LARVAL GOBIIDAE (TELEOSTEI: PERCIFORMES) OF CARRIE BOW CAY, BELIZE, CENTRAL AMERICA. Carole C. Baldwin and David G. Smith 1

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1 BULLETIN OF MARINE SCIENCE, 72(3): , 2003 LARVAL GOBIIDAE (TELEOSTEI: PERCIFORMES) OF CARRIE BOW CAY, BELIZE, CENTRAL AMERICA Carole C. Baldwin and David G. Smith 1 ABSTRACT Little descriptive and specific taxonomic information is available regarding the early life history stages of Caribbean coral-reef fishes. Ongoing studies at the Smithsonian Institution s research station at Carrie Bow Cay, Belize, involving the rearing of netcollected larval fishes is allowing specific identifications of numerous larval types. Field protocol includes preserving larval types in ethanol plus butylated hydroxytoluene to enhance the retention of orange and yellow pigments. Studies of fish larvae at Carrie Bow during the summer months of several years between have yielded generic or specific identifications of 21 goby larvae belonging to ten genera. Separating closely related larval types in the field was facilitated by microscopic observations of combined patterns of melanophores and chromatophores. Identification of morphological types was aided by comparing countable features of larvae and reared juveniles with those of adult Caribbean gobies from USNM collections. Continued implementation of the methods outlined herein should prove valuable in identifying much more of the ichthyoplankton fauna of the Caribbean. Species-level identifications of larvae of coral reef fishes will render these life history stages useful in a variety of studies including those of phylogenetic relationships, ecology, as well as reproductive and fisheries biology. Including information from larval morphology in systematic studies of the Gobioidei may help clarify poorly understood relationships within the Suborder. Supraspecific patterns of chromatophores warrant further investigation as a novel suite of phylogenetically informative ontogenetic features. The identities of pelagic larval stages constitute one of the largest gaps in our knowledge of the coral-reef fish fauna of the Caribbean Sea. Hindrances to specific identification include high species diversity in many coral-reef fish groups, absence in larval stages of features diagnostic of adults and difficulty in recognizing larvae of closely related species as distinct. For gobioids worldwide, Ruple (1984) estimated that larvae are known for less than 5% of the approximately 2000 species and those known are mostly from Japanese waters. Hildebrand and Cable (1938), Peters (1983) and Ruple (1984) described, or illustrated larvae of several Atlantic goby species, three of which (Bathygobius soporator, Ctenogobius boleosoma and Gobionellus oceanicus) are known from the Caribbean. Wyanski and Targett (1985, 2000) described transformation larvae and juveniles of several gobies from the western North Atlantic, including C. boleosoma and G. oceanicus. With the exception of a few comments on live coloration (e.g., Wyanski and Targett, 2000: 712), previous descriptions of larval western Atlantic or Caribbean gobies have not documented patterns of chromatophores. To provide specific identifications of larvae of Caribbean reef fishes, we have been conducting fieldwork for a number of years at the Smithsonian s research station at Carrie Bow Cay, Belize, a small, coral-fringed island on the Belizean Barrier Reef (16º48.5'N, 88º05'W). Our moderate success in this endeavor is largely due to the development, implementation and refinement of specific field methods. Our protocol includes collecting living larvae in a moored plankton net, anesthetizing selected larvae for purposes of mi- 1 Order of authorship alphabetical 639

2 640 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 croscopic typing, preserving examples of each type in ethanol plus butylated hydroxytoluene to enhance retention of chromatophores (Smith, 1995), and rearing selected larvae through transformation. We have discovered that larvae of closely related reef-fish taxa often differ from one another most conspicuously in the type and distribution of chromatophores. The fact that these color patterns are lost in specimens preserved with traditional methods (e.g., fixation in 5 10% formalin and subsequent preservation in 70 75% ethanol) may help explain why recognizing distinct larval types in coral reef fishes historically has been difficult. To identify larvae, we are combining comparisons of counts from cleared-and-stained larvae and those of adults known to occur in the area with attempts to rear net-collected larvae to post-settlement juvenile stages. Quite often, larval types thought to be conspecific transformed into different species and types thought to be different transformed into the same species. This trial and error strategy has allowed us to identify numerous fish larvae to species, but it is an ongoing process and considerably more work is needed to cover adequately even one of the most speciose reef-fish families in the Caribbean. In this paper, we describe 21 larval gobies from Carrie Bow Cay that we have identified to date. The purposes of the descriptions are to (1) provide diagnostic information that will aid others in identifying larval Caribbean Gobiidae; (2) highlight the distinctive chromatophore patterns in the larvae; and (3) provide sufficient anatomical detail of the goby larvae to render the descriptions potentially useful in future phylogenetic studies. Additionally, because we are sampling pelagic stages of fishes that as adults may be cryptic and difficult to collect, this ongoing work should expand our knowledge of the fish fauna of the area. For example, Smith and Thacker (2000) described larval microdesmids from Carrie Bow that apparently represent larval stages of undescribed species. METHODS NOMENCLATURE. The most recent phylogenetic analysis of gobioid relationships (Thacker, 1998) did not resolve the longstanding question of how many monophyletic families are contained within the suborder Gobioidei. We follow Hoese and Gill (1993) in recognizing certain genera of the former Eleotrididae as members of the gobiid subfamily Eleotridinae. Of interest here are Eleotris, Erotelis, and an unidentified eleotridine, the larvae of which are described herein with other Gobiidae. We also include Ptereleotris in this compilation rather than publish a separate description for the sole non-gobiid gobioid in this work. The phylogenetic position of Ptereleotris within the Gobioidei is unclear (e.g., Harrison, 1989; Thacker, 1998, 2000), but does not appear to be with the Microdesmidae (Thacker, 2000) as previously proposed (Hoese and Gill, 1993) and commonly recognized (e.g., Eschmeyer, 1990). FIELD PROTOCOL. Descriptions are based on rearing studies conducted in two- to three-week field periods during June September over four yrs (June 1993, July August 1994, August September 1996 and August September 1997). Pelagic fish larvae were collected with a neuston net of 505 µm mesh fitted onto a m rectangular frame made of pvc pipe. The net was secured by rope to the pier on the east side of Carrie Bow Cay and fished over the reef flat. The current along the east side of Carrie Bow flows roughly north south, and was, with rare exception, sufficient in velocity to extend the net fully. Neither current speed nor depth at the sampling site was measured, but Greer and Kjerfve (1982) noted that current speed near the study site averaged 6 cm s 1, and, based on observations of the plankton net when fished, depth varied tidally from slightly < 0.5 m to slightly more (i.e., the bottom of the net frame remained on or near the bottom and the top at or near the surface). Duration of each set of the net was typically min, a time experimentally deter-

3 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 641 mined to maximize survival of captured larvae and minimize the number of crustaceans, especially crab larvae, per sample. Sets were made at night, usually between sunset and 0100 hrs, but sampling was often terminated earlier in the evening if a bright moon rose. Contents of the cod-end bucket of the plankton net were emptied into a plastic tray and carried into the laboratory. Selected specimens were anesthetized, microscopically identified to morphological type if possible using previously prepared notes and illustrations, then transferred outdoors to breeding cages set in a flow-through seawater system. The anesthetic solution comprised methanesulfonate salt (MS222) and seawater, and was prepared by pinching a tiny amount of the salt with forceps and adding it to a petri dish of seawater. For new types, at least the first specimen was preserved as a voucher specimen and returned to USNM. Others collected were kept alive in the rearing facility. Specimens designated for preservation were fixed overnight in 5% seawater-buffered formalin, and then transferred for several hrs to 30% ethanol + BHT (butylated hydroxytoluene) and then finally to 75% ethanol + BHT. The combination of ethanol + BHT serves to preserve orange and yellow chromatophores in fish larvae (Smith, 1995). Sketches and notes of new larval types were made daily. Photographs were taken of most larval types, usually while larvae were in the anesthetic solution (body transparent), but sometimes after preservation (body opaque). Some of these photographs can be viewed at Larvae in the rearing facility were fed living brine shrimp, new cultures of which were started daily from dehydrated eggs. The brine-shrimp containers were aerated using a controlled flow of air from a SCUBA cylinder. TERMINOLOGY. Characterizations of body depth (e.g., elongate, deep), head length and eye size follow Leis and Trnski (1989). Accordingly, characterization of eye size in the text is based on eye diameter as a percentage of head length. For consistency with other measurements, eye diameter in Table 2 is given as a percentage of standard length. Dorsal-pterygiophore formula is that of Birdsong et al. (1988). Scales in a longitudinal series are those between pectoral- and caudal-fin bases. Diagnostic features given throughout the paper refer to those of postflexion larvae, and descriptions are limited to postflexion and juvenile stages. Reared juveniles were used primarily for purposes of identification by comparing them with preserved juvenile and adult museum specimens. Accordingly, morphometric data were not recorded for most reared juveniles. The absence of preflexion larvae in our material precludes description of features such as sequence of fin formation and early ontogenetic changes in pigmentation. Characters listed under Diagnostic Features are typically not repeated in the subsequent description except occasionally to provide additional detail. In describing coloration of larvae, chromatophore is used as a general term for either a red or yellow color-producing pigment cell. Erythrophore refers to a red-orange spot and xanthophore to yellow. Abbreviations used for counts within Diagnostic Features section of text include the following: D = dorsal fin, A = anal fin, P 1 = pectoral fin, V = vertebrae, DF = dorsal-pterygiophore formula, Ep = epurals, and AFP = anal-fin pterygiophores anterior to first haemal spine. MATERIAL EXAMINED Bathygobius curacao, 78 specimens: USNM , , , , , Bathygobius soporator, 3: USNM Coryphopterus A, 72: USNM , , , , , Coryphopterus A 1, 1: USNM Coryphopterus A 2, 7: USNM , Coryphopterus A 3, 1: USNM Coryphopterus A 4, 1: USNM Coryphopterus B, 19: USNM , , , , Coryphopterus B 1, 2: USNM Coryphopterus C, 84: USNM , , Coryphopterus C 1, 7: USNM , , Ctenogobius saepepallens, 1000+: USNM , , , , , , Gnatholepis thompsoni, 370: USNM , , , , , Gobionellus oceanicus, 9: USNM , , ; comparative material: 30 specimens from Beaufort, NC: USNM , ,

4 642 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 Nes longus, 41: USNM , , , Priolepis hipoliti, 8: USNM , , , Psilotris amblyrhynchus, 11: USNM Eleotris sp, 2: USNM , Erotelis smaragdus, 6: USNM , Eleotridinae sp, 1: USNM Ptereleotris helenae, 3: USNM , , ; comparative material: two specimens from Tobago, USNM DIAGNOSTIC FEATURES OF LARVAL GOBIIDAE OF BELIZE Counts and measurements of selected net-collected and reared gobiid larvae are given in Tables 1 and 2, respectively. Body elongate to moderately deep, usually slightly deeper at pectoral-fin base (12 25% SL) than at anus (12 24% SL) except in Gobionellus oceanicus, Erotelis smaragdus, and Eleotridinae sp. (10 13% SL at pectoral-fin base, 11 14% SL at anus); body considerably narrower at caudal peduncle (6 12% SL). Gas bladder typically large and conspicuous. Head usually moderate in size (20 33% SL), slightly larger (34 36% SL) in some larvae of P. hipoliti and B. soporator, and slightly smaller (18 20% SL) in G. oceanicus. Eye round, 4 10% SL, greater than 5% SL except in G. oceanicus and the eleotridines. Dorsal fin divided, first dorsal with six or seven spines, the last spine usually separated from the others by a gap and often very small and not easily discernible in early postflexion stages. Each pterygiophore of first dorsal fin a single structure, separate distal radials lacking (e.g., Birdsong et al., 1988: fig. 1). First dorsal spine in supernumerary association with first pterygiophore. Second dorsal fin comprising 8 14 elements (22 24 in Ptereleotris helenae), each serially supported by a pterygiophore that, with the exception of the posteriormost, includes a separate distal radial. First element of second dorsal fin spinous in juveniles and adults but not easily distinguished from soft rays in larvae. Segmentation of soft rays sometimes visible in early postflexion larvae only under high microscopic power. Anal fin comprising 8 15 elements (22 23 in P. helenae), anteriormost a spine in juveniles and adults but indistinguishable from remaining soft rays in larvae. Soft anal-fin rays of larvae often cryptically segmented as in dorsal fin. First anal-fin element in supernumerary association with first anal-fin pterygiophore but supported by a separate distal radial (e.g., Hoese and Gill, 1993: fig. 7). All other anal-fin elements except posteriormost also associated with separate distal radial of serially associated pterygiophore. Pectoral fin with rays, length < 25% SL except longer in P. hipoliti (26 34% SL) and some specimens of Coryphopterus; pectoral fin very small (ca. 9 12% SL) in G. oceanicus and the unidentified eleotridine. Pelvic fins separate or united with or without frenum. Vertebrae Dorsalpterygiophore formulae , , ; epurals one or two; anal-fin pterygiophores anterior to first haemal spine one or two, usually two. Internal melanophores present on gas bladder, usually as a dorsal cap, and sometimes very dense. Most species also with melanin internally on posterior portion of gut. Pigmentation in the form of melanophores, chromatophores, or both, on ventral region of posterior half of trunk, and usually (except in P. helenae) along ventral midline in region of pelvic-fin base, throat, or abdomen. Bathygobius spp. distinctive in having a preponderance of xanthophores (vs. erythrophores) on the trunk (but see description of a variant under B. soporator), and Coryphopterus spp., Ctenogobius saepepallens, and Gnatholepis thompsoni consistently exhibiting a single erythrophore at angle of lower jaw (associated

5 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 643 Table 1. Bow Cay, Frequency distributions of Belize, Central America. selected counts and dorsal-pterygiophore formulae (Birdsong et al., 1988) of larval and reared juvenile Gobiidae from Carrie 2nd Dorsal Ana l Pectora l T axon Size (mm SL ) B athygobiu s c uraca o * B athygobius soporator * 5.3, C oryphopterus A * C oryphopterus A * C oryphopterus A * C oryphopterus A * C oryphopterus A * (? ) 4 C oryphopterus B * C oryphopterus B * C oryphopterus C * C oryphopterus C * C tenogobius saepepallens * h G natholepi s t hompson i * G obionellu s o ceanicu s * (? ) N es longus ** P riolepis hipoliti * P silotris amblyrhynchus ** E leotris sp. * E rotelis smaragdus * (? ) E leotridinae s p. * 10.5 (no data ) P tereleotris helenae * ( ) ( ) (21 )

6 644 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 Table 1. Continued. * Vertebrae T axon Size (mm SL ) 2 5 a 2 6 b 2 6 c 2 7 d 2 7 e 2 8 f 2 8 g D F B athygobiu s c uraca o * B athygobius soporator * 5.3, C oryphopterus A * C oryphopterus A * 7. 9 No dat a No dat a 1 C oryphopterus A * No dat a No dat a 2 C oryphopterus A * 7. 8 No dat a No dat a 3 C oryphopterus A * 7. 6 No dat a No dat a 4 C oryphopterus B * C oryphopterus B * 7. 8 No dat a No dat a 1 C oryphopterus C * No dat a C oryphopterus C * No dat a 1 C tenogobius saepepallens * h G natholepi s t hompson i * G obionellu s o ceanicu s * N es longus ** P riolepis hipoliti * P silotris amblyrhynchus ** E leotris pisonis * (10+15 ) E rotelis smaragdus * (10+15 ) E leotridinae s p. * 10.5 (no data ) P tereleotris helenae * Six spines specimen, a in first nubbin dorsal in other fin; ** Seven specimens less spines than in ca. first 9.0 dorsal mm SL; fin; DF a9+16; b10+16; c9+17; - dorsal-pterygiophore d10+17; formula. e11+16; f11+17; g12+16; hsixth dorsal spine not visible in 7.7-mm SL

7 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 645 Table 2. Measurements (in % SL) of gobiid larvae. PAL - preanal length, PDL - predorsal length, HL - head length, SNL - snout length, ED - eye diameter, BDP1 body depth at pectoral-fin base, BDA - body depth at anus, BDCP - body depth at caudal peduncle, P1L - pectoral-fin length. SL (mm) (n) PAL PDL HL SNL ED BDP1 BDA BDCP P 1 L Bathygobius curacao (3) (2) (17) (15) Bathygobius soporator 5.3 (1) (1) Coryphopterus A (4) (19) (13) (11) 1 Coryphopterus A 7.9 (1) (6) Coryphopterus A 7.4 (1) Coryphopterus A 7.8 (1) Coryphopterus A 7.6 (1) 49? Coryphopterus B (8) (6) (2) (1) Coryphopterus B 7.8 (1) Coryphopterus C 6.0 (1) (4) (25) (21) (3) Coryphopterus C 6.9 (1) Ctenogobius saepepallens 7.4 (1) bent (15) (14) Gnatholepis thompsoni (3) (18) (6)

8 646 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 Table 2. Continued. SL (mm) (n) PAL PDL HL SNL ED BDP1 with a melanophore in some Coryphopterus). The eleotridines forming a readily identifiable group based on the presence of conspicuous melanophores on caudal peduncle. Scales lacking in all net-collected gobiid larvae, but present in some reared specimens, suggesting that onset of development may coincide with transformation and settlement. Tiny teeth visible in both jaws in most cleared and stained larvae, teeth easily discernible in whole specimens only in Nes longus. Bathygobius curacao (Metzelaar) (Figs. 1, 17A) BDA BDCP Gobionellus oceanicus (3) (1) Nes longus (2) (3) (4) Priolepis hipoliti (2) (3) Psilotris amblyrhynchus (2) (3) E leotris sp (1) Erotelis smaragdus 11.0 (1) (3) E leotridinae sp (1) Ptereleotris helenae 12.6 (1) Diagnostic Features. Small elongate body; D: VI, I-9; A: I, 8 9 (modally 8); P 1 : 16 17; V: 10+17; DF: ; Ep: 1; AFP: 2. Approximately five large melanophores on ventral midline along posterior part of trunk, one around anus and six along dorsal midline; internal melanophores along myosepta of epaxial and hypaxial musculature; xanthophores associated with trunk melanophores and a single erythrophore present at base of caudal fin; posterior end of caudal peduncle without pigment. Pectoral fin large, reaching posteriorly beyond anterior base of anal fin; pelvic fins united, frenum present. Identification. Reared through transformation. Reared juveniles have the pelvic fins completely united and the two uppermost pectoral-fin rays nearly free from one another, P 1 L

9 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 647 Figure 1. Bathygobius curacao, 6.5 mm SL. Pectoral fin drawn from right side, dorsal and ventral trunk pigmentation drawn from specimen of 5.8 mm SL. a combination of features diagnostic of Bathygobius (Böhlke and Chaplin, 1993). Reared juveniles have scales in a longitudinal series which, together with the low number of pectoral-fin rays (16 or 17), is characteristic of B. curacao (Böhlke and Chaplin, 1993). Possibly corroborating this identification is the observation that reared specimens of B. curacao are smaller (ca mm SL) than the reared specimen of B. soporator (20.0 mm SL, see below), despite similar pre-rearing sizes of larvae (5 6 mm) and rearing times. Bathygobius curacao grows only to ca. 63 mm (2.5"), whereas B. soporator may reach 152 mm (6"; Böhlke and Chaplin, 1993). Material. 54 larval specimens (nine cleared and stained), mm SL; 24 reared specimens (four cleared and stained), mm SL. General Morphology. Depth at pectoral-fin base 17 21% SL, depth at anus 15 19% SL, depth at caudal peduncle 7 10% SL; moderate large head, length 29 33% SL; small moderate eye, diameter 24 33% HL; pectoral fin extending posteriorly to vertical through second anal-fin ray, length 15 21% SL; pelvic fin reaching vertical through anus; preanal length 51 56% SL. S dorsal- and anal-fin bases slightly shorter than length of caudal peduncle. Tiny teeth present on dentary in some specimens. Reared juveniles with teeth in both jaws and with prominent head papillae. Melanophores. Head with distinctive pigmentation including one patch of melanophores just below dentary symphysis; usually several melanophores on lateral aspect of dentary; a few in a line on posterior third of maxilla and sometimes a tiny bit of pigment on premaxilla; one melanophore at angle of lower jaw; and sometimes a branched melanophore on each frontal over hindbrain. A melanophore on ventral midline of isthmus, one on anterior part of pelvic girdle, and usually two on abdomen above pelvic fin. Posteroventral wall of abdominal cavity with pigment that continues ventrally as external pigment around anus. The anterior three melanophores of the ventral midline series on posterior portion of body paired, posterior two melanophores unpaired. The series of large melanophores along dorsal midline beginning just in front of first dorsal fin, second melanophore beneath fifth, or sixth dorsal spines, third and fourth beneath the second dorsal fin, and fifth and sixth on dorsal midline of caudal peduncle. No melanophores on any fins. Internal melanophores present in posterior region of branchial chamber, continuous with cap of pigment over gas bladder. Pigment also present along most myosepta of epaxial and hypaxial musculature. For epaxial musculature, beginning anteriorly with ca. the sixth or seventh vertebra, pigment extending along dorsal surface of each centrum and then continuing dorsally and laterally as shield of pigment along each myoseptum. Internal pigmentation associated with epaxial musculature not extending posteriorly beyond fifth preural vertebra. Ventrally, internal pigment beginning on the first caudal ver-

10 648 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 tebra and extending to about vertebra 23 (V23), with gaps of no pigment on one or more of V As with epaxial musculature, pigment in hypaxial musculature extending as a shield along each myoseptum. Reared juveniles with many melanophores on top of head and on operculum; cheeks and underside of head lightly pigmented or unpigmented. Approximately six faint bars of pigment present from dorsal midline to near lateral midline. The most prominent pigment comprising a series of about eight irregular blotches along length of body just ventral to lateral midline. First dorsal fin with a band of pigment across middle one-third of each spine, and scattered melanophores present on second dorsal and caudal fins. Other fins without pigment. Chromatophores. Yellow pigment present at tip of lower jaw and on dorsal and ventral portions of trunk in association with the series of large melanophores; a single orange spot on base of lower lobe of caudal fin. Variation. Two specimens have patterns of pigmentation nearly identical to that of B. curacao except that the spot on the base of the lower caudal-fin lobe is yellow. The variants have the same numbers of second dorsal- and anal-fin elements as B. curacao (ten second dorsal, nine anal), but the pectoral fin is not completely formed. Bathygobius curacao and B. mystacium are both small members of the genus, and numbers of pectoral-fin rays will typically separate them (B. curacao usually with 16 or 17, B. mystacium usually with > 18; Böhlke and Chaplin, 1993). Further rearing studies of Bathygobius larvae are needed to determine if the variants represent B. curacao, B. mystacium or an undescribed species. Bathygobius soporator (Valenciennes) (Figs. 2, 3A, 17B) Diagnostic Features. Body elongate; D: VI, I-9; A: I,8; P 1 : 18 (dorsal portion of fin poorly developed and additional rays may differentiate); V: 10+17; DF: ; Ep: 1; AFP: not assessable because anal fin damaged. Three four very large stellate melanophores on ventral midline on posterior half of body, two on dorsal midline beneath posterior half of second dorsal fin, and a patch of partially internal pigment between these midlaterally; xanthophores associated with the stellate melanophores along dorsal midline and those on ventral midline along anal-fin base, and a single erythrophore present at base of caudal fin; a melanophore on membrane of each of second through fifth second dorsal-fin elements, and anal fin with flags of pigment distally on ca. third through fifth elements. Pelvic fins united, frenum present. Figure 2. Bathygobius soporator, 6.3 mm SL. Dorsal, anal, and pelvic fins drawn from Bathygobius sp., 5.4 mm SL.

11 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 649 A B C D Figure 3. Ventral views of larval Gobiidae: (A) Bathygobius soporator, 6.3 mm SL; (B) Coryphopterus A, 6.4 mm SL; (C) Ctenogobius saepepallens, 9.5 mm SL; (D) Gnatholepis thompsoni, 9.4 mm SL. Identification. A single specimen reared through transformation. Reared juvenile has the pelvic fins completely united and two of the uppermost pectoral-fin rays nearly free from one another, a combination of features diagnostic of Bathygobius (Böhlke and Chaplin, 1993). The reared specimen has 18 pectoral-fin rays, a count within the extremes of B. soporator, B. curacao, and B. mystacium, but not the modal number for any of those; however, Böhlke and Chaplin (1993) noted that a count of 18 pectoral rays is rare for B. curacao (usually 16 or 17) and B. mystacium (usually more than 18). Robins et al. (1986) noted that B. soporator and B. curacao can be distinguished by the presence of a notched tongue in the latter, but we have observed a notched tongue in all three of the western Atlantic Bathygobius species. Our identification of this goby type as B. soporator is based on the presence in the reared specimen of about 39 scales in a longitudinal series (there are in B. soporator, in B. curacao, and in B. mystacium). Furthermore, the reared specimen has a series of about eight pigment spots along the body, just below the lateral midline, which are very similar to spots observed in small

12 650 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 preserved specimens of B. soporator at USNM. Bathygobius curacao also has a similar series of midlateral spots, but in that species the spots extend ventrally from the lateral midline to near the ventral midline, whereas in B. soporator and our reared specimen, they are more circular blotches that are restricted to near the midline. Bathygobius mystacium does not have a longitudinal series of midlateral spots. Material. Two larval specimens, 5.3 and 6.3 mm SL, the larger cleared and stained after examination and illustration; one reared specimen, 20.0 mm SL. General Morphology. Depth at pectoral-fin base 19 21% SL, depth at anus 17 19% SL, depth at caudal peduncle 8 9% SL; moderate large head, length 30 36% SL; small moderate eye, diameter 24 26% HL; pectoral fin nearly reaching vertical through anus, length about 19% SL; pelvic fin extending slightly more posteriorly than pectoral, reaching vertical through or just anterior to anus; preanal length 57% SL. Anal-fin base slightly shorter than length of caudal peduncle, second dorsal-fin base equal to, or slightly longer than length of caudal peduncle. Scales lacking in larvae, but reared juvenile with about 39 in a longitudinal series. The juvenile with the same dorsal and anal counts as the larvae and with 18 pectoral-fin rays on both sides. Melanophores. A patch of pigment on gular just posterior to dentary symphysis and a single melanophore at angle of lower jaw. An elongate melanophore on ventral midline of isthmus, just anterior to a large stellate melanophore on pelvic-fin base. A row of three spots of pigment present on ventral midline of abdomen above pelvic fins. No pigment on first dorsal, pectoral or pelvic fins. Gas bladder lightly pigmented dorsally. Reared juvenile with most of the head (except ventral aspect) and trunk covered with scattered melanophores (more numerous dorsally). In dorsal view, spots on trunk appearing in four groups that approximate bands, one beneath first dorsal fin, two beneath second dorsal fin, and one on caudal peduncle. Dorsal fin with pigment on and between most spines and rays. Anal fin with small streaks of pigment on distal half of fourth through sixth elements. Caudal fin with sparse pigment along most of the lengths of central rays. Chromatophores. See Diagnostic Features. The reared juvenile lacked chromatophores. Variation. One specimen, 5.4 mm SL, is nearly identical to B. soporator in pattern of pigmentation except that chromatophores on the trunk are orange vs. yellow, four myosepta in the region of the posterior ends of second dorsal and anal fins bear distinct lines of internal melanophores, and internal melanophores occur anteriorly along vertebral column. In life, internal orange pigment along the posterior end of the vertebral column is striking. Dorsal-, anal-and pectoral-fin counts of this variant are identical to those of B. soporator, but reared juveniles in which number of lateral scales and body size could be assessed are lacking. Remarks. It is unclear how many species of Bathygobius exist in the western Atlantic and Caribbean, and as noted by Böhlke and Chaplin (1993: 603), B. soporator is composed of a number of poorly defined nominal subspecies. Our identification of larval B. soporator is tentative, pending further investigation of Atlantic members of the genus. We note that pigmentation of our larval specimens differs from that of reared larvae of B. soporator described by Peters (1983) in having several melanophores on anterior elements of the second dorsal fin and in lacking a melanophore at the base of the ventral caudal-fin lobe.

13 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 651 Figure 4. Coryphopterus A, 7.8 mm SL; fin membranes and pectoral and pelvic fins drawn from 6.2 and 7.1 mm SL specimens. Coryphopterus Gill (Figs. 3B, 4 6, 17C E) Diagnostic Features. Elongate body; D: VI, I-7 10; A: I, 7 10; P 1 : 12 19; V: 26, usually 10+16; DF: ; Ep: 1; AFP: 2. A series of melanophores along ventral midline from anterior elements of anal fin to posterior end of caudal peduncle, usually with a short gap in series a third to half way along its length; a melanophore midventrally at base of pelvic fin and another one just anterior to it; ca oblique, subcutaneous bars of reddish pigment on body above anal fin and on caudal peduncle; a vertical streak of reddish pigment on base of caudal fin, some red/black pigment extending onto proximal portion of ventral caudal-fin rays. Pelvic fins separate or united, frenum absent. Identification. Reared through transformation. Of the gobiid genera known to occur in Belize, only Coryphopterus, Lophogobius, Lythrypnus and Priolepis have six spines in the first dorsal fin, 26 vertebrae, and a DF of Numerous larvae with those features reared in our studies appear to be species of Coryphopterus because the transformed specimens lack a high median head crest (present in Lophogobius), have sensory pores on the head (absent in Lythrypnus and Priolepis) and have a fully scaled trunk (naked anteriorly in Lythrypnus). In addition, field-caught specimens of Coryphopterus personatus form a nearly uninterrupted ontogenetic series with certain net-collected larvae identified to this Coryphopterus group. Material. 194 specimens (66 cleared and stained), mm SL; counts taken from 69 specimens. General Morphology. Depth at pectoral-fin base (17 22% SL), depth at anus (15 20% SL), depth at caudal peduncle (8 11% SL); head moderate large, length 26 36% SL; small moderate round eye, diameter 22 32% HL; pectoral fin falling well short of anus, extending posteriorly to vertical through posterior dorsal-fin spines, length 12 30% SL; pelvic fin extending slightly more posteriorly than pectoral, nearly reaching vertical through anus; preanal length 47 56% SL. Bases of second dorsal and anal fins slightly shorter than length of caudal peduncle. Melanophores. Scattered melanophores sometimes occurring on top of head. The series of melanophores along anal-fin base paired, those posterior to anal fin unpaired median spots (Fig. 3B). Some reddish pigment usually associated with these melanophores. Small melanophores sometimes occurring at angle of lower jaw and at base of caudal fin, in both cases associated with erythrophores. Dorsal trunk pigment absent or comprising one to a series of melanophores on dorsal midline. A transverse streak of black pigment

14 652 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 Figure 5. Melanophore patterns for Coryphopterus A C drawn on Coryphopterus A template (see Fig. 5). (A) top to bottom: Coryphopterus A and variants A 1, A 2, A 3 ; (B) Coryphopterus B (top) and variant B 1 ; (C) Coryphopterus C (top) and variant C 1. sometimes present internally behind brain. Dorsal surface of gas bladder with several melanophores. Some black pigment present over posterior end of intestine near anus. Chromatophores. A small erythrophore usually present at angle of lower jaw, often in association with a melanophore. An erythrophore sometimes present at anterior tip of lower jaw. Midventral melanophores also usually associated with erythrophores. The series of internal oblique (anterodorsal to posteroventral) reddish bars confined largely to Figure 6. Dorsal view of melanophores on head of Coryphopterus spp. (A) Coryphopterus C 1 ; (B) Coryphopterus B 1 ; (C) Coryphopterus A 3.

15 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 653 ventral half of body, often widening dorsally in region of vertebral centra. Pigment associated with vertebrae often continuing anteriorly to the head. Some specimens with superficial streaks of red on ventral half of myomeres just anterior to anal-fin origin. Erythrophores sometimes present along dorsal margin of body. A vertical streak of red present at base of caudal fin, the pigment often extending posteriorly along proximal parts of some lower caudal-fin rays; melanophores sometimes co-occurring with this red pigment. Some diffuse reddish pigment present internally in branchial cavity. A transverse streak of red sometimes occurring internally behind brain, in the same position where other individuals have a black streak. Variation. Coryphopterus larvae can be sorted into three morphological types based on fin-ray counts (Coryphopterus A, Coryphopterus B, Coryphopterus C in Table 1). For each morph, there is typically some variation in pigmentation, and there is ambiguity regarding the number and identity of species represented in our material. We describe the larvae below using letter designations (A, B, C for the primary morphs, A 1, A 2, etc., for variants within those morphs), and provide comments on their possible identification. We include only those characters or character states that, in combination, distinguish morphs from one another. Coryphopterus A (Figs. 3B, 4, 17C) Diagnostic Features. D: VI, I-9; A: I, 9; P 1 : (usually 19). Internal red bars relatively inconspicuous and not extending anteriorly beyond a vertical through anus. One or two melanophores sometimes present on dorsal midline just behind posterior end of second dorsal fin. No other dorsal melanophores present. No melanophores on top of head and no erythrophore at tip of lower jaw. Internal transverse streak of pigment behind brain red. Identification. The presence of ten second dorsal- and ten anal-fin elements characterizes C. glaucofraenum Gill, C. dicrus Böhlke and Robins, C. thrix Böhlke and Robins, and C. eidolon Böhlke and Robins. Coryphopterus glaucofraenum, C. dicrus, and C. thrix modally have 19 pectoral-fin rays, although only C. glaucofraenum and C. thrix have as the extremes (C. dicrus and C. eidolon have 18 20). We suspect that at least some of our Coryphopterus A material represents C. glaucofraenum, as this is the most common and widely distributed species of the genus in the western Atlantic and a very common goby around Carrie Bow Cay. Material. 69 larval specimens (nine cleared and stained), mm SL; seven reared specimens (three cleared and stained), mm SL. Variation. One specimen, 8.5 mm SL (Coryphopterus A 1 in Tables 1 and 2, Fig. 5A), is similar to Coryphopterus A in having relatively faint internal red bars and two melanophores on the dorsal midline near the posterior end of the second dorsal fin. However, this larva also has additional melanophores on the dorsal midline that extend anteriorly to the head, a few melanophores on the frontals, and two conspicuous melanophores on the medial side of the pectoral-fin base. Eight specimens, mm SL, (Coryphopterus A 2 in Tables 1 and 2, Fig. 5A) resemble Coryphopterus A but are distinctive in having melanophores on the distal part of at least several of the anterior anal-fin elements. Most lack melanophores on the dorsal

16 654 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 midline, although one may be present, and some erythrophores are present on the base of the dorsal fin. One specimen has an erythrophore at the tip of the lower jaw. One specimen, 7.9 mm SL (Coryphopterus A 3 in Tables 1 & 2, Figs. 5A, 6C) differs from Coryphopterus A in having a distinctive pattern of melanophores on top of the head: there is a pair of longitudinal rows of spots extending from the occiput to the posterodorsal edge of the eye, and a single median row above the anterior lobe of the brain. There are no melanophores on dorsal midline. One specimen, 7.6 mm SL (Coryphopterus A 4 in Tables 1 & 2) differs from Coryphopterus A in the pattern of pigmentation on the posterior end of body: three (vs. two) spots are present on the dorsal midline posterior to dorsal fin; two melanophores (vs. none) are present on the trunk at the base of the penultimate and pre-penultimate second dorsal elements, a roughly horizontal line of orange pigment preceding the melanophores and a line of yellow succeeding them posteriorly; a small patch of orange pigment is present over the hypural plate (vs. no pigment); a patch of yellow pigment occurs on the upper lobe of the caudal-fin base, above the red pigment characteristic of all Coryphopterus; and the body is more slender (Table 2). Because all of the variants described above share with larvae of Coryphopterus A the presence of ten second dorsal-fin elements, ten anal-fin elements and 18 or 19 pectoral rays, they may represent morphological diversity within a single species or multiple species. Further study is needed. Coryphopterus B (Figs. 5B, 17D) Diagnostic Features. D: VI, I-7 9 (usually 8); A: I, 7 9 (usually 8); P 1 : (usually 15). Internal red bars broad, well developed and extremely prominent. Bars beginning slightly anterior to vertical through anal-fin origin and extending posteriorly to near base of caudal fin. Each bar somewhat expanded in region of vertebral centrum and extending dorsally to a point about halfway between vertebral centrum and dorsal margin of body. The two posteriormost bars, associated with the penultimate and pre-penultimate vertebrae, not extending below vertebral centra. No pigment present over ultimate vertebra. A prominent erythrophore at tip of lower jaw. Internal transverse streak of pigment behind brain black. Few or no melanophores on dorsal midline, but a few erythrophores sometimes present. No melanophores on top of head. An elongate band of red pigment extending from posterodorsal edge of opercle to gas bladder. Identification. Coryphopterus B larvae have not been identified. Although we might be underestimating numbers of fin rays in whole larval material, two cleared and stained specimens unquestionably have nine second dorsal-fin elements, eight nine anal-fin elements, and 15 pectoral-fin rays. Of the material examined by Böhlke and Robins (1960: Table 1), only two of 77 specimens of C. glaucofraenum, one of 22 C. alloides Böhlke and Robins, and one of three C. thrix had nine second dorsal-fin elements. The last is the only significant percentage, but the sample size is small, and our counts of an additional eight specimens of C. thrix lowers the frequency of nine dorsal elements to one of 11. Only C. alloides has as few as eight anal elements and nine modally, but that species typically has ten second dorsal-fin elements and 16 or 17 pectoral-fin rays. Coryphopterus personatus (Jordan and Thompson) and C. hyalinus Böhlke and Robins are the only species that have as few as 15 pectoral-fin rays (the modal count for those species), but they

17 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 655 have 10 or 11 second dorsal- and anal-fin elements and appear to be represented by our Coryphopterus C larvae (see below). It seems likely that Coryphopterus B larvae may represent an undescribed species. Material. 19 specimens (two cleared and stained), mm SL. Variation. Two specimens, 7.7 and 8.0 mm SL (Coryphopterus B 1 in Tables 1 and 2, Figs. 5B, 6B) have prominent internal red bars arranged as in Coryphopterus B, but they differ in having a series of melanophores on the dorsal midline from the head to the caudal peduncle and melanophores dorsally on the head, in an arc above the eye, and on several dorsal-fin spines. One specimen reared for six days has what appear to be fully divided pelvic fins. Aside from Coryphopterus personatus and its close relatives, C. hyalinus and C. lipernes Böhlke and Robins, which have a black circumanal ring in juveniles and adults that is lacking in the reared specimen of this larval type, the only other species with divided pelvic fins is C. alloides, which, as mentioned, has more second dorsal-fin elements and pectoral rays than larvae of Coryphopterus B (Table 1). Coryphopterus C (Figs. 5C, 17E) Diagnostic Features. D: VI, I-9 10; A: I, 9 10; P 1 : (usually 15). Prominent superficial streaks of red pigment on ventral half of anterior myosepta between verticals through gas bladder and origin of anal fin. The series of internal oblique bars extending from vertical through anterior end of anal fin to vertical slightly before posteriormost midventral melanophore. Diffuse reddish spots present above vertebrae from occiput to caudal base, merging with oblique bars where present (i.e., on posterior half of body). Most of these spots slightly separated from rest and located over terminal vertebra, anterior to streak on caudal-fin base. No melanophores on top of head, and no erythrophore at tip of lower jaw. Identification. There are only two known species of Atlantic Coryphopterus that have 11 second dorsal-fin elements: C. personatus and C. punctipectophorus Springer, and the latter is known only from deep water off the west coast of Florida. Furthermore, C. punctipectophorus has pectoral-fin rays, whereas C. personatus has (usually 15). A specimen reared through transformation developed the black circumanal spot characteristic of C. personatus and the related C. hyalinus and C. lipernes and C. personatus is common around Carrie Bow Cay. In addition, field-caught specimens of C. personatus form an almost uninterrupted ontogenetic series with our Coryphopterus C larvae. We conclude that our larvae with 11 second dorsal-fin elements represent C. personatus. We are less certain of the identity of our Coryphopterus C specimens with 10 second dorsal-fin elements. Of 40 specimens of adult C. personatus examined by Böhlke and Robins (1962: Table 1), 35 had 11 second dorsal-fin elements and five had 10, a ratio of 7:1. Of 20 Coryphopterus C larvae (17 cleared and stained) examined by us for meristic features, 17 have 11 second dorsal-fin elements, and three have 10, a ratio of 5.7:1. Specimens with 10 second dorsal elements were thus slightly more common than in Böhlke and Robins s sample. Possibly, some of our larvae represent C. hyalinus, which modally has 10 second dorsal elements, 10 anal elements, and (usually 15) pectoral rays. Coryphopterus personatus and C. hyalinus are very similar in appearance and habit and some doubt has been raised about their distinctness (K. Cole and J. Tyler, pers. comm). Although we can detect no consistent differences between Coryphopterus C larvae with

18 656 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, second dorsal elements and those with 11, we nevertheless acknowledge that those with 10 may be C. hyalinus. It is less likely that our larvae represent the related C. lipernes, as it is a less common species around Carrie Bow and has more pectoral-fin elements (16 18, usually 17, in C. lipernes vs , usually 15, in C. personatus/hyalinus). Material. 84 specimens (17 cleared and stained), mm SL; one reared, 9.0 mm SL. Variation. Seven specimens, mm SL (Coryphopterus C 1 in Tables 1 and 2, Fig. 5C), resemble Coryphopterus C in having superficial red streaks on the anterior myosepta, but they differ in having melanophores dorsally on the head, arranged in a roughly V-shaped patch with the apex between the eyes (Fig. 6A). Of three specimens cleared and stained, two have 11 second dorsal elements and one has 10; all three have 11 anal elements, and two specimens for which pectoral-fin counts were obtained have 15 rays. These counts suggest that Coryphopterus C 1 larvae are variants of C. personatus. Ctenogobius saepepallens (Gilbert and Randall) (Figs. 3C, 7, 17F) Diagnostic Features. Elongate body; D: VI, I-10 or 11 (modally 11); A: I, (modally 12); P 1 : (modally 16); V: 10+16; DF: ; Ep: 2; AFP: 2. A prominent, vertically elongate, internal melanophore along posterior end of gut, terminating ventrally on left and right sides of anus and usually associated with erythrophores; a compound pigment spot on caudal peduncle just posterior to anal-fin base composed of a horizontally oriented melanophore on ventral midline and a vertically elongate erythrophore. Pelvic fins united, frenum present. Identification. Reared through transformation. Juveniles have the pelvic fins united, upper pectoral rays interconnected, trunk completely scaled, fewer than 35 scales in longitudinal series, six dorsal-fin spines, pores in cephalic lateral-line system and one more ray in the anal fin than dorsal fin. These features are characteristic of Gobionellus, several large-scale species (i.e., with fewer than 46 scales in longitudinal series) of which are now classified as Ctenogobius (Pezold, 1984), including C. smaragdus (Valenciennes), C. boleosoma (Jordan and Gilbert), C. stigmaticus (Poey), C. pseudofasciatus (Gilbert and Randall), and C. saepepallens (Gilbert and Randall) known to occur in the western Caribbean. Ctenogobius boleosoma and C. smaragdus typically have 11 second dorsal- and 12 anal-fin elements, vs. 12 and 13, respectively, in our larvae and C. stigmaticus, C. pseudofasciatus, and C. saepepallens. Pigmentation of reared juveniles (see description below) matches nearly identically pigmentation described by Gilbert and Randall (1968) for C. saepepallens, most notably the presence of five horizontally elongate patches of melanophores on the lateral midline of body, a triangular patch on the opercle, a suborbital bar, and irregular streaks of spots on the dorsal fin. Ctenogobius stigmaticus has four or five dark bars on the lower part of the cheek and a shoulder spot (Gilbert and Randall, 1968), and C. pseudofasciatus has a dark blotch on the posteroventral part of the cheek (Gilbert and Randall in Gilbert and Kelso, 1971); these features are not present in our juveniles or wild-caught C. saepepallens. Material larvae (35 cleared and stained), mm SL; eight reared specimens (three cleared and stained), mm SL.

19 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 657 Figure 7. Ctenogobius saepepallens, 9.5 mm SL. General Morphology. Depth at pectoral-fin base 15 18% SL, depth at anus 13 16% SL, depth at caudal peduncle 7 8% SL; moderate head, length 21 26% SL and small moderate round eye, diameter 20 28% HL; pectoral fin falling well short of anus, terminating posteriorly at vertical through ca. fourth dorsal-fin spine (length 12 15% SL); pelvic fin extending slightly more posteriorly than pectoral fin but also falling short of vertical through anus; preanal length 44 57% SL; length of second dorsal- and anal-fin bases considerably greater than length of caudal peduncle. Juveniles without scales on head, but trunk fully scaled, about scales in longitudinal series. Well-developed teeth, including small canines, present in both jaws. Melanophores. Head usually without melanophores, one spot sometimes present on gular just below dentary symphysis and rarely a single melanophore present on opercle. One horizontally elongate melanophore usually present on ventral midline just anterior to pelvic fin. In ventral view, the vertically elongate melanophore on posterior gut appearing as a bilateral pair of spots around anus, but in cleared and stained specimens, a single, large, median, primarily internal melanophore evident, covering posterior end of gut and terminating at anus. One to five melanophores usually occurring on anal-fin base (typically bilaterally paired, but some specimens with more melanophores on one side than the other). No pigment on dorsal portion of trunk. Pectoral fin usually lacking pigment, but one tiny melanophore sometimes present basally on one of upper rays. Pelvic fin sometimes with one spot on membrane joining two innermost rays. Gas bladder heavily pigmented dorsally. In reared juveniles, melanophores scattered over most of head except gular region and ventral and posterior parts of lower jaw. Concentrated areas of melanophores occurring in two places on head: (1) in a bar that extends posteroventrally from ventral surface of anterior third of eye and (2) in a triangular patch of closely spaced spots on middle part of opercle. In addition to numerous scattered melanophores, trunk with pigment concentrated in five horizontal dashes on lateral midline, the dashes roughly evenly spaced from beneath anterior part of pectoral fin to caudal peduncle. Melanophores sometimes extending dorsally and ventrally from dashes to form faint saddles of pigment. All fins with pigment: Patches of melanophores occurring on membranes of first and second dorsal fins, creating four roughly horizontal stripes on each fin; anal fin with small melanophores uniformly scattered across fin; dorsal half of pectoral fin with scattered spots at least basally; pelvic fin always with two distinct lines of pigment on membranes between fourth and fifth soft rays, and membrane between other rays sparsely, or heavily pigmented; caudal fin with melanophores densely covering membranes between rays of lower lobe, pigment broken into patches in upper lobe forming several vertical rows. Chromatophores. Gular melanophore described above sometimes associated with an erythrophore (sometimes only the erythrophore present) and an erythrophore present at

20 658 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 angle of lower jaw. A red bar sometimes present on top of the snout between anterior margins of eyes, and usually two internal patches present on posterodorsal region of head, one (on occiput) above the other (lateral). Internal erythrophores also occurring in posterior region of gill chamber. Two chromatophores present on ventral midline, one preceding the pelvic fin and located just anterior to the melanophore there, and one medial to pelvic-fin base. Orange pigment usually associated with the conspicuous melanophore at anus, and pigment at posterior base of anal fin always a compound feature comprising a median melanophore and vertically elongate, internal erythrophore that extends dorsally to notochord. Reared juveniles lacking erythrophores. Variation. Differences among larvae in counts (second dorsal, anal and pectoral rays) and pigment (especially presence or absence of gular, opercular and pectoral-fin melanophores and the wide variation in number of melanophores along the anal-fin base) could indicate that our larvae represent more than one species. For example, larvae with 12 second dorsal-fin elements, 13 anal-fin elements and 17 pectoral rays could be C. pseudofasciatus, which modally has those counts (Gilbert and Randall in Gilbert and Kelso, 1971); however, there is no consistent correlation between non-modal counts in our larvae and a specific pigment pattern, and all non-modal counts are within the extremes of counts for C. saepepallens given by Gilbert and Randall (1968). We thus interpret the variation as intraspecific. Furthermore, all larvae identified as C. saepepallens based on pigment characters and then reared transformed into a single morph, nearly identical to preserved museum specimens of juvenile and adult C. saepepallens. Remarks. Wyanski and Targett (2000) noted that live coloration of 9.5 and 10.1 mm SL specimens of C. boleosoma included an erythrophore at the tip of the lower jaw, a vertical reddish-orange streak between thoracic and abdominal regions, and a vertical streak on the caudal peduncle originating from the ventral midline. Those features, plus a series of melanophores along the anal-fin base in C. boleosoma, also characterize C. saepepallens and may be indicative of a close relationship between the two species. Ctenogobius saepepallens is the most abundant larva collected on the reef flat at Carrie Bow Cay. Adults live in burrows in sandy, or silty bottoms generally in depths less than 70 ft, and have been taken in sea grass and mangrove habitats (Gilbert and Randall, 1968). Ctenogobius saepepallens was represented by a single specimen in Greenfield and Johnson s (1999) extensive collections of Gobiidae from Belize and Honduras, and adults have not yet been collected at Carrie Bow Cay; nevertheless, the abundance of larvae suggests a large population in the area. Gnatholepis thompsoni Jordan (Figs. 3D, 8, 17G) Diagnostic Features. Body elongate; D: VI, I-11; A: I, 11; P 1 : (modally 17); V: (modally 10+16); DF: ; Ep: 2; AFP: 2. A prominent internal erythrophore at posterior base of anal fin, extending obliquely from ventral midline to near posterior base of dorsal fin; one erythrophore at distal tip of second anal-fin element; no melanophores on ventral midline; melanophores usually associated with first and second dorsal-fin spines and anterior dorsal-fin soft rays; bar of melanophores above and below eye variously present or absent; larger specimens with melanophores on opercular series, frontals, and along dorsal-fin base. Pelvic fins partially united, frenum present.

21 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 659 Figure 8. Gnatholepis thompsoni, 9.4 mm SL. Identification. Reared through transformation. Juveniles have the pelvic fins united, all pectoral rays interconnected, the body (including cheek and opercle) scaled, six spines in first dorsal fin, pores in the cephalic lateral-line system, a very distinct suborbital bar of melanophores, an equal number of second dorsal- and anal-fin elements, and no prolonged central caudal rays. Among western Atlantic and Caribbean gobies, this combination of features is found only in Gnatholepis thompsoni (Böhlke and Chaplin, 1993). Material. 370 larvae (12 cleared and stained), mm SL; 31 reared specimens (eight cleared and stained), mm SL. General Morphology. Depth at pectoral-fin base 15 19% SL, depth at anus 14 17% SL, depth at caudal peduncle 7 10% SL; moderate head, length 24 29% SL, and round eye of moderate size, diameter 27 32% HL; pectoral fin bent or broken in most specimens, otherwise extending to vertical through anus, length ca % SL; pelvic fin not extending as far posteriorly as pectoral fin; preanal length 47 52% SL. Pelvic fins joined by a membrane along anterior half of two innermost rays; sucking disk beginning to form in postflexion larvae as a frenum between left and right spines. Length of second dorsaland anal-fin bases considerably greater than length of caudal peduncle. Reared juveniles with scales on trunk, cheeks and opercle, and numerous small teeth in both jaws. Melanophores. Head without melanophores in many specimens, but some with a bar of pigment extending dorsally and ventrally from the eye (see Remarks below), and some specimens with tiny spots on the opercle and frontal. No melanophores along ventral midline. Trunk without melanophores in small specimens, but a series of spots occurring along dorsal-fin base in most specimens larger than ca. 9.1 mm SL. First and second dorsal fins typically with a small amount of melanin on distal part of membranes of first and second elements (and sometimes third element of second dorsal). One to several horizontally elongate melanophores usually present on one to several central pectoral-fin rays (one per ray), typically at a point about one-fourth the length of the ray from the base. Internally, melanophores present along dorsal curvature of notochord and in a dense cap over gas bladder. Reared juveniles with a well- delineated subocular bar extending posteroventrally from about ventralmost point of eye to near ventral midline. Short bar of pigment extending anterodorsally above eye. In some specimens, a nearly diagonal line of dark pigment extending through eye, connecting supra- and subocular bars. Trunk covered with many small patches of melanophores arranged in roughly three or four horizontal rows. Melanophores also present on membranes of first and second dorsal fins, conspicuously absent only near midpoint of length of each ray and on membrane between first and second fins. Chromatophores. In addition to the diagnostic slash of internal orange pigment on posterior part of trunk and erythrophore on distal tip of second anal-fin ray, anterior end

22 660 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 of gular usually with patch of erythrophores (xanthophores also present in some specimens), anterior tips of dentary and premaxilla typically with a small amount of orange pigment, and angle of lower jaw with orange spot. Posterodorsal region of head yellow. Ventral midline with an elongate dash of orange pigment on pelvic girdle and another (sometimes much larger) line just anterior to it. A series of erythrophores present along anal-fin base. Pectoral fin with a patch of orange pigment on bases of about 5 7 rays in middle to lower part of fin. Pectoral-fin erythrophores typically equally vivid on medial and lateral aspects of rays. Internally, orange pigment associated with posteroventral end of gut and visible externally at the anus. Remarks. Gnatholepis thompsoni is very common in our larval-fish collections. Adults are common at Carrie Bow on sand bottom around small patch reefs and rubble. Gnatholepis thompsoni was the second most abundant goby species in Greenfield and Johnson s (1999) collections from Belize and Honduras. The supra- and subocular bars of melanophores are present in 10 specimens, mm SL, absent in six specimens, mm SL. Counts of cleared and stained specimens of both morphs, as well as other aspects of pigmentation, strongly suggest that each is the larva of G. thompsoni, and we suspect intraspecific variation in the onset of development of this ocular pigment. Supraand subocular bars of pigment are present in all reared juveniles of G. thompsoni > ca. 10 mm SL. The most characteristic feature of G. thompsoni larvae is the large, obliquely oriented, elongate erythrophore at the posterior base of the anal fin. Unlike the internal erythrophore in C. saepepallens, located in a similar position, this pigment in G. thompsoni is not associated with a melanophore. Gnatholepis thompsoni can be distinguished from C. saepepallens also by the absence of melanophores on the ventral midline, presence of erythrophores on the pectoral fin, second anal-fin element, and along anal-fin base (C. saepepallens and many other gobies with melanophores along anal-fin base), and usually by having 12 (vs. modally 13 in C. saepepallens) anal-fin elements and 17 (vs. 16) pectoral rays (Table 1). Additionally, G. thompsoni usually has a deeper body, larger head and eye, and longer pectoral fin (Figs. 7,8; Table 2). Gobionellus oceanicus (Pallas) (Figs. 9, 18A) Diagnostic Features. Body elongate; D: VI, I-13; A: I, 14; P 1 : ca. 18; V: 10+16; DF: ; Ep: 2; AFP: 2. No external melanophores. Erythrophores present on snout, above eye, posterior to brain, and on ventral aspect of gas bladder; xanthophores present on ventrolateral aspect of caudal peduncle. Body slightly deeper at anus than at pectoral-fin base; head length, eye diameter, snout length, and pectoral-fin length smaller relative to standard length than in most other larval gobioids described herein from Belize (Table 2). Pelvic fins united, frenum present. Identification. Gobionellus oceanicus is the only known western Atlantic goby that has 14 second dorsal-fin elements, 15 anal-fin elements, and a DF of Our larvae resemble those described by Hildebrand and Cable (1938) as G. oceanicus, although those authors did not give fin-ray counts. Material. Nine larvae (three cleared and stained), mm SL. General Morphology. Depth at pectoral-fin base 10 12% SL, depth at anus 11 13% SL, depth at caudal peduncle 6 7% SL; head small, length 18 20% SL; eye small, diam-

23 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 661 Figure 9. Gobionellus oceanicus, 11.5 mm SL. eter 18 21% HL; pectoral fin small, reaching vertical through first or second dorsal-fin spine (length 10 12% SL); pelvic fin very short; preanal length 54 55% SL. Bases of second dorsal and anal fins much longer than length of caudal peduncle. Melanophores. No superficial melanophores. Internally, melanin present dorsally on gas bladder. Chromatophores. Small erythrophores occurring at tip of snout, at a point midway between tip of snout and anterior margin of eye, and dorsally on head above eye. In one 12.8 mm SL specimen, erythrophores also present at dentary symphysis and along ventral midline preceding and following pelvic-fin base. Diffuse red pigment present behind base of brain and on underside of gas bladder. Red or yellow pigment present in a patch (often diffuse) on ventrolateral aspect of caudal peduncle. Remarks. The absence of superficial melanophores in our ca mm SL specimens presumably is diagnostic only for the pelagic stage; Wyanski and Targett (2000) noted that numerous external melanophores appear in mm SL transformation specimens of G. oceanicus. Nes longus (Nichols) (Figs. 10, 18B) Diagnostic Features. Body moderately elongate to elongate; D: VII, I-12; A: I, 10 11; P 1 : 17 18; V: or 12+16; DF: ; Ep: 1; AFP: 1 2. A conspicuous, expanded melanophore on ventral midline at posterior end of anal fin and a pair of smaller melanophores on either side of anterior part of anal-fin base. Pelvic fins united by membrane extending along entire length of innermost rays, frenum present (Smith and Baldwin, 1999: fig. 2C). Body scales and head pores absent in reared juveniles. Identification. Reared through transformation. A combination of morphological and meristic features distinguishes N. longus from all other known western Atlantic gobies. Among genera with seven spines in the first dorsal fin, only Psilotris, Gobulus, and Nes lack head pores and scales. Psilotris species differ in having separate pelvic fins and no more than 11 elements in the second dorsal fin. Gobulus myersi also has 11 second dorsal- and 10 anal-fin elements, as opposed to 13 and 11 12, respectively, in N. longus. Nes longus has 28 total vertebrae, but it is unusual in that the number of precaudal/caudal vertebrae varies between 11/17 and 12/16 (Böhlke and Robins, 1968: 144). Material. Nineteen larvae (five cleared and stained), mm SL; 22 reared specimens, mm SL.

24 662 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 Figure 10. Nes longus, 10.5 mm SL. General Morphology. Depth at pectoral-fin base 18 22% SL, depth at anus 16 19% SL, depth at caudal peduncle 9 11% SL; head moderate, length 27 32% SL; eye small, diameter 21 25% HL; pectoral fin reaching vertical through ca. sixth or seventh dorsalfin spine, length 16 22% SL; pelvic fin not extending as far posteriorly as pectoral fin, terminating at vertical through ca. fifth or sixth dorsal-fin spine; preanal length 53 58% SL. Bases of second dorsal and anal fins about twice length of caudal peduncle. Welldeveloped teeth in both jaws. Melanophores. A short black streak on ventral midline immediately before base of pelvic fins. A few small melanophores on bases of uppermost rays of lower caudal-fin lobe. Internal melanophores on dorsal surface of gas bladder and on dorsal and lateral surfaces of intestine. Juveniles retaining the distinctive ventral trunk melanophores as internal blotches but also developing the mid-lateral bar-like blotches characteristic of adults; melanophores also present on head and fins. Chromatophores. Erythrophores present on gular region, behind gill chamber, at anterior base of vertebral column, and internally on ventral surface of posterior end of intestine. Red pigment also associated with the pre-pelvic melanophore, the paired melanophores above anterior part of anal fin, and melanophores on caudal fin. Priolepis hipoliti (Metzelaar) (Figs. 11, 18C) Diagnostic Features. Body moderately elongate. D: VI, I-9; A: I, 8; P 1 : 17 18; V: 10+16; DF: ; Ep: 1; AFP: 2. Trunk covered with erythrophores from vertical through dorsal-fin origin to vertical through posterior end of dorsal fin on dorsal portion of trunk, to vertical through caudal peduncle on ventral portion of trunk. Pectoral fin large, reaching vertical through anterior elements of anal fin. Pelvic fins partially united, frenum absent. Identification. Reared through transformation. Four genera of western Atlantic gobies have a DF of and 26 vertebrae: Coryphopterus, Lophogobius, Lythrypnus and Priolepis. Coryphopterus has sensory pores on the head (absent in reared specimens of Priolepis); Lophogobius has a crest on the head and a more horizontal mouth opening, neither of which is present in the transformed specimens of Priolepis; and Lythrypnus has fewer pectoral-fin rays (13 17 vs in Priolepis). Material. Five larvae (one cleared and stained), mm SL; three reared specimens, mm SL.

25 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 663 Figure 11. Priolepis hipoliti, 11.0 mm SL. General Morphology. Depth at pectoral-fin base 20 27% SL, depth at anus 19 25% SL, depth at caudal peduncle 10 14% SL; head moderately large, length 31 36% SL; eye small to moderate, diameter 21 28% HL; pectoral fin long, extending posteriorly at least to vertical through first anal-fin element to about vertical through seventh element, length 26 34% SL; pelvic fin extending to vertical just anterior to origin of anal fin; pelvic fins united by membrane extending along anterior three-fourths of medial rays; preanal length 53 60% SL. Bases of second dorsal and anal fins about equal in length to (or slightly longer than) length of caudal peduncle. Head pores absent, scales present in transformed individuals. Three distinct radial rows of sensory papillae on caudal fin and a short vertical row of four papillae at its base. Melanophores. No superficial melanophores. Internal melanophores present around anus, dorsally on gas bladder, and in orbit. Reared individuals with melanophores on head and bases of spines and second dorsal-fin elements. Chromatophores. Erythrophores occurring on dentary, at angle of lower jaw, on ventral midline in region of breast and throat, and internally behind brain. Red coloration of trunk most intense posteriorly, the entire red area forming a broad, slightly oblique bar. Anterior end of pigmented area also intense in color, erythrophores concentrated on myosepta. Caudal peduncle pale, without erythrophores; transition between red and pale regions abrupt, with only a line of red pigment extending along ventral margin of body between posterior end of anal- and caudal-fin bases. A vertical streak of red present over posterior margin of ventral hypural plate, extending onto basal part of lower caudal rays. Erythrophores present distally on spines of dorsal fin, on posterior elements of second dorsal and anal fins, and on pectoral fin. Remarks. Priolepis hipoliti is one of the most distinctive goby larvae collected at Carrie Bow Cay because of its bright red trunk. Psilotris amblyrhynchus Smith and Baldwin (Figs. 12, 18D) Diagnostic Features. Body elongate; D: VII, I-10 or 11; A: I, 9 10; P 1 : 18 19; V: 11+16; DF: ; Ep: 1; AFP: 2. A conspicuous, expanded melanophore on ventral midline over posterior end of anal fin; an erythrophore, but no melanophore, midventrally above anterior part of anal fin. Pelvic fins united by membrane extending along anterior

26 664 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 Figure 12. Psilotris amblyrhynchus, 13.0 mm SL (modified from Smith and Baldwin, 1999). one-third and one-half of innermost rays, frenum absent (Smith and Baldwin, 1999: fig. 2A). Scales and head pores lacking in reared, transformed specimens. Identification. Reared through transformation. Material. Nine larvae (four cleared and stained), mm SL; two reared specimens, 13.8 and 16.8 mm SL. General Morphology. Depth at pectoral-fin base 19 21% SL, depth at anus 16 18% SL, depth at caudal peduncle 9 10% SL; head moderate, length 29 32% SL; eye small, diameter 22 24% HL; pectoral fin reaching vertical through posterior end of first dorsal fin, length 18 22% SL; pelvic fin terminating posteriorly beneath posterior extreme of pectoral fin; preanal length 52 56% SL. Bases of second dorsal and anal fins about twice the length of caudal peduncle. Melanophores. A black streak present on ventral midline immediately before base of pelvic fins. The large melanophore on ventral midline over posterior end of anal fin with a dorsal extension internally. Melanophores also occurring internally on dorsal surface of gas bladder and posterior end of intestine. Chromatophores. A large erythrophore on ventral midline above anterior part of anal fin. Remarks. Larvae of P. amblyrhynchus closely resemble those of Nes longus, differing most conspicuously in lacking a second ventral melanophore over the anterior part of the anal fin. Living and BHT-preserved specimens often have an erythrophore in this position. Larval P. amblyrhynchus also differ from N. longus in lacking melanophores on the lower caudal-fin rays, having fewer second dorsal-fin elements (11 or 12 vs. 13) and vertebrae (27 vs. 28), and lacking a frenum between pelvic-fin spines (Smith & Baldwin, 1999: Fig. 2). Eleotris sp. (Figs. 13, 15A, 18E) Diagnostic Features. Body elongate; D: VI, I-8; A: I, 8; P 1 : 16; V: 10+15; DF: ; Ep: 2; AFP: 2. A nearly vertical row of conspicuous melanophores on caudal peduncle at base of caudal fin; no melanophores on dorsal midline. Eye very small; pectoral fin short, falling well short of vertical through first dorsal-fin spine; pelvic fins short, separate. Second dorsal- and anal-fin bases shorter than length of caudal peduncle. Identification. The combination of vertebrae and a dorsal-pterygiophore formula of is diagnostic for Eleotris and Erotelis in the western Atlantic. Of the known Caribbean species, only Eleotris amblyopsis and E. perniger (= E. pisonis of the systematic and ecological literature of the region - Pezold, 2001; pers. comm.) have nine

27 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 665 Figure 13. Eleotris sp., 13.5 mm SL. second dorsal elements and nine anal elements. The two species are separable on the basis of scale counts and cephalic neuromast patterns (Pezold, 2001), neither of which was observed in our specimens. Material. Two larvae, 12.5 and 13.0 mm SL, the latter cleared and stained. General Morphology. Depth at pectoral-fin base 14% SL, depth at anus 15% SL, depth at caudal peduncle 10% SL; head moderate, length 26% SL; eye very small, diameter 18% HL; mouth oblique, lower jaw protruding slightly; pectoral fin reaching vertical through ca. 8 th myomere, length 16% SL; pelvic fin terminating posteriorly well before posterior end of pectoral fin; preanal length 55% SL. Melanophores. A dark streak present on lateral surface of distal three-fourths of maxilla and another on anterolateral surface of dentary; ventral to lower jaw pigment, a melanophore present on lateral edge of gular region and another at angle of lower jaw. Melanophores also present in suborbital patch directly beneath eye and sometimes encircling most of eye. Internal melanophores present on posterolateral surface (otic region) of neurocranium. A series of melanophores along midventral line between isthmus and gas bladder, forming a continuous line of pigment when expanded; much of this ventral pigment internal. Similar series of ventral midline/internal melanophores occurring between anus and base of caudal fin. The pigment on caudal peduncle sometimes extending onto bases of central rays of lower caudal-fin lobe, and small melanophores present on distal portions of dorsal- and ventralmost principal caudal-fin rays. Pigment present on dorsal surface of gas bladder and internally on posterior wall of intestine at anus. Chromatophores. Prominent erythrophores on ventral midline along anal-fin base and caudal peduncle and on dorsal midline along caudal peduncle. Orange and yellow chromatophores associated with vertical row of melanophores on caudal peduncle, the yellow extending onto proximal portions of central caudal rays. Erythrophores present internally along top of gut anterior to gas bladder; some diffuse red pigment above gas bladder and around vertebral column about halfway between gas bladder and hypural plate. Silvery reflective pigment at base of tail lateral to melanophores. Remarks. Larval Eleotris sp. closely resembles that of Erotelis smaragdus, described below. The two differ principally in numbers of fin rays and in pattern of pigmentation. Eleotris sp. lacks the short, vertical rows of small melanophores rising from the ventral margin of the body characteristic of E. smaragdus and has the following features of pigmentation lacking in E. smaragdus: a dark streak of pigment on the distal portion of the upper jaw; conspicuous melanophores on the caudal peduncle that are arranged in a nearly vertical row; and melanophores restricted to the distal portions of the upper- and lowermost principal caudal-fin rays.

28 666 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 Figure 14. Erotelis smaragdus, 11.5 mm SL. Erotelis smaragdus (Valenciennes) (Figs. 14, 15B, 18F) Diagnostic Features. Body elongate; D: VI, I-10; A: I, 9; P 1 : ca. 18; V: 10+15; DF: ; Ep: 2; AFP: 2. An oblique row of conspicuous melanophores on caudal peduncle, extending slightly onto ventral lobe of caudal fin, and melanophores scattered along middle of most principal caudal-fin rays. Dorsal midline without melanophores. Eye small. Body slightly deeper at anus than at pectoral-fin base. Pelvic fins short, separate. Dorsal- and anal-fin bases much shorter than caudal peduncle. Identification. The combination of vertebrae and a dorsal-pterygiophore formula of is diagnostic for Eleotris and Erotelis in the western Atlantic. Erotelis smaragdus has 11 second dorsal- and 10 anal-fin elements, whereas Eleotris sp. has 9 and 9, respectively. Material. Six specimens (one cleared and stained), mm SL General Morphology. Depth at pectoral-fin base % SL, depth at anus 11 13% SL; depth at caudal peduncle 8 9% SL; head moderate, length 23 26% SL; eye very small, diameter 14 18% HL. Mouth oblique, lower jaw protruding slightly; pectoral fin nearly reaching vertical through anterior base of spinous dorsal fin, length 15 20% SL; pelvic fin very short, terminating at vertical through midpoint or slightly beyond midpoint of longest pectoral ray; preanal length 54 56% SL. Melanophores. A small melanophore present near anterior tip of upper jaw and one to several along lower jaw. A melanophore present at angle of lower jaw, and pigment occurring in suborbital patch directly below eye. Internal melanophores present on posterolateral surface (otic region) of neurocranium. A series of melanophores present along ventral midline between isthmus and gas bladder, forming a continuous line of pigment when expanded; this pigment mostly internal. A series of short, vertical rows of small melanophores extending dorsally from ventral margin of body posterior to anus, rows spaced about one per myomere. Superficial melanophores present on bases of anal-fin elements and sometimes occurring more distally on rays. Internal pigment occurring on dorsal surface of gas bladder, posterior side of intestine at anus, and along ventral margin of body between anus and base of caudal fin. Chromatophores. A small erythrophore near tip of snout. An erythrophore present on dorsal midline between posterior end of dorsal fin and caudal-fin base. Erythrophores cooccurring with the melanophores between anus and caudal-fin base. Diffuse red pigment along top of gut. Diffuse patch of yellow pigment around vertebral column beneath posterior end of dorsal fin, on lateral midline of caudal peduncle, and at base of caudal fin.

29 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 667 A B C Figure 15. Melanophore patterns on caudal peduncle of eleotridine larvae. (A) Eleotris sp., 13.5 mm SL; (B) Erotelis smaragdus, 11.5 mm SL; (C) Eleotridinae sp., 10.5 mm SL. Unidentified Eleotridinae (Fig. 15C) Diagnostic Features. Body elongate, slightly deeper at anus than at pectoral-fin base. Eye small. Pelvic fins small and separate. No suborbital pigment. A single internal melanophore in gill cavity, directly medial to edge of opercular flap in front of pectoral-fin base. Another melanophore present on dorsal midline just posterior to dorsal fin. A roughly oblique bar of large melanophores on caudal peduncle, extending broadly onto bases of several rays of lower caudal lobe; upper caudal lobe with melanophores in vertical line at proximal bases of principal rays; several ventral rays of lower caudal lobe with melanophores scattered along mid-length of rays, no melanophores along lengths of rays of dorsal caudal lobe. Bases of dorsal and anal fins shorter than length of caudal peduncle. Identification. With only a single, twisted specimen available, we were unable to obtain reliable counts and chose not to clear and stain the specimen in efforts to preserve the diagnostic pattern of pigmentation. Identification of this larval type must await examination of additional material. Two eleotridine species that occur in Belize for which we have not identified larvae are Dormitator maculatus and Gobiomorus dormitor. Material. A single specimen, 10.5 mm SL. General Morphology. Depth at pectoral-fin base ca. 13% SL, depth at anus ca. 14% SL, depth at caudal peduncle ca. 9% SL; head moderate, length ca. 21% SL; eye small, diameter ca. 23% HL; mouth oblique, lower jaw protruding slightly; pectoral fin reaching vertical through anterior dorsal-fin base, length ca. 11% SL; preanal length ca. 54% SL. Melanophores. Pigment present near tip of upper jaw. Streak of pigment present on anterior margin of lower lip, and several melanophores present on anterior region of gular. A melanophore at angle of lower jaw. A series of melanophores along ventral margin of body from isthmus nearly to caudal-fin base (except gap in series beneath gas bladder), partially merged to form an irregular streak. Melanophores on dorsal surface of gas bladder. Internal pigment on posterior side of intestine near anus. Chromatophores. No data, specimen faded. Remarks. This specimen resembles Eleotris sp. and E. smaragdus in general body shape and many aspects of pigmentation. It lacks pigment behind the brain visible in Eleotris sp. and Erotelis smaragdus, and it has an internal melanophore in the gill cavity lacking in the others. Eleotridinae sp. also differs from Eleotris sp. and E. smaragdus in having a vertical series of melanophores on the base of the upper lobe of the caudal fin and in lacking melanophores along the middle or distal regions of the principal rays of the

30 668 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 upper lobe. The oblique series of melanophores on the caudal peduncle in Eleotridinae sp. is similar to that of E. smaragdus, but the series begins lower on the peduncle in the former (near the center of the caudal peduncle). Eleotridinae sp. is the only one of the three that has a melanophore on the dorsal margin of the body. Ptereleotris helenae (Randall) (Figs. 16, 18G) Diagnostic Features. Body elongate; D: VI, I-21 23; A: I, 21 22; P 1 : 21; V: 10+16; DF: ; Ep: 1; AFP: 1. Mixed chromatophores and melanophores present along dorsal- and anal-fin bases; melanophores along dorsal-fin bases superficial, those along anal-fin base subcutaneous. Anterior soft rays of second dorsal and anal fins longer than posterior elements; pelvic fins separate; caudal fin strongly emarginate. Bases of seconddorsal and anal fins much longer than the very short caudal peduncle. Identification. The fin-ray counts and the dorsal-pterygiophore formula are unique to Ptereleotris among western Atlantic gobioid fishes. The separate pelvic fins and elevated anterior dorsal- and anal-fin rays further distinguish it. Two species of Ptereleotris occur in the western Atlantic: P. calliurus (Jordan and Gilbert [ex Bean] 1882) and P. helenae (Randall, 1967). They are distinguished by body color and length of caudal fin, neither of which is useful for identifying the larvae; meristic features do not differ between the two species. Because P. calliurus is known only from Florida, whereas P. helenae occurs in the Caribbean, it seems likely that our larvae represent P. helenae. To our knowledge, adult Ptereleotris have not been collected in Belize. Material. Three specimens (one cleared and stained), mm SL. General Morphology. Depth at pectoral-fin base 15% SL, depth at anus 15% SL, depth at caudal peduncle 9% SL; head moderate, length 27% SL; eye moderate, diameter 26% HL; mouth strongly oblique; pectoral fin reaching just beyond vertical through base of sixth dorsal-fin spine, length 16% SL; pelvic fin extending nearly as far posteriorly as pectoral fin; preanal length 52% SL. Melanophores. Large, complex melanophore present middorsally on occiput over posterior part of brain. A melanophore present on dorsal portion of trunk at base of second dorsal-fin spine and one at base of sixth dorsal-fin spine. A series of paired superficial melanophores along base of second dorsal fin, melanophores discrete and spaced about one per ray anteriorly, more closely spaced and sometimes contiguous posteriorly. Paired subcutaneous melanophores present along base of anal fin, more closely spaced posteriorly than anteriorly. A few short streaks of pigment present on basal part of several lower caudal rays. Pigment present on intestine just dorsal to anus and on dorsal surface of gas bladder. Figure 16. Ptereleotris helenae, 12.5 mm SL.

31 BALDWIN AND SMITH: LARVAL GOBIIDAE OF CARRIE BOW CAY, BELIZE 669 Chromatophores. Erythrophores associated with melanophores along both dorsal and anal fins; yellow pigment present along base of posterior half of second dorsal fin. Red pigment present on basal part of caudal fin and midventrally from isthmus to pelvic-fin base. Figure 17. Chromatophore patterns in larval Gobiidae from Belize. (A) Bathygobius curacao, (B) Bathygobius soporator, (C) Coryphopterus A, (D) Coryphopterus B, (E) Coryphopterus C, (F) Ctenogobius saepepallens, (G) Gnatholepis thompsoni.

32 670 BULLETIN OF MARINE SCIENCE, VOL. 72, NO. 3, 2003 Figure 18. Chromatophore patterns in larval Gobiidae from Belize. (A) Gobionellus oceanicus, (B) Nes longus, (C) Priolepis hipoliti. (D) Psilotris amblyrhynchus, (E) Eleotris sp., (F) Erotelis smaragdus, (G) Ptereleotris helenae.