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The effects of short term exposure to cyperdicot on behavioural and haematological responses in 300 Clarias gariepinu swere investigated. The fish were randomly divided into three groups of 30 fish. Fish in first treatment group were exposed to tap water and served as control, while those in second and third groups were treated with 0.04 and 0.08 mg l-1 of Cyperdicot, respectively. The 24, 48, 72 and 96 h LC 50 values were1.462, 1.094, 1.030 and 0.800 mg l-1 , respectively. The safe level for the insecticide varied from 8 x 10 -3 to 8 x 10 -4 mg l-1 . Fish exposed to sub-lethal concentrations of insecticide exhibited alterations in various blood parameters including significant reductions in RBC count, Hb and PCV. A cyperdicot-induced dose-and time-dependent significant increase in W B C count from day 10 onward was observed, while values of blood indices such as MCV, MCH and MCHC in treated fish were not significantly different from those of the control group (P>0.05). This study revealed that the short term exposure to cyperdicot on behavioural and haematological responses in Clarias gariepinus elicited reduction of RBC, Hb and PCV values while MCV and MCH caused both macrocytic and microcytic anemia in the fish.

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Fecundity and condition factor of Clarias angullaris were studied in Oguta Lake for eight weeks. Forty species of C. anguillaris were studied. The length-weight relationship, fecundity, condition factor and gonad-osomatic indices were factors employed for assessment of health status of the fish. The mean length and weight of the C. anguillaris collected were 27.46 ± 1.47 (12.00-38.50) cm and 391.26 ± 17.92 (144.60-553.40) g respectively. Some of the morphometrics manifested linkage and C. anguillaris exhibited a coefficient of determination (R2) of 0.008, and Pearson's correlation coefficient (r) of -0.091. Fecundity-weight relationship of C. anguillaris was also not significant (p=0.062) with a Pearson's correlation coefficient (r) of -0.357 and coefficient of determination (R 2 )=0.127. The variations in condition factor of C. anguliaris at Oguta Lake was 19.96% (R 2 =0.1996) and this was explained by the variations in GSI. Clarias anguillaris from the Oguta Lake showed negative allometric growth pattern which implied that the fish species is increasing in length faster than its weight. This could be as a result of the polluted nature of the Lake, shortage of food supply, diseases which might have altered the fish speciation.