Zooplankton Abundance and Growth of Carps in Farm-Ponds of Different Agro-Climatic Zones of Karnataka

Abstract

Availability of planktons / natural fish food plays an important role in getting better growth of fish from farm ponds. Study was carried out to evaluate the zooplankton community and growth performance of Carp fishes in farm ponds of coastal and malnad agro-climatic regions of Karnataka. All the ponds were manured with cowdung and poultry manure @ 2000 kg/ha. for the production of planktons. Catla, Rohu and common carp fingerlings were stocked in all the ponds @ 10,000 nos. /ha in 1:1:1 ratio and fishes were fed with groundnut oil cake and rice bran (in 1:1 ratio) @ 5% of the body weight every day. The water samples from all the ponds were collected and filtered for zooplanktons using nylon bolting cloth (60 µm). The growth of fishes in terms of weight was recorded. The analyzed zooplankton planktons were classified into 5 class’s viz., Rotifera, Protozoa, Copepoda, Cladocera and Ostracod. Among zooplanktons observed, copepod contributed maximum to zooplankton community followed by rotifers, cladocerans and ostracod. In coastal ponds the average maximum number of zooplankton 10,368 Cells/m3 and minimum number of 176 Cells/m3 were observed. In Malnad ponds the average maximum number of zooplankton 21,797 Cells/m3 and minimum number of 1579 Cells/m3 were observed. The average maximum growth of Catla, Rohu and Common carp was observed in coastal ponds were 884.42, 640.1 and 692.27 gms respectively and in Malnad farm ponds 1080.71, 954.19 and 1023.18 gms respectively. Use of cowdung and poultry manure in combination was found useful for getting better growth in farm ponds of both the regions.