A feeding trial was conducted to evaluate the effect of inclusion of different levels of shrimp meal with fish meal on growth, feed utilization, water quality and cost implication of the diet O. niloticus fingerlings. A total of two hundred and four (204) fish with an initial weight of 2.93+ 0.55g were stocked in twelve (12) tanks of dimension 1.8 x 1.3 x 0.36m3 for 12 weeks. Four diets (D1, D2, D3 and D4) contained 100% SM, 70% SM and 30% FM, 50% SM and 50% FM, 30% SM and 70% FM respectively, were fed twice daily to satiation. Final weight gain was 4.65±1.72g, 3.89±0.96g, 3.58±0.65g, 3.73±0.80g for the treatments respectively. The highest mean weight gain (4.98±0.31g) and specific (4.57±0.69%) growth rates were in fish fed with 100% SM (D1) and lowest (3.59±0.15g, 17.7±0.17% respectively) in fish fed 50% SM and 50% FM (D3). Protein efficiency ratio was highest in D1 and lowest in D4. Feed conversion ratio was lowest in diet D1 and highest in D4. Survival rate was good in all the treatments having the highest in D2 and lowest in D1. Diet 1 had the best growth followed by D2, D4 and D3 respectively. Cost implication and water quality parameters showed no significant differences (p>0.05) among the diets. Results showed that SM could replace FM by 100% without having any negative effect on the growth and tend to be uneconomically efficient at such inclusion level. 

Assessment was carried on the growth and microbial flora presence in African catfish (Clarias gariepinus) larvae fed with live food(Artemia) and commercial feed (Aller Aqua). Two days old larvae (n=200) of average weight (4.8± 0.01mg)and length (6.16±0.03mm)were reared in triplicates for 21 days in plastic tanks (40cm x 25cm x 25cm) dimension. The experiment was done in 12 hours static and 12 hours flow through periods each day. The physico-chemical parameters were within acceptable range for catfish culture except in the static periods were ammonia was present in values (0.30 ± 0.00) that are unacceptable. However, nitrate and nitrite were present but in low values. Both feeds showed commendable performance in growth parameters, but Artemia with lower crude protein content did better. There were presence of Total heterotrophic bacteria, Vibro, Total coliform and Salmonella/Shigella in the microbial analysis of the fish waters in all the treatment. Apart from total heterotrophic bacteria that was significantly present in all the experimental waters Vibro, Total coliform and Salmonila/Shigella were less than thirty(<30)cfu. Also, fish gets olderthe quantity of microbial flora present in the fish waters reduces.

A total of 150 fingerlings of Tilapia guinensis, were acclimated for a period of 14days. A static bioassay was used during the period of the experiment. Mortality was measured at different time intervals of 10hr, 12hr, 16hr, 20hr, 46hr and 52hr for the range finding test, using different concentrations of paraquat (120mg/l, 60mgl, 30mg/l and 15mg/l). Acute toxicity test, using different concentrations of paraquat (10mg/l, 5mgl, 2.5mg/l and 1mg/l) was used to measure mortality of 4, 0, 0 and 0 respectively, for 96hrs. The test established the LC50 (10mg/L) of paraquat on fingerlings of T.guinensis. Three sublethal treatments (5mg/L, 2.5mg/L and 1mg/L) and five lethal treatments (120mg/L, 60mg/L, 30mg/L, 15mg/L and 10mg/L) were used during the period of the experiment. The higher the concentration (30mg/L,60mg/L and 120mg/L) of paraquat, the higher the mortality (0, 1 and 5) by the end of 10hr, thus the dose of the test chemical made the poison. Although herbicide such as paraquat can be used in the control of weed; biological and mechanical weed control methods are still better as they may pose little or no threat to the life of T. guinensis.