Effects of Enrichment of Fish Pond on Growth Performance of Carps A Guide to Increase Fish Yield

An investigation of the effects of enrichment of fish pond on growth performance of Catla catla, Labeo rohita and Cyprinus carpio in Thatta District was carried out in earthen ponds located at the Chilya Fish Hatchery, Chilya, Thatta (Sindh). These ponds were fertilized with two organic manures (poultry manure and cowdung) and two inorganic fertilizers (nitrophos and urea).The length-weight relationships of carps under the enrichment of these four fertilizers followed almost isometric growth pattern except for Catla catla and Labeo rohita under urea and Cyprinus carpio under cowdung and urea. Among the four fertilizers, urea showed relatively less yield, as it only augment nitrogen deficiency. The rate of increase fish yield was corresponded with the enrichment response in the form of planktonic biomass. These fertilizers supply adequate levels of nutrients necessary for production of primary producers and ultimately for the fish.