Practical Manual B.Voc

Clarias batrachus

Phylum: Chordata

Class: Actinopterygii

Order: Siluriformes

Family: Clariidae

Genus: Clarias

Species: C. batrachus


1. The walking catfish (Clarias batrachus) is a species of freshwater air breathing catfish native to Southeast Asia, but alsointroduced outside its native range where it is considered an invasive species. It is named for its ability to "walk" across dry land, to find food or suitable environments. While it does not truly walk as most bipeds or quadrupeds do, it has the ability to use itspectoral fins to keep it upright as it makes a sort of wiggling motion with snakelike movements.[1] This fish normally lives in slow-moving and often stagnant waters in ponds, swamps, streams and rivers, flooded rice paddies or temporary pools which may dry up. When this happens, its "walking" skill allows the fish to move to other sources of water. Considerable taxonomicconfusion surrounds this species and it has frequently been confused with other close relatives.[2]





Heteropneustes fossilis

Phylum: Chordata

Class: Actinopterygii

Order: Siluriformes

Family: Heteropneustidae

Genus: Heteropneustes

Species: H. fossilis




Inhabits freshwater, rarely brackish waters. This is primarily a fish of ponds, ditches, bheels, swamps and marshes, but it is sometimes found in muddy rivers. It is able to tolerate slightly brackish water. Its air-breathing apparatus enables it to exist in almost any kind of water. Generally, during the dry season singi lives in semiliquid and semi-dry mud, and even when the mud dries up they take their bodies to the bottom of fissures and crevices formed by the cracking mud. Fertilised eggs are adhesive, demersal and spherical in form.


Chanos chanos
Phylum: Chordata

Subphylum: Vertebrata

Order: Gonorynchiformes

Family: Chanidae
Genus: Chanos

Body fusiform, elongated, moderately compressed, smooth and streamlined. Body colour silvery on belly and sides grading to olive-green or blue on back. Dorsal, anal and caudal fins pale or yellowish with dark margins. Single dorsal fin with 2 spines and 13-17 soft rays. Short anal fin with 2 spines and 8-10 soft rays, close to caudal fin. Caudal fin large and deeply forked with large scale flaps at base in adults. Pectoral fins low on body with axillary (inner basal) scales. Pelvic fins abdominal with axillary scales and 11 or 12 rays. Scales cycloid, small and smooth, 75-91 on lateral line. No scutes (modified pointed scales) along belly. Transparent 'adipose' tissue covers eye. Mouth small and terminal without teeth. Lower jaw with small tubercle at tip, fitting into notch in upper jaw. No bony gular plate between arms of lower jaw. Four branchiostegal rays supporting underside of gill covers. Gill rakers fine and numerous. Attains typical length of 1 m but may reach maximum length of 1.8 m (male).