| Main Ref. | Lima, F.C.T., C. Silva-Oliveira, C. Oliveira and T.C. Faria, 2025 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | always different morphology between mature adults |
| Different colors | |
| Remarks | Mature males present small bony hooks restricted to the pelvic fins. Pelvic-fin hooks are present on the unbranched ray, plus anteriormost 3?4 branched rays, in both anterior and posterior branches, with 2?4 hooks per ray segment. Specimens presenting pelvic-fin bony hooks ranged from 2.41 to 2.94 cm SL. Females lack fin hooks and reach considerably larger sizes, while 30 females with ripe gonads ranged from 2.97 to 3.62 cm SL. |
| Striking features | |
| Body shape lateral (shape guide) | |
| Cross section | oval |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Type of scales | cycloid scales |
| Diagnosis |
This species is distinguish the species from its congeners and Hemigrammus species by the following characters (see the original description where the long diagnosis looks more as an identification key): humeral blotch very conspicuous, well-defined, and elongated with a shorter and posterior backward extension; longer anal fin, with a higher number of branched anal-fin rays (17?21 vs. 11?14); caudal peduncle blotch large, symmetric, extending into the basis of the middle caudal fin rays; etc. Other distinguishing characters are listed species by species (Ref. 132985). |
| Ease of Identification | difficult to identify using external characters only. |
| Lateral Lines | 1 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 | 1 |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | 2 - 2 |
| Soft-rays total | 9 - 10 |
| Adipose fin | present |
| Attributes | forked; more or less normal |
| Fins number | 1 |
| Spines total | 4 - 4 |
| Soft-rays total | 17 - 21 |
| Pectoral | Attributes more or less normal |
| Spines 1 | |
| Soft-rays 10 - 11 | |
| Pelvics | Attributes more or less normal |
| Position abdominal | |
| Spines 1 | |
| Soft-rays 6 - 7 |