Impact of organic manures or supplementary diet on plankton production and growth and fecundity of an indian major carp, Cirrhina mrigala (Ham.), in fish ponds

Abstract

The paper deals with the qualitative and quantitative analyses of phytoplankton and zooplankton and growth and fecundity of Cirrhina mrigala (Ham.) in ponds receiving cow dung and poultry droppings alone and in combination at 20 000kg ha −1 year −1, or supplementary diets composed of rice bran and groundnut oil cake (at 2% of the fish body weight). Both phytoplankton and zooplankton and growth rate of fish were significantly higher in ponds receiving poultry droppings alone and in combination with cow dung. However, cow dung alone failed to increase the pond productivity and hence the growth of fish. The contribution of various groups to the plankton population also differed with respect to the manures. Absolute fecundity and fecundity per g ovary weight was greatest in fish reared in ponds treated with poultry droppings alone.