| Main Ref. | Kottelat, M. and J. Freyhof, 2007 |
| Appearance refers to | Male; Female |
| Bones in OsteoBase |
| Specialized organs | no special organs |
| Different appearance | males alike females |
| Different colors | males alike females |
| Remarks |
| Striking features | striking type of mouth |
| Body shape lateral | eel-like |
| Cross section | circular |
| Dorsal head profile | |
| Type of eyes | more or less normal |
| Type of mouth/snout | sucker-like |
| Position of mouth | sub-terminal/inferior |
| Type of scales | |
| Diagnosis |
With 58-65 trunk myomeres. The trunk is mottled in ammocoetes. The caudal fin is of spade-like shape and grey to black. The exolateral teeth are villiform, very small, weakly developed and frequently absent. |
| Ease of Identification | likely to be confused with closely related species. |
| 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 | no striking attributes |
| Fins number | 2 |
| Finlets No. | Dorsal 0 - 0 |
| Ventral 0 - 0 | |
| Spines total | 0 - 0 |
| Soft-rays total | 0 - 0 |
| Adipose fin | absent |
| Attributes | pointed; more or less normal |
| Fins number | |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes absent |
| Spines | |
| Soft-rays | |
| Pelvics | Attributes suppressed/absent |
| Position | |
| Spines | |
| Soft-rays |