| Main Ref. | Winterbottom, R., 1985 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | |
| Body shape lateral | eel-like |
| Cross section | circular |
| Dorsal head profile | |
| Type of eyes | more or less normal |
| Type of mouth/snout | more or less normal |
| Position of mouth | terminal |
| Type of scales | |
| Diagnosis |
Dorsal lateral line (LL) unbranched; ventral LL consists of a single section on each side of the abdomen; LL pores opening from middle of posterior margins of LL scales. Operculum with scales. A dark spot above the pectoral fin. |
| Ease of Identification |
| Lateral Lines | 3 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 | 7 - 8 |
| on upper limb | 1 - 2 |
| total | |
| Vertebrae | |
| preanal | |
| total | 64 - 68 |
| Attributes | continuous with caudal fin |
| Fins number | 2 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | 1 - 1 |
| Soft-rays total | 58 - 64 |
| Adipose fin | absent |
| Attributes | more or less truncate; confluent |
| Fins number | 1 |
| Spines total | 0 - 0 |
| Soft-rays total | 45 - 50 |
| Pectoral | Attributes more or less normal |
| Spines 0 | |
| Soft-rays 7 - 9 | |
| Pelvics | Attributes suppressed/absent |
| Position | |
| Spines 0 | |
| Soft-rays 0 - 0 |