Inimicus didactylus (Pallas, 1769)

Maximum Body Length

Adult Inimicus didactylus can reach a maximum body length of 26 centimeters.

Body Coloration

Their body is red or sandy yellow with light blotches, a coloration that closely matches the surrounding sandy or coral seabed they inhabit.

Camouflage Effect

This camouflage makes them extremely difficult to detect in their natural habitat.

Skin Characteristics

Their skin lacks scales except along the lateral line, and is covered in venomous spines and wart-like glands that give it a knobby texture.

Head Morphology

The head is flattened, depressed, and concave; the eyes, mouth, and nostrils project upwards and outwards from the dorsal side of the head.

Sexual Dimorphism Status

Scientists do not believe this species exhibits sexual dimorphism.

Dorsal Fin Structure

For fin morphology: the dorsal fin consists of 15 to 17 spines and 7 to 9 soft rays.

Caudal Fin Structure

The caudal fin has 2 to 4 spines and 4 to 14 soft rays, with dark bands at its basal and subterminal positions.

Pelvic Fin Structure

The pelvic fin has one spine and 3 to 5 soft rays.

Pectoral Fin Ray Trait

The pectoral fin contains 10 to 12 rays; the two most caudal rays on each pectoral fin are detached from the rest of the fin and angled ventrally.

Detached Pectoral Ray Function

The fish use these two rays to prop up the front of their body and to "walk" along the substrate bottom.

Pectoral Fin Ventral Pattern

The ventral surface of the pectoral fins has broad black bands with smaller, lighter spots at both the basal and distal ends.

Inimicus Congener Band Variation

In the closely related species I. filamentosus, these bands are weaker, while I. sinensis has yellow spots within these bands.

Species Distinguishing Trait

This trait is a key distinguishing feature between these otherwise nearly identical species.