| Main Ref. | Poutiers, J.M., 1998 |
| Appearance refers to |
| specialized organs | |
| different appearance | |
| different colors | |
| remarks |
| Striking features | |
| Body shape lateral | |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Diagnosis | Shell rather thick and large (attaining 25 cm in length), subcircular in outline, with a short and ill-defined posterior ear which is not drawn out into a wing-like process. Anterior margin markedly protruding beyond the tip of anterior ear. Outer surface of valves, when not worn, with densely set, flattened, imbricating concentric scales and moderately long, parallel-sided and flattened spines with tapering or rounded ends; spines lying relatively flat on surface of valves, arranged in radial rows and often strongly projecting on shell margins. hinge completely devoid of teeth. Colour: outside of shell greyish brown or green to nearly black in ground colour, with radial stripes of white or yellowish markings corresponding to the basal portion of old flattened spines. Internal nacreous area silvery, with a darker smoky hue and a hint of red and green iridescence on border. Non-nacreous area very dark. |
| 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 | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | |
| Fins number | |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | |
| Adipose fin |
| Attributes |
| Fins number | |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes |
| spines | |
| soft-rays | |
| Pelvics | Attributes |
| Position | |
| spines | |
| soft-rays |