Effects of fish stocking density on growth and survival of Silver carp (Hypophthalmichthys molitrix) fry in Jashore, Bangladesh

Abstract

The experiment was operated in 9 consecutive weeks in nine earthen nursery ponds having the same area (0.09 acre) and depth (0.8 m). Seven days old fries of Silver carp (Hypophthalmichthys molitrix) were stocked at 4000, 5000 and 6000 fries/decimal in three treatments with three replications as T-1, T-2 and T-3, respectively to observe the growth and survival. At stocking, hatchlings were the same batch-rearing with an average length and weight of 0.44 ± 0.05 cm and 0.14 ± 0.05 mg, respectively. Wet mustered oil cake and commercial nursery feed containing 30% crude protein were given by two weeks interval, initially according to the bodyweight; the feeding rate was 14% in the first two weeks, gradually reduced to 12, 10 and 8%, respectively in the following week intervals. Water quality parameters and plankton sufficiency were observed every 15 days interval and was found within the acceptable range. Growth performance (6.458 g), survival rate of fingerlings (85.76%) and total production (22151g/decimal) were found highest in T-1 followed by T-2 and T-3. The study concluded that expect better production of fry up to fingerlings, proper stocking density should be maintained in pond fish culture in Jashore region of Bangladesh.