| Main Ref. | Bragança, P.H.N., M.A. Barbosa and J.L. Mattos, 2013 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | |
| Body shape lateral | short and / or deep |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Type of scales | |
| Diagnosis |
Differs from its unique congener, Nematocharax costai, by having the following characters: presence of hooks or spinules on dorsal and pelvic-fins (vs. absence); more than seven anal-fin rays with spinules (vs. five rays); absence of a long dark pink horizontal mark on the caudal peduncle (vs. presence); four or fewer supraneurals (vs. five); pelvic-fin filament pale rosy (vs. yellow) (Ref. 93323). |
| 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 | first fin ray very elongated |
| Fins number | 1 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | |
| Adipose fin | present |
| Attributes | forked |
| Fins number | |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes more or less normal |
| Spines | |
| Soft-rays | |
| Pelvics | Attributes rays very elongated |
| Position abdominal before origin of D1 | |
| Spines | |
| Soft-rays |