Capture fisheries of Kontagora Reservoir, Niger State, Nigeria

A study of the capture fisheries of Kontagora Reservoir was carried out between January - December, 2007, using statistical frame and catch assessment survey methods. Five fish families comprising seven fish species were recorded. Hemichromis fasdatus, a cichlid was the most dominant species with mean value of 414.3 and 7715Kg in terms of number and weight respectively. Nineteen commercial fishermen were recorded, with the following fishing gears: gill net, cast nets, long lines, and Malian traps. The fishing craft included wooden canoe. The total mean catch of the fishermen were 4.40(1.36) kg/canoe or 167(52.64) fishes/canoe. The reservoir was productive in comparison with other smaller but productive African lakes. The monitoring, control and surveillance (MCS) system was suggested for management consideration, with emphasis on registration of fishermen and their fishing equipment, enforcement of minimum mesh size of 3” and establishment of community based cooperative scheme

Growth performance of fingerlings of Clarias gariepinus fed fermented seed of Senna obtusifolia (Linn)

The effects of replacing soybean meal with graded levels of fermented Senna obtusifolia seed meals (SOSM) on the growth performance of Clarias gariepinus were investigated. Five isonitrogenous (42% crude protein) and isocaloric (25.7% NFE) diets were formulated in which fermented replaced soybean meal (SBM) at 0% (SOSM0), 25% (SOSM25), 50% (SOSM50), 75% (SOSM75) and 100% (SOSM100) inclusion levels and a commercial feed (CmF) as the second control. Three hundred and sixty (360) fingerlings of (Clarias gariepinus) mean weight (2.85±0.01g) were stocked at (20) fish per tank volume in triplicate groups per treatment and fed 3% body weight twice a day of the experimental diets for 180 days. The feeding rate was adjusted after weighing. The water qualities were within range recommended for Clarias gariepinus. There were no significant differences (p> 0.05) in growth performance and nutrient utilization between the control groups and those fed the fermented SOSM diets at 25%. The commercial, 0% and 25% groups had the highest mean weight gain (279 to 280 g), significantly (P<0.05) superior to the groups that received the, 50%, 75% while the group that received 100% SOSM diet had the poorest mean weight gain (132.72g). Feed conversion ratios (FCR) of all treatments ranged from (1.75 to 2.18). These values increased slightly by increasing levels of fermented SOSM from 50 to 100%. The best FCR, 1.75± 0.02, recorded for fish fed 25% fermented SOSM indicated a superior level of utilization of the SOSM diet by the fish. There was no significant difference (P>0.05) in the protein intake among the group of fish fed 0 and 25%, but significant difference (P<0.05) occur in fish fed 50, 75 and 100% fermented SOSM respectively. Protein efficiency ratio (PER) exhibited significant differences (P<0.05) in all treatments except in the control diets that were not statistically different (P>0.05) from the fish fed the 25% fermented SOSM. The PER values increased among the experimental fish with respect to the quantity of total feed intake. There were no significant differences (P>0.05) in apparent net protein utilization (ANPU) among treatments CmF, 0% and 25%. The ANPU was highest in fish fed 0% fermented SOSM (91.6±0.04) while fish fed 75 and 100 % fermented SOSM in diets were 71.4±0.02 and 73.4±0.03 were the least. There was a significant (P<0.05) difference in the effect of the inclusion levels of fermented (SOSM) on final body carcass composition among treatments. This study showed that soybean meal can be substituted with fermented Senna obtusifolia seed meal up to 25% level in Clarias gariepinus diets without any negative effects on the growth and feed efficiency.Keywords: Growth; fermented Senna obtusifolia (Linn); Clarias gariepinus fingerling