Comparison of production efficiency in extensive and semi intensive systems of L. vannamei farming

Level of shrimp culture technology which called culture system, related to density of larvae in pond (stocking density), the investment capacity of farmer and shrimp production. Hence the system chosen according to production capicity, the volume of investment required, return on investment and profitability factors will be important.The aim of the present study was to compre of extensive and semi-intensive farming of L. vannamei in terms of growth, survival, specific growth rate and production in the period of 110 days (period culture), with approach of technical and economic aspects.In this study, shrimp post larve a(PL12) stocked with density of 10 and 30 PL /m2, respectively, in extensive and semi-intensive ponds. In extensive system, shrimp feeding was based on fertilization and natural production of pond (live food) and in semi-intensive pond based on formulated diet. Average length, weight, survival rate, specific growth rate and yield in the extensive system was 96.3 (mm), 7.33 (gr), 65.53%, 4.99, 560 (kg/ha) and in semi-intensive, 129 (mm), 1.53 (gr), 87.23%, 5.56, 4082 (kg/ha), respectively.the results of this research showed that off measured factors have higher value in semi-intensive culture than extensive method .and in Comparision between tow systems , T-test showed significant difference (P<0.05).