Analysis of growth in high saline nursery and grow-out culture of Litopenaeus vannamei on the southeast coast of India

This study presents a comprehensive analysis of the nursery and grow-out phases in the aquaculture of Pacific white shrimp ( Litopenaeus vannamei ). In the nursery tank, a constant salinity of 43 ppt was maintained, alongside pH fluctuations (7.7-8.2), dissolved oxygen levels (6.5-7.5 ppm), alkalinity variations (140-200 ppm), and ammonia concentrations (0.1-0.2 ppm). Microbial populations exhibited 300-500 yellow colonies (cfu/ml) and 60-80 green colonies (cfu/ml). Shrimps, stocked at 6.7 pieces per litre, demonstrated impressive growth, reaching an average body weight of 0.90 grams, with a daily gain of 0.031 grams and a survival rate of 87%.The transition to grow-out ponds featured diverse stocking densities (10-17 m 2 ) and salinity levels (45-48 ppt). Water quality parameters, including hydrogen ion concentration (7.9-8.5), dissolved oxygen (4-4.5 ppm), ammonia (0.1 ppm), alkalinity (100-120 ppm), magnesium (1000 ppm), and calcium (900 ppm), were carefully managed. Beneficial bacteria ranged from 300 to 700 cfu/ml, while harmful bacteria varied from 40 to 120 ppm. Survival rates were highest in Ponds 1C, 1D, and 1E (80-90%), with a feed conversion ratio (FCR) of 1.4 in Pond 1E and 1.5 in others. Peak daily growth occurred in Ponds 1B, 1D, and 1E at 0.4 grams, with the greatest growth of 33 grams observed in Ponds 1D and 1E. Pond 1A yielded the highest harvest quantity at 1640 kg, accompanied by the highest feed usage at 2500 kg. This study underscores the significance of effective water quality management in optimizing growth and survival in Pacific white shrimp aquaculture.