Effects of different aquaculture modes on growth performance, size distribution, and muscle nutritional composition of juvenile <i>Procambarus clarkii</i>

This study evaluated the effects of two aquaculture modes on Procambarus clarkii growth, size distribution, and muscle quality. Two models were compared: Pond A (high density: 4,428 ind/mu, small size: 3.5 g; control group) and Pond B (low density: 2,261 ind/mu, large size: 9.0 g) over 30 days. Results showed that Pond B significantly enhanced weight gain and the proportion of size 1 and size 2 compared to Pond A (P&lt;0.05), while the control group exhibited a higher hepatosomatic index and proportion of Size 4 crayfish. Although proximate composition (moisture, lipid, ash) and muscle textural properties (hardness, springiness, chewiness, etc.) were unaffected, Pond B crayfish showed significantly lower muscle crude protein content and reduced levels of specific amino acids (glutamate, serine, tyrosine, methionine, lysine; P&lt;0.05). Fatty acid analysis revealed significantly higher saturated (C16:0, C18:0) and monounsaturated (C16:1, C20:1) fatty acids, but lower C18:1n9, linoleic acid (LA), and docosahexaenoic acid (DHA) in Pond B (P&lt;0.05); linolenic acid, arachidonic acid, eicosapentaenoic acid (EPA), and total PUFA remained unchanged. The low-density/large-size model optimizes growth performance and commercial size yield, increasing high-value individuals. However, it compromises specific nutritional aspects (protein, certain amino acids, and key fatty acids). As essential amino acid totals, proximate components (excluding protein), PUFA, and texture were unaffected, this model is recommended for maximizing economic return, though dietary strategies to mitigate nutritional alterations warrant further investigation.