Growth Performance and Biochemical Profiles of Fairy Shrimp (<i>Streptocephalus sirindhornae</i>) Fed Natural Diets at Low and High Stocking Densities.

Abstract

This study investigates the growth performance, gut content composition, and biochemical profiles of the fairy shrimp <i>Streptocephalus sirindhornae</i> cultured with natural diets under low and high stocking densities (20 and 40 ind. L^-1). Fairy shrimp were reared for 15 days in 1 m³ floating cages placed in earthen ponds. On day 15, individuals in the low-density treatment exhibited significantly greater body weight (0.074 ± 0.013 g) and total length (20.97 ± 0.90 mm) than those in the high-density group. A total of 54 food taxa were identified in the gut contents, with phytoplankton comprising the dominant fraction (91%). In contrast, 105 food taxa were recorded in the culture ponds, including 54 phytoplankton and 51 zooplankton taxa; chlorophytes (27 taxa, 50%) and rotifers (33 species, 63.46%) were the most diverse groups. Fairy shrimp feeding on natural pond foods exhibited high levels of essential amino acids, with monounsaturated fatty acids dominating and linoleic acid (C18:2n6c) representing the principal polyunsaturated fatty acid. Overall, the results indicate that low-density rearing enhances fairy shrimp growth, while the high diversity of natural food organisms contributes to the favorable nutritional composition of <i>S. sirindhornae</i>.