282 



Fishery Bulletin 89(2). 1991 



Central America, and also along the Caribbean coast 

 of Colombia. 



Bathymetric distribution Symphurus caribbeanus 

 inhabits shallow water. Of 94 specimens for which 

 depth information was available, the majority (78/94, 

 83%) were collected in 20 m or less (Table 11), and^ap- 

 proximately half were collected in waters shallower 

 than 10 m. All life stages are represented among the 

 shallowest collections. The deepest capture (29 m) is for 

 one lot (UMML 34341) comprising 16 individuals. 



Ecology Other than depth of occurrence and geo- 

 graphic distribution, little is known about ecological 

 requirements of this species. Austin and Austin (1971) 

 included nine specimens of S. caribbeanus in their 

 survey of feeding habits of fishes inhabiting mangrove 

 areas in southwestern Puerto Rico. These specimens, 

 ranging in size from 30 to 104 mm SL, had fed mostly 

 on polychaetes and small, benthic crustaceans, and in- 

 dividuals collected at night had undigested food in their 

 stomachs, suggesting nocturnal feeding. 



Comparisons Among Atlantic members of the S. pla- 

 gusia complex, S. caribbeanus most closely resembles 

 and occurs sympatrically with S. plagusia and juvenile 

 and subadult S. tessellatus. There is overlap also in 

 some meristic features of S. caribbeanus and S. civi- 

 tatium, but these species are otherwise quite distinct. 

 Symphurus caribbeanus differs considerably from S. 

 oculellus. Differences between S. caribbeanus and 

 these other species were discussed previously in "Com- 

 parisons" sections under the accounts for S. plagusia, 

 S. civitatium, S. tessellatus, and S. oculellus. 



Meristic values of S. caribbeanus overlap those of 1 1 

 other Atlantic species of Symphurus. Symphurus 

 caribbeanus is readily distinguished from six deep- 

 water Atlantic species with similar meristic values (S. 

 marginatus (Goode and Bean) and S. piger, occurring 

 in the Gulf of Mexico and Caribbean; two western 

 North Atlantic species, S. pusillus and undescribed 

 species C of Munroe (1987); the western South Atlan- 

 tic S. ginsburgi Menezes and Benvegnii; and the 

 eastern Atlantic S. nigrescens) in ID pattern (1-4-3 vs. 

 1-3-2 in the others) and peritoneal pigmentation (un- 

 pigmented versus dark -black, visible through both sides 

 of abdominal wall in the others). Symphurus carib- 

 beanus differs from two diminutive eastern Atlantic 

 species, S. lubbocki and S. reticulatus, in ID pattern 

 (1-4-3 vs. 1-3-2), dentition on ocular-side jaws (absent 

 or reduced in S. caribbeanus versus complete row in 

 the others), and longitudinal scale counts (78-89 in S. 

 caribbeanus versus 95 or more in S. lubbocki and S. 

 reticulatus). Symphurus caribbeanus differs from the 

 eastern Atlantic S. normani in ID pattern (1-4-3 vs. 



1-3-3), peritoneal pigmentation (unpigmented versus 

 spotted in S. normani), and S. caribbeanus lacks the 

 small ctenoid scales on the blind sides of the dorsal and 

 anal fin rays that are present in S. normani. Sym- 

 phurus caribbeanus differs further from the western 

 South Atlantic S. trewavasae and S. kyaropterygium 

 Menezes and Benvegnii, in caudal-fin-ray count (12 vs. 

 10) and ID pattern (1-4-3 vs. 1-3-3 in S. trewavasae, 

 1-4-2 in S. kyaropterygium). Symphurus caribbeanus 

 also lacks the pupillary operculum and fin membrane 

 ostia characteristic of S. kyaropterygium. 



Three shallow-water, western Atlantic species— S. 

 diomeoleanus, which occurs in sympatry with S. carib- 

 beanus, and the allopatric S. plagiusa and 5. urospilus 

 Ginsburg— have meristic features similar to those of 

 •S. caribbeanus. Symphurus caribbeanus differs from 

 these species in caudal-fin-ray count (12 vs. 10 in S. 

 diomedeanus and S. plagiusa, 11 in 5. urospilus) and 

 pigmentation of the vertical fins. The vertical fins of 

 S. caribbeanus have an alternating series of blotches 

 and unpigmented areas and the caudal fin lacks an 

 ocellated spot, unlike the vertical fins in S. diomedeanus 

 which have fewer, nearly spherical spots; or those of 

 •S. plagiusa and S. urospilus, that are uniformly pig- 

 mented without darkly-pigmented blotches throughout 

 their lengths; or the caudal fin in S. urospilus that has 

 an ocellated spot. From S. plagiusa, S. caribbeanus fur- 

 ther differs in the absence of a black opercular spot and 

 the small ctenoid scales on the blind-side dorsal and 

 anal fins characteristic of S. plagiusa. Symphurus 

 caribbeanus is further distinguished from S. diome- 

 deanus and 5. urospilus in lacking a pupillary oper- 

 culum (present in the others). 



Meristic values of S. caribbeanus overlap those of six 

 eastern Pacific species possessing either a 1-4-3 or 1-5-3 

 ID pattern, including S. leei, S. atricaudus, S. mela- 

 nurus, S. williamsi, S. fasciolaris, and S. melasmato- 

 theca. Symphurus caribbeanus differs from all of these 

 species in lacking a pupillary operculum (present in the 

 others). Of all these species, 5. caribbeanus appears 

 most similar to S. williamsi but differs in lacking small 

 ctenoid scales on the blind sides of the dorsal and anal 

 fin rays (present in S. williamsi) and in having pig- 

 mented blotches in the dorsal and anal fins (versus dor- 

 sal and anal fins without blotches in S. williamsi). Sym- 

 phurus caribbeanus also differs from S. atricaudus in 

 lacking small ctenoid scales on the ocular-side dorsal 

 and anal fin rays and in having an alternating series 

 of pigmented blotches in the dorsal and anal fins (scales 

 present and fins uniformly pigmented in S. atricaudus). 

 From S. melanurus, S. caribbeanus differs in that S. 

 melanurus possesses a fleshy ridge on the ocular-side 

 lower jaw and the first dorsal fin ray reaches a ver- 

 tical equal with or anterior to the anterior margin of 

 the upper eye, whereas S. caribbeanus lacks a fleshy 



