Effects of Water Depth on Growth Performance of Indian Major Carps at a Poly Culture System in Bangladesh

The main aim of this study was to assess the effects of water depth on the growth performance (length and weight) of table size Indian major carp (Gibelion catla, Labeo rohita, and Cirrhinus mrigala) fishes. Fishes were recorded under different depth (1.20 m, 1.80 m and 2.80 m) for about eight months from February 2016 to September 2016. Water depth was considered as treatment 1 (T1) for 1.20 m, treatment 2 (T2) for 1.80 m and treatment 3 (T3) for 2.80 m, respectively. Randomized Complete Block Design (RCBD) with two replications of each treatment was differentiated at significant level 5%. Various water quality parameters such as water temperature, dissolve oxygen, transparency, and pH were also recorded. The survival rate was found maximum (99.23±0.4%) for Labeo rohita fish at 2.80 m water depth and lowest (95±2.1%) survival rate was observed for Gibelion catla fish at 1.20 m water depth. Results of this study showed that Gibelion catla, Labeo rohita and Cirrhinus mrigala fish cultivated at four feet depth of water produces lowest average weight of 1398 g, 1048 g and 1050 g, respectively with an average length of 47 cm, 49.2 cm and 46.4 cm, respectively. The maximum average weight of fish 3667 g, 2700 g and 2800 g were obtained at 2.80 m depth of water with the maximum average length of 63.2 cm, 60.0 cm and 58.6 cm for Gibelion catla, Labeo rohita and Cirrhinus mrigala fish, respectively. From this study, it can be observed that the fishes cultivated at low depth of water yielded lowest, and shorter in length in contrast to the carps cultivated at higher depth of pond water. However, the growth of Gibelion catla was notably high among other carps.