The breeding biology of Clarias albopunctatus Nichols & LaMonte, 1953 in semi-intensively managed ponds in the floodplain of the River Anambra, Nigeria

Abstract— In ponds in the floodplain of the River Anambra, Nigeria, Clarias albopunctatus matured after the first year when they were 101–150 mm in total length. Gonad development was more rapid in males than in females. The breeding season lasted from March to September, and recruitment of the clariids into the artisanal fishery began from the latter month. The number of oocytes in both ovaries ranged from 1974 to 9310. Fecundity-weight relationship was linear and positively correlated: Y = 1451.64+ 77.19 x , r ²= 0.82. Spawnable oocytes, which constituted over 91% of gonad weight, ranged from 1.05 to 1.75 mm in diameter. A minor and major communal spawning involving Clarias macromystax, C. agboyiensis and C. albopunctatus took place in the inundated grassy areas of the floodplain. Migration of 4-month-old juveniles towards the main river or floodplain ponds, which appeared to be triggered by current speed in the spawning ground, occurred during the night and in groups.