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Fishery Bulletin 89(2). 1991 



Symphurus oculellus, new species 

 Figures 2, 4d, 5, 6b-c 



Synonymy 



Symphurus atricaudus (not of Jordan and Gilbert 1880). 

 Puyo 1949:179 (French Guyana; counts, color descrip- 

 tion, poor figure; distinguished from S. plagusia). 



Diagnosis A Symphurus characterized by the follow- 

 ing combination of characters: predominant 1-4-3 ID 

 pattern; 12 caudal fin rays; unpigmented peritoneum; 

 lacking small ctenoid scales on the blind sides of the 

 dorsal and anal fin rays; prominent fleshy ridge on 

 ocular-side lower jaw; no pupillary operculum; 99-106 

 dorsal fin rays; 81-88, usually 83-88, anal fin rays; 

 52-55, usually 53-54, total vertebrae; 85-98, usually 

 86-93, scales in longitudinal series; relatively long jaws 

 with posterior extension of maxilla usually reaching to 

 the vertical through posterior margin of pupil of lower 

 eye, occasionally extending to or slightly beyond the 

 vertical through posterior margin of lower eye; rela- 

 tively small eye (68-104 HL, x 84); dorsal fin origin 

 usually at or occasionally slightly anterior to the ver- 

 tical line through the anterior margin of upper eye; 

 ocular surface dark- to light-brown with 10-14 well- 

 developed, sharply contrasting, somewhat narrow, 

 dark-brown crossbands on head and trunk; outer sur- 

 face of ocular-side opercle with dark melanophores in 

 diffuse circular pattern or with melanophores coalesced 

 into somewhat rounded pigment spot; inner lining of 

 opercle and isthmus more heavily pigmented on ocular 

 surface than blind side; and dorsal, anal, and caudal 

 fins with an alternating series of pigmented blotches 

 and unpigmented areas. 



Description Symphurus oculellus is a relatively large 

 tonguefish attaining maximum lengths of approximate- 

 ly 189mm SL. ID pattern usually 1-4-3 (33/38), infre- 

 quently 1-3-4 (2), 1-5-3 (1), 1-4-2 (1), or 1-3-3 (1) (Table 

 1). Caudal fin rays 12 (49/53 specimens), less frequently 

 11 (Table 2). Dorsal fin rays 99-106 (Table 3). Anal fin 

 rays 81-88, usually 83-88 (Table 4). Total vertebrae 

 52-55, usually 53-54 (34/37) (Table 5); abdominal 

 vertebrae 3 + 6. Hypurals 4. Longitudinal scale rows 

 85-98, usually 86-93 (Table 6). Scale rows on head 

 posterior to lower orbit 19-23, usually 19-20 (Table 7). 

 Transverse scales 36-42, usually 38-40 (Table 8). 



Proportional measurements appear in Tables 16 and 

 17. Body relatively elongate with gradual taper pos- 

 teriorly; body depth relatively narrow (231-297 SL, 

 x 274), and nearly uniform from vertical through anal 

 fin rays 10-15 and extending posteriorly^ mid-point 

 of body. Preanal length 189-243 SL, x 206; some- 

 what shorter than body depth. Head relatively short 

 (168-218 SL, x 182), shorter than body depth. Head 



Table 16 



Summary of morphometries expressed in thousandths of stan- 

 dard length (except SL in mm) for the holotype (USNM 

 159606) and 13 paratypes of Symphurus oculellus. (Abbrevia- 

 tions defined in Methods section.) 



relatively wide (198-281 SL, x 217); usually greater 

 than head length (HW/HL 1.1-1.5, x 1.2); lower head 

 lobe (79-111 SL, as 93) considerably narrower than 

 upper head lobe (126-151 SL, x 139). Lower opercu- 

 lar lobe of ocular side (264-341 HL, x_292) wider than 

 upper opercular lobe (174-246 HL, x 211). Postorbi- 

 tal length 112-153 SL, x 125. Snout (Fig. 4d) moder- 

 ately long (190-227 HL, x 209), slightly rounded or 

 truncate, covered with small ctenoid scales. Anterior 

 nostril not reaching anterior margin of lower eye when 

 depressed posteriorly. Dermal papillae well developed 

 on blind-side snout and chin regions, but not particular- 

 ly dense, occasionally extending onto ocular-side snout. 

 Jaws relatively long; upper jaw length 221-258 HL, 

 x 238; posterior extension of maxilla usually reaching 

 to vertical through posterior margin of pupil of lower 

 eye, occasionally to or slightly beyond vertical through 

 posterior margin of lower eye. Ocular-side lower jaw 

 with distinct, fleshy ridge nearposterior margin (Fig. 

 4d). Chin depth 214-291 HL, x 248. Lower eye rela- 

 tively small (68-104 HL, x 84); upper eye usually 

 slightly anterior to lower eye; eyes not covered with 

 scales; usually only 1-3 small, ctenoid scales in narrow 

 interorbital space. Interorbital space sometimes equal- 

 ing half the diameter of the lower eye. Pupillary oper- 

 culum absent. Length of dorsal fin base 953-968 SL, 

 x 961. Dorsal fin origin (Fig. 4d) usually at, or occa- 

 sionally slightly anterior to, vertical line through an- 



