest. General background information on local fishes, including a preliminary list of species, can be found in Miquelarena et al. (2000). The purpose of this study is to diagnose and describe a new species of the genus Bryconamericus Eigenmann, 1907 for the upper Paraná basin in north-eastern Argentina, and to present a list of species which occur with Bryconamericus mennii. Material and methods The material was collected by the authors and students of the Facultad de Ciencias Naturales and Museo during field survey trips made to Aristóbulo del Valle (27 07 S W). Additional material was examined at: The British Museum of Natural History (BMNH), England; Instituto de Limnología Dr. Raúl A. Ringuelet (ILPLA), Argentina; Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN), Argentina; Pontificia Universidade Catolica do Rio Grande do Sul (MCP), Brazil; Museo de La Plata (MLP), Argentina; Museu de Zoologia da Universidade de Sâo Paulo (MZUSP), Brazil, and the National Museum of Natural History, Smithsonian Institution (USNM), USA. Sampling was conducted using various types of equipment such as hook and line, trawl nets, scoop nets, a cast net, and fyke nets. This last technique was used following Colautti (1998). Water samples were collected for chemical data, following methodology proposed in Golterman & Clymo (1969). Measurements to the nearest 0.01 mm were made using a Digimess digital caliper following the methods of Miquelarena & Aquino (1995, 1999). Counts were made with a WILD M8 stereomicroscope. Osteological observations were made on twelve specimens cleared and counter-stained (c&s) for bone and cartilage following Taylor and Van Dyke (1985). Data on type material includes the number of specimens examined, shown in brackets, standard length (SL) in mm, indicating the range and the mean (X) shown in brackets, locality data, collector, and date. In the description, the first meristic value corresponds to the holotype, the other values being the paratype range and the mean (X) shown in brackets. For the rest of the species, only the number of specimens, shown in brackets, and the SL range are provided. Unless otherwise stated, the locality is Cuñá-Pirú creek, in the Cainguás Department of Misiones province. Histological sections in paraffin wax, stained with haematoxylin-eosin, were prepared to show different stages of gonadal maturity of the new species. The physical geography of the Paraná River region was taken from Mazza (1961). Additional material examined All localities in Argentina unless indicated. Bryconamericus agna: ANSP (4 paratypes), Tabay stream (27 00 S W), Paraná basin, Municipio Libertador General San Martín, Misiones, coll. D. Achino et al., Nov Bryconamericus eigenmanni: USNM (holotype of Astyanax eigenmanni Evermann & Kendall, 1906), Río Primero, Córdoba, , J. W. Titcomb; MLP 6-VII (8), second Mallín-Tanti stream, Córdoba; MLP 6-VII (55), Cachimayo stream near Taninga, Córdoba. Bryconamericus exodon: ILPLA 1331 (30), San Nicolás (33 19 S W), Buenos Aires; ILPLA 1332, Porta Saracusa, Brazil, km 1585, coll. H. López and H. Calandra, Oct Bryconamericus iheringii: BMNH (Tetragonopterus iheringii, Boulenger, 1887, lectotype), 64.7 SL, São Lorenço, Rio Grande do Sul state, Brazil, H. von Ihering; BMNH (11 paralectotypes), SL, same locality as lectotype; ILPLA 293 (5), SL, Matanza River, Buenos Aires, coll. Taberner and Belloni, 09 Nov. 1974; ILPLA 294 (5), SL, Laguna de Lobos (35 17 S W), Buenos Aires, coll. A. Miquelarena et al., Mar. 1996; ILPLA 298 (5), SL, Laguna Chascomús (35 36 S W), Buenos Aires, coll. J. Iwazskiw, 07 Ago. 1984; MCP (3), SL, Ouro stream, Feliz / Caxias do Sul (RS 452), Brazil, coll. L. R. Malabarba et al., 30 Abr. 1987; MLP 21-II-90-1 (2), La Ramadita stream, road to Tafí del Valle, Tucumán, coll. H. López et al., Mar. 1983; MZUSP (17), Caí River, 5.5 km from Sao Sebasticao do Caí, RS, Brazil, coll. Exp. MZUSP- USNM, 08 Dic. 1979; MZUSP (22), Amoio Chasqueiro, road Pelotas Jaquarao, RS, Brazil, coll. Exp. MZUSP-USNM, 14 Dic Bryconamericus stramineus: ILPLA 320 (2), SL, Río de la Plata, Buenos Aires, coll. N. García Romero and M. Remes Lenicov, Apr. 1995; ILPLA 339 (5), SL, Aguas Calientes stream (San Francisco River basin), Jujuy, coll. R. Menni et al., 29 Mar. 1987; ILPLA 739 (2), SL, Federación, Entre Ríos (31 00 S W), coll. A. Espinach Ros et al., aqua vol. 6 no

29 Amalia M. Miquelarena, Lucila C. Protogino, Ramiro Filiberto, and Hugo L. López 11 Mar. 1993; ILPLA 1087 (1), 44.0 SL, Paraná de las Palmas River, close to Central Nuclear Atucha (33 58 S W), Buenos Aires, coll. L. Mercado, 13 Jun Bryconamericus sylvicola: MACN 8072 (holotype), 65.6 mm SL, Central stream (25 50 S W), tributary of the Urugua-í River, tributary of the Paraná River, Misiones, coll. F. Plajer, Nov. 1983; MACN , (13 paratypes), SL; MACN 8075 (2 c&s), same locality as holotype. Bryconamericus thomasi: ILPLA 282 (128), Aguas Calientes stream (San Francisco River basin), Jujuy, coll. A. Miquelarena et al., 1987; ILPLA 288 (7), Metán River, Salta, coll. A. Miquelarena et al., 28 Mar Bryconamericus mennii n. sp. (Fig. 1, Table II) Holotype: ILPLA 1251 (1), male, 46.6 SL, Cuña-Pirú creek (27 10 S W), Departamento Cainguás, Misiones province, Argentina, coll. A. Miquelarena and R. Filiberto, 18 Sep Paratypes: 47 specimens; ILPLA 1060 (4), 3 females, 1 male, ( SL, X= 49.9), coll. R. Filiberto and L. Alcalde, 19 Jul. 1998; ILPLA 1164 (5), 3 females, 2 males, ( SL, X= 48.2), coll. R. Filiberto and L. Protogino, 29 Nov. 1999; ILPLA 1165 (5), females, ( SL, X= 49.8), 30 Nov. 1999; ILPLA 1166 (14), 6 females, 8 males, ( SL, X= 44.0), 01 Dec. 1999; ILPLA 1330 (7), 5 females, 2 males, ( SL, X= 38.6), coll. A. Miquelarena and R. Filiberto, 18 Sept. 2000; ILPLA 1329 (12), c&s, all paratypes from the same locality as holotype. Nontype specimens: ILPLA 389 (3), ( SL, X= 36.7), Urugua-í creek at Isla Palacios, Misiones, (25 50 S W) collected by Toresani et al., Feb Diagnosis Bryconamericus mennii, differs from other members of the genus Bryconamericus by the following combination of characters: external premaxillary series of teeth composed of an irregular row of tricuspid and narrow teeth; branched anal fin rays 16-19; perforated scales along lateral line 37-40; body elongated, greatest depth % of SL; and distinct colour pattern composed of a wide longitudinal silver stripe extending up to the middle caudal fin rays and a vertically elongated humeral spot. Other characters that distinguish Bryconamericus mennii are the existence of weak sexual dimorphism, and the lack of bony hooks on fins in males. Description Body elongate. Head short and robust; snout short and rounded. Mouth terminal. Eye relatively large ( % of head length). Dorsal profile of body almost straight up to beginning of dorsal fin base, slightly concave at level of supraoccipital process; descending smoothly from dorsal fin base origin to adipose fin base origin, and nearly straight and parallel to ventral profile from end of adipose fin base to upper procurrent rays of caudal fin. Ventral profile of body rounded as far as beginning of pelvic fin base; ventral surface flattened at this level. Caudal peduncle low, moderately elongated. Origin of anal fin base at level of last ray of dorsal fin. Pectoral fins reaching or extending slightly beyond start of pelvic fins; pelvic fins short, reaching or almost reaching start of anal fin. Upper jaw slightly protruding beyond lower jaw. In cleared and stained material, posterior end of maxilla reaching level of anterior edge of orbit (lateral ethmoids) and anterior edge of infraorbital 2. Infraorbitals well-developed, 6; third largest, its ventral and posterior edges contacting sensory canal of preopercle. Posterior edge straight and short in dorsal and pelvic fins, slightly rounded pectoral and caudal fins. Dorsal fin rays ii, 8 (including holotype). Pectoral fin rays i,10,i (i,9,i - i,11,i; X = i,10,i). Pelvic fin rays i,6,i (i,5,i-i,6,i; X = i,6,i). Anal fin rays iii,18 (iii-iv, 16-19; X = iv,17). Absence of bony hooks on rays of pelvic and anal fins in both females and males. Caudal fin principal rays ; dorsal procurrent rays 12-13, and ventral procurrent rays Fig. 1. Bryconamericus mennii, n.sp., ILPLA Holotype male, 46.6 mm SL. 71 aqua vol. 6 no

30 A new species of Bryconamericus from the Cuña-Pirú creek in north-eastern Argentina, with comments on accompanying fishes Table l. Chemical parameters of water in Cuña-Pirú stream, Misiones province. Sept./ 97 Jul. / 98 Nov. / 99 Dec. / 99 Conductivity (µs cm -1 ) ph Total dissolved solids (mg l -1 ) HCO3- (mg l -1 ) CO32- (mg l -1 ) SO42- (mg l-1) nd Cl- (mg l -1 ) nd nd nd nd Na+ (mg l -1 ) K+ (mg l -1 ) Ca2+ (mg l -1 ) Mg2+ (mg l -1 ) Mg/Ca (Mg+Ca) / (Na+K) nd: not detected. Table II. Morphometric data of Bryconamericus mennii presented as percentages of standard length and of head length. Character Holotype Male Paratypes Range Mean SD n Total length Standard length As a percentage of SL Head length Body depth Predorsal distance Prepectoral distance Prepelvic distance Preanal distance Caudal peduncle length Caudal peduncle depth Pectoral pelvic distance Pelvic anal distance Dorsal length Pectoral length Pelvic length Anal length Dorsal fin base Anal fin base As a percentage of head length Orbital diameter Snout Interorbital width Maxilla length SD: standard deviation aqua vol. 6 no

31 Amalia M. Miquelarena, Lucila C. Protogino, Ramiro Filiberto, and Hugo L. López Cycloid scales regularly distributed on body. Single row of scales at base of anal fin, 8 (6-8; X=7). Scales present at caudal fin base. Lateral line complete, perforated scales 38 (37-40; X=38). Predorsal scales 10 (10-13; X= 11). Rows of scales from dorsal fin origin to lateral line 5 (including holotype), and from lateral line to anal fin origin 4 (4-5; X = 4). Vertebrae 38. Supraneurals 4-5, typically 5. Gill rakers Maxilla short, with 3 to 5 teeth along ventral margin (Fig. 2a), with 3 or 4 cusps each. Premaxilla with long, ascending process. Two rows of premaxillary teeth; outer row with 4-5 tricuspid teeth (Fig. 2b), first and last teeth narrower and slightly higher than central ones; these occupy a more internal position and give an irregular appearance to the outer row; inner row with 4 teeth, 3 to 5 cusps each. Dentary with 8 to 10 teeth composed of four large anterior teeth all of similar size, with 4 or 5 cusps each, followed by series of smaller teeth, usually with 3 cusps each (Fig. 2c). All teeth cusped typically showing characteristic morphology of worn central cusps and rudimentary lateral cusps. Colour in life: Dorsal area of head and body olive drab, iridescent. Opercular area lilac-blue and iridescent. Very wide, silvery longitudinal band, scales wide. Black pigmentation on posterior edge of scales along longitudinal band. All fins bright orange with black stripes. Colour in alcohol: Dorsal area of head and body greyish green, ventral area silvery white. Vertically elongate humeral spot, separated by 1 or 2 scales from opercular membrane. Wide, dark lateral band along sides, somewhat expanded at base of caudal fin and thinner over middle caudal fin rays. Pectoral, dorsal, anal, and caudal fins greyish. Pelvic fins translucent. Interradial membranes of dorsal and anal fins bear many chromatophores. Chromatophores on pectoral and pelvic fins primarily concentrated along rays. Etymology Named after our friend and colleague Dr. Roberto C. Menni, researcher and professor of the Facultad de Ciencias Naturales y Museo (UNLP), whose work has contributed significantly to the development and advancement of marine and freshwater ichthyology in Argentina. Distribution and habitat Bryconamericus mennii is known from the upper Paraná basin in Misiones province: Cuñá-Pirú and Urugua-í streams, tributaries of the Paraná River, in north-eastern Argentina. The Cuñá-Pirú creek, one of these tributaries (Figs. 3; 4 a-b) is a small, clear fastflowing stream with a rock and sand bed and vegetated margins. The water temperature ranges from 19.3 to 33.4 C during the summer. Water chemical data (Table I) are similar to those reported by Maglianesi (1973) from the Upper Paraná River. Sexual dimorphism No obvious features of sexual dimorphism such as the absence of hooks on fins. However, the distal edge of the anal fin can be different in males and females: slightly concave to almost straight in males, concave, with inflexion point at approximately the first third of fin length in females. This is not a consistent difference; sex could be verified only by dissection. Fig. 2. Bryconamericus mennii, n. sp., ILPLA a) Righ maxilla; b) Righ premaxilla; c) Righ hemimandibulla. Discussion The characid genus Bryconamericus Eigenmann (in Eigenmann, McAtee, & Vard, 1907) comprises approximately 30 to 40 relatively small-sized species (Géry, 1977). It is found from Central America (Géry, 1977) to Sierra de la Ventana, south of Buenos Aires (Menni et al., 1988). Géry (1977) divides the species of this genus into two artificial groups. Following this classification, Bryconamericus mennii is placed in the diaphanus group, which is characterized by usually having total anal fin rays and 4-6 transverse scales above the lateral line. In the Plata basin, the diaphanus group is represented by the following species: B. agna Azpelicueta & Almirón, 2001, from the Paraná basin in Misiones; B. eigenmanni (Evermann & Kendall, 1906) with a distribution restricted to the Sierras Grandes area in Córdoba; B. exodon Eigenmann, 1907, in the Bermejo River basin in Salta, 73 aqua vol. 6 no

32 A new species of Bryconamericus from the Cuña-Pirú creek in north-eastern Argentina, with comments on accompanying fishes Fig. 3. Area of study, Cuña-Pirú creek, Misiones, Argentina. Argentina and Paraguay and in the Paraná River delta at San Nicolás de los Arroyos (Buenos Aires); B. iheringii (Boulenger, 1887) widely distributed in the Plata basin (see Menni et al., 1984); B. stramineus Eigenmann, 1908 in Uruguay, Paraná and Río de la Plata basins; B. sylvicola Braga, 1998 from Paraná basin in Misiones, and B. thomasi Fowler, 1940 in the upper Bermejo and Pasaje-Juramento-Salado basins, in north-western Argentina. Within this group, Bryconamericus mennii is more closely related to the species with elongated bodies: B. eigenmanni, B. exodon and B. stramineus. It also shares a silvery lateral band and an irregular row of narrow external premaxillary teeth with the last two species. The new species differs from B. eigenmanni by the following characters: 1- a very wide, silvery lateral band extending onto the middle caudal fin rays, vs. band fading at the anterior end, becoming darker caudally, and ending as a triangular spot at the caudal fin base; 2- males without bony hooks on pelvic and anal fins, vs. males with bony hooks on pelvic and anal fins (Miquelarena & Aquino, 1999); 3- premaxillary ascending process long, vs. short (Miquelarena & Aquino, 1999). From a geographic standpoint, B. eigenmanni is known only from the province of Córdoba in central Argentina (Miquelarena & Aquino, 1999). The new species differs from B. exodon by the combination: body depth % SL vs % SL; lesser number of branched anal fin rays (16-19 vs ); caudal fin coloration greyish vs. presence of black-tipped lobes; a vertically elongate humeral spot, vs. a small humeral spot; and absence in males of bony hooks in the fins vs. presence (pers. obs.). The new species can be distinguished from B. stramineus by the characters: greater depth of body ( SL vs % SL); greater number of maxillary teeth (3-5 vs. 1-3); a vertically elongate a b Fig. 4. a) Type locality of Bryconamericus mennii, n. sp., Cuña-Pirú creek, Misiones, Argentina; b) A section of the Cuña-Pirú creek at the study site. Photos by A. Mique - l arena. aqua vol. 6 no

33 Amalia M. Miquelarena, Lucila C. Protogino, Ramiro Filiberto, and Hugo L. López humeral spot vs. a very faint humeral spot, and the absence of bony hooks in the fins of males vs. presence (pers. obs.). Additionally, Bryconamericus mennii is distinguished from the remaining 4 species by the following characters: from B. agna, by having lesser body depth ( % SL, X= 32.4 vs % SL, X= 36.3); lesser number of branched anal fin rays (16-19, X= 17 vs , X= 20); dentary teeth, 8-10 vs. dentary teeth 6-7; absence of bony hooks on anal and pelvic fins in males, vs. very small hooks present on anal fin rays and larger hooks on pelvic fin rays (Azpelicueta & Almirón, 2001); mouth terminal vs. mouth subterminal; premaxilla with ascending process long, vs. premaxilla with ascending process short; external premaxillary teeth tricuspid arranged in an irregular series vs. tetra- and pentacuspid teeth arranged in a regular series; internal premaxillary teeth with 3-5 cusps vs. 6-7 cusps; maxilla bearing 3-5 teeth with 3-4 cusps vs. maxilla bearing 2 or 3 pentacuspid teeth. According to the original description and to the available type material, B. agna is very similar to B. sylvicola and might be a synonym for this species. From B. iheringii by the following morphometric characters: predorsal distance ( % SL vs % SL); length of base of anal fin ( % SL vs % SL); external premaxillary teeth arranged in an irregular series vs. external premaxillary teeth arranged in a regular series (Miquelarena, l986); lesser number of gill rakers on first gill arch (14-15 vs , Miquelarena & Aquino, l995); and absence of bony hooks in fins of males vs. presence (Miquelarena & Aquino, l995). The new species differs from B. thomasi by the combination: greater number of scales on the lateral line series (37-40 vs ); greater number of branched rays in anal fin (16-19, X= 17 vs , X= 14); the morphology of the anal fin in males, which is slightly concave or nearly straight vs. markedly convex (Miquelarena & Aquino, l995); and absence of bony hooks vs. presence (Miquelarena & Aquino, 1995). From B. sylvicola, by the combination: the lesser body depth ( % SL vs % SL); a smaller number of branched rays in the anal fin (16-19 vs ); mouth terminal vs. mouth subterminal; external premaxillary teeth tricuspid, arranged in an irregular series vs. tetra- and pentacuspid teeth arranged in a regular series; internal premaxillary teeth with 3-5 cusps vs. 4-7 cusps; and males without bony hooks in the pelvic and anal fins vs. very small hooks present on anal fin rays and larger hooks on pelvic fin rays (Braga, 1998). Bryconamericus mennii can also be differentiated from other species of the genus found in southern and eastern Brazil. The species is distinguished from B. lambari Malabarba & Kindel, 1995, a species described from the tributaries of Laguna dos Patos basin, by the presence of a wide silvery longitudinal band (absent in B. lambari) and by the absence of bony hooks on the ventral and anal fins (present in B. lambari). From B. ornaticeps Bizerril & Peres Neto, 1995, by the greater body depth ( % SL vs % SL) and the greater number of branched rays in the anal fin (16-19 vs ). The presence of Bryconamericus mennii may lend weight to the theory advanced by different authors that due to their particular characteristics the interior water courses of Misiones province comprise areas of endemism (see Miquelarena et al., 1997). Fig. 5. Testicular tissue sections, Bryconamericus mennii, n. sp.; a) General view; b) Detail of spermatozoa in cyst (C) and free in the lumen of the tubules (LT). 75 Remarks Noticeable dimorphic characters have been recorded in several species of the genus Bryconamericus. For instance in males of B. pectinatus Vari & Siebert (1990) described an unusually elaborate distal portion of the first unbranched rays of the anal fin. Likewise, Miquelarena & Aquino (1999) described the modification of the pelvic fin rays into a basket-like structure in males of B. eigenmanni. Another dimoraqua vol. 6 no

34 A new species of Bryconamericus from the Cuña-Pirú creek in north-eastern Argentina, with comments on accompanying fishes phic character frequently reported is the presence of bony hooks on the anal and ventral fins of males. This condition has been reported, for example, in B. eigenmanni, B. iheringii, and B. thomasi (Miquelarena & Aquino, 1995; 1999), B. stramineus (pers. obs.), B. sylvicola (Braga, 1998), and B. lambari (Malabarba & Kindel, 1995). Variation in the development and morphology of the fins, especially the anal fin, has also been reported as sexually dimorphic in some species, varying from highly noticeable, as in B. thomasi (Miquelarena & Aquino, 1995) to weak, as in Bryconamericus mennii. The hypothesis of lack of gonadal maturity to explain the absence of bony hooks on the fins of males of Bryconamericus mennii, or any other dimorphic feature that could allow clear external recognition of sex, was tested by examining the histology of the gonads. In specimens measuring mm SL, the testicular tissue sections showed advanced maturity (Fig. 5a, b), presenting all spermatogenetic cell types, including spermatozoa both in cysts (C) and free in the lumen of tubes (LT). In most females the ovaries were full of oocytes at a very advanced state of maturity. Co-occuring fish species The fishes of Cuñá-Pirú creek comprise 25 species belonging to the orders Characiformes, Siluriformes, Gymnotiformes, Synbranchiformes, and Perciformes, distributed in 12 families and 19 genera. Some of these are exploited commercially (e.g. Eigenmannia trilineata, Gymnotus carapo) and others (e.g. Astyanax eigenmanniorum, Bryconamericus iheringii, Synbranchus marmoratus, E. trilineata) are used as live bait in different areas of the country. Along with both the annual and miniature species, these species are considered some of the most endangered. The fish from the Paraná River and its tributaries are a food resource for the native Mbyáguarani inhabitants of the Cuña-Pirú valley, especially Prochilodus lineatus, a species not recorded during our sampling. Order Characiformes FAMILY HEMIODONTIDAE Apareiodon piracicabae (Eigenmann, 1907) Parodon piracicabae Eigenmann, in Eigenmann & Ogle, 1907: 6-7 (type locality: Piracicaba, Estado de São Paulo, Brazil). A. piracicabae Eigenmann, 1916: Material examined: ILPLA 1052 (2), SL. Distribution: This species is known from the upper Paraná basin in Brazil and Argentina. Miquelarena et al. (1997) reported it from several localities in the Urugua-í Valley, Misiones province, Argentina. Remarks: See Miquelarena et al. (1997) comments on morphometric and meristic characters of A. piracicabae. This species is caught for the aquarium trade. FAMILY CHARACIDAE Oligosarcus brevioris Menezes, 1987 O. brevioris Menezes, 1987: (type locality: Pelotas River basin, Rio Grande do sul, Brazil). Material examined: ILPLA 467 (1), SL; ILPLA 1054 (2), SL; ILPLA 1053 (5), SL; ILPLA 1055 (2), SL; ILPLA 1252 (1), 84.2 SL. Distribution: Menezes (1987) reported this species from the upper Uruguay basin in Brazil and Argentina. It is also known in the Yabotí-Guazú stream, a tributary of the Uruguay River in the province of Misiones (Braga, 1994). Remarks: No commercial value. Astyanax abramis (Jenyns, 1842) Tetragonopterus abramis Jenyns, 1842: 123 (type locality: Paraná River) A. abramis Fowler, 1906: 439 Material examined: ILPLA 1057 (1), 93.6 SL; ILPLA 1056 (4), SL. Distribution: Ringuelet et al. (1967) mentioned this species for the Paraná River, middle Uruguay River and the Río de la Plata. López et al. (1984) and Butí & Miquelarena (1995) reported it from Salta and the upper Salí River (Trancas Department) in Tucumán. Miquelarena et al., (1997) reported it from the Arroyo Urugua-í Valley, Misiones. Remarks: No commercial value. Astyanax cf. eigenmanniorum Material examined: ILPLA 478 (1), 42.8 SL; ILPLA 1152 (15), SL; ILPLA 1153 (2), SL; ILPLA 1158 (1), 74.3 SL; ILPLA 1154 (3), SL; ILPLA 1155 (2), SL; ILPLA 1156 (14), SL; ILPLA 1157 (6), SL, Tateto stream, Cainguás Department, Misiones. Distribution: See López et al. (1980) and Menni et al. (1984). Remarks: The specimens collected are considered to be close to A. eigenmanniorum on the basis of the number of scales along the lateral line (33-36). However, the following series of morphometric and meristic differences were recorded between the specimens collected in the Cuñá-Pirú creek and specimens of A. eigenmanniorum from Buenos Aires province: snout slightly longer ( vs ) in head length, anal fin base longer ( vs ) in SL; total number of anal fin rays (21-28 vs ); aqua vol. 6 no

35 Amalia M. Miquelarena, Lucila C. Protogino, Ramiro Filiberto, and Hugo L. López upper transverse scales (5-7 vs. 5-6), and lower transverse scales (4-6 vs. 4-5). Used commercially as bait. Astyanax fasciatus (Cuvier, 1819) Chalceus fasciatus Cuvier, 1819: 352 (type locality: Brazilian rivers). A. fasciatus Fowler, 1906: 346. Material examined: ILPLA 1058 (1), SL. Distribution: The southern limit of this species, which is known throughout the Paraná area of Argentina, is the Salado River in southern Buenos Aires province (see Menni et al., 1992). Remarks: Used commercially as bait. Astyanax sp. (Fig. 6) Material examined: ILPLA 1159 (7), SL; ILPLA 1253 (2), SL; ILPLA 1160 (1), 72.4 SL. Remarks: This unidentified species most closely resembles A. fasciatus, based on the following morphometric characters: head in SL; body depth in SL; predorsal length in SL; eye large, in head length; and snout short, in head length. Nevertheless, the specimens collected in the Cuñá-Pirú creek differ from A. fasciatus in having a greater number of maxillary teeth (2-4 vs. 1). creek, presently referred to as B. iheringii, possess intermediate characteristics between this species and B. sylvicola. A detailed study might determine whether it belongs to the latter species or to a population of B. iheringii which may have a wider range of variation in the cusps of the external premaxillary teeth and the anal fin rays. For additional comments on B. iheringii, see Miquelarena & Aquino (1995, 1999). No commercial value. Bryconamericus stramineus Eigenmann, 1908 B. stramineus Eigenmann, 1908: 105 (type locality: Piracicaba; Uruguay River). Material examined: ILPLA 1208 (5), SL. Distribution: Miquelarena & Aquino (1995) reported this species from the Uruguay, Paraguay and Paraná Rivers and the Río de la Plata. Remarks: No commercial value. FAMILY CRENUCHIDAE Characidium cf. zebra (Fig. 7) Material examined: ILPLA 1061 (1), 56.3 SL; ILPLA 1167 (1), 72.2 SL. Distribution: The species is mentioned from several localities in Argentina (see Menni et al., 1992). Remarks: Following Buckup s (1992) comments on C. zebra, we provisionally refer the specimens collected in the Cuñá-Pirú creek to that species. Caught for the aquarium trade. Fig. 6. Astyanax sp. about 65 mm SL, Cuña-Pirú creek, Misiones, Argentina, not preserved. Photo by R. Filiberto. Bryconamericus cf. iheringii Material examined: ILPLA 466 (2), SL; ILPLA 1059 (2), SL; ILPLA 1161 (4), SL; ILPLA 1162 (5), SL; ILPLA 1163 (5), SL; ILPLA 1254 (5), SL. Distribution: This species is widely distributed in Argentina, see Menni et al. (1984) and Miquelarena & Aquino (1995). Remarks: The specimens collected in the Cuñá-Pirú Fig. 7. Characidium cf. zebra, about 69 mm SL, Cuña- Pirú creek, Misiones, Argentina, not preserved. Photo by R. Filiberto. Order Siluriformes FAMILY AUCHENIPTERIDAE Glanidium ribeiroi Haseman, 1911 Glanidium ribeiroi Haseman, 1911: 381, fig. 78 (type locality: Porto União da Victoria, Paraná, Brazil). Material examined: ILPLA 1172 (1), 77.7 SL. 77 aqua vol. 6 no

36 A new species of Bryconamericus from the Cuña-Pirú creek in north-eastern Argentina, with comments on accompanying fishes Distribution: Gómez & Somay (1985) reported this species from several localities in the Iguazú River basin and the Urugua-í Valley, in Misiones province. Remarks: No commercial value. FAMILY PIMELODIDAE Heptapterus mustelinus (Valenciennes, 1840) Pimelodus mustelinus Valenciennes, in Cuvier & Valenciennes, 1840: 165 (type locality: Río de la Plata). H. mustelinus Günther, 1864: 271. Material examined: ILPLA 1209 (1), 63.9 SL; ILPLA 1174 (2), SL; ILPLA 1173 (2), SL, Tateto stream, Cainguás Department, Misiones. Distribution: This species has been reported from Salta and several localities of the upper Salí River, the Trancas Department in Tucumán (Buti and Miquelarena, 1995), from the provinces of Santiago del Estero, Catamarca, Córdoba, and Buenos Aires (López et al., 1996), and from Misiones province (Gómez & Chébez,1996). Remarks: No commercial value. Rhamdella sp. Material examined: ILPLA 468 (3), SL; ILPLA 1019 (11), SL; ILPLA 1201 (6), SL; ILPLA 1175 (10), SL; ILPLA 1176 (2), SL, Tateto stream, Cainguás Department, Misiones. Remarks: This species is characterized by its slim body, short maxillary barbel and a unique colour pattern to be described elsewhere (Bockman & Miquelarena, MS). Trichomycterus davisi (Haseman, 1911) Pygidium davisi Haseman, 1911: 380 (type locality: Iguassú River, near Serrinha Paraná, Brazil). T. davisi Burgess, 1989: 322. Material examined: ILPLA 1071 (1), 46.8 SL; ILPLA 1178 (1), 62.9 SL; ILPLA 1188 (2), SL, Tateto stream, Cainguás Department, Misiones. Distribution: Mentioned throughout the Iguazú River basin in Argentina and Brazil. Miquelarena & Fernández (2000) recorded this species for the Iguazú and upper Paraná basins in Misiones. Remarks: No commercial value. FAMILY LORICARIIDAE Ancistrus cirrhosus (Valenciennes, 1840) (Fig. 8) Hypostomus cirrhosus Valenciennes, in Cuvier & Valenciennes, 1840: (París, ed.): (Strabourg ed.) (type locality: Buenos Aires, Río de Janeiro). A. cirrhosus Kner, 1854: 272 Material examined: ILPLA 469 (2), SL; ILPLA 1062 (1), 86.7 SL; ILPLA 1063 (1), 46.4 SL; ILPLA 1179 (11), SL; ILPLA 1180 (10), SL; ILPLA 1181 (12), SL; ILPLA 1182 (4), SL; ILPLA 1183 (4), 74,4-99,4 SL; ILPLA 1184 (2), SL, Tateto stream, Cainguás Department, Misiones. Rhamdia quelen (Quoy & Gaimard, 1824) Pimelodus quelen Quoy & Gaimard, 1824: 228 (type locality: Brazil). R. quelen Eigenmann & Eigenmann, 1888: 126. Material examined: ILPLA 1069 (4), SL; ILPLA 1070 (2), SL; ILPLA 1177 (1), SL. Distribution: Menni et al. (1992) considered this species restricted to Argentina. Miquelarena & López (1995) reported its presence in the Lagunas Encadenadas system ( S, º30 W) in western Buenos Aires province. According to Silfvergrip (1996) specimens of R. quelen collected in Argentina have often been assigned to R. sapo (Valenciennes, 1840). Remarks: Sport-fishing and commercial value (López et al., 2001). FAMILY TRICHOMYCTERIDAE Fig. 8. Ancistrus cirrhosus, male, about 90 mm SL, Cuña-Pirú creek, Misiones, Argentina, not preserved. Photo by R. Filiberto. Distribution: Miquelarena et al. (1994) summarized the information available on the presence of this species in Argentina. Remarks: Our specimens differ from those examined by Muller (1990) in possessing a greater number of premaxillary teeth (44-65 vs ) and mandibular teeth (50-74 vs ). Miquelarena et al. (1994) provide information on morphometric and meristic aqua vol. 6 no

37 Amalia M. Miquelarena, Lucila C. Protogino, Ramiro Filiberto, and Hugo L. López data, pigmentation and anatomical features. Caught for the aquarium trade. Hypostomus commersoni Valenciennes, 1840 Hypostomus commersoni Valenciennes, in Cuvier & Valenciennes, 1840: (type locality: São Francisco River, Brazil; La Plata). Material examined: ILPLA 1185 (8), SL; ILPLA 1186 (2), SL. Distribution: López & Miquelarena (1991) reported this species from several localities in Argentina. Remarks: Caught for the aquarium trade. Distribution: Described by López & Castello (1966) from the Río de la Plata near Núñez and Cambaceres, and from the Luján River in Buenos Aires and Paraná River in Rosario. Remarks: Used commercially as bait and in the aquarium trade. FAMILY GYMNOTIDAE Gymnotus cf. carapo (Fig. 10) Material examined: ILPLA 1171 (1), SL. Rineloricaria sp. Material examined: ILPLA 1064 (1), 48.6 SL; ILPLA 1210 (1), 59.5 SL; ILPLA 1065 (2), SL (c&s); ILPLA 1190 (8), SL; ILPLA 1189 (2), SL, and ILPLA 1191 (6), SL, Tateto stream, Cainguás Department, Misiones province. Distribution: Cuña-Pirú creek basin, Cainguás Department in Misiones province. Remarks: This is probably a new species related to R. latirostris but differs from it by its larger orbital diameter and by the lower interorbital width as percentage of head length (M. Rodríguez, pers. comm.) No commercial value. Order Gymnotiformes FAMILY STERNOPYGIDAE Eigenmannia trilineata López & Castello, 1966 (Fig. 9) Eigenmannia trilineata López & Castello 1966: 1-12 (type locality: Río de la Plata). Material examined: ILPLA 1168 (3), SL; ILPLA 1169 (5), SL; ILPLA 1170 (2), SL. Fig. 10. Gymnotus cf. carapo, about 107,3 mm SL, Cuña- Pirú creek, Misiones, Argentina, not preserved. Photo by R. Filiberto. Distribution: Ringuelet (1975) reported this species in Argentina throughout the Paraná basin area. López et al. (1984) mentioned it from the Salado basin in Buenos Aires. This widely distributed genus, is still in need of a thorough revision to resolve its species composition (Mago Leccia, 1994 and Britski et al., 1999). Remarks: Used commercially as bait and in the aquarium trade. Order Synbranchiformes FAMILY SYNBRANCHIDAE Fig. 9. Eigenmannia trilineata, about 190 mm SL, Cuña- Pirú creek, Misiones, Argentina, not preserved. Photo by R. Filiberto. Synbranchus marmoratus Bloch, 1795 S. marmoratus Bloch, 1795: 87 (type locality: Suriname). Material examined: ILPLA 1192 (1), 74.0 ST, Tateto stream, Cainguás Department, Misiones. Distribution: This species is widely distributed in Argentina, extending southwards to Buenos Aires province (38 08 S W) and westwards to San Juan province (31 37 S W), (Cione & Barla, 1997; López, 2001). Remarks: Used commercially as bait. 79 aqua vol. 6 no

38 A new species of Bryconamericus from the Cuña-Pirú creek in north-eastern Argentina, with comments on accompanying fishes Order Perciformes FAMILY CICHLIDAE Crenicichla lepidota Heckel, 1840 C. lepidota Heckel, 1840: 429 (type locality: Guaporé River, Matto Grosso, Brazil). Material examined: ILPLA 889 (2), SL; ILPLA 1066 (3), SL; ILPLA 1193 (1), 74.4 SL; ILPLA 1194 (1), 96.6 SL, Tateto stream, Cainguás Department, Misiones. Distribution: According to Lucena and Kullander (1992), status of this species is somewhat problematic; these authors state that it has ample geographical range in the Paraguay and Paraná Rivers (after Guairá), and Middle Uruguay basins, as well as along the coast of Rio Grande do Sul. Ringuelet et al. (1967) reported C. lepidota from the Río de la Plata and its tributaries. Remarks: Caught for the aquarium trade. Crenicichla sp. (Fig. 11) Material examined: ILPLA 1195 (3), SL; ILPLA 890 (8), SL; ILPLA 891 (1), SL; ILPLA 1196 (5), SL; ILPLA 1088 (4), SL; ILPLA 1089 (1), SL; ILPLA 1198 (3), SL; ILPLA 1199 (4), SL; ILPLA 1200 (2), SL; ILPLA 1197 (3), SL, Tateto stream, Cainguás Department, Misiones. Fig. 11. Crenicichla sp. about 120 mm SL, Cuña-Pirú creek, Misiones, Argentina, not preserved. Photo by R. Filiberto. Distribution: Cuña-Pirú creek basin, Cainguás Department, Misiones province. Remarks: Presently undescribed species is probably related to the missioneira group sensu Lucena & Kullander, No commercial value. Gymnogeophagus sp. (Fig. 12) Material examined: ILPLA 470 (7), SL; ILPLA 888 (2), SL; ILPLA 1067 (2), SL; ILPLA 1068 (5), SL; ILPLA 1202 (17), SL; ILPLA 1203 (7), SL; ILPLA 1090 (1), SL; ILPLA 1204 (2), SL; ILPLA 1205 (1), 83.1 SL; ILPLA 1206 (2), SL; ILPLA 1207 (7), SL, Tateto stream, Cainguás Department, Misiones. Fig. 12. Gymnogeophagus sp., male, about 90 mm SL, Cuña-Pirú creek, Misiones, Argentina, not preserved. Photo by R. Filiberto. Distribution: Cuña-Pirú creek basin, Cainguás Department, Misiones province. Remarks: This undescribed species differs from all other members of the genus Gymnogeophagus in its colour pattern and the number of upper lateral line scales. Malabarba and Reis (pers.com.) are presently working on a description of the species based on the material collected from the middle Uruguay River and its tributaries, both in Brazil and in Argentina. Acknowledgements We are grateful to Roberto Menni (MLP) and Adriana Aquino (AMNH) for their critical review and for checking the English. We also thank Gustavo Chiaramonte (MACN); Roberto Reis (MCP); Osvaldo Oyakawa (MZUSP); Richard Vari and Susan Jewett (USNM); Anne Marie Hine (MNH) and Mark Sabaj (ANSP) for their assistance, hospitality and/or loan of material. We thank Carlos Tremouilles (MLP), who completed the final drafts of the figures and Analía Nessi (UBA-CONICET) and Juan Iwaszkiw (ILPLA ) for the histological preparation and interpretation of gonadal tissue. Thanks are also due to Patricia Battistoni and Justina Ponte for technical assistance and to the anonymous referee for his comments. aqua vol. 6 no

39 Amalia M. Miquelarena, Lucila C. Protogino, Ramiro Filiberto, and Hugo L. López References Azpelicueta, M. M., & A. Almirón A new species of Bryconamericus (Characiformes, Characidae) from the Paraná basin in Misiones, Argentina. Revue suisse de Zoologie, 108 (2): Bizerril, C. R. S. F., & P. R. Peres-Neto Redescription of Bryconamericus microcephalus (Ribeiro, 1908) and description of a new species of Bryconamericus (Characidae, Tetragonopterinae) from eastern Brazil. Comunicaçôes do Museu de Ciências e Tecnologia da PUCRS. Iheringia, Série Zoologia, Porto Alegre, 8: Bockman, F. A., & A. M. Miquelarena. Anatomy and phylogenetic of a new species of the catfish genus Rhamdella (Siluriformes, Pimelodidae, Heptapterinae) from north-eastern Argentina. (MS). Braga, L Los Characidae de Argentina de las subfamilias Cynopotaminae y Acestrorhynchinae. En: Programa de Fauna de Agua Dulce, (PRO- FADU). (Ed. Z. A. de Castellanos), 40 (6): Estudio Sigma S. R. L., Buenos Aires. Braga, L Una nueva especie de Bryconamericus (Ostariophysi, Characidae) del río Urugua-í, Argentina. Revista del Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Hidrobiología, 8 (3): Britski, H. A., S. de Silimon, K. Z., & B. S. Lopes Peixes do Pantanal. Manual de identificaçâo. EMBRAPA-SPI; Corumbá, 184 pp. Buckup, P. A Redescription of Characidium fasciatum, Type species of the Characiinae (Teleostei, Characiformes). Copeia, 1992 (4): Butí, C., & A. Miquelarena Ictiofauna del Río Salí superior, Departamento Trancas, Tucumán, República Argentina. Acta Zoológica Lilloana, 43 (1): Casciotta, J. R., Gómez, S. E., & N. I. Toresani Gymnogeophagus che, una nueva especie de la familia Cichlidae de la cuenca del río Paraná (Perciformes, Labroidei). Revista del Museo Argentino de Ciencias Naturales Bernardino Rivadavia, nueva serie, 2 (1): Cione, A., & M. J. Barla A new locality for the Synbranchid Synbranchus marmoratus (Teleostei: Percomorpha) in southern Buenos Aires province, Argentina. Neotrópica, 43 ( ): Colautti, D Sobre la utilización de trampas para peces en las lagunas pampásicas. Revista de Ictiología, 6 (1/2): Géry, J Characoids of the world. T.F.H. Publications, Neptune City, New Jersey, 672 pp. Golterman, H. L., & R. S. Clymo Methods for chemical analysis of fresh water. IBP Handbook N 8, Blackwell Scientific Publications, Oxford and Edinburgh, 166 pp. Gómez, S. E., & J. C. Chébez Peces de la provincia de Misiones. En: Fauna misionera, catálogo sistemático y zoogeográfico de los vertebrados de la provincia de Misiones (Argentina). (Ed. J. C. Chébez): L.O.L.A., Buenos Aires. Gómez, S. E., & D. E. Somay La ictiofauna del Parque Nacioanl Iguazú (Argentina). I. Sobre Steindachnerina inscripta y Glanidium riberoi (Pisces, Siluriformes). Historia Natural, 5 (23): López, H. L Estudio y uso sustentable de la biota austral: ictiofauna continental argentina. Revista Cubana de Investigaciones Pesqueras (Suplemento Especial, versión electrónica) 39 pp. ISSN CUB López, H. L., & A. M. Miquelarena Los Hypostominae (Pisces: Loricariidae) de Argentina. En: Programa de Fauna de Agua Dulce, (PROFADU). (Ed. Z. A. de Castellanos), 40 (2): Estudio Sigma S. R. L., Buenos Aires. López, H. L., Arámburu, R. H., Miquelarena, A. M., & R. C. Menni Nuevas localidades para peces de agua dulce de la República Argentina l. Limnobios, 1 (10): López, H. L., Baigún, C., Iwaszkiw, J. M., Delfino, R., & O. H. Padin La cuenca del Salado: uso y posibilidades de sus recursos pesqueros. Editorial de la Universidad Nacional de La Plata (EDULP), La Plata, 60 pp, 2 t. y 8 fig. López, H. L., Miquelarena, A. M., Menni, R. C., & J. R. Casciotta Nuevas localidades para peces de agua dulce de la República Argentina. V. Historia Natural, 4 (9): López, H. L., Protogino, L. C., & A. E. Aquino Ictiología continental Argentina: Santiago del Estero, Catamarca, Córdoba, San Luis, La Pampa y Buenos Aires. Aquatec, Boletín Técnico, 3: López R. B., & H. P. Castello Eigenmannia trilineata ( Teleostomi, Sternopyginae ) nueva especie hallada en el Río de la Plata. Comunicaciones del Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Zoología, 4 (2): Lucena, C. A. S., & S. O. Kullander The Crenicichla (Teleostei: Cichlidae) species of the Uruguai River drainage in Brazil. Ichthyological Exploration of Freshwaters, 3 (2): Maglianesi, R. E Principales características químicas y físicas de las aguas del Alto Paraná y Paraguay inferior. Physis, 32 (85): Mago Leccia, F Electric fishes of the continental waters of America. Fundación para el Desarrollo de las Ciencias Físicas, Matemáticas y Naturales (FUDECI), Caracas, 206 pp, 13 t. Malabarba, L. R., & A. Kindel A new species of the genus Bryconamericus Eigenmann, 1907 from Southern Brasil (Ostariophysi: Characidae). Proceedings of the Biological Society of Washington, 108 (4): Mazza, G Recursos hidraúlicos superficiales. En: Serie Evaluación Recursos Naturales Argentina (Primera Etapa) Tomo IV, Volumen 1. (Ed. Consejo 81 aqua vol. 6 no

40 A new species of Bryconamericus from the Cuña-Pirú creek in north-eastern Argentina, with comments on accompanying fishes Federal de Inversiones): 459 pp. Buenos Aires, Argentina. Menezes, N. A Três espécies novas de Oligosarcus Günther, 1864 e redefiniçao taxonômica das demais espécies do gênero (Osteichthyes, Teleostei, Characidae). Boletim Zoologia Universidade do Sâo Paulo, 11: Menni, R. C., López, H. L., Casciotta, J. R., & A. M. Miquelarena Ictiología de áreas serranas de Córdoba y San Luis (Argentina). Biología Acuática, 5: Menni, R. C., López, H. L., & R. H. Arámburu Ictiofauna de Sierra de la Ventana y Chasicó (Provincia de Buenos Aires, Argentina). Zoogeografía y parámetros ambientales. Anales Museo de Historia Natural de Valparaiso, 19: Menni, R. C., Miquelarena, A. M., López, H. L., Casciotta, J. R., Almirón, A. E., & L. C. Protogino Fish fauna and environments of the Pilcomayo-Paraguay basins in Formosa, Argentina. Hydrobiologia, 245: Miquelarena, A. M Estudio de la dentición en peces caracoideos de la República Argentina. Biología Acuática, 8: Miquelarena, A. M., & A. E. Aquino Situación taxonómica y geográfica de Bryconameicus thomasi Fowler, 1940 (Teleostei, Characidae). Revista Brasilera do Biologia, 55 (4): Miquelarena, A. M., & A. E. Aquino Taxonomic status and geographic distribution of Bryconamericus eigenmanni Evermann & Kendall, 1906 (Characiformes: Characidae). Proceedings of the Biological Society of Washington, 112 (3): Miquelarena, A. M., & L. Fernández Presencia de Trichomycterus davisi (Haseman, 1911) en la cuenca del Alto Paraná misionero (Silurifromes: Trichomycteridae). Revista de Ictiología, 8 (1/2): Miquelarena, A. M., & H. L. López Fishes of the Lagunas Encadenadas (province of Buenos Aires, Argentine) a wetland of international importance. Freshwater Forum, 5 (1): Miquelarena, A. M., López, H. L., & A. E. Aquino Los Ancistrinae (Pisces: Loricaridae) de Argentina. En: Programa de Fauna de Agua Dulce, (PROFADU). (Ed. Z. A. de Castellanos), 40 (5): Estudio Sigma S. R. L., Buenos Aires. Miquelarena, A. M., & L. C. Protogino Una nueva especie de Oligosarcus (Teleostei, Characidae) de la cuenca del Río Paraná, Misiones, Argentina. Iheringia, Série Zoologia, Porto Alegre, 80: Miquelarena, A. M., Protogino, L. C., & H. L. López Fishes from the Arroyo Urugua-í (upper Paraná basin, Misiones, Argentina) before impoundment of the dam. Revue française d Aquariologie, 24 (3-4): Miquelarena, A. M., López, H. L., Protogino, L. C., & R. Filiberto Ictiología. En: Informe UNLP- EMSA de Diagnóstico Ambiental de la Reserva Privada UNLP del Valle del Arroyo Cuña-Pirú. (Ed. J. D. Williams, H. Povedano y M. Espósito,) UNLP- EMSA, La Plata. Muller, S. F Systématique du genere Ancistrus Kner (Teleostei, Loricariidae): approches morphologique et génétique. Thèse Nº 3072, Genève, Museúm d histoire naturelle, 299 pp. Ringuelet, R. A Zoogeografía y ecología de los peces de aguas continentales de la Argentina y consideraciones sobre las áreas ictiológicas de América del Sur. Ecosur, 2 (3): Ringuelet, R. A., Arámburu, R. H., & A. Alonso de Arámburu Los peces argentinos de agua dulce. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC). La Plata, Buenos Aires, 602 pp. Silfvergrip, A. M. C A systematic revision of the Neotropical catfish genus Rhamdia (Teleostei, Pimelodidae). Department of Vertebrate Zoology, Swedish Museum of Natural History, Stockholm, 156 pp. 8 pls. Taylor, W. R., & G. C. Van Dyke Revised procedures for staining and clearing small fishes and other vertebrates for bone and cartilage study. Cybium, 9: Vari, R. P., & D. J. Siebert A new unusually sexually dimorphic species of Bryconamericus (Pisces: Ostariophysi: Characidae) from the Peruvian Amazon. Proceeding of the Biological Society of Washington, 103 (3): aqua vol. 6 no

41 aqua, Journal of Ichthyology and Aquatic Biology Austrolebias jaegari (Cyprinodontiformes: Rivulidae: Cynolebiatinae): a new annual fish from the Laguna dos Patos system, southern Brazil, with a redescription of A. gymnoventris (Amato) Wilson J. E. M. Costa 1 and Morevy M. Cheffe 2 1) Laboratório de Ictiologia Geral e Aplicada, Departamento de Zoologia, Universidade Federal do Rio de Janeiro, Cidade Universitária, Caixa Postal 68049, CEP , Rio de Janeiro, RJ, Brazil. wcosta@acd.ufrj.br. 2) Laboratório de Ictiologia, Museu de História Natural, Universidade Católica de Pelotas, Rua Félix da Cunha, 412, CEP , Pelotas, RS, Brazil. mcheffe@hotmail.com. Accepted: Keywords Annual killifishes, Laguna dos Patos, Systematics, Phylogeny, Austrolebias, Rivulidae Abstract Austrolebias jaegari n. sp. from Pelotas, southern Brazil, is described, and A. gymnoventris (Amato) from Rocha, eastern Uruguay, is redescribed; both species share four synapomorphies: absence of scales on venter, body contact organs of male restricted to anteroventral portion of body side, absence of suborbital and supraorbital dark bars in live specimens, and a unique colour pattern on male body side. Austrolebias jaegari differs from A. gymnoventris by possessing a longer pectoral fin and, in the male, having contact organs on pectoral fin, a more anteriorly positioned anal fin origin, and narrower body bars. Resumo Austrolebias jaegari n. sp. de Pelotas, sul do Brasil, é descrita, e A. gymnoventris (Amato) de Rocha, leste do Uruguai, é redescrita; ambas espécies compartilham quatro sinapomorfias: ausência de escamas em ventre, órgãos de contato de macho restritos à porção anteroventral de lado de corpo, ausência de barra escura suborbital e supraorbital em exemplares vivos, e um padrão de colorido exclusivo em lado de corpo de macho. Austrolebias jaegari difere de A. gymnoventris por possuir nadadeira peitoral mais longa e macho ter órgãos de contato em nadadeira peitoral, origem de nadadeira anal mais anteriormente posicionada e barras de corpo mais estreitas. Zusammenfassung Austrolebias jaegari n. sp. aus Pelotas (südliches Brasilien) wird erstmals beschrieben, und A. gymnoventris (Amato) aus Rocha (östliches Uruguay) wird neu beschrieben; beide Arten teilen sich vier Synapomorphien: Abwesenheit von Schuppen am Abdomen, die Kontaktorgane am Körper der Männchen sind auf die anteroventrale Körperseite beschränkt, Abwesenheit von suborbitalen und supraorbitalen dunklen Streifen in lebenden Exemplaren und ein einzigartiges Farbmuster auf den Seiten der Männchen. Austrolebias jaegari unterscheidet sich von A. gymnoventris dadurch dass sie längere Brustflossen hat und die Männchen mit Kontaktorganen an der Brustflosse aufgerüstet sind; auch der Ansatz der Afterflosse liegt weiter nach vorn und die Körperstreifen sind schmaler. Résumé Austrolebias jaegari n. sp. de Pelotas, sud du Brésil, est décrit et A. gymnoventris (Amato) de Rocha, est de l'uruguay, est redécrit; les deux espèces partagent quatre caractéristiques: l'absence d'écailles sur le ventre, les organes de contact du mâle réduits à la portion antéroventrale du flanc, l'absence de barres foncées suborbitales et supraorbitales sur spécimens vivants et un patron de coloration unique des flancs du mâle. Austrolebias jaegari se distingue d'a. gymnoventris par une pectorale plus longue et, chez le mâle, par des organes de contact sur la pectorale, la naissance de l'anale située plus antérieurement et des lignes plus fines sur le corps. Sommario Alla descrizione aggiornata di A. gymnoventris (Amato) proveniente da Rocha, Uruguay orientale si aggiunge la descrizione di una nuova specie Austrolebias jaegari raccolta a Pelotas, Brasile meridionale; le due specie condividono quattro caratteri sinapomorfici: assenza di squame sul ventre, organi di contatto del maschio ristretti alle porzioni anteroventrali dei fianchi, assenza di barre scure sottorbitali e sopraorbitali in esemplari vivi e diversa co - lorazione dei fianchi nei maschi. Austrolebias jaegari differisce da A. gymnoventris per avere pinne pettorali 83 aqua vol. 6 no

42 Austrolebias jaegari a new annual fish from the Laguna dos Patos system, southern Brazil, with a redescription of A. gymnoventris più lunghe, organi di contatto anche sulle pinne pettorali, l origine della pinna anale posta più anteriormente e barre sui fianchi più strette. Introduction The great diversity of cynolebiatine annual fishes in the Laguna dos Patos system, a coastal region of southern Brazil and eastern Uruguay, has been recently reported in a series of taxonomic studies (Amato, 1986, 1987; Costa & Cheffe, 2001, 2002). Over 15 annual fish species are endemic to this area, belonging to the genera Cynopoecilus Regan, Megalebias Costa and Austrolebias Costa. Austrolebias gymnoventris was first described on the basis of specimens collected in two close localities, near Velázquez and Castillos respectively, Rocha Department, Uruguay. The original description is restricted to fin rays and longitudinal scale counts, with some details of head morphology and fin positions, and some data on the colour pattern. Subsequent collections (Reichert, 1994; Reichert et al., 1997) proved that A. gymnoventris also occurs in other localities (i.e., Camino del Indio and Lascano) near the type locality. The object of this paper is to describe a new species, closely related to A. gymnoventris, from Pelotas, southern Brazil, and to redescribe A. gymnoventris based both on paratypes and topotypes. Material and Methods Measurements and counts follow Costa (1995); all measurements are presented as percentages of standard length (SL). Counts of pelvic, pectoral and caudal fin rays and vertebrae were made only on cleared and counter-stained specimens (c&s) prepared according to Taylor & Van Dyke (1985); the compound caudal centrum was counted as a single element in vertebrae numbers. Nomenclature for frontal squamation follows Hoedeman (1958) and terminology for cephalic neuromasts is according to Costa (2001). Selected osteological characters presented in descriptions are those considered phylogenetically informative for Austrolebias according to Costa (in press). Abbreviations for institutions are: MCP, Museu de Ciências e Tecnologia da Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, MUCP, Museu de História Natural, Universidade Católica de Pelotas, Pelotas, MZUSP, Museu de Zoologia da Universidade de São Paulo, São Paulo, and UFRJ, Universidade Federal do Rio de Janeiro, Rio de Janeiro. Austrolebias jaegari n. sp. (Figs. 1-2; Table I) Holotype: MCP 28574, male, 30.4 mm SL; Brazil: Rio Grande do Sul: Pelotas: swamp at Banhado do Timba, Corredor das Tropas, approximately 31 30'S 52 20'W; collected by M. Cheffe, G. Maurício & N. Jaegar, 30 August 2000, with a dip net. Paratypes: Brazil: Estado do Rio Grande do Sul: Pelotas: MCP 28575, 1 male, 23.5 mm SL, and 4 females, mm SL; MUCP 2538, 4 males, mm SL; all collected with holotype. - UFRJ 5429, 1 male, 26.6 mm SL, and 6 females, mm SL; UFRJ 5430, 3 males, mm SL, and 3 females, mm SL (c&s); same locality; M. Cheffe & F. Silveira, 23 August MUCP 2583, 5 females, mm SL; same locality; collected by M. Cheffe & F. Silveira, 22 October MUCP 2518, 2 males, mm SL, and 3 females, mm SL; Arroio Santa Bárbara floodplains, approximately; collected by M. Cheffe, 23 August All paratypes collected with a dip net. Fig. 1. Austrolebias jaegari, UFRJ 5430, male, paratype, 28.4 mm SL; Brazil: Rio Grande do Sul: Pelotas. Photo by N. Jaegar. Fig. 2. Austrolebias jaegari, UFRJ 5429, female, paratype, 21.1 mm SL; Brazil: Rio Grande do Sul: Pelotas. Photo by N. Jaegar. Diagnosis Similar to A. gymnoventris and distinguished from all other congeners by lacking scales on venter (vs. scales covering whole venter), body contact organs restricted to anteroventral portion of male body side (vs. contact organs over whole ventral half of flank), absence of suborbital and supraorbital dark marks in live specimens (vs. conspicuous dark grey to black supraorbital and suborbital bars), and male body side dark brownish grey with light grey bars on anterior portion, becoming narrow and faint on the posterior portion (vs. never a similar colour pattern). It differs from A. gymnoventris by having papillate contact aqua vol. 6 no

43 Wilson J. E. M. Costa and Morevy M. Cheffe organs on pectoral fin of male (vs. no papillate contact organs on pectoral fin), longer pectoral fin ( % SL in male and % SL in female, vs % SL in male and % SL in female), anal fin origin of male between pleural ribs of vertebrae 6 and 8 (vs. between pleural ribs of vertebrae 8 and 10), dorsal fin origin of male in a vertical between pectoral fin base and anus (vs. vertical through pelvic-fin base or anterior to it), and anterior light body bars of male narrower (widest bar % SL, vs % SL). Description Morphometric data for holotype and nine paratypes are given in Table I. Male larger than female, largest male 30.4 mm SL. Dorsal profile approximately straight to slightly concave on head, convex between snout and dorsal fin base end, approximately straight on caudal peduncle. Ventral profile convex from lower jaw to end of anal fin base, nearly straight on caudal peduncle. Body slender, compressed, maximum body width approximately 1.9 in maximum body depth in larger males. Greatest body depth at vertical through dorsal fin origin. Snout blunt, jaws short. Tip of dorsal and anal fins rounded. Anteromedian rays of anal fin of female not lengthened, anal fin profile approximately semicircular. Urogenital papilla of male not attached to anal fin. Caudal fin rounded. Pectoral fin elliptical. Posterior margin of pectoral fin reaching vertical through base of sixth anal fin ray in male, and urogenital papilla in female. Tip of pelvic fin reaching base of third anal fin ray. Pelvic fin bases in close proximity, but fins not medially united. Dorsal fin origin on a vertical between pelvic fin base and anus in male, and between anus and urogenital papilla in female. Anal fin origin on a vertical through base of third or fourth dorsal fin ray, and between pleural ribs of vertebrae 6 and 8 in male, and through base of third dorsal fin ray and between pleural ribs of vertebrae 9 and 10 in female. Dorsal fin rays in male, in female; anal fin rays in male, in female; caudal fin rays 20-23; pectoral fin rays 12; pelvic fin rays 5. Scales large, cycloid. Lateral and dorsal surface of body and head entirely scaled; no scales on ventral surface of head and venter, except for some scales just anterior to pelvic fin base, sometimes also absent. Frontal squamation E or F-patterned. No transverse row of scales on anal and pectoral fin bases. Longitudinal series of scales 26-27; transverse series of scales 12; scale rows around caudal peduncle 16. One prominent cteniform contact organ on each scale of anteroventral portion of body side of male, below lateral line of neuromasts. No contact organs on fins, except a few minute ones on inner surface of distal portion of first and second most dorsal pectoral fin ray of male. Supraorbital neuromasts Autopalatine with small, rounded dorsomedial projection. Basihyal triangular, its longest width about 75% its length; basihyal cartilage long, about 50% total basihyal length, with slight lateral projection. Six branchiostegal rays. Two to four teeth on second pharyngobranchial. Gill-rakers on first branchial arch Posterior arm of parasphenoid narrow. Dermosphenotic absent. Ventral process of posttemporal short, sometimes vestigial. Total vertebrae Coloration: Male: Side of body dark brownish grey, with six to nine light grey bars; widest bar % SL; anterior four bars in close proximity, separated by neighbouring bars by space twice wider than bar width; posterior bars faint, narrower, substituted by vertical series of dots on caudal peduncle, and separated among themselves by broad space, about seven times bar width. Dorsum dark brownish grey. Head bright blue; suborbital and supraorbital bars absent, but faint suborbital bar present in preserved specimens. Iris brown; faint grey bar through eye. Dorsal fin dark brownish grey with orange-pink iridescence and white dots. Caudal and anal fins dark brownish grey with white dots on basal region; broad bright blue zone along distal border of anal fin; dorsal portion of caudal fin with orange-pink iridescence. Pectoral fin hyaline. Pelvic fin bright blue. Female: Side of body light brown, with dark grey spots, usually vertically elongated; no distinctive darker spots on anterocentral portion of flank. Venter Fig. 3. Geographic distribution of A.jaegari and A. gymnoventris. 85 aqua vol. 6 no

44 Austrolebias jaegari a new annual fish from the Laguna dos Patos system, southern Brazil, with a redescription of A. gymnoventris pale golden. Head light brown, opercular region pale golden; suborbital or supraorbital bars absent. Iris yellow. Unpaired fins hyaline; faint, small grey spots on unpaired fins, becoming dark grey on dorsal and anal fin bases. Etymology The name jaegari is in honour of the late photographer Norberto Henrique Jaegar, in recognition of his enthusiasm and dedication to the conservation of natural areas. Distribution Known from the type locality region, the floodplains of the southern inner shore of Laguna dos Patos, southern Brazil (Fig. 3). This species was previously collected by Roberto Krebs Baltar, in 1972, Capão do Leão, about 15 km W from the type locality, but no material was preserved for study. Austrolebias gymnoventris (Amato, 1986) (Fig. 4; Table II) Cynolebias gymnoventris Amato, 1986: 2 (original description, floodplains of Arroyo India Muerta, 150 m from the National Route 13, and 50 m from the road, near Velázquez, Rocha, Uruguay, approximately 34 06'S 54 16'W). Material examined: Uruguay: Departamento de Rocha: MZUSP 36450, 1 paratype; MZUSP 36451, 1 paratype; Arroyo India Muerta floodplains, 150 m from the National Route 13, and 50 m from the road; L. H. Amato, G. Dittricht and C. Pérez, 10 Sept UFRJ 5254, 6 specimens examined; UFRJ 5253, 6 ex. (c&s); MUCP 2502, 13 ex.; Uruguay: same locality; M. Cheffe, 7 July Fig. 4. Austrolebias gymnoventris, MUCP 2502, male, topotype, 30.3 mm SL: Uruguay: Rocha: Velazquez. Photo by N. Jaegar. Diagnosis Similar to A. jaegari and differing from all other species of the genus by the absence of scales on venter (vs. entire venter covered in scales), body contact organs restricted to anteroventral portion of male body side (vs. extending to the whole ventral half of flank), absence of suborbital and supraorbital dark marks in live specimens (vs. conspicuous dark grey to black supraorbital and suborbital bars), and male body side dark brownish grey with light grey bars on anterior portion, becoming narrow and faint on the posterior portion (vs. never a similar colour pattern). It is distinguished from A. jaegari by not having contact organs on pectoral fin (vs. papillate contact organs on pectoral fin of male), shorter pectoral fin ( % SL in male and % SL in female, vs % SL in male and % SL in female), anal fin origin of male between pleural ribs of vertebrae 8 and 10 (vs. between pleural ribs of vertebrae 6 and 8), dorsal fin origin of male in a vertical through pelvic fin base or anterior to it (vs. vertical between pectoral fin base and anus), and anterior light body bars of male narrower (widest bar % SL, vs % SL). Description Morphometric data for 10 specimens are given in Table II. Male larger than female, largest male 30.3 mm SL. Dorsal profile approximately straight to slightly concave on head, convex between snout and dorsal fin base end, approximately straight on caudal peduncle. Ventral profile convex from lower jaw to end of anal fin base, nearly straight on caudal peduncle. Body slender, compressed, maximum body width approximately 1.8 in maximum body depth in larger males. Greatest body depth at vertical through dorsal fin origin. Snout blunt, jaws short. Tip of dorsal and anal fins rounded. Anteromedian rays of anal fin of female not lengthened, anal fin profile approximately semicircular. Urogenital papilla of male not attached to anal fin. Caudal fin rounded. Pectoral fin elliptical. Posterior margin of pectoral fin reaching vertical between base of first and fourth anal fin ray in male, and between pelvic fin base and anus in female. Tip of pelvic fin reaching base of third anal fin ray in male, and between urogenital papilla and base of first anal fin base in female. Pelvic fin bases in close proximity, but fins not medially united. Dorsal fin origin in vertical through pelvic fin base or anterior to it in male, and through anus in female. Anal fin origin in vertical through base of third or fourth dorsal fin ray and between pleural ribs of vertebrae 8 and 10 in male, and through base of third dorsal fin ray and between pleural ribs of vertebrae 9 and 10 in female. Dorsal fin rays in male, in female; anal fin rays in male, in female; caudal fin rays 21-23; pectoral fin rays 12; pelvic fin rays 5. Scales large, cycloid. Lateral and dorsal surface of body and head entirely scaled; no scales on ventral surface of head and venter, except for some just anterior to pelvic fin base. Frontal squamation E- or F-patterned. No transverse row of scales on anal and pectoral fin bases. Longitudinal series of scales 26-27; aqua vol. 6 no

45 Wilson J. E. M. Costa and Morevy M. Cheffe Table I. Morphometric data of Austrolebias jaegari. males females Holotype Paratypes MCP MUCP MUCP MUCP MUCP MUCP MUCP MCP MCP MUCP SL [mm] In percents of standard length Body depth Caudal peduncle depth Predorsal length Prepelvic length Length of dorsal fin base Length of anal fin base Caudal fin length Pectoral fin length Pelvic fin length Head length Head depth Head width Snout length Lower jaw length Eye diameter Table II. Morphometric data of Austrolebias gymnoventris (all MUCP 2502). males females SL [mm] In percent of standard length Body depth Caudal peduncle depth Predorsal length Prepelvic length Length of dorsal fin base Length of anal fin base Caudal fin length Pectoral fin length Pelvic fin length Head length Head depth Head width Snout length Lower jaw length Eye diameter transverse series of scales 11-13; scale rows around caudal peduncle 16. One prominent cteniform contact organ on each scale of anteroventral portion of body side of male, below lateral line of neuromasts. No contact organs on fins. Supraorbital neuromasts Autopalatine with small rounded dorsomedial projection. Basihyal triangular, its longest width about 85 % its length; basihyal cartilage long, about 50 % length of basihyal, with slight lateral projection. Six branchiostegal rays. Two to four teeth on second pharyngobranchial. Gill-rakers on first branchial arch Posterior arm of parasphenoid narrow. Dermosphenotic absent. Ventral process of posttemporal short, sometimes vestigial. Total vertebrae Coloration: Male: Side of body dark brownish grey, with five to nine light grey bars; widest bar % SL; anterior bars in close proximity, separated by neighbouring bars by space about twice wider than bar width; posterior bars faint, narrower, and separated among themselves by broad space, about seven times bar width. Dorsum dark brownish grey. Head bright blue; suborbital and supraorbital bars absent, but faint suborbital bar present in preserved specimens. Iris brown; faint grey bar through eye. Dorsal fin dark brownish grey with yellowish-pink iridescence and white dots. Caudal and anal fins dark brownish grey with white dots; broad bright blue zone along distal border of anal fin; dorsal portion of caudal fin with 87 aqua vol. 6 no

46 Austrolebias jaegari a new annual fish from the Laguna dos Patos system, southern Brazil, with a redescription of A. gymnoventris yellowish pink iridescence. Pectoral fin hyaline. Pelvic fin bright blue. Female: Side of body light brown, with dark grey spots, sometimes vertically elongated; rarely distinctive darker spot on anterocentral portion of flank. Venter pale golden. Head light brown, opercular region pale golden; suborbital or supraorbital bars absent. Iris yellow. Unpaired fins hyaline; faint small grey spots on unpaired fins, becoming dark grey on dorsal and anal fin bases. Distribution Arroyo del Ceibo basin, a southern tributary of Laguna Mirim, and adjacent coastal plains, Rocha Department, eastern Uruguay (Fig. 3). Discussion Monophyly of the assemblage comprising Austrolebias jaegari and A. gymnoventris is well corroborated. Both species share some apomorphic conditions not found elsewhere among cynolebiatines: venter without scales, prominent contact organs restricted to anteroventral portion of male body side, and colour pattern of male flank consisting of dark brownish grey with light bars on anterior portion, becoming narrow and faint on the posterior portion of body. In addition, absence of suborbital and supraorbital dark marks in live specimens shared by these two species, is a unique condition among species of the clade comprising Austrolebias and Megalebias (Costa, in press). In other species of Austrolebias and species of all other genera of the Cynolebiatinae, the venter is completely scaled, and never a similar colour pattern of body is found. Prominent contact organs are present in some species of the clade comprising Austrolebias and Megalebias (e.g. A. robustus (Günther) and M. wolterstorfii (Ahl)) (Costa, in press), but scattered over most surface of body side, never restricted to the anteroventral portion as occurring in A. jaegari and A. gymnoventris. Conspicuous dark grey to black supraorbital and suborbital bars are primitively present within the clade encompassing Austrolebias and Megalebias (Costa, in press), contrasting with the faint bars of A. jaegari and A. gymnoventris visible only in preserved specimens. Acknowledgements Thanks are due to N. Jaegar, G. Maurício and F. Silveira for help during collecting trips, to N. Jaegar for the photographs, to L. Amato for donation of specimens (in MZUSP), and to O. Oyakawa for the loan of material. This study was supported by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico - Ministério de Ciência e Tecnologia) and FAPERJ (Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro). References Amato, L. H Seis especies nuevas del genero Cynolebias Steindachner, 1876, de Uruguay y Paraguay (Cyprinodontiformes, Rivulidae). Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo, 162: Amato, L. H Descripción de Cynolebias cyaneus n. sp., nuevo pez anual del Estado de Rio Grande do Sul, Brasil (Cyprinodontiformes, Rivulidae). Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo, 163: Costa, W. J. E. M Pearl killifishes, the Cynolebiatinae: systematics and biogeography of a neotropical annual fish subfamily (Cyprinodontiformes: Rivulidae). TFH, Neptune City, 128 pp. Costa, W. J. E. M Phylogeny and classification of Rivulidae revisited: Evolution of annualism and miniaturization in rivulid fishes (Cyprinodontiformes: Aplocheiloidei). Journal of Comparative Biology, 3: Costa, W. J. E. M The neotropical annual fish genus Cynolebias (Cyprinodontiformes: Rivulidae): phylogenetic relationships, taxonomic revision and biogeography. Ichthyological Exploration of Freshwaters, 12: Costa, W. J. E. M The annual fish genus Cynopoecilus (Cyprinodontiformes: Rivulidae): taxonomic revision, with descriptions of four new species. Ichthyological Exploration of Freshwaters, 13: Costa, W. J. E. M. (in press). Monophyly and phylogenetic relationships of the neotropical annual fish genera Austrolebias and Megalebias (Cyprinodontiformes: Rivulidae). Copeia. Costa, W. J. E. M. & M. M. Cheffe Three new annual fishes of the genus Austrolebias from the laguna dos Patos system, southern Brazil, and a redescription of A. adloffi (Ahl) (Cyprinodontiformes: Rivulidae). Comunicações do Museu de Ciências e Tecnologia da PUCRS, Série zoologia, 14: Hoedeman, J. J Rivulid fishes of the Antilles. Studies on the Fauna of Curaçao and other Caribbean Islands, 32: Reichert, J. J Laminas y datos complementarios sobre las especies del genero Cynolebias Steindachner 1876, halladas y descritas para el Uruguay, hasta el año Acuariologia Comunicaciones Ictiologicas, 6: Reichert, J. J., F. Prieto & H. Salvia Fächerfische aus Uruguay. DKG-Journal, supplementheft, 5: Taylor, W. R. & G. C. Van Dyke Revised procedures for staining and clearing small fishes and other vertebrates for bone and cartilage study. Cybium, 9: aqua vol. 6 no

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48 aqua Journal of Ichthyology and Aquatic Biology Vol. 6 (2), November 2002 Contents Gerald R. Allen: Descriptions of two new species of damselfishes (Pomacentridae: Pomacentrus) from Madagascar Marta S. C. Soares, João Pedro Barreiros, Luis Sousa & Ricardo S. Santos: Agonistic and predatory behaviour of the lizardfish Synodus saurus (Linnaeus, 1758) (Actinopterygii: Synodontidae) from the Azores Ivan Sazima: Juvenile grunt (Haemulidae) mimicking a venomous leatherjacket (Carangidae), with a summary of Batesian mimicry in marine fishes Amalia M. Miquelarena, Lucila C. Protogino, Ramiro Filiberto, and Hugo L. López: A new species of Bryconamericus (Characiformes: Characidae) from the Cuña-Pirú creek in north-eastern Argentina, with comments on accompanying fishes Wilson J. E. M. Costa and Morevy M. Cheffe: Austrolebias jaegari (Cyprinodontiformes: Rivulidae: Cynolebiatinae): a new annual fish from the Laguna dos Patos system, southern Brazil, with a redescription of A. gymnoventris (Amato) Papers appearing in this journal are indexed in: Zoological Record; Biolis - Biologische Literatur Information Senckenberg; Cover photo: Austrolebias jaegari, UFRJ 5430, male, paratype, 28.4 mm SL; Brazil: Rio Grande do Sul: Pelotas. Photo by N. Jaegar. Fig. 4. Austrolebias gymnoventris, MUCP 2502, male, topotype, 30.3 mm SL: Uruguay: Rocha: Velazquez. (See the Ms from Wilson J. E. M. Costa and Morevy M. Cheffe in this issue on pages ) Photo by N. Jaegar.