Getahun, Abebe (Professor)Yalew, Alayu2020-11-252023-11-092020-11-252023-11-092018-12-12http://etd.aau.edu.et/handle/123456789/23556Being a potential species for the development of Ethiopian aquaculture, some aspects of the reproductive biology, larval rearing and growth performance of the African catfish, C. gariepinus had never been addressed. Hence this research aims to compare the performance of different size classes on their reproductive biology different z the artificial propagation, larval rearing and table size production of the African catfish, C. gariepinus in captivity. Different sizes of broodstock groups were injected with pituitary extract and compared for fecundity, number of fertilized eggs and the number of survived early larvae produced. The larvae were provided with zooplanktons multiplied in ponds at different feeding intervals to determine the best feeding frequency. The African catfish were cultured in extensive, semi intensive and intensive systems at different stocking densities and the best performing stocking rate was determined for each system. The income return of the different practices was compared and evaluated t identify the best practice for Ethiopia. The result indicated that fecundity of 500-600g weighed broodstocks was 51,800 eggs/kg bodyweight but only 47,000 eggs/kg was spawned from 1000-1200 g weighed broodstocks. The percentage survival of early larvae from small sized broodstocks and larger ones was 81% and 76%, respectively. The larvae fed on local zooplankton performed successfully and zooplankton multiplied in ponds replaced imported Artemia nauplii effectively. At feeding frequency of four times a day (every three hrs), larvae showed an average daily weight gain of 18.9 mg/day which was 19% more compared to those fed fewer times and less frequently. The percentage survival was 95% for the group fed four times a day and 75%, 93% and 87% for larvae fed twice, three times and five times a day, respectively. The most preferred stocking density in terms of weight gain and survival was 1fish/m2 for extensive, 5 fishes/m2 for semi-intensive and 90 iv fishes/m3 for intensive system. And the final harvest or yield was better in ponds or tanks at higher stocking density; 2fish/m2 for extensive, 10 fishes/m2 for semi-intensive and 100 fishes/m3. The average yield was 0.66kg/m2 for extensive pond culture, 4.77kg/m2 asemi-intensive pond culture and 53.4 kg/m3 in intensive culture during 8 months period. Hence, for a better productivity, fish should be stocked at a rate of 2 fishes/m2 in extensive and 10 fishes/m2 in semi-intensive pond culture and 100 fishes/m3 in intensive tank culture. Comparison of the different culture practices for economic benefit (considering fish sale), indicated that semi intensive culture system benefitted more with a profit index value of 13 compared to intensive culture with 9.28. In conclusion, African catfish female parent with 500g and more live weight can be used as a broodstock in a hatchery rearing. Feeding live zooplankton cultured in plankton ponds could be the most consistent technique for Ethiopia since importation of Artemia cyst is not sustainable. For the sake of alternative fisheries and to run profitable business, catfish farming in a semi intensive pond using feed formulated from local ingredients would be a solution.enArtificial SpawningCopepodsDiversityFertilizationIncubationLatency PeriodLivefoodMiltMultiplication PondParent StockPituitary ExtractProfit IndexStrippingThesis