Species Identification and Optimizing Salinity to Enhance Reproduction and Life Cycle in Amphipoda sp.

The sustainable production of high-quality live feed is essential for the success of modern aquaculture. Amphipods, particularly Amphipoda sp., offer considerable potential due to their high nutritional value, small body size, and adaptability to diverse aquatic environments. However, the availability of consistent cultured amphipod populations remains limited, largely due to reliance on wild-caught individuals and suboptimal rearing protocols. This study aimed to assess the effects of salinity on the reproduction, life cycle synchronization, and nutritional profile of Amphipoda sp. to support the development of standardized cultivation practices. Experimental treatments were conducted using three salinity levels (25, 30, and 35ppt) under controlled conditions. DNA barcoding confirmed the identity of Amphipoda sp. with 84.16% similarity to existing sequences in the NCBI database. Reproductive performance peaked at 30ppt with a production of 510 eggs/day, while lower and higher salinity levels led to reduced fecundity. Life cycle observations revealed clear morphological differentiation between juvenile and adult stages, including sexual dimorphism. Amino acid profiling through LC-MS/MS indicated that samples from Situbondo had higher concentrations of L-alanine, L-glutamic acid, glycine, L-isoleucine, and L-leucine compared to samples from Jepara, supporting their superior nutritional potential. These findings highlight the critical role of salinity in optimizing reproductive output and feed quality in Amphipoda sp., emphasizing the need for precise environmental management.