| Main Ref. | Last, P.R., 1997 |
| Appearance refers to | |
| Bones in OsteoBase |
| Specialized organs | |
| Different appearance | |
| Different colors | |
| Remarks |
| Striking features | none |
| Body shape lateral | short and / or deep |
| 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 |
Body firm, very deep, oval, and compressed. Operculum absent; gill opening reduced to a vertical slit on the side of the body; gill membrane broadly united to isthmus. Dorsal and anal fins preceded by a series of 5 to 10 blade-like spines with anterior and posterior points. Pelvic fins absent. Caudal fin deeply forked, the lower lobe longer than the upper. Color is gray above grading to silvery white towards the belly, with small black dots all over the body. Fins are faintly yellow; vertical fins with dark edges. |
| Ease of Identification |
| 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 | 0 |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total | 34 - 37 |
| Attributes | other |
| Fins number | 1 |
| Finlets No. | Dorsal 0 - 0 |
| Ventral 0 - 0 | |
| Spines total | 0 - 0 |
| Soft-rays total | 37 - 43 |
| Adipose fin | absent |
| Attributes | forked; asymmetric |
| Fins number | 1 |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes more or less normal |
| Spines 0 | |
| Soft-rays 24 - 27 | |
| Pelvics | Attributes suppressed/absent |
| Position absent | |
| Spines | |
| Soft-rays |