www.sciencejournal.in UGC Approved Journal No: 63495 Volume 8, Issue 2 (2019) ISSN: 2319–474X (p); 2319–4758 (e) © 2019 DAMA International. All rights reserved. 55 STUDY ON THE MANAGEMENT PROTOCOL, GROWTH, YIELD AND ECONOMICS OF LITOPENAEUS VANNAMEI (BOONE, 1931) WITH VARIED STOCKING DENSITIES AND SALINITIES AT SPECIFIED COMMERCIAL CULTURE TANKS OF PURBA MEDINIPUR, WEST BENGAL, INDIA. Anupam Maiti 1 , Deep Sankar Chini 1 , Manojit Bhattacharya 1 , Avijit kar 1 , Tapas Kumar Dutta 2 , Utpal Kumar Sar 3 , Bidhan Chandra Patra 1 1 Centre for Aquaculture Research, Extension and Livelihood, Department of Aquaculture Management and Technology, Vidyasagar University, Midnapore, West Bengal 721 102, India. 2 Department of Zoology, Bankura Sammilani College, Bankura, West Bengal 722102, India 3 Directorate of Fisheries, Port Blair, Andaman and Nicobar Administration, India ABSTRACT White leg shrimp (Litopenaeus vannamei) production is now most demanding and high economic value culture practices through worldwide. The main objectives of the present studies is to evaluate growth, yield and economics of the species with varied stocking densities, salinity and management practices at commercially cultured six ponds with gradients of salinity, stocking density and survivability in study area of Purba Medinipur, West Bengal with different days of culture periods. During the crops harvest the final average body weight was 22.40gm, 23.00gm, 26.00gm, 20.25gm, 18.40gm & 16.10gm and yields (in Kg/Ha./Crop) are 9246.72, 8280.00, 5200.00, 8922.96, 8402.91 and 7545.68 respectively. The average daily gains (gm/day/Shrimp) are 0.235, 0.23, 0.24, 0.217, 0.204 & 0.178 and FCR value measured 1.25, 1.27, 1.38, 1.21, 1.05 & 1.04 respectively. The result showed the profit (in percentage value) is 42.84, 43.72, 32.82, 30.42, 19.09, 19.09 and 7.30 from pond P1 to P6 respectively. At the harvesting the highest growth rate observed at lowest final stocking (20/m 2 ) densities but higher yields observed at the final stocking density (SD) of around 40/m 2 though highest profit percentage at 35/m 2 of SD at the same unit area. The best management practice with good quality of seeds for culture periods of 100 ± 10 days fetching higher margin of profit. The shrimps are observed to grow well at the salinity range from 5.00ppt to 25.5 ppt. It is observed that with 80% survivability after sixty ± five days of culture (DOC) the average body weight (BW) was 10.00 ± 01gm/Shrimp. The optimum management of feed, water quality and disease control should be followed during management practices to get the higher profit in this shrimp culture. KEYWORDS: Feed Conversion Ratio, Growth, Litopenaeus vannamei, Management practices, Stocking Density. INTRODUCTION The production of aquaculture related organism has rapidly grown-up enormously in the last few years (Karuppasamy and Mathivanan 2013). In 2006 Crustacean aquaculture has followed the equal growth in which the yearly production has stands with about 05 million tons (Department 2000). Now a day’s Penaeid shrimps are most favored in aquaculture for shrimp farming which leads to expansion of the aquaculture areas (Pasharawipas et al. 2005). Now India ranks in second position after China in saline water shrimp production worldwide (Ravuru and Mude 2014b). Due to the high profitability and high demanding market, farmers are cultured with organic and inorganic fertilizer, high amount of stocking densities and artificial feed to earn the maximum profit (Ayyappan 2006). Besides, there is a chance of higher stress for the growing organism with the over intensification. Under stress the pathogens present in the pond may enter and cause disease resulting in severe mortality. From last couple of years Asian countries were severely affected with many viral diseases like White Spot Disease and faced massive economic losses particularly due to continuous outbreak (Krishna et al. 2015). Since 2012-13, in India the production of white leg shrimp Litopenaeus vannamei has become highest crustacean species than the P.monodon (Alcivar-Warren et al. 2007; Frias-Espericueta et al. 2001). Among other species, L. vannamei has represented about 90% of saline water shrimp culture in the Western part of hemisphere due to its fast growth and short culture period (McGraw et al. 2002; Saoud et al. 2003). Usually survival, growth and production of