Freshwater fish Oreochromis niloticus were exposed to sublethal concentrations of zinc for short and
long terms. Responses of hematological parameters which include red blood cells count (RBC) and
hemoglobin content (Hb) were investigated. Serum aspartate aminotransferase (AST) and alanine
aminotransferase (ALT) activities were also determined. Two hundred and forty fish (24.30 ± 2.85 g)
were distributed randomly in twenty four glass aquaria (80 L) with stocking density of 10 fish for each.

The present study was performed in earthen ponds with a total area of 1.25 feddan each and water column of 1.25 meter. The objectives of this study were to evaluate the effect of source of fertilizers (organic and inorganic) on growth performance, feed and nitrogen utilization, whole body composition, water quality, plankton abundance, costs and net returns of Nile tilapia monosex reared in earthen ponds.

The influence of replacing diet fish meal LT94 (FM) with different levels of full fat soybean meal (FFSB) on growth
performance and enzymes activity in stomach, hepato-pancreas and intestine were investigated for Nile tilapia Oreochromis
niloticus. Four diets (D1, D2, D3 and D4) were formulated 0, 15, 20, and 20 g/100 protein of diets + DL-methionine by
replacing FFSB with fish meal respectively. Proximate composition of the diets was determined. The growth of O. niloticus