| Main Ref. | Malabarba, L.R., M.C. Malabarba and R.E. Reis, 2015 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | |
| Body shape lateral | |
| Cross section | compressed |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Type of scales | |
| Diagnosis |
This species is distinguished from its congeners, except G. gymnogenysgymnogenys by its more elongate body (body depth 34.9-38.3% SL, mean = 36.7 vs. 38.6-44.2 % SL, mean = 40.6 in gymnogenys specimens larger than 6.5 cm SL), and by the continuous iridescent olivaceous coloration of males (vs. clearly demarcated iridescent blue spots on the center of each scale) (Ref. 118066). |
| 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 | 6 - 7 |
| on upper limb | 4 - 5 |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | |
| Fins number | 1 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | 13 - 15 |
| Soft-rays total | 9 - 11 |
| Adipose fin |
| Attributes |
| Fins number | 1 |
| Spines total | 3 - 3 |
| Soft-rays total | 8 - 10 |
| Pectoral | Attributes |
| Spines | |
| Soft-rays | |
| Pelvics | Attributes |
| Position | |
| Spines | |
| Soft-rays |