EFFECTS OF STOCKING DENSITY ON PERFORMANCE OF CULTIVABLE CARPS IN SOUTHERN BHUTAN

Abstract

The effect of different stocking rates on growth performance of two fish species namely Rohu (Labeo rohita) (Hamilton 1882) and Cauvery white carp (Cirrhinus mrigala) (Hamilton 1822) was evaluated in 180 days of culture period. Four different treatments were evaluated. The treatments were stocking rates of two fish m-2 as T1, four fish m-2 as T2, six fish m-2 as T3 and eight fish m-2 as T4. The experiment was conducted in National Research and Development Centre for Aquaculture, Gelephu, Bhutan. All other management aspects such as feeding, manuring, fertilization and liming were same for all treatment ponds. The initial average weight and length of Rohu was 8.10 g and 8.74 cm, respectively, whereas the initial average weight and length of Cauvery white carp was 7.49 g and 9.20 cm, respectively. Fishes were fed @ 5% of body weight for three times a day: morning at 8.00 am, afternoon at 12.00 pm and evening at 5.00 pm. Fish growth parameters were recorded monthly through sampling 30 fish of each species from each treatment pond. Although, there was no significant difference among pond parameters, the final fish body weight was significantly greater for the stocking rate of four fish m-2. The findings suggest that stocking rate of four fish m-2 is most appropriate in achieving optimum growth of Rohu and Cauvery white carp in subtropical region of Bhutan.