| 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 | eel-like |
| 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 | superior |
| Type of scales | scales embedded or partly/completely absent |
| Diagnosis |
Body extremely elongate and compressed. Pelvic fins diminutive, composed of a scale-like spine and a rudimentary soft ray. Body is silvery, jaws and opercle blackish. Inside of mouth and gill cavities 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 | 0 |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total | 133 - 142 |
| Attributes | extending over most of the back length |
| Fins number | 1notched No |
| Finlets No. | Dorsal 0 - 0 |
| Ventral 0 - 0 | |
| Spines total | 39 - 44 |
| Soft-rays total | 88 - 96 |
| Adipose fin | absent |
| Attributes | more or less truncate; more or less normal |
| Fins number | 1 |
| Spines total | 2 - 2 |
| Soft-rays total | 76 - 83 |
| Pectoral | Attributes more or less normal |
| Spines | |
| Soft-rays | |
| Pelvics | Attributes other (see diagnosis) |
| Position thoracic behind origin of D1 | |
| Spines 1 | |
| Soft-rays 1 - 1 |