鳗鲡(Anguilla japonica)性腺发育和饥饿胁迫下生物学指标及体内蛋白质与氨基酸含量变化

VARIATIONS OF BIOLOGICAL INDICATORS AND PROTEIN AND AMINO ACID CONTENT IN ANGUILLA JAPONICA DURING GONAD DEVELOPMENT AND STARVATION STRESS

自然条件下,鳗鲡(Anguilla japonica)自降河入海至性腺发育成熟需洄游数千公里、耗时半年以上,且整个过程中不摄食。本文以降海洄游、人工促熟和长期饥饿(20个月)三种状态下的鳗鲡为材料,研究其在性腺发育和饥饿胁迫时的主要生物学指标(包括肥满度、肝体比、脏体比、性腺指数、含肉率)以及肌肉、肝脏和性腺中的粗蛋白与氨基酸含量的变化情况,以探讨鳗鲡性腺发育和饥饿胁迫下的营养物质来源与变化。结果发现:人工促熟鳗鲡的肝体比、脏体比和性腺指数显著高于降海洄游鳗鲡(P<0.05),而含肉率、肝脏和卵巢内的粗蛋白含量、氨基酸总量、必需氨基酸总量以及非必需氨基酸总量均显著低于降海洄游鳗鲡的含量(P<0.05);长期饥饿鳗鲡的肥满度、肝体比、含肉率、肌肉(鲜样)、肝脏内的粗蛋白、氨基酸总量、必需氨基酸总量以及必需氨基酸占氨基酸总量的比值显著低于降海洄游鳗鲡(P<0.05)。结果表明,鳗鲡性腺发育所需要的营养物质主要来源于肌肉,其性腺的发育依赖自身营养物质在体内的流动和转化,肌肉中的必需氨基酸和非必需氨基酸均被利用,转化成性腺发育所需要的物质。

We investigated the changes of major biological indices（the condition factor, hepatosomatic index, viscerosomatic index, and gonadosomatic index）, meat content ratio, and the contents of crude protein and amino acid in muscle, liver, and gonads among three groups of eel Anguilla japonica, i.e., artificially-induced maturation eels, long-term fasting eels（20 months）, and wild broodstock eels. The results show that the hepatosomatic index, viscerosomatic index, and gonadosomatic index of induced maturation eels were significantly greater than that of wild broodstock eel（P〈0.05）, while the meat content, crude protein content, total amino acids, total essential amino acids and the total non-essential amino acids content in liver and ovary were significant smaller than those of wild broodstock eel（P〈0.05）. The condition factor, hepatosomatic index, meat content, crude protein, total amino acids, total essential amino acids, and total non-essential amino acids in muscle and liver of long fasting eels（20 months） were significantly smaller than those of the wild broodstock eels（P〈0.05）. The results imply that the nutrients required by A. japonica during gonad development were supplied from muscle, and both essential amino acids and non-essential amino acids were utilized to meet the nutrients demand from gonadal development.