| Main Ref. | Eccles, D.H., 1992 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | none |
| Body shape lateral | eel-like |
| Cross section | circular |
| 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 | terminal |
| Diagnosis |
Dorsal fin origin is about midway between pectoral fin and anus. Caudal fin confluent with dorsal and anal fin. Body is mottled with dark brown pigmentation. |
| Ease of Identification |
| Lateral Lines | 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 | 0 |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | continuous with caudal fin |
| Fins number | 1 |
| Finlets No. | Dorsal 0 - 0 |
| Ventral 0 - 0 | |
| Spines total | 0 - 0 |
| Soft-rays total | |
| Adipose fin | absent |
| Attributes | other (see diagnosis) |
| Fins number | 1 |
| Spines total | 0 - 0 |
| Soft-rays total |
| Pectoral | Attributes more or less normal |
| Spines | |
| Soft-rays | |
| Pelvics | Attributes suppressed/absent |
| Position | |
| Spines | |
| Soft-rays |