Optimizing live transport conditions for Macrobrachium rosenbergii: Temperature and prawn-water mass ratio effects on survival, stress physiology and metabolic adaptation

This study aimed to optimize live transport strategies for Macrobrachium rosenbergii by systematically examining transport conditions and underlying metabolic response mechanisms, with the ultimate goal of improving transport survival and product quality. The study analyzed the influence of varying transport temperatures and prawn-to-water mass ratios on survival rate, physiological indexes and tissue integrity in M. rosenbergii . The findings indicated that ammonia nitrogen accumulation emerged as the primary limiting factor for transportation survival. During short-duration transport (12 h), a combination of low temperature (16℃) and a high prawn-to-water mass ratio (1:2) significantly enhanced survival rates (up to 100 % in the T16–3 group) and substantially mitigated immune stress and oxidative damage. However, after extended-duration transport (24 h), the antioxidant system was gradually depleted, lipid peroxidation increased, and significant damage to hepatopancreatic tissue occurred. The survival rate in the high temperature (20℃) and anhydrous transport group declined sharply due to accelerated metabolism and an imbalance in osmotic pressure. Metabolomics techniques were subsequently used to examine the effects of live transport on the metabolic processes of M. rosenbergii . The findings revealed that the T16–3 group positively regulates environmental stresses by providing energy and performing detoxification functions through amino acid metabolic pathways. Groups T16–1 and T16–2 reduced immunity and energy availability by inhibiting autophagy-related and linoleic acid metabolic pathways. Groups T18–3 and T20–3 resisted the stressful environment by activating a wide range of metabolic changes, but still caused severe damage to the prawn. This study offers a scientific foundation for optimizing the live transport of M. rosenbergii , thereby improving transport efficiency, reducing costs, and ensuring product quality and freshness. • T16-3 group ensured full survival by alleviating ammonia stress and oxidative damage through metabolic regulation. • Extended transport depleted antioxidants and increased hepatopancreatic damage. • T18-3 and T20-3 groups had severe tissue damage despite metabolic adaptations.