Three new species of genus Trimma from Palau, Western Pacific (Percomorpha: Gobiidae)

Transcription

1 aqua, International Journal of Ichthyology Three new species of genus Trimma from Palau, Western Pacific (Percomorpha: Gobiidae) Richard Winterbottom 1, 2 and Margaret Zur 1 1) Department of Natural History, Royal Ontario Museum, 100 Queen s Park, Toronto, Ontario, M5S 2C6, Canada. rickw@rom.on.ca 2) Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, M5S 3G5, Canada Received: 22 June 2007 Accepted: 14 September 2007 Abstract Three new species of the Indo-Pacific gobiid genus Trimma are described, based primarily or entirely on material from Palau. Trimma gigantum n. sp. is characterized by the presence of predorsal scales, elongate dorsal spines, six dark saddles along the dorsum on a yellow background, fully scaled cheek and opercle, a fifth pelvic fin ray that is branched dichotomously once, and large adult size (to 30 mm SL). It appears to be a relatively deep-water species (57-73 m). Trimma randalli n. sp. also has a yellowish body, and scales on the cheek, opercle and in the predorsal midline, but lacks saddles across the dorsum and has a black caudal fin edged with white. There is a photographic record of this species from the Philippines. Trimma tauroculum n. sp. is immediately distinguishable from all other described species by the presence of a large (about 1.25 times pupil diameter) brownblack ocellated spot on the upper body, its anterior margin immediately above the pectoral-fin base, no scales in the predorsal midline, and no elongate dorsal spines. There is a photographic record of this species from Ulithi Atoll, Yap Islands (western Carolines). Zusammenfassung Beschrieben werden drei neue Arten der indo-pazifischen Meergrundel-Gattung Trimma vorwiegend oder gänzlich auf der Grundlage von Material aus der Gegend um Palau. Trimma gigantum n. sp. ist durch folgende Merkmale gekennzeichnet: Vorhandensein prädorsaler Schuppen, verlängerte Rückenstacheln, sechs dunkle Sattelflecken am Rücken auf gelbem Untergrund, volle Beschuppung auf Wangen und Kiemendeckel, fünfter Bauchflossenstrahl, der sich einmal dichotom verzweigt, und besondere Größe der erwachsenen Tiere (bis 30 mm SL). Die Art scheint eher in größerer Tiefe zu leben (57 bis 73 m). Trimma randalli n. sp. hat ebenfalls eine gelbliche Grundfarbe sowie Schuppen auf Wangen, Operculum und in der prädorsalen Mittellinie, doch fehlen hier die Sattelflecken am Rücken, und die Schwanzflosse ist schwarz mit einem weißen Rand. Zu dieser Art gibt es einen fotografischen Beleg von den Philippinen. Trimma tauroculum n. sp. lässt sich leicht von allen anderen beschriebenen Arten unterscheiden: Ihre Vertreter besitzen einen großen braunschwarzen Augenfleck (etwa 1,25-facher Pupillendurchmesser) im oberen Körperbereich, dessen vorderer Rand gleich über der Brustflossenbasis beginnt, haben außerdem keine Schuppen in der prädorsalen Mittellinie und keine verlängerten Rückenstacheln. Es gibt einen fotografischen Beleg dieser neuen Art vom Ulithi-Atoll, Yap- Inseln (westliche Karolinen). Résumé Trois nouvelles espèces du genre Trimma de l Indo-Pacifique sont décrites sur base de matériel originaire principalement ou exclusivement de Palau. Trimma gigantum n. sp. se caractérise par la présence d écailles prédorsales, d épines dorsales allongées, de six taches sombres sur fond jaune, en selle sur le dos, de joues et d opercules entièrement couverts d écailles, d un cinquième rayon de la pelvienne dichotomiquement divisée une seule fois et d une taille importante (jusqu à 30 mm LS). Cette espèce semble vivre en eau relativement profonde (57-73 m). Trimma randalli n. sp. a également un corps jaunâtre et des écailles sur la joue, l opercule et la ligne médiane prédorsale, mais n a pas de taches en selle sur le dos et présente une caudale noire bordée de blanc. Il existe une photographie de cette espèce des Philippines. Trimma tauroculum n. sp. se distingue nettement de toutes les autes espèces décrites par la présence d une grande tache brun noir en ocelle (à peu près 1,25 fois le diamètre de la pupille) sur le haut du corps, d une marge antérieure au-dessus de la base de la pectorale, par l absence d écailles sur la ligne médiane prédorsale et d épines dorsales allongées. Il existe une photographie de cette espèce de Ulithi Atoll, îles Yap (Carolines occidentales). Sommario Tre nuove specie di gobidi dell Indo-Pacifico appartenenti al genere Trimma sono descritte sulla base di esemplari provenienti principalmente o interamente da Palau. Trimma gigantum n. sp. è caratterizzata dalla presenza di scaglie predorsali, spine dorsali allungate, sei macchie scure a forma di sella lungo il dorso disposte su un fondo giallo, guance ed opercolo completamente ricoperti da scaglie, quinto raggio pelvico ramificato dicotomicamente una volta sola e grandi dimensioni dell adulto (fino a 30 mm SL). È una specie che vive in acque relativamente profonde (57-73 m). Trimma 13 aqua vol. 13 no October 2007

2 Three new species of genus Trimma from Palau, Western Pacific (Percomorpha: Gobiidae) randalli n. sp. si presenta anch essa con corpo giallastro e scaglie sulle guance, sull opercolo e lungo la linea predorsale, ma non ha macchie a sella sul dorso e ha la pinna caudale nera bordata di bianco. Esiste un reperto fotografico di questa specie nelle Filippine. Trimma tauroculum n. sp. è immediatamente distinguibile da tutte le altre descritte per la presenza di una larga macchia ocellata marrone-nero (circa 1.25 volte il diametro della pupilla) sulla parte superiore del corpo, il suo margine anteriore immediatamente sopra la base della pettorale, per l assenza di scaglie sulla linea mediana predorsale e spine dorsali non allungate. Esiste un reperto fotografico di questa specie presso l atollo Ulithi, Isole Yap (Caroline occidentali). INTRODUCTION Trimma Jordan and Seale, 1906, contains some 85 species of small (usually less than 30 mm SL), often colourful gobiids with a moderately compressed head and body. They are primarily associated with Indo- Pacific coral reefs. Members of the genus may be recognized by the lack of cephalic sensory canal pores, much reduced cephalic sensory papillae pattern, wide gill opening extending to below the vertical limb of the preopercle or anterior to this, lack of spicules on the outer gill rakers of the first gill arch (possibly or even probably a homoplastic character state), less than 12 dorsal and anal rays, and a fifth pelvic fin ray that is equal to or more than 40% the length of the fourth pelvic fin ray. There are 53 valid species of Trimma, and approximately 35 additional known species remain to be described. However, recent collections below normal scuba collecting depths (> ca 50 m) consistently contain previously unknown species of the genus, including one of the species described here from material collected in Palau in METHODS Methods follow Winterbottom (2002), except that pectoral and pelvic fin ray branching is described from preserved material stained with a cyanine blue solution as outlined in Saruwatari et al. (1997), and circumpeduncular scales are counted in a zig-zag manner around the narrowest portion of the caudal peduncle. Lengths are given as standard length (SL) and are in millimeters. Values for holotype are given in bold where appropriate. Abbreviations for repositories of material examined follow Leviton et al. (1985). Non-type material listed is confined to material collected for subsequent genomic analyses. Figures 2, 5 and 7 were each produced from multiple digital images taken with a Nikon D100 camera attached to a Zeiss SV8 dissecting microscope at slightly incremental focal planes. These were collated into a single image using Achimed (GT Vision). Trimma gigantum n. sp. Giant pygmy goby (Figs 1, 2A-C, 3A) Material examined: A total of two collections, 25 specimens (23 types), mm SL, from the Republic of Palau. Holotype: ROM 80353, 27.7 mm SL female, Augulpelu reef (aka as the Short Drop-off), cave in steep reef slope, N E, 73 m, P. Colin, 28 March Paratypes: AMS I , 2, mm SL, collected with the holotype. FMNH , 2, mm SL, collected with the holotype. ROM 80367, 2, mm SL, Augulpelu reef, overhang in steep reef slope, N E, 57 m, P. Colin, 29 March ROM 80658, 14, mm SL, collected with the holotype. ROM C&S 1774, 2, mm SL, ex-rom 80658, collected with the holotype. Non-type material: Tissue samples for genetic Fig. 1. Trimma gigantum, 27.7 mm SL female holotype, Augulpelu Reef, Palau, ROM Photo by R. Winterbottom. aqua vol. 13 no October

3 analysis, both collected with the holotype: ROM T00667, male, 26.6 mm SL. ROM T00668, male 25.5 mm SL. Diagnosis: Trimma gigantum is a member of the T. tevegae species complex (sensu Winterbottom 2005), with a broad interorbital space and a greatly expanded first haemal arch. It is characterized by predorsal scales, second and third dorsal spines elongate, a fleshy, longitudinal ridge in the interorbital midline, no postorbital trenches, scales covering the cheek and opercle, fifth pelvic fin ray is usually branched dichotomously once, a pattern of six dark saddles across the dorsum on a pale yellow background, and large adult size (to about 30 mm SL). Description: The description is based on the holotype and up to 22 paratypes. Dorsal fins VI + I 8-9 (x =8.1, n=15), second and third spine usually elongate, with second spine reaching posteriorly as far as base of last element of second dorsal fin, fin rays usually all branched (one specimen with both elements of last ray unbranched); anal fin I (x =8.0, n=13); pectoral fin (x =15.9, n=15) with 6-11 branched rays in approximate centre of fin, reaching posteriorly to a vertical line with first few elements of anal fin; pelvic fin I 5, no frenum, basal membrane no more than 10% of length of fifth ray, often vestigial, first four rays with one sequential branch, fifth ray branched dichotomously once (two of 15 with unbranched fifth ray) and 40-60% length of fourth, fourth ray reaching posteriorly to a vertical line with second to fifth element of anal fin. Lateral scales (x=24.7, n=15); anterior transverse scales 8-10 (x=9.1, n=14); posterior transverse scales (x=7.8, n=14); predorsal scales (x=16.3, n=14); rows of cycloid scales across midline of breast, and 1-2 additional single scales in midline on pelvic fin base; cycloid scales in 2-3 vertical columns on pectoral base; scales on head extending into interorbital space almost to mid eye (Fig. 2A); cheek with scales in 2-3 rows plus 1-2 additional scales; opercle with scales in 4-5 rows (Fig. 2B); circumpeduncular scales 12, (n=10). Gill opening extending anteroventrally to below anterior margin of pupil. Upper jaw with an outer row of 6-8 spaced medium curved canines near symphysis and an inner row of small coniform teeth. Lower jaw with an outer row of medium canines across front of jaw, followed by two irregular rows, a middle row of small teeth and an inner row of medium sized canines, inner rows of teeth may extend to coronoid process of dentary. Tongue tip parenthesis-shaped. Gill rakers on first arch Richard Winterbottom and Margaret Zur 18-20= , (x=22.8, n=9). Anterior nasal opening a tube just above upper lip, posterior nasal opening a rimmed pore midway between upper lip and eye (Figs 2A, 2B), nasal sac slightly elevated. Fig. 2. Trimma gigantum, A. dorsal view of head; B. lateral view of head; both 25.0 mm SL male paratype, Augulpelu Reef, ROM 80658, specimen stained with Cyanine Blue; C: dorsal view of head of unstained specimen, 26.5 female paratype, Augulpelu Reef, ROM Photo and digital manipulation by R. Winterbottom. 15 aqua vol. 13 no October 2007

4 Three new species of genus Trimma from Palau, Western Pacific (Percomorpha: Gobiidae) Bony interorbital % pupil width, with a median fleshy, longitudinal interorbital ridge, no postorbital trench. Pleural ribs of tenth abdominal vertebra arch outwards and then medially, their distal tips almost meeting each other and tips of first haemal arch in midline. Thin haemal arches of first caudal vertebra describe a similar trajectory and join in midline (Fig. 3A). Both conditions similar to illustration of Trimma taylori (Lobel, 1979) given by Winterbottom (1984, fig. 26). Haemal arches of the second caudal vertebra fused proximally for about half their length before diverging and then joining at their distal tips. C o l o u r p a t t e r n : From slides of two freshly collected female specimens, ROM (27.7) and ROM (29.9). Background colour yellow with scale pockets outlined on the upper half of the body, some outlined scale pockets extending below the midlateral septum on the anterior half of the body, especially in the anterodorsal region of the abdomen (see Fig. 1). Six diffuse dark saddles present across the dorsum. The saddles are not solid areas of pigment but are formed by increasing and decreasing concentrations of chromatophores that outline the scale A B Fig. 3. Anterior view of first caudal vertebra of A. Trimma gigantum, 22.2 mm SL male paratype, Augulpelu Reef, ROM 1774CS; B. T. tauroculum, 16.0 mm SL male paratype, Eleven Islands, ROM 1776CS. Photo and digital manipulation by R. Winterbottom. pockets. The first saddle lies just anterior to the origin of the first dorsal fin; second adjacent to bases of spines 2-5; third between bases of sixth dorsal spine and first dorsal ray; fourth below bases of rays 3-6; fifth beginning just posterior to base of last dorsal ray, and sixth situated just anterior to base of first procurrent caudal fin ray. The bars extend ventrally about half-way to the midlateral line (first four) to almost reaching that position (last two). Width of anterior two bars about half eye diameter, the posterior four about equal to eye diameter in greatest width. Dorsal fins with a dark basal stripe and an adjacent yellow stripe, each about one scale width in height. Distal portion of the first dorsal spines orange. Centre of the caudal fin yellow, with outer fin rays and procurrant rays orange. Pectoral base, pectoral fin, opercle and area just behind the eye a reddish colour. Centre of snout deep red, upper lip and lower jaw a more diffuse shade of red, sides of snout yellow. Scales on head posterodorsal to eye with margins heavily invested with chromatophores. Iris with a yellow inner ring around the pupil and four alternating bands of reddishbrown and purple, these bands about half as wide as the yellow interspaces. A median line of chromatophores present from the posterior margin of the anal fin to the ventral procurrent rays. A dark, internal, tapering stripe extends along the body from the top of the opercle almost to the caudal fin, about one pupil width at the anterior end and becoming very narrow (one half scale width) around the middle of the body. C o l o u r i n a l c o h o l : Background colour offwhite with scale pockets outlined on dorsal half of the body, outlining of scales sometimes extending to below the midlateral septum on anterior half of the body, including the opercular scales. A few chromatophores present on the upper two-thirds of the pectoral base with a heavier concentration at the top of the pectoral base. Medial line of chromatophores from base of the anal fin to procurrent rays of the caudal peduncle. Sprinkling of chromatophores on body below the midlateral septum. A dark basal stripe present in the first and second dorsal fins approximately a scale width in height, some pigment present in interradial membranes of the first three spines of the first dorsal fin. Distal portion of second dorsal fin hyaline. A few scattered chromatophores at the base of the anal fin and along the final fin ray and in the pelvic fins. The caudal fin has scattered chromatophores at the tips of the fin rays and in the interradial membranes of the upper and lower fin rays. aqua vol. 13 no October

5 Richard Winterbottom and Margaret Zur Pectoral fins hyaline. Breast, belly and cheek immaculate. Chromatophores on the interorbital ridge and centre of snout and upper lip. Chromatophores also present on dorsal and posterior portions of the membrane surrounding the eye socket. The shallow groove immediately on either side of the interorbital ridge has little or no pigment, and this lighter stripe continues anterolaterally down the snout to just before the base of the posterior nostril. This contrast creates a pigmented shape similar in outline to a church with central steeple on the snout (Fig. 2C). Six saddles are still visible across the dorsum. The pattern of the saddles is quite consistent from specimen to specimen, but their size or position may vary by one or two scale widths. First saddle is either immediately anterior or one scale anterior to the first dorsal fin, the second saddle is positioned between the first and fifth element of the first dorsal fin, the third saddle covers the gap between the first and second dorsal fins, the fourth saddle is between the third and seventh elements of the second dorsal fin, the fifth saddle begins immediately or is one scale behind the second dorsal fin and the sixth saddle is immediately anterior to the procurrent rays of the caudal peduncle. Affinities: Trimma gigantum is easily distinguished from most other species of Trimma by the presence of six dark moderately sized saddles across the dorsum, predorsal scales, a wide interorbital with a median fleshy ridge, and a fully scaled cheek and opercle. Trimma fraena (Winterbottom, 1984) has eight light saddles (vs. dark), interorbital and postorbital trenches vs. no trenches, and is the only species of Trimma known thus far with a frenum. Trimma anaima (Winterbottom, 2000) has four very small saddles and no predorsal scales. Trimma haima (Winterbottom, 1984) has 14 light saddles (red when alive) and no predorsal scales. Trimma fishelsoni (Goren, 1985) (northern Red Sea) shares many characteristics with Trimma gigantum, including predorsal scales, numerous scales on cheek and opercle, elongate filamentous second and third dorsal spines, and a ridge in the interorbital which is heavily pigmented with chromatophores. Both species have scale pockets clearly outlined above the midlateral septum, with chromatophore concentrations varying across the dorsal surface to create saddles. Trimma gigantum can be distinguished from T. fishelsoni by the number of predorsal scales and the pattern of pigment across the dorsum, caudal fin, and snout. The predorsal scale count in both species is often difficult to determine because of the way the scales overlap. Trimma fishelsoni has between predorsal scales vs in T. gigantum. Preserved specimens of T. fishelsoni have pigment on the caudal fin base and at the base of the caudal fin rays; slides of freshly collected material show two pupil-sized yellow spots at the base of the caudal fin extending onto the fin rays. Preserved specimens of T. gigantum have no pigment at the base of the caudal fin, although a few chromatophores may be present at the tips and in the interradial membranes of the upper and lower fin rays of the caudal fin; slides of fresh material show a thin yellow line along the posterior margin of the hypural plate. Trimma fishelsoni was described as having four dark blotches on the dorsum which are created by the heavy outlining of the scale pockets across the dorsal surface of the body. These blotches run together to form a continuous dark stripe along the dorsum. Trimma gigantum has six distinct and easily separated saddles across the top of the body. The centre and sides of the snout of T. fishelsoni are evenly covered with melanophores and chromatophores. A lighter stripe on either side of the interorbital ridge of T. gigantum creates a pigmented patch similar to the outline of a church with a central steeple on the snout, which is not present in T. fishelsoni. It is, of course, possible that the differences described above could be a reflection of the apparent widely separated localities of these two species (northern Red Sea vs. Palau). Attempts have been made to obtain fresh tissue samples for DNA analysis of the latter species to investigate this possibility genetically, but to no avail as yet. Tissue samples were taken from two specimens of Trimma gigantum collected with the holotype and analyzed for genetic sequence diversity in the cytochrome c oxidase subunit 1 gene (CO1) for the Barcode of Life (BOL) program at the University of Guelph. The results of the analysis for this gene were identical. Distribution: Trimma gigantum has so far been found only between m on the outer drop-off of Augulpelu Reef in Palau. This site, also known as the Short-Drop-Off, lies to the south-east of the island s capital city of Koror. Etymology: Named for the Greek word gigas, gigantas meaning giant, in allusion to the extremely large size (for a species of Trimma) of the new taxon. Trimma gigantum has been informally referred to as Trimma RW sp 90 (undescribed species, in litt.). 17 aqua vol. 13 no October 2007

6 Three new species of genus Trimma from Palau, Western Pacific (Percomorpha: Gobiidae) Trimma randalli n. sp. Randall s pygmy goby (Figs 4, 5A-B) Material examined: A total of 11 lots, 29 specimens (28 types), mm SL, all from the Republic of Palau Holotype: ROM 80040, 16.0 mm SL male, due southwest of channel cut between Garreru and Babeldaob Island, N E, coral and coral rubble bottom on slight slope, rubble up to one metre deep with fine sand and silt, m, R. Winterbottom, W. Holleman, M. Winterbottom, J. Dendy and M. Mesubed, 15 April Paratypes: AMS I , 4, mm SL, Ngargol Island, 15 m, dipnet and light, G. Allen and W. Starck, no collection date. BPBM 31425, 19.7 mm SL, Koror Island, Chandelier Cave, 6.0 m, by hand, J. E. Randall, 11 July BPBM 31437, 7, mm SL, Koror Isand, Chandelier Cave, 6.0 m, quinaldine and handnet, R. Pyle, 12 July CAS 60046, 6, mm SL, Babelthuap (= Babeldaob Island), Gongolungel Strait, N E, bottom of coral, coralline algae and sand, 15.2 m, rotenone and dipnets, H. H. Dewitt and party, 25 September CAS 60048, 19.6 mm SL, Koror Island, reef off Arappu Point, N E, bottom of rock, coral and sand, 15.2 m, rotenone and dipnets, H. H. Dewitt and party, 19 November FMNH , 14.8 mm SL, ex-rom ROM 80034, 16.0 mm SL, lagoon, edge of large patch reef on west coast of Babeldaob Island, N E, steep, 70 reef slope of corals/coral rock, a few small caves and undercuts with fine sand/silt substrate, m, rotenone, R. Winterbottom, W. Holleman, M. Winterbottom, J. Dendy and M. Mesubed, 15 April ROM 80298, 2, mm SL, SE of artificial channel between Garreru and Babeldoab Island, N E, 70 reef slope with mostly coral rubble, m, rotenone, R. Winterbottom, W. Holleman, M. Winterbottom, J. Dendy and M. Mesubed, 16 April ROM 80335, 17.3 mm SL, west coast of Babeldaob Island, just south of Satan s Corner, N E, dead coral and rubble, inner reef slope well inshore of fringing reef, 2-12 m, W. Holleman, M. Winterbottom, M. Westneat, J. Cooper and A. Rice, 25 March ROM 81041, 3, mm SL, ex-rom 80040, collected with the holotype. ROM 1775CS, 15.6 mm SL, ex-rom Non-type Material: Tissue sample for genetic analysis: ROM T00941, 14.4 mm SL, collected with ROM Diagnosis: Trimma randalli is characterized by the presence of scales on the cheek, opercle, pectoral fin base and the predorsal midline, a moderate to well developed interorbital trench with steep sides, no postorbital trenches and no enlarged teeth in the upper jaw. In preserved specimens the ground colour is yellow with a strikingly black caudal fin, in freshly dead material the ground colour is mustard-yellow and the caudal fin rays are deep red with black interradial membranes, edged with a white band. Description: The description is based on the holotype and 27 paratypes (except where indicated otherwise). Dorsal fins VI + I 8-9 (x=8.0, one specimen with 9 rays), adpressed second spine elongate, reaching to the middle of the second dorsal fin; all rays branched (except sometimes both elements of the last); anal fin I 8-9 (x=8.1, 2 specimens with 9 rays), all rays usually branched (first and/or last may be unbranched); pectoral fin (x=16.0) all rays unbranched, reaching posteriorly to a vertical line from between the genital papilla and the first element of the anal fin; pelvic fin I 5, no frenum, basal membrane 20-40% of the fifth pelvic fin ray, first four rays with one sequential branch, fifth ray usually unbranched but variable, (n=24; unbranched (16), one dichotomous branch bilaterally (6), one side branched-one side unbranched (2)), fifth ray 40- Fig. 4. Trimma randalli, 16.0 mm SL male holotype, Garreru I., Palau, ROM Photo by R. Winterbottom. aqua vol. 13 no October

7 Richard Winterbottom and Margaret Zur 50% the length of the fourth; fourth ray reaching posteriorly to a vertical line above the second to fourth element of the anal fin. Lateral scales (x=24.3, 26 once); anterior transverse scales 7; posterior transverse scales 6-7 (x=6.1); predorsal scales (x=8.1, n=28), anteriormost scale level with posterior margin of pupil (Fig. 5A); 2-5 rows of cycloid pre-pelvic scales with an additional one or two scales on pelvic fin base; pectoral base with 3-5 cycloid (total) scales, cheek with 3-8 scales in one row either below and/or behind eye (Fig. 5B), one specimen with an additional single scale beneath eye and above main scale row; opercle with 5-8 scales in 2 or 3 rows; circumpeduncular scales 12 (n=7). Gill opening extending anteroventrally to a line between mid pupil and anterior margin of the pupil. Upper jaw with a single irregular row of closely spaced small coniform teeth with no enlarged teeth; lower jaw with a row of closely spaced medium to small canines across the front of jaw and an irregular inner row of small coniform teeth which extend all the way around jaw to coronoid process of dentary. Tongue tip round or parenthesis shaped. Gill rakers on first arch =19-22 (n=21, holotype not examined). Anterior nasal opening at the tip of a long narrow tube, posterior nasal opening a pore with a raised rim, both nasal openings on a raised oval sac on anterior portion of snout with anterior tube adjacent to upper lip. Bony interorbital 25-35% pupil width, with a moderate to well developed, steep-sided interorbital trench and slight (rarely) or no postorbital trenches. First haemal arch similar to that illustrated for T. tauroculum (Fig. 3 B), with a separate haemal canal and a distal opening between halves of arches before they fuse to form haemal spine. C o l o u r p a t t e r n (fresh): From slides of four males, ROM (16.0 mm SL); ROM (16.0, 18.7 mm SL); and ROM (16.1 mm SL). Background of body and head yellow-brown, with red tinges on the head and caudal peduncle (see Fig. 4). Margins of scales distinctly outlined with a thin line of dark chromatophores, with large greybrown subdermal chromatophores and smaller, more superficial, darker grey-brown chromatophores liberally scattered over the scale pockets, more intense on the cheek and especially intense on the snout. An hour-glass shaped, diffuse, light bar on the caudal peduncle, about two scales wide at the dorsal and ventral edges and one wide at the midline, liberally sprinkled with dark grey melanophores, especially dorsally, and centred lateral to the second preural centrum. First dorsal fin with a half pupil-diameter wide yellow-orange stripe with numerous dark chromatophores scattered in the membrane between spines four to six (and in the membrane from the sixth spine to the dorsum) which continues to the anterior of the fin as a narrowing band of grey chromatophores, rest of fin hyaline but with fine light grey chromatophores distally between spines one to three, spines dark red-brown; second dorsal with a similar but wider yellow-orange stripe occupying from the basal two-thirds of fin anteriorly to the entire height of the fin posteriorly, dark chromatophores most intense at middle of fin length, distal fourth of fin hyaline with light grey chromatophores. Anal fin similar, but less orange and with more dark chromatophores, especially posteriorly and distally. Basal one-third (dorsally) to two thirds (ventrally) of caudal fin-rays deep red, becoming darker distally, fin membrane black, becoming lighter distally, fin rimmed with dirty white, widest dorsally (almost one-quarter of the ray length), less wide ventrally (about one-tenth of fin-ray length), Fig. 5. Trimma randalli, 16.1 mm SL male paratype, Garreru I., Palau, ROM 80298, specimen stained with Cyanine Blue. A. dorsal view of head. B. lateral view of head. Photo and digital manipulation by R. Winterbottom. 19 aqua vol. 13 no October 2007

8 Three new species of genus Trimma from Palau, Western Pacific (Percomorpha: Gobiidae) and narrowest medially (about one-twentieth of ray length). Pectoral fin membrane hyaline, fin rays yellow-brown but with a diffuse darker bar one-quarter pupil-width wide made up of dark chromatophores on the bases of the rays; pelvic fin membrane hyaline, rays with numerous dark chromatophores. Iris red with a heavy infusion of dark chromatophores, especially anterodorsally and along the posteroventral outer rim, inner rim thinly margined with light yellow. Male genital papilla liberally endowed with dark chromatophores. When first collected underwater, the fish appears to be bright yellow with a white caudal saddle and a black caudal fin with an intensely white or bluish-white margin. The yellow and red components of the colour pattern fade rapidly after death to a dirty dark grey. C o l o u r i n a l c o h o l : Ground colour straw yellow, with head and body sprinkled heavily with chromatophores. Nape, snout, lips, chin, dorsal surface and posterior portion of the caudal peduncle darker than the rest of the body due to increased concentrations of chromatophores. Caudal fin appears primarily black with interradial membranes almost covered with pigment. Caudal fin rays almost covered with a slightly lighter brown pigment. Chromatophores and melanophores extend almost to the tips of the central fin rays. Upper and lower corners and the central tips of the fin rays and interradial membranes hyaline. First dorsal fin with chromatophores scattered along the fin rays, some chromatophores sprinkled at the base of the interradial membranes, distal portion of membranes hyaline. Second dorsal and anal fins with a dark basal stripe about pupil-diameter in width, distal portion hyaline. Margin of the eye mottled with black and silver. The pectoral and pelvic fin rays have pigment along the sides of the individual fin rays, with more pigment on the pectoral than pelvic rays. Pigment cells are scattered over the belly and breast areas. The genital papillae in males is mostly black with a light median line that extends from the bottom one-third to the tip (tip is entirely light); the female papilla is rounded with an almond-shaped dark patch on each side, the tip and the central area are pale. Affinities: Trimma randalli is easily distinguished from all other Trimma by the light coloured body including caudal peduncle and very dark caudal fin. Two other species, Trimma flavatrum (Hagiwara & Winterbottom, 2007) and T. RW sp 91 (an undescribed species) both have a dark peduncle and light caudal fin. Trimma tevegae (Cohen & Davis, 1969) and T. nasa (Winterbottom, 2005) each have a dark spot (reddish in life) on the caudal peduncle which extends onto the base of the caudal fin, with most of the fin hyaline. Trimma randalli shares several characteristics with T. flavatrum and T. tevegae, but it does not have the extensive, open haemal arch on the first caudal vertebrae shared by members of the T. tevegae species group. All three species have scales on the cheek, opercle, pectoral base and the midline of the nape. The pectoral fin rays of all three species are unbranched with T. randalli having rays vs for T. flavatrum and T. tevegae. Trimma tevegae and T. flavatrum almost always have an unbranched fifth pelvic fin ray (branched in 4 of 35 and 1 of 11 specimens examined respectively) and T. randalli usually has an unbranched fifth pelvic fin ray (15 of 23 specimens examined). When alive, T. flavatrum has red pectoral fin rays, the dorsal and anal fins with a dark basal stripe and a wide yellow to orange band which often extends to the tips of the fins (tips sometimes hyaline). The pectoral fins of T. randalli are hyaline and the second dorsal and anal fins have a wide basal yellow stripe which extends almost to the tips of the fins with dark chromatophores in the interradial membranes. The first dorsal fin has a wide yellow stripe in the posterior half of the fin and a narrowing band of grey chromatophores in the anterior half. The tips of the medial fins are hyaline. Tissue samples from one specimen of Trimma randalli were analyzed for the Barcode of Life (BOL) program at the University of Guelph and the genetic sequence is available from the authors. Distribution: Currently known only from the northern Palauan Islands (Babeldaob and Koror), and Busuanga Island (north-east of Palawan, Philippines), based on a photograph by J. T. Williams. Etymology: Named for John E. (Jack) Randall, guru of the alpha-taxonomy of Indo-Pacific marine fishes, who first brought specimens of this species to our attention, and who has made a special effort to collect and photograph Trimma for RW s research program. Trimma randalli has been informally referred to a Trimma RW sp 40 (undescribed species, in litt.). Trimma tauroculum n. sp. Bullseye pygmy goby (Figs 3B, 6, 7A-B, 8) Material examined: A total of nine lots, 66 type specimens, mm SL, all from the Republic aqua vol. 13 no October

9 Richard Winterbottom and Margaret Zur of Palau. Holotype: ROM 80302, 15.7 mm SL female, off west coast of Pelilieu, steep 80 drop-off slope with a few caves and recesses, some coarse sand, coral and rock, N E, m, R. Winterbottom, W. Holleman, M. Winterbottom, M. Westneat, A. Rice and J. Cooper, 12 April Paratypes: AMS I , 9, mm SL, Augulupelu Reef, 46 m, G. Allen et al., 24 January AMS I , 2, mm SL, Bairakaseru Island, 53 m, G. Allen and W. Stark, 20 February BPBM 31960, 3, mm SL, Augulupelu Reef, drop-off, m, W. A. Starck II, G. Allen and J. Condit, 26 January FMNH , 3, mm SL, ex-rom ROM 74806, 18.3 mm SL, SW corner of Augulpelu Reef, caves and ledges in almost vertical drop-off, N, E, m, 21 April, 2004, R. Winterbottom, B. Hubley, D. Winterbottom, and A. Bauman. ROM 80027, 13, mm SL, outer reef due west of Eleven Island, almost vertical slope, coral, limestone interspersed with coarse sand chutes, N E, m, R. Winterbottom, W. Holleman, M. Winterbottom, M. Westneat, A. Rice and J. Cooper, 23 March ROM 80324, 8, mm SL, off west coast of Pelilieu, 50 slope, scattered limestone and coarse shell sand, outer reef, N E, m, R. Winterbottom, W. Holleman, M. Winterbottom, M. Westneat, A. Rice and J. Cooper, 24 March ROM 80354, 3, mm SL, Augulpelu Reef, short drop-off, cave in steep reef slope, N, E, 73 m, P. Colin, 28 March ROM 80380, 19.2 mm SL, Babeldaob Island, north tip of barrier reef on west side, 75 slope on drop-off, high relief rocky outcrops, some coral sand, N, E, m, R. Winterbottom, W. Holleman, M. Winterbottom, M. Westneat, J. Cooper and A. Rice, 30 March ROM 80389, 16, mm SL, Augulpelu Reef, short drop-off, near east tip, N, E, m, R. Winterbottom, W. Holleman, M. Winterbottom, M. Westneat, J. Cooper and A. Rice, 31 March ROM 81691, 4, mm SL, collected with the holotype, 12 April ROM 1776CS, 3, mm SL, ex- ROM Non-type material: Tissue samples for genetic analysis: ROM T00607, 15.0 mm SL, collected with ROM ROM T00669, female, 17.2 mm SL, collected with ROM ROM T00707, 15.0 mm SL, collected with ROM ROM T00708, 13.3 mm SL, collected with ROM Diagnosis: Trimma tauroculum is characterized by lacking scales on the cheek, opercle and midline of the nape, a fifth pelvic fin ray that is branched sequentially once, a moderate interorbital trench and a short and narrow postorbital trench. Living specimens are red with a white belly, a large brown-black spot larger than the eye immediately above the pectoral fin base and numerous smaller dark spots present across the nape. In preserved specimens the dark spots remain but the ground colour is yellow. Description: The description is based on the holotype and up to 27 paratypes. Dorsal fins VI + I 9-10 (x=9.0, n=28, 10 once), second and third spine not elongate, rays all branched or all but last branched; anal fin I 8, n=27, rays all branched or all but first branched; pectoral fin (x=17.9, n=28) with 5-10 branched rays in approximate centre of fin, reaching posteriorly to a vertical line varying from first to fifth elements of anal fin; pelvic fin I 5, no frenum, basal membrane 10-30% of the length of Fig. 6. Trimma tauroculum, 18.6mm SL female paratype, off Eleven Island, Palau, ROM Photo by R. Winterbottom. 21 aqua vol. 13 no October 2007

10 Three new species of genus Trimma from Palau, Western Pacific (Percomorpha: Gobiidae) fifth ray, first four rays with one sequential branch, fifth ray branched sequentially once, with lateral branch about 10% longer than medial branch, and % of fourth, fourth ray reaching posteriorly in a vertical line varying between third to ninth element of anal fin. Lateral scales (x=24.6, n=25); anterior transverse scales (x=8.6, n=23, seven once); posterior transverse scales 7-8 (x=7.4, n=23); no predorsal scales, but scales present on head on either side of nape to just behind eye (Fig. 7B); 2-4 rows of cycloid scales on breast with one or two single scales on pelvic base; 8-13 cycloid scales on pectoral base in 2-3 vertical rows; anterior extent of scales on head varies between immediately behind eye and one pupil width behind eye; cheek and opercle scaleless; circumpeduncular scales 12 (n=6). Gill opening extending anteroventrally to below the posterior margin of pupil to anterior margin of pupil. Upper jaw with a full outer row of large canines and two to three irregular rows of small, tightly packed coniform teeth immediately behind outer teeth. Lower jaw with a row of large curved spaced canines Fig. 7. Trimma tauroculum, 17.4 mm SL paratype, Palau, ROM 81691, specimen stained with Cyanine Blue. A. dorsal view of head. B. lateral view of head. Photo and digital manipulation by R. Winterbottom. across front of the jaw and an inner row of canine teeth which extend around dentary with small coniform teeth interspersed irregularly between larger teeth. Tongue tip truncate or bilobed. Gill rakers on first arch =15-20 (x=17.3, n=19). Anterior nasal opening a tube, posterior nasal opening pore-like with a raised rim, both on a raised oval nasal sac positioned midway or slightly anterior to midpoint on snout. Bony interorbital % (usually 33%) pupil width, with a moderate to well developed interorbital trench and a slightly developed postorbital trench. Sensory papillae as in Fig. 7, none on main part of cheek. Dorsal margin of haemal canal of first caudal vertebra bordered by centrum, arches then fuse in midline for about a quarter of total vertical height before diverging to form an open medial space that extends for about 35% of height before fusing in midline for final 30% of total height (Fig. 3B). C o l o u r p a t t e r n (fresh): Based on slides of one male, ROM 74806, (18.3 mm SL), and two females, ROM (18.7 mm SL) and ROM (15.9 mm SL). Background of body semi-translucent yellow with a tapering, internal, diffuse brownish-red stripe along the vertebral column, its width greater than the eye diameter anteriorly and about pupildiameter posteriorly and ending just before the ural vertebrae, in which is a scattering of dark chromatophores, especially in the dorsal half (see Fig. 6). The dorsal and ventral margins of the stripe on the caudal peduncle are edged by diffuse yellow stripes, which are apparently also internal. The outermost margins of the first one or two dorsalmost rows of scales are thinly outlined with dark red, although this tends to fade out posteriorly on the body, and the scale centres below the second dorsal fin may be semi-translucent off-white or yellow. Immediately above the pectoral fin base is a 1.25 eye diameter brown-black spot surrounded by a narrow off-white halo; its anterior margin lies just anterior to a vertical with the nape a little in front of the spine of the first dorsal fin and its posterior margin is in line with a vertical from between the bases of the fifth and sixth dorsal spines. The abdomen is off-white between the bases of the pelvic and anal fins. Two rows of three dark brown, half- to full-pupil diameter rounded spots pass anteroventrally from the posterodorsal region of the nape to the posterior margin of the eye; the spots are separated from each other by an almost honeycomb network of off-white lines. A third, but much vaguer row (especially so ventrally) may be present between the large spot below the first dorsal aqua vol. 13 no October

11 Richard Winterbottom and Margaret Zur fin and the posteroventral margin of the eye. The opercle is reddish-brown, grading into yellow brown on the cheek, which in turn grades to dark brown on the snout. A lighter yellow-brown bar between the anterior one-third of the pupil and the posterior margin of the maxilla may be present. The inner rim of the iris is margined with red, grading to yellow-red distally, and is darker dorsally. The membranes of the median fins are translucent but all are heavily invested with small, dark chromatophores. The first dorsal fin has two rows of one-quarter pupil-diameter yellow to orange, often dark centred, spots separated from the dorsum and each other by about the same distance, and mostly centred on or immediately behind the shafts of the spines (the fourth spine lacks the spot in the ventral row). The second dorsal fin has similar (lighter yellow and not dark-centred) spots but the rows are ill-defined and the spots more irregular in occurrence. The basal half of the caudal fin also has scattered, light yellow spots. The anal fin may have a yellowish diffuse band either just ventral to the base of the fin or at about the middle region of the rays. The rays of the pectoral fin are margined with dark red, those of the pelvic fin are grey with a few dark chromatophores; the fin membranes are hyaline. When alive (Fig. 8), the ventral half of the fish is pale off-white, grading to white on the a b d o m e n. The dorsum is greyish-white, the brownish-red internal body stripe is lighter and yellower. The lines between the spots on the nape are lighter, and that surrounding the very large spot above the pectoral fin base is bright white. The iris is a lighter reddish-yellow and the dorsal margins of the orbit have a few narrow transverse bands. The membranes of the median fins are more translucent, although the dark chromatophores are still evident. The rows of spots in the first dorsal fin are darker, those in the other median fins are more diffuse and less evident. C o l o u r i n a l c o h o l : Background colour of body straw yellow with an even sprinkling of chromatophores becoming less concentrated posteriorly. A large eye diameter sized brown spot is present on the body immediately above the pectoral fin. The spot is partially surrounded by a narrow light band and an outer narrow ring of chromatophores on the sides and dorsal portion of the spot. Numerous diffuse brown spots made up of chromatophores present on head behind eye, half to full pupil diameter in size, and which are usually surrounded by an offwhite halo and separated from one another by a thin line of melanophores. Snout dusky with some specimens having distinct clusters (12-25% pupil diameter) of chromatophores separated by melanophores. Scattered melanophores on cheek, opercle and pectoral base. Anal and caudal fins translucent with heavy concentrations of melanophores in the interradial membranes. Dorsal fins with heavy concentrations of melanophores in the interradial membranes with rows of light spots usually centred on the fin rays, first dorsal with two rows of light spots, second dorsal with three rows of light spots on the fins. Pelvic fins with a few melanophores in the interradial membranes, pectoral fins hyaline. Affinities: Trimma tauroculum is easily distinguished from all other species of Trimma by the very Fig. 8. Trimma tauroculum, live specimen (not collected), Palau. Photo by H. Nagano. 23 aqua vol. 13 no October 2007

12 Three new species of genus Trimma from Palau, Western Pacific (Percomorpha: Gobiidae) large 1.25 eye diameter brown-black spot above the pectoral fin base and the rows of smaller brown spots on the nape separated by the honeycomb pattern. The recently described Trimma nomurai (Suzuki & Senou, 2007) has a similar large brown spot just posterodorsal to the base of the pectoral fin but differs from T. tauroculum in having 5-6 predorsal scales (vs. none) and an elongate second dorsal spine (vs. no elongate spines). Three other species, Trimma fangi (Winterbottom & Chen, 2004), T. agrena (Winterbottom & Chen 2004), and T. stobbsi (Winterbottom, 2001) each have a much smaller (half pupil diameter) spot just above the posterior margin of the opercle and T. sheppardi (Winterbottom, 1984) has two small spots (half pupil diameter in total) just above the posterior edge of opercle and anterior edge of pectoral base. Trimma fangi has light spots and blotches on the head and nape and a fifth pelvic fin ray that is branched dichotomously twice vs. dark spots on the nape and a fifth pelvic fin ray that is branched sequentially once. Trimma agrena and T. stobbsi both have a naked predorsal with scales on either side of the midline similar to T. tauroculum, but T. agrena has light spots on the cheek (orange in living specimens) rather than dark spots across the nape, and T. stobbsi has no additional spots. Tissue samples were taken from four specimens of Trimma tauroculum from three different capture locations and analyzed for genetic sequence diversity in the cytochrome c oxidase subunit 1 gene for the Barcode of Life (BOL) program at the University of Guelph. The results of the analysis for this gene in these four specimens were identical. Distribution: Trimma tauroculum has so far only been found on the outer reefs at Palau, at depths generally greater than 25 m. A photograph of what is almost definitely this species by G. R. Allen, from Ulithi Atoll, Yap Islands, was recently received by RW. If correctly identified, it would extend the range to the western Caroline Islands. Etymology: The specific name is a combination of the Latin taurus, a bull, and oculus, an eye, in allusion to the distinctive bulls-eye like marking above the pectoral fin that characterizes the new species. Trimma tauroculum has been informally referred to as Trimma RW sp. 59 (undescribed species, in litt.). ACKNOWLEDGEMENTS It is a pleasure to thank all RW s friends and colleagues who have helped collect and document Indo- Pacific fishes over the years, especially the fish teams on the 2004 and 2006 Palau expeditions and Pat Colin, as well as all the collections managers who have willingly supplied us with a seemingly neverending stream of Trimma specimens from the collections in their care. A special thank you to Andrew Bauman, the Marine Unit Chief, Office of Environmental Response and Coordination, for all his help and support in obtaining permits for us, and smoothing our way in Palau in so many other ways, to Wouter Holleman (South African Institute of Aquatic Biodiversity, Grahamstown) for his boundless enthusiasm, sheer hard work, and his willingness to discuss everything under the sun, and to Mark Westneat (Field Museum of Natural History, Chicago), for his major contribution to both the financing and the success of the 2006 expedition (plus, of course, for reminding us of how to really fish). We also would like to thank Hiroshi Nagano for permission to use his excellent photograph of Trimma tauroculum in this paper, and Robert Hanner and his Barcode of Life team at the University of Guelph for undertaking the genetic analyses. Grateful thanks to the Members Volunteer Committee and the ROM Foundation for supplying many grants for fieldwork over the past two decades. The research and part of the fieldwork expenses have been generously supported by NSERC Discovery Grant OGP 7619 to RW. REFERENCES LEVITON, A. E., GIBBS, R. H. JR., HEAL, E. & DAWSON, C. E Standards in herpetology and Ichthyology. Part 1: Standard symbolic codes for institutional resource collections in herpetology and ichthyology. Copeia (1985): SARUWATARI, T., LOPEZ, J. A. & PIETSCH, T. W Cyanine blue: a versatile and harmless stain for specimen observation. Copeia (1997): SUZUKI, T. & SENOU, H Two new species of the gobiid fish genus Trimma (Perciformes: Gobioidei) from Southern Japan. Bulletin of the National Museum of Natural Sciences, A 1: WINTERBOTTOM, R A review of the gobiid fish genus Trimma from the Chagos Archipelago, central Indian Ocean, with the description of seven new species. Canadian Journal of Zoology 62: WINTERBOTTOM, R Two new species of Trimma (Gobiidae) from the central, western and south Pacific. aqua, Journal of Ichthyology and Aquatic Biology 5(2): WINTERBOTTOM, R A new species of the gobiid fish Trimma from the Western Pacific and Northern Indian Ocean coral reefs, with a description of its osteology. Zootaxa 218: WINTERBOTTOM, R Two new species of the Trimma tevegae species group from the western Pacific (Percomorpha: Gobiidae). aqua, Journal of Ichthyology and aqua vol. 13 no October