| Main Ref. | Bigorne, R., 1990 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | no special organs |
| Different appearance | males alike females |
| Different colors | males alike females |
| Remarks | Base of anal fin rays in adult males greatly expanded with thin sheets of bone (Ref. 27585). |
| Striking features | none |
| Body shape lateral | fusiform / normal |
| Cross section | compressed |
| Dorsal head profile | more or less straight |
| Type of eyes | more or less normal |
| Type of mouth/snout | more or less normal |
| Position of mouth | sub-terminal/inferior |
| Type of scales | cycloid scales |
| Diagnosis |
Dorsal base 0.41-0.68 x anal fin base. Pectorals as long as head, posterior end does not extend origin of pelvic fins. Caudal peduncle thin, height 14.4-22.9x of SL. Dark grey-black or brown coloration. |
| Ease of Identification |
| Lateral Lines | 1 Interrupted: No |
| Scales on lateral line | 53 - 66 |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | |
| Scale rows below lateral line | |
| Scales around caudal peduncle | |
| Barbels | 0 |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | no striking attributes |
| Fins number | 1 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | 0 - 0 |
| Soft-rays total | 14 - 19 |
| Adipose fin | absent |
| Attributes | forked; more or less normal |
| Fins number | 1 |
| Spines total | 0 - 0 |
| Soft-rays total | 25 - 31 |
| Pectoral | Attributes more or less normal |
| Spines | |
| Soft-rays | |
| Pelvics | Attributes more or less normal |
| Position abdominal before origin of D1 | |
| Spines | |
| Soft-rays |