| Main Ref. | Costa, W.J.E.M. and A.C. De Luca, 2010 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | |
| Body shape lateral | elongated |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Type of scales | cycloid scales |
| Diagnosis |
Can be diagnosed from all congeners, except Rivulus igneus, by the presence of a dark greenish blue blotch on the upper portion of the opercle, and lower jaw, distal portion of anal fin and lower portion of caudal fin orange in males. Differs from Rivulus igneus by having fewer scales in the longitudinal and transverse series and by the presence of a black round spot on the upper portion of the caudal-fin base in females (Ref. 86530). |
| 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 | 16 - 16 |
| Barbels | |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | |
| Fins number | 1 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | 10 - 11 |
| Adipose fin | absent |
| Attributes | more or less truncate |
| Fins number | |
| Spines total | |
| Soft-rays total | 16 - 17 |
| Pectoral | Attributes more or less normal |
| Spines | |
| Soft-rays 16 - 16 | |
| Pelvics | Attributes |
| Position abdominal before origin of D1 | |
| Spines | |
| Soft-rays 7 - 8 |