| Main Ref. | Collette, B.B., 1999 |
| Appearance refers to | Male; Female |
| Bones in OsteoBase | Skull, Spine |
| Specialized organs | no special organs |
| Different appearance | always different morphology between mature adults |
| Different colors | males alike females |
| Remarks | Larger males with the head profile vertical with development of a bony crest. |
| Striking features | striking shape of body |
| Body shape lateral (shape guide) | elongated |
| Cross section | compressed |
| Dorsal head profile | clearly convex |
| Type of eyes | more or less normal |
| Type of mouth/snout | more or less normal |
| Position of mouth | terminal |
| Type of scales | cycloid scales |
| Diagnosis |
This species is distinguished by having the following characters: mature males with prominent bony crest in front of the head; greatest body depth in adults less than 25% of standard length; tooth patch on tongue small and oval; single dorsal fin extending from above eye almost to caudal fin with 58-66 rays; a concave anal fin extending from anus almost to caudal fin; pectoral fin more than half of head length; lateral-line scales at least 200 (Ref. 9648). Colour of body metallic blue-green on the back (fading to grey with green tinge when dead), sides silver with golden sheen, and 1 row of dark spots or golden blotches running below dorsal fin and 1, 2, or more rows on and below lateral line, some scattered irregularly; dorsal and anal fins black, the latter with a white edge; pectoral fins pale; caudal fin silvery with a golden sheen; in juveniles, only tips of caudal-fin lobes white, pelvic fins black (Ref. 9648). |
| Ease of Identification |
| Lateral Lines | 1 Interrupted: No |
| Scales on lateral line | 200 |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | |
| Scale rows below lateral line | |
| Scales around caudal peduncle | |
| Barbels | 0 |
| Gill clefts (sharks/rays only) | absent |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | 13 - 14 |
| total | 31 - 31 |
| Attributes | extending over most of the back length |
| Fins number | 1 |
| Finlets No. | Dorsal 0 - 0 |
| Ventral 0 - 0 | |
| Spines total | 0 - 0 |
| Soft-rays total | 58 - 66 |
| Adipose fin | absent |
| Attributes | forked; more or less normal |
| Fins number | 1 |
| Spines total | 0 - 0 |
| Soft-rays total | 25 - 31 |
| Pectoral | Attributes more or less normal |
| Spines 0 | |
| Soft-rays | |
| Pelvics | Attributes more or less normal |
| Position thoracic behind origin of D1 | |
| Spines 0 | |
| Soft-rays |