Evaluation of health status of Indian major and minor carps cultured in West Bengal, India

In Indian freshwater aquaculture, which largely depends on carps, diseases have become a major problem. This study evaluated the health status of Catla catla, Labeo rohita, Cirrhinus mrigala and Labeo bata cultured in West Bengal, India by determining the Health Assessment Index (HAI) and coefficient of variation (CV) of HAI values of each species as well as the superoxide anion production. The annual mean HAI value was the highest for L. rohita (77.51) and least for L. bata (55.30). The highest and lowest CV of HAI values were recorded for L. bata (95.80) and C. mrigala (52.55), respectively . The HAI values correlated negatively ( P <0.05) with temperature. The HAI distinguished successfully among the species, seasons and sampling areas on the grounds of temperature and water quality, with higher index values recorded in carps grown in poorly managed ponds. Labeo bata exhibited higher immune responsiveness compared to other carps. Labeo rohita was the most susceptible to diseases. The results on the high production of oxygen radicals by phagocytic cells of L. bata together with low HAI and high CV values suggested that this species may resist biotic and abiotic stressors well under culture conditions. The results suggested that HAI and superoxide anion production can be used to assess the health status of carps under the culture conditions.