Fig. 1.

Semen characteristics in male Nile tilapia (O. niloticus) after exposure to 1 mg/l (1 ppm) of malathion for 10 days. T1 (□) was negative control (unexposed, fed basal diet). T3 ($■$) was positive control (exposed, fed basal diet). T4 ($■$) and T5 ($■$) were pollen fed, but the later was returned to diet during toxin treatment. Values (mean ± SE; n = 5 per group) with different letters were significantly different at P < 0.05.