On the mortality of carp fry in nursery ponds and the role of plankton in their survival and growth

Abstract

As in China, collection of millions of early fry of major carps from rivers and stocking them in nurseries for rearing is a common |practice in India, particularly in Bengal, Bihar and Orissa. Different types of ponds, small or large, seasonal or perennial, shallow or deep, are used as nurseries; and different methods of preparation of the ponds are followed. There is, however, very little reliable information about these practices, most of which are known only to a few farmers who keep the information as family secrets handed down from generation to generation. On such important aspects like the density of stocking and percentage of survival, also, our information is meagre. Even the expert fish farmer is unable to ensure that his nursery pond will yield a satisfactory return every year.