Effects of stocking density on growth performance,muscle amino acids,and fatty acids of Penaeus monodon

YU Hanxiu; XU Jinzhen; LIN Xiangri; LI Jinxin; HUANG Yongchun; TANG Hainan

doi:10.13557/j.cnki.issn1002-2813.2025.22.014

Abstract：This experiment aimed to investigate the effects of different stocking densities on the growth performance and muscle nutritional composition of Penaeus monodon.Healthy Penaeus monodon with good vitality and an average body weight of(2.55±0.19)g were selected and randomly divided into six groups,with three replicates per group.The stocking densities for each group were 225(group D225),300(group D300),375(group D375),450(group D450),525(group D525),and 600 shrimps/m3(group D600),respectively.The pre-test period was seven days,and the formal test period was 42 days.The results showed that as the stocking density increased,the survival rate of Penaeus monodon significantly decreased(P＜0.05).Final body weight,final body length,and weight gain rate all exhibited a trend of first increasing and then decreasing.The coefficient of variation for body weight and body length showed a trend of first decreasing,then increasing,and then decreasing again.The relationship between body weight and body length in all groups fit a power function correlation.Regarding muscle nutritional composition,17 amino acids and 17 fatty acids were detected in all groups.Amino acid analysis indicated that the total amino acid content(ΣTAA),total essential amino acid content(ΣEAA),total non-essential amino acid content(ΣNEAA),and total umami amino acid content(ΣUAA)in group D300 were significantly higher than those in the other groups(P＜0.05).The concentrations of arginine and alanine showed a decreasing trend with increasing stocking density,with groups D225 and D300 had significantly higher content than the other groups(P＜0.05).Fatty acid analysis revealed that the total polyunsaturated fatty acid content(ΣPUFA),total n-3 polyunsaturated fatty acid content(Σn-3 PUFA),total n-6 polyunsaturated fatty acid content(Σn-6 PUFA),and docosahexaenoic acid(DHA)content in groups D300,D375,and D450 were significantly higher than those in the other groups(P＜0.05).The study shows that both excessively low and high stocking densities are detrimental to the growth of Penaeus monodon and affect the accumulation of amino acids and fatty acids in the muscle.Considering growth performance and nutritional quality indicators,the suitable stocking density range for Penaeus monodon is recommended to be 300～375 shrimps/m3.