| Main Ref. | Winterbottom, R., 1985 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | |
| Body shape lateral (shape guide) | 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 |
| Type of scales | |
| Diagnosis |
Shoulder without the ocellated spot. Anterior interorbital pore absent. Preopercular canal with 6 pores. No scales on cheeks, opercles and nape. Gill membranes fused ventrally and free from isthmus. |
| Ease of Identification |
| Lateral Lines | 1 Interrupted: No |
| Scales on lateral line | 7 - 22 |
| 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 | |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | 45 - 50 |
| Adipose fin | absent |
| Attributes | more or less truncate; more or less normal |
| Fins number | 1 |
| Spines total | 0 - 0 |
| Soft-rays total | 36 - 40 |
| Pectoral | Attributes more or less normal |
| Spines | |
| Soft-rays 8 - 10 | |
| Pelvics | Attributes suppressed/absent |
| Position | |
| Spines | |
| Soft-rays |