Analysis of some Aspects of Biology on Selected Fish species in River Hadejia, Jigawa State Nigeria

Analysis of some aspect of biology on selected species in River Hadejia, was carried out by analyzing the following, food and feeding habits using two method which are frequency of occurrence and dominant methods, forage to carnivore ratio,( F/C) was also estimated, water analysis was carried out purposely to find the food-fit in the body of water. The forage to carnivore ratio was estimated to be 3:1. while table 1-3 summaries the food items of Tilapia zill Orechromis niloticus and sarotherodon  galilaeus. Figure 1, summaries inter and intra specific competition among fish species. Keywords:- Frequency occurrence, dominant, forage carnivore, food

Investigation of aspects of reproductive cycles of some selected fish species in River Hadejia, Jigawa State, Nigeria.

This work aims to analyse some aspects of reproductive cycles of some selected fish species in River Hadejia was carried out from July 2012 at June 2013. The following aspects were considered, reproduction and breeding cycles, sex determination, fecundity and Gonado – Samatic Index (GSI). Table 1 and 2 show the summary of the results obtained. While tables 3-12 show the detailed results obtained for the different stages of maturity and gonad development. The Gonado Somatic Index (GSI) was calculated as the percentage of Gonad-weight per body weight. Fecundity was determined by direct enumeration using a digital counter and egg diameter was determined using ocular eye piece with stage micrometer. Keywords: Reproduction, fecundity, Gonad Somatic Index (GSI)