Fig. 2.

Effect of in vitro malathion exposure on motility rate (A–C) and duration (D–F) of male Nile tilapia (O. niloticus) semen fed control (○) or pollen (•) diet. Seminal fluid (2 μl) was diluted in distilled water (498 μl) contained malathion of selected concentration (1.00, 0.10 and 0.01 ppm). Initial motility (0 s.) and motility after 20 s. of exposure as well as the duration of motility (sec.) at 0, 30 and 60 s. were scored. Motility score was assessed as a percentage of the total number of spermatozoa following 10 s period of activation. Data were expressed as mean ± SE (n = 5) with different letters at the same time point were significantly different at P < 0.05 as compared with control.