author(s)
Banasree Biswas, SK Das and Amit Mandal

abstract
The present status and deviations from the classical management practices of composite farming of Indian major carps (IMC) have been investigated in North 24 Parganas district of West Bengal, India. Classical six species combination, ratio of IMC and exotic carps were not being followed by the farmers in general, as 75% of them cultured carps with 7-10 species with a stoking density of 15000 nos. fingerling ha^-1. 71.68% farmers who produced more than 5 tonnes ha^-1yr^-1 stocked their pond twice in a year instead of once. Although the number of species stocked by the farmers was highly variable among the farmers, it was found that six species combination was optimal so, far the production level is concerned (y= -0.163x²+2.018x-0.38; R²= 0.68). Application of 350-400 kg ha^-1 agricultural lime and 200-250 kg ha^-1 fertilizer (urea + single super phosphate = 1:1) to achieve annual yield, was found to be optimal towards fish production. Production level declined as the depth of the pond increased from 5 to 9 feet. Inclusion of readily available carbohydrate source like molasses and boiled starch in supplementary feed preparation was conspicuous. Most of the respondents stock a variety of species and many of them (mrigal, bata, black carp, punti, prawn) can effectively use the heterotrophic pathway of production utilizing the benthic detritus, the feed types adopted by the respondents were proved to be beneficial in attaining such satis1factory production level. Incorporation of variable ingredients with the conventional mixture of rice bran and oil cake proved to be superior as feed than the later usually recommended in composite farming of carps. The remarkable introductions in the original six species combination were minor carps like bata (Labeo bata), Japani punti (Puntius javanicus), tilapia (Oreochromis niloticus); minor fish like mola (Amblypharyngodon mola) carplet and scampi (Macrobrachium rosenbergii). Majority of the farmers used to stock more silver carp (Hypophthalmichthys molitrix) because of it’s high growth rate though it exerted a direct bearing upon catla (Catla catla).