Common carp (Cyprinus carpio) germplasm were sourced from Bauchi and Ibadan aimed at studying their hatchability from the various intraspecific crosses and effect of frequencies of feeding on stocking density of Carp fry. Both male and female were injected with Ovaprim at 0.5ml/kg body weight intramuscularly at a single dose. The number of eggs in 1 gram mass was determined, Fertilization rate and percentage of hatchability were calculated. One hundred and eighty (180) fry of Cyprinus carpio were randomly picked and distributed in nine bowls of 50 litres at three stocking densities with replicates for each treatment. The frequencies of feeding were in these order; Ten (10) fry per bowl of 50 litres were fed twice a day, Twenty ( 20) fry per bowl of 50 litres were fed four times a day, Thirty (30) fry per bowl of 50 litres were fed six times a day, respectively for 8 weeks with 30gm of 0.2mm Coppens starter diet. The Ib♀ x Ba♂ cross had the highest hatchability though highest fertilization rate was recorded by Ba♀ X Ba♂ cross. The various crosses had above 50% hatchability, though percentagehatchability differed significantly at (P <0.05). While the growth pattern of the different stocking densities at different feeding frequencies differed significantly (p<0.05). The intra specific crossing of different sexes from the two sources gave a higher yield as can be seen with the IB♀ x BA♂. Whereas carp fry stocked at a lower stocking density with a fewer feeding frequency had best growth.
Effects of temperature and body weight on ventilation volume of common carp (Cyprinus carpio L.)
