Comparison of growth, proximate and minerals composition of commonly polycultured fish species by replacing surface feeder fish

Abstract

The experiment was conducted in the earthen ponds as two experimental groups were set each stocked with three different fish species at the rate of 800/Acre in the semi intensive polyculture system by supplementing inorganic and organic fertilizers in the ponds. Fish were stocked at the ratio of 35:40:25 in both the ponds designated as group 1 and group 2. Group 1 pond was stocked with Catla catla (C. catla) a surface feeder, Labeo Rohita (L. rohita) a column feeder and Cirrhinus mrigala (C. mrigala) bottom feeder, respectively, while, in group 2 only (C. catla) was replaced with (Hypophthalmichthys molitrix) H. molitrix as a surface feeder keeping other species the same as in group 1. At the end of experiment H. molitrix showed considerably high weight gain (P< 0.05) in group 2 as compare to column and bottom feeder fish species, conversely in group 1 higher weight gain was comparatively prominent in column and bottom while, C. catla showed low weight gain. Mean values of water quality parameters were conducive however temperature fluctuated between 26°C-29°C. Significantly higher values of (P<0.05) crude protein, fats, carbohydrates, Mg (%) and K (%) was recorded in the H. molitrix than C. catla. The results of the study showed that H. molitrix probably consumed all the phytoplankton density by filtering the water continuously resulting in the reduction of growth in other fish species in the polyculture system.