| Main Ref. | Nakamura, I. and N.V. Parin, 1993 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | striking shape of body |
| Body shape lateral | elongated |
| Cross section | compressed |
| Dorsal head profile | clearly convex |
| Type of eyes | more or less normal |
| Type of mouth/snout | more or less normal |
| Position of mouth | terminal |
| Type of scales | |
| Diagnosis |
Body greatly elongated and compressed. Mouth large with fang-like teeth. Tips of both jaws with dermal processes. Color is blackish brown; dorsal and anal fins pale brown; buccal and branchial cavities and peritoneum black. |
| Ease of Identification |
| Lateral Lines | 1 Interrupted: No |
| Scales on lateral line | |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | |
| Scale rows below lateral line | |
| Scales around caudal peduncle | |
| Barbels | |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total | 36 - 38 |
| Attributes | extending over most of the back length |
| Fins number | 2 |
| Finlets No. | Dorsal 2 - 2 |
| Ventral 2 - 2 | |
| Spines total | 20 - 21 |
| Soft-rays total | 16 - 19 |
| Adipose fin | absent |
| Attributes | forked; more or less normal |
| Fins number | 1 |
| Spines total | 1 - 1 |
| Soft-rays total | 15 - 19 |
| Pectoral | Attributes more or less normal |
| Spines 0 | |
| Soft-rays 13 - 14 | |
| Pelvics | Attributes joint to one spine only |
| Position thoracic behind origin of D1 | |
| Spines 1 | |
| Soft-rays 0 - 0 |