水产学报2026，Vol.50Issue(5)：209-225,17.DOI:10.11964/jfc.20251015146
拟穴青蟹幼蟹对饲料亮氨酸的需求量
Dietary leucine requirement of juvenile mud crab(Scylla paramamosain)
摘要
Abstract
The mud crab(Scylla paramamosain)is the most farmed marine crab species in China.However,the lack of system-atic research on its nutritional requirements has hindered the development of high-quality complete formulated feeds,which poses a major bottleneck to achieving sustainable,efficient,and green development of the industry.This study aimed to determ-ine the optimal dietary leucine requirement for juvenile mud crabs S.paramamosain[initial weight of(15.07±0.97)mg].Five isonitrogenous and isoenergetic diets were formulated with leucine levels of 2.09%(Leu 1),2.39%(Leu 2),2.66%(Leu 3),2.99%(Leu 4),and 3.34%(Leu 5).After an 8-week feeding trial,crabs fed diets with leucine levels between 2.09%and 2.66%exhibited significantly improved growth performance,including final body weight(FBW),weight gain(WG),and specific growth rate(SGR).However,growth was significantly suppressed when leucine levels exceeded 2.99%.At the physiological level,appropriate leucine supplementation(2.09%-2.66%)enhanced digestive enzyme[trypsin(TRY)]and metabolic enzyme[alanine aminotransferase(ALT)and aspartate aminotransferase(AST)]activities in the hepatopancreas.Concurrently,the expression of key genes in the TOR signaling pathway(tor,akt,s6k1,eif4e2,4e-bp21)was significantly upregulated.In con-trast,excessive leucine(2.99%-3.34%)induced oxidative stress,as evidenced by suppressed antioxidant enzymes[superoxide dismutase(SOD)and catalase(CAT)]activities and elevated malondialdehyde(MDA)content.Immune-related gene expres-sions[lysozyme(lzm)and prophenoloxidase(proPO)]were also inhibited.Analysis of the hepatopancreatic microbiota revealed that optimal leucine levels promoted a higher abundance of Thiothrix,which was positively correlated with growth indicators,digestive and metabolic enzyme activity,and antioxidant capacity.Conversely,high leucine levels significantly increased the proportion of potential pathogens like Vibrio and Photobacterium,which were associated with oxidative damage.Based on a second-order polynomial regression model of WG,the optimal dietary leucine requirement for juvenile S.para-mamosain was determined to be 2.41%.This study addresses the gap in key nutrient requirements data for juvenile S.para-mamosain,laying an important theoretical foundation for the development of high-quality formulated diet.关键词
拟穴青蟹/亮氨酸/生长性能/抗氧化能力/肝胰腺微生物Key words
Scylla paramamosain/leucine/growth performance/antioxidant capacity/hepatopancreatic microorganisms分类
农业科技引用本文复制引用
徐含颖,韩涛,曹译文,吴正球,王骥腾,陶如冰,封文萍,孙玉龙,董雰,陈强..拟穴青蟹幼蟹对饲料亮氨酸的需求量[J].水产学报,2026,50(5):209-225,17.基金项目
浙江省万人计划(2022R52021) （2022R52021）
浙江省"十四五"农业新品种选育重大科技专项(2021C02069-6) （2021C02069-6）
浙江省教育厅一般科研项目(Y202457266) （Y202457266）
浙江省省属高校基本科研业务费专项(2024J004-3) Ten-thousand Talents Plan of Zhejiang Province(2022R52021) （2024J004-3）
Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural Varieties(2021C02069-6) （2021C02069-6）
Scientific Research Fund of Zhejiang Provincial Education Department(Y202457266) （Y202457266）
Fundamental Research Funds for Zhejiang Provincial Universities and Research Institutes(2024J004-3) （2024J004-3）
