Length-weight Relationships and Condition Factor Studies in Three Major Carps Reared under Integrated Polyculture System

Length-weight relationships and condition factor of three fish species, viz. Catla catla, Labeo rohita and Cirrhina mrigala have been computed to see the responses of different fertilization regimes (nitrogen levels from broiler droppings) on the degree of fish well-being. The fork length-weight relationships of three fish species under five nitrogen levels followed almost isometric pattern of growth except Labeo rohita under 0.10, 0.13 and 0.16 g nitrogen levels. However, among the three fish species Catla catla exhibited significantly higher weight gains against fork length increments to follow the cube law of isometric growth. The condition factor of all the three fish species in relation to size fluctuated significantly among treatments. This fluctuation was dependent upon the planktonic productivity indices of ponds that was regulated according to the feeding habits, age and growth rates of fish.