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Fishery Bulletin 89(2). 1991 



next smallest female was 111mm SL and had small 

 developing ova in the gonads. All other females were 

 larger than 130mm SL, had elongate ovaries, and were 

 considered sexually mature. 



Etymology From the latin "oculus" (eye), plus "ellus" 

 (little), in reference to the relatively small size of the 

 eye in this species compared with that of S. tessellatus. 



Geographic distribution (Fig. 5) A tropical species 

 with a fairly restricted distribution along the inner con- 

 tinental shelf of northeastern South America from 

 Guyana (57°W) to northeastern Brazil (2°S, 40°W) 

 where the majority of specimens have been collected. 

 All but one specimen (UMML 12265; 2°20'S) were 

 collected north of the Amazon outflow. Since little 

 systematic sampling has been conducted on the inner 

 continental shelf off equatorial Brazil, it is not known 

 whether the new species occurs more frequently in 

 areas immediately south of the outflow from the 

 Amazon River. 



Bathymetric distribution Symphurus oculellus oc- 

 curs at moderate shelf depths (7-110m) and does not 

 appear to utilize nearshore habitats or estuarine en- 

 vironments as nursery areas as do S. plagusia and 

 S. tessellatus. Specimens ranging from 76 to 189 mm 

 SL have been collected in offshore habitats, with most 

 (52/57, or 91%) being collected between 11 and 70m 

 (Table 10). At these depths, it is occasionally collected 

 with adult S. tessellatus; however, size differences be- 

 tween the two species in these collections are quite 

 striking. All S. tessellatus collected with S. oculellus 

 were large adults ( > 130 mm SL), while the S. oculellus 

 were a mixture of sizes, with juveniles as small as 78 

 and 82 mm SL. 



Remarks Not all specimens that are the basis of cita- 

 tions in the synonymies of S. plagusia and S. tessellatus 

 could be examined, so it is impossible to determine if 

 any specimens of S. oculellus were included among 

 material listed in earlier accounts on Symphurus from 

 northern South America. It is possible that specimens 

 of S. oculellus were included in the study by Lowe- 

 McConnell (1962), since some of the trawl stations in 

 that study were at appropriate depths to capture S. 

 oculellus. Lowe-McConnell listed all tonguefish cap- 

 tured as S. plagusia but did not include descriptive ac- 

 counts for the specimens, thus preventing positive 

 identification. 



The fish described by Puyo as S. atricaudus (Jordan 

 and Gilbert) is clearly S. oculellus. Symphurus oculel- 

 lus may be distinguished from the eastern Pacific S. 

 atricaudus by the following characters: dorsal fin rays 

 99-106 vs. 94-101 in S. atricaudus; anal fin rays 81-88 



vs. 77-84; scales 85-98 vs. 104-115. Additionally, S. 

 oculellus lacks a pupillary operculum and scales on the 

 blind-side posterior rays of the dorsal and anal fins 

 (both present in S. atricaudus). 



Comparisons Among Atlantic members of the S. pla- 

 gusia complex, S. oculellus most closely resembles and 

 is largely sympatric with S. tessellatus and S. plagusia. 

 Characteristics distinguishing S. oculellus from these 

 species were discussed in the "Comparisons" sections 

 under the accounts for S. plagusia and S. tessellatus, 

 respectively. Symphurus oculellus is most easily dis- 

 tinguished from the two remaining Atlantic species 

 belonging to this complex (S. civitatium and S. carib- 

 beanus) by differences in counts for dorsal fin rays 

 (99-106 vs. 96 or fewer in S. caribbeanus and S. civi- 

 tatium), anal fin rays (81-89 vs. 80 or fewer), and total 

 vertebrae (52-55 versus 51 or fewer in S. caribbeanus 

 and S. civitatium). 



Among other Atlantic Symphurus, some meristic 

 values of S. oculellus overlap those of three relatively 

 deep-water species: the eastern Atlantic S. vanmelleae 

 Chabanaud and S. ligulatus Cocco, and the western 

 Atlantic S. marginatum. Additionally, S. oculellus has 

 pigmented dorsal and anal fins reminiscent of those of 

 the sympatrically occurring S. diomedeanus. Compar- 

 able fin-ray or vertebral counts are the only similarities 

 between S. oculellus and the deep-water species. Sym- 

 phurus oculellus is otherwise distinctive from all three 

 species in ID pattern (1-4-3-2-2 vs. 1-2-2-1-2 in S. 

 vanmelleae, 1-2-2-2-2 in S. ligulatus, and 1-3-2-2-2 in 

 S. marginatum), peritoneal pigmentation (unpigmented 

 versus black in the others), and pigmentation of the 

 dorsal and anal fins (alternating series of blotches and 

 unpigmented areas in S. oculellus versus uniformly 

 pigmented fins in the other species). From S. diome- 

 deanus, S. oculellus differs in caudal-fin-ray count (12 

 vs. 10 in S. diomedeanus), and lacks a pupillary oper- 

 culum (present in S. diomedeanus). In S. oculellus, the 

 dorsal and anal fins have an alternating series of 

 somewhat rectangular-shaped, pigmented blotches and 

 unpigmented areas beginning in the mid-body region 

 and continuing posteriorly inclusive of the caudal fin, 

 whereas in S. diomedeanus the dorsal and anal fins 

 have fewer, nearly spherical spots only in the posterior- 

 most portions of these fins, and the caudal fin usually 

 lacks pigmented spots completely (only rare specimens 

 have a spot present on the caudal fin). 



There are seven eastern Pacific Symphurus with 

 similar ID patterns, comparable fin-ray counts, or pig- 

 ment patterns reminiscent of those observed in S. 

 oculellus. Of these seven species, only S. chabanaudi 

 and S. elongatus are similar to S. oculellus in lacking 

 a pupillary operculum. Many meristic features of S. 

 oculellus completely overlap those of the eastern Pacific 



