A Comparative Study on the Gonadosomatic Index and Milt Volume of Four Populations of Clarias gariepinus (Burchell, 1822) Broodstock Strains from North-East Nigeria

This study was carried out to compare and assess the Gonadosomatic Index (GSI) and Milt Volume of African catfish (Clarias gariepinus) from four population strains in the North-East of Nigeria. The broodstocks for the experiment were collected from lake Alau in Borno State, Lake Dadin Kowa in Gombe State, Lake Maladumba in Bauchi State and Lake Mayo Ranewo in Taraba State. The experiment was carried out at the hatchery complex of the Department of Fisheries, University of Maiduguri. A total of eighty C. gariepinus, twenty from each lake were collected. Standard methods were used to determine the gonadosomatic index and milt volume of the broodstock fish. The result obtained showed that the highest GSI value in males was 0.48±0.14 for fish caught from Lake Mayo Ranewo and the lowest GSI in males value was 0.28±0.01 for fish caught from Lake Maladumba. While the highest GSI value in females was 9.18±2.48 for fish caught from Lake Maladumba and the lowest GSI in females value was 4.06±0.65 for fish caught from Lake Dadin Kowa. There was a significant difference (P<0.05) on the GSI among the males and females fish broodstocks among Lakes The highest milt volume 2.66±0.16 was recorded for fish caught from Lake Mayo Ranewo and the lowest milt volume in males value was 2.32±0.11 and 2.32±0.11 for fish caught from Lake Alau and Lake Dadin Kowa respectively. The results obtained in this study have increase our knowledge on the reproductive biology of wild C. gariepinus from the North-East of Nigeria and have also provided relevant information for fisheries and aquaculture management as well as breeding programmes.