| Main Ref. | Bertaco, V.A. and L.R. Malabarba, 2010 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks | Male easily recognized by the presence of bony hooks on the anal- and pelvic-fin rays; no gill gland was observed on first gill arch (Ref. 85819). |
| Striking features | |
| Body shape lateral | elongated |
| Cross section | compressed |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Type of scales | cycloid scales |
| Diagnosis |
This species is readily distinguished from its congeners, except H. beni, by the number of branched anal-fin rays (17 vs. 18-34). It differs from H. beni by the number of lateral line scales (39 vs. 44-53), and by the number of scale rows above and below lateral line (6 and 5 vs. 7-8 and 6-8, respectively); from H. helleri and H. mikrostiktos which have lower branched anal-fin rays (19-23 and 18-21), H. tridens differs by the number of lateral line scales (39 vs. 40-42 and 42-45, respectively) (Ref. 85819). |
| Ease of Identification |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | 39 - 39 |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | 6 - 6 |
| Scale rows below lateral line | |
| Scales around caudal peduncle | 14 - 14 |
| Barbels | |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | 10 - 10 |
| on upper limb | 5 - 5 |
| total | |
| Vertebrae | |
| preanal | 18 - 18 |
| total | 40 - 40 |
| Attributes | |
| Fins number | |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | 8 - 8 |
| Adipose fin |
| Attributes |
| Fins number | |
| Spines total | |
| Soft-rays total | 7 - 7 |
| Pectoral | Attributes |
| Spines | |
| Soft-rays 10 - 10 | |
| Pelvics | Attributes |
| Position | |
| Spines | |
| Soft-rays 6 - 6 |