Airbreathing Catfish

Airbreathing catfishes are fishes comprising the family Clariidae of order Siluriformes. There are about 14 genera and 100 species of clariids. All the clariids are freshwater species.

Although clariids occur in India, Syria, southern Turkey, and large parts of Southeast Asia, their diversity is the largest in Africa.

Clariid catfishes are characterized by an elongated body, the presence of four barbels, long dorsal and anal fins, and especially by the autapomorphic presence of a suprabranchial organ, formed by tree-like structures from the second and fourth gill arches. This suprabranchial organ, or labyrinth organ, allows some species the capability of traveling short distances on land (‘walking catfishes’).

The dorsal fin base is very long and is not preceded by a fin spine. The dorsal fin may or may not be continuous with the caudal fin, which is rounded. Pectoral and pelvic fins are variously absent in some species. Some fish have small eyes and reduced or absent pectoral and pelvic fins for a burrowing lifestyle. A few species are blind.

Within the Clariidae family, body forms range from fusiform (torpedo-like) to anguilliform (eel-like). As species become more eel-shaped, a whole set of morphological changes have been observed, such as decrease and loss of the adipose fin, continuous unpaired fins, reduction of paired fins, reduction of the eyes, reduction of the skull bones, and hypertrophied jaw muscles.