Optimal water temperature and pH for development of eggs and growth of spawn of common carp (Cyprinus carpio)

The objective of the present study was to determine the influenceof water temperatures (26, 28 and 30 degrees C) and pH (5.5, 6.5, 7.5 and 8.5) variations on the hatchability of eggs and growth of spawn of common carp, Cyprinus carpio. The present results indicated that percentage of hatchability of eggs and incubation period decreased with increase in temperatures from 26 to 30 degrees C and pH levels from 5.5 to 8.5. Highest percentage hatchability of eggs (98.79 +/- 1.23), maximum incubation period (78 +/- 1.30 h), maximum weight gain (3.59 +/- 0.89 g), length gain (48.61 +/- 1.93 mm), specific growth rate (SGR) (12.24 +/- 0.26% day(-1)) and highest survival (96%) were recorded with pH 7.5 and water temperature 26 degrees C. Second order polynomial regression analysis relates the highest weight gain (3.59 g) at water pH 7.39, SGR (12.30) at pH 7.32 and water temperature 26 degrees C. The present results suggest that water pH 7.5 at water temperature 26 degrees C is best for hatchability of eggs and pH 7.39 for growth of spawn of Cyprinus carpio at same water temperature.