Clarias ngamensis

Clarias ngamensis, a clariid catfish
found in Lake Malawi; illustration from Jubb (1967), used by permission
of A. A. Balkema Publishers
The "Blunttooth catfish" (Clarias ngamensis, of which Clarias mellandi is a junior synonym) is a nonendemic clariid found in southern Africa from the Cunene River on the Atlantic coast to the Lower Zambezi on the Indian Ocean. It is also reported from Lake Malawi (FishBase; Eccles, 1992). In parts of its range, C. ngamensis can attain a total length of 73 cm (28¾ inches) and may weigh 4 kg (8.8 pounds).

Its diet consists of mollusks, crustaceans, insects, and fish, which it finds in its preferred habitats of swamps and riverine floodplains. Hard foods are broken by the wide, almost semicircular patch of blunt, granular teeth behind the upper jaw on the vomer, a median skull bone. According to Skelton (1993), breeding occurs "...during the summer rainy season, large numbers of fishes moving into shallow flooded drainage channels to spawn. Males show a higher growth rate than females and maturity is reached at about 250 mm TL. Lives for 5 or 6 years."

Clarias ngamensis is easily distinguished from C. gariepinus and C. theodorae, the other nonendemic clariids found in Lake Malawi, by the presence of a short, low, adipose dorsal fin between the rayed dorsal fin and the tail (see illustration above).

The above illustration by Hilda M. Jubb, from Jubb (1967), is reproduced here through the kind permission of Mr. A. T. Balkema of A. A. Balkema Publishers, Rotterdam.

The Cichlid Fishes of Lake Malawi, Africa: MalawiCichlids.com