Effect of Cyclop-Eeze on Growth and Survival of SHG (Swollen Hindgut Syndrome) Infected Penaeus monodon (Fabricius, 1798) Postlarvae under Two Different Stocking Densities

Abstract

In recent years, the diseases of shrimp slowed down the development of shrimp culture. Swollen hind gut syndrome (SHG) of tiger shrimp, Penaeus monodon postlarvae is common problem in shrimp hatcheries. Post larvae infected with SHG are generally rejected by the hatcheries and farmers, as stocking of SHG seeds or postlarvae are supposed to cause several problems such as size variation, white fecal disease. Loose shell syndrome etc., resulting is severe loss in form production and earning. In the present study an attempt carried to culture the giant tiger shrimp, P.monodon by using post larvae having swollen hindgut syndrome (SHG). In the present study an attempt has been made to culture the SHG infected post larvae of giant tiger shrimp, Penaeus monodon in six ponds each with 0.5 ha near Karlapalem village of Guntur district in Andhra Pradesh, India. In 3 ponds the seeds were stocked in high stocking density (18/ m) and remaining 3 ponds in low stoking density (9 / m). In both the cases, the Cyclop-eeze feed was mixed with Godrej (Godrej Agro Vet Vijayawada) feed and provided to the seeds and survival was calculated and compared. The salinity of the ten ponds was ranging between 12 to 28 ppt and pH was 7.8 to 8.4. Minimum 3.6 ppm dissolved oxygen and maximum 5.5 ppm was recorded during the culture period. The temperature was ranging between 26 to 31oC and the transparency was 35 to 55 cm. Harvesting was done in low density ponds (A1, A2 and A3) at DOC 140 and high density ponds (B1, B2 and B3)) it was harvested at DOC (Days of culture) 170. Average body weights of the low density ponds were 40.5 g and high density ponds were 32.6 g. Highest survival (82%) was recorded in low density ponds and the lowest survival was (64 %) recorded in high density ponds. Maximum production was reported in low density ponds (1,494 Kg / 40.5 g / 140 Doc) and minimum production was observed in high density ponds (1,878 kg / 32.6 g / 170 Doc). The maximum amount of feed was consumed by the shrimps in high density ponds (3474 kg) and minimum was in low density ponds (1973 kg). So the FCR (Food conversion ratio) for low density ponds were 1.32 and high density ponds were 1.85. The net profit obtained from the shrimps in high density ponds is Rs.57, 691 and net profit obtained from low density ponds is Rs. 2, 15,300. The results of the present study showed that there is significant difference (P<0.05) in growth and survival and FCR between two stocking densities of the SHG infected postlarvae. Present study revealed that high profit in the shrimp farming was obtained by the optimum or low (8-10 Pl’s/M) stocking density. Above results revealed that the effect of the SHG infected P.monodon postlarvae can be cultured in low stocking densities and harvested as similar to the normal seed provided the best farm management practices are followed by the shrimp farmer. To get better profit, proper nursery stocking, feeding with Cyclop-Eeze, proper water quality management and feed management is crucial.