The Relationship of Ova Diameter to Fertilization Rates, Hatching Rates, Survival Percentages and Specific Growth Rates in the Common Carp and Indian Major Carps

Abstract

The effects of different ova diameters on hatching, growth and survival of fry of the common carp (Cyprinus carpio var. communis, Cyprinidae) and Indian major carps viz.Catla catla, Labeo rohita, Cirrhinus mrigala (Cyprinidae) were examined. The four female brooders of different weight and size of each of Cyprinus carpio var. communis, Catla catla; Labeo rohita and Cirrhinus mrigala were collected. The highest mean ova diameter was observed in (Cyc 4) 1.235 ± 0.006 mm, (Cc 4) 5.386 ± 0.098 mm, (Lr 4) 4.94 ± 0.167 mm and (Cm 4) 4.95 ± 0.091 mm; highest fertilization rate (Cyc 4) 92.48%, (Cc 4) 85.42%, (Lr 4) 89.64%, (Cm 4) 86.49%; highest hatching percentage (Cyc 4) 82.32%, (Cc 4) 79.67%, (Lr 4) 81.28%, (Cm 4) 80.17% and highest survival (Cyc 4) 75.57%, (Cc 4) 76.36%, (Lr 4) 80.51%, (Cm 4) 68.35% respectively. The specific growth rate was also found highest in Cyprinus carpio var. communis (Cyc 4) 5.94%, Catla catla (Cc 4) 5.62%, Labeo rohita (Lr 4) 5.81% and Cirrhinus mrigala (Cm 4) 5.86% in fry of brooders having maximum weight. The direct relationship of ova diameter to fertilization rate, hatching, survival percentage and the specific growth rate of Cyprinus carpio var. communis, Catla catla, Labeo rohita and Cirrhinus mrigala were recorded. However, after the fifth week, the growth rate of spawn reduced in all the groups and was least at the end of the eighth week.