| Main Ref. | Iwamoto, T. and A. Williams, 1999 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized 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 10-11; first dorsal fin with 10 or 11 segmented rays (rarely 12); underside of snout with broad naked median swath, pores of lateralis system small, inconspicuous; body scales covered with narrow, lanceolate spinules in slightly convergent rows; 7-9.5 scale rows below origin of second dorsal fin, 36-41 lateral line scales over distance equal to predorsal length; trunk lacking prominent broad dark girdle; first dorsal fin all black; anterior dermal window of light organ more or less on transverse line connecting pelvic fin insertions; upper jaws 29-33% of HL; orbit to preopercular distance 33-38% of HL; inner gill rakers on first arch 10-13. |
| 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 | |
| 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 |
| Attributes | pointed; confluent |
| Fins number | 1 |
| Spines total | 0 - 0 |
| Soft-rays total |
| Pectoral | Attributes more or less normal |
| Spines 0 | |
| Soft-rays 18 - 22 | |
| Pelvics | Attributes more or less normal |
| Position thoracic before origin of D1 | |
| Spines 0 | |
| Soft-rays 10 - 11 |