| Main Ref. | Menezes, N.A. and A.C. Ribeiro, 2010 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks | Anal fin of sexually mature males with bilateral hooks on posterior edge of last unbranched ray and anterior and posterior branches of anterior 9 branched rays. Number of hooks increasing from anteriormost to about fifth ray and then decreasing towards ninth ray (Ref. 85166). |
| Striking features | |
| Body shape lateral | fusiform / normal |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Type of scales | |
| Diagnosis |
Can be diagnosed from all its known congeners, except Oligosarcus jenynsii, Oligosarcus perdido, Oligosarcus acutirostris, Oligosarcus solitarius and Oligosarcus hepsetus, by the number of perforated lateral line scales (55-65). Shares with the first two species the absence of a premaxillary foramen, present in the last three species and differs from Oligosarcus jenynsii by having a smaller orbital diameter and the tip of the pectoral fin failing to reach the pelvic-fin origin, and from Oligosarcus perdido by the presence of more horizontal scale rows around the caudal peduncle. Description: Dorsal-fin rays ii,9; anal-fin rays iv-v,22-28; pectoral-fin rays i, 13-16; pelvic-fin rays i, 7 (Ref. 85166). |
| Ease of Identification |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | |
| Pored lateral line scales | 55 - 65 |
| Scales in lateral series | |
| Scale rows above lateral line | 10 - 12 |
| Scale rows below lateral line | 8 - 10 |
| Scales around caudal peduncle | 21 - 25 |
| Barbels | |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | 22 - 25 |
| Vertebrae | |
| preanal | |
| total |
| Attributes | no striking attributes |
| Fins number | |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | 11 - 11 |
| Adipose fin | present |
| Attributes | forked |
| Fins number | |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes more or less normal |
| Spines | |
| Soft-rays 14 - 17 | |
| Pelvics | Attributes more or less normal |
| Position abdominal before origin of D1 | |
| Spines | |
| Soft-rays 8 - 8 |