ASSESSMENT OF CLARIAS GARIEPINUS BROODSTOCK QUALITY AND LARVA SURVIVAL RATES FED DIETARY DATE PALM MEAL FOR SUSTAINABLEAQUACULTURE

摘要

Low fry survival rate and scarcity of quality fish seed have continued to hinder the growth of aquaculture in Africa. The present study investigated inclusion of oven-dried Date palm meal (DPM) in Oarias gariepinus broodstock diets at 0,2.5, 5.0,7.5 and 10% level as diets I to 5 (five dietary treatments) but isonitrogenous at 40% crude protein. Five female broodstocks with average body weight of 1. 10±0.06 kg were stocked into a tank of 1.5m3 and fed formulated diets for 8 weeks in triplicates.Two gravid females were selected per treatment, induced for breeding and were stripped for incubation after I I hours latency period. Hatchlings were monitored for a week after cleaning and 500 each was transferred in batches and stocked per unit of treatmentin triplicates. The larva were fed artemia diet at 50g per feeding regime 6 times daily with adjustment on weekly basis for 3 weeks. Proximate composition of experimental fish was carried out and data on weight changes in fish were recorded forthnightly. Fish carcass analysis and growth performance were significantly (p<0.05) affected by dietary DPM treatment since crude protein increased along with DPM inclusion levels. Specific growth rate and Feed Conversion Ratio exhibited significant increase withincrease in level DPM inclusion in the broodstock diets and weight gain of fish fed diet I (control) showed 170g while that fed diet 5(10% DPM) recorded 260g. Weight of eggs stripped were only marginally different among treatment. Hatchability rate washighest (88.40±0.20%) in fish fed 7.5% (diet 4) which was only marginally different from fish fed diet 5 (86.80±0.40%) while fish fed 0% DPM (control) had the least hatchability rate (76.70± 0.1 1%). Fry monitored for 3 weeks under intensive feeding showed progressive mean weight gain, specific growth rate, protein efficiency ratio and superior feed conversion ratio from control to treatment 5. Survival rate was lowest in control (83.60%) and no mortality was recorded in treatments 3,4 and 5.This trend implied that dietary date palm meal promote growth in fish, enhance hatchability rate and fry survival, and ensure quality fish production. Production of fish feed with date palm at 7.5% inclusion is sufficient for quality fish production with high fry survival rate on sustainable basis.