| Main Ref. | Whitehead, P.J.P., G.J. Nelson and T. Wongratana, 1988 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | no special organs |
| Different appearance | males alike females |
| Different colors | males alike females |
| Remarks |
| Striking features | none |
| Body shape lateral | elongated |
| 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 | terminal |
| Type of scales | cycloid scales |
| Diagnosis |
Belly with 5 or 6 pre-pectoral needle-like scutes, none behind, and a series of membrane-like post -pelvic scutes more or less concealed by the scales. Maxilla short, tip blunt; first supra-maxilla large, elongate, more than twice length of second. Pectoral fins wing-like; pelvic fins small; dorsal fin minute, the second unbranched fin ray elongated. A distinct dark blotch behind gill opening. |
| Ease of Identification |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | 50 - 51 |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | 0 - 0 |
| Scale rows below lateral line | 0 - 0 |
| Scales around caudal peduncle | |
| Barbels | 0 |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | 25 - 27 |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | greatly reduced or absent |
| Fins number | 1 |
| Finlets No. | Dorsal 0 - 0 |
| Ventral 0 - 0 | |
| Spines total | 0 - 0 |
| Soft-rays total | 3 - 4 |
| Adipose fin | absent |
| Attributes | forked; more or less normal |
| Fins number | 1 |
| Spines total | 0 - 0 |
| Soft-rays total | 51 - 57 |
| Pectoral | Attributes more or less normal |
| Spines 0 | |
| Soft-rays | |
| Pelvics | Attributes more or less normal |
| Position abdominal before origin of D1 | |
| Spines 0 | |
| Soft-rays 7 - 7 |