| Main Ref. | Iwamoto, T. and A. Williams, 1999 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | no special organs |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | long whip-like tail |
| Body shape lateral (shape guide) | elongated |
| Cross section | compressed |
| Dorsal head profile | more or less straight |
| Type of eyes | more or less normal |
| Type of mouth/snout | other (see diagnosis) |
| Position of mouth | sub-terminal/inferior |
| Type of scales | ctenoid scales |
| Diagnosis |
Pelvic fin rays 11-12; height first dorsal fin about equal to or more than head length; underside of head scaled, but lacking prominent pores of sensory lateralis system; body scales with dense covering of broadly shield-shaped spinules; 5.5-7.5 scale rows below origin of second dorsal fin, 36-42 lateral line scales over distance equal to predorsal length; trunk completely encircled by broad dark band, although sometimes rather faint; first dorsal fin uniformly blackish; anterior dermal window of light organ scarcely developed, usually apparent only as triangular anterior protrusion of naked periproct, situated behind line connecting insertions of pelvic fins; orbit to preopercle distance 38-44% of head length; upper jaw 29-34%; gill rakers on inner side of first arch 9-10. Snout protruding, angular. |
| 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 |
| Attributes | |
| Fins number | 2 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | 2 - 2 |
| Soft-rays total | |
| Adipose fin | absent |
| Attributes | pointed; confluent |
| Fins number | 1 |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes more or less normal |
| Spines 0 | |
| Soft-rays 18 - 23 | |
| Pelvics | Attributes more or less normal |
| Position thoracic before origin of D1 | |
| Spines 0 | |
| Soft-rays 11 - 12 |