Optimizing Aquaculture Practices in Novel Streamlined Ras: Evaluating Stocking Density and Feeding Regimens on Production Performance, Growth Physiology, and Meat Quality of Largemouth Bass(Micropterus Salmoides)

Abstract

In this study, a novel streamlined recirculating aquaculture system(sRAS) was proposed to address the need for the transformation and upgrading of China's aquaculture industry. The system significantly improves the uniformity of the flow field and the stability of the water quality in the culture pool by optimizing the water intake structure, oxygenation method, system composition, etc. It also has the advantages of low construction cost, easy to manage, low operation cost, and conducive to the growth of fish. The effects of culture densities of 60, 100, and 140 fish/m3 and feeding frequencies of 2, 3, and 4 times per day on the growth performance, body index, muscle texture, serum biochemical indexes, liver antioxidant capacity, and intestinal digestive enzyme activities of largemouth bass were systematically investigated using largemouth bass. Specific growth rate (SGR) and weight gain rate (WGR) were significantly better in the low-density group (60 fish/m3) than in the medium- versus high-density group, whereas the high-density group (140 fish/m3) showed negative effects such as decreased energy reserves, impaired hepatic metabolic function, increased oxidative stress, and elevated markers of liver injury. Regarding feeding frequency, 3 times/day feeding frequency showed the best performance regarding growth and meat quality, whereas 4 times/day feeding frequency increased digestive enzyme activities but triggered oxidative stress and immune load simultaneously. This study provides a scientific basis for the industrial application of streamlined recirculating aquaculture systems, suggesting a culture density of 60-100fish/m3 and a feeding frequency of 3 times/day for factory farming.

Keywords: recirculating aquaculture systems, Micropterus salmoides, System development, stocking density, Feeding frequency