Study of growth, survival rate and final harvesting of Litopenaeus vannamei impact of 25, 35 and 50 (per/m2) stocking densities

For the first time in research program and species diversity the white legged shrimp (Litopenaeus vannamei) was introduced in Iran in 2005 by Iranian Fisheries Research Organization. In two recent years two projects was carried out successfully in Hele Research Station and according of these projects study of growth, survival rate and final harvesting of Litopenaeus vannamei impact of 25, 35 and 50 (per/m2) stocking densities was done .Nine 0.4 ha earthen ponds were stocked from 26 June 2006 to 11 November 2006 and the rate of stocking was 100000,140000 and 200000 Pl in 25, 35 and 50 per /m2 respectively. We also carried out daily test of pH, temperature and dissolve oxygen two times per day but transparency, depth and salinity one time per day. The mean weight in 120 days was 17/84±2/6, 16/03±1/9 and14/09±2/3 grams in 25, 35 and 50 per /m2 respectively and highest weight was seen in 25 density. Results demonstrated that there was a significant relation (P<0.05) between mean weight. The yield were 1745, 2055 and 2425 kg/pond although 4/3, 5/1 and 6 ton/ha in 25, 35 and 50 per /m3 respectively. The maximum and minimum survival rate 97/96 and 88/46 was seen in 25 and 50 per/m2. The minimum FCR 1.43 was seen in 25 per /m2. For economical calculating just by using the cost of larva and feeding indicates that the highest benefit percentage was seen in 25 density. The average of salinity, pH, temperature and dissolve oxygen were 36.1-37 ppt, 8.1, 30.2-30.6 degrees centigrade and 5.9- 6.4 mg/l.

Iranian Fisheries Science Research Institute

Published