太湖秀丽白虾抱卵前后肌肉生化组成和能量密度变动*

 于2008年4-5月在太湖三山岛水域采集秀丽白虾(Exopalaemon modestus)的未抱卵虾、抱卵虾和已出苗虾样本，对肌肉中相关指标进行了分析测定,旨在研究繁殖期秀丽白虾肌肉生化组成和能量密度的变动。结果表明：秀丽白虾繁殖期干物质含量为20.28%-20.82%，粗脂肪含量为1.42%-1.62%，能量密度为4.510-4.774 kJ/g，均显示未抱卵虾>抱卵虾>出苗虾；粗蛋白和粗灰分含量变幅较小，分别为16.57%-17.12%和1.31%-1.40%。秀丽白虾对蛋白质的利用主要在繁殖前期，抱卵后氨基酸总量下降6.96%，必需氨基酸含量下降8.89%，赖氨酸、精氨酸和亮氨酸的降幅最为明显。肌肉中不饱和脂肪酸含量均显著高于饱和脂肪酸含量，比值为1.76∶1-1.90∶1。不饱和脂肪酸主要消耗于抱卵后至出苗期间，单不饱和脂肪酸含量下降13.43%，其中C16∶1下降42.38%；多不饱和脂肪酸的消耗以必需脂肪酸C18∶2为主，降幅为33.05%。秀丽白虾繁殖期粗蛋白和粗灰分含量相对稳定，脂肪是其代谢能量的主要来源，但出苗后肌肉脂肪含量和能量密度的降幅均低于一般鱼类。

Variation of Biochemical Components and Energy Density in Muscle of Exopalaemon modestus in Breeding Season in Taihu Lake

The objective was to study the variation of biochemical components and energy density in muscle of Exopalaemon modestus in breeding season From April to May in 2008, antepartum shrimps, incubatory shrimps and postpartum shrimps were collected from waters of Sanshan Island in Taihu Lake, and the relational parameters were mensurated and analyzed The results showed that contents of dry matter were 20.28%-20.82%, crude fat were 1.42%-1.62% and energy density showed 4.510-4.774kJ/g, above indexes of antepartum shrimps were all the highest in three stocks, while those of postpartum shrimps were the lowestThe contents of crude protein and ash, which showed tiny variation, were 16.57%-17.12% and 1.31%-1.40% respectively In the prophase of breeding season,the content of crude protein showed a slightly decrease of 3.21%, while amount of total amino acids and essential amino acids decreased 6.96% and 8.89%,respectively, and remarkable decrease of lysine, arginine and leucine could be found In each stage of breeding season,the contents of unsaturated fatty acid in muscle were significantly higher than those of saturated fatty acid, with the ratio of 1.76-1.90 In the anaphase of breeding season, unsaturated fatty acids were consumed substantially, and the content of monounsaturated fatty acids decreased 13.43%, which was more than those of saturated fatty acids and polyunsaturated fatty acids The content of C16∶1 decreased most obviously in monounsaturated fatty acids, and so was C18∶2 in polyunsaturated fatty acids, the ranges of them were 42.38% and 33.05% respectively By means of comparative analysis on biochemical components and energy density in muscle of E. modestus in breeding season, it could be found that the contents of crude protein and crude ash were relatively stable, fat was the main source of metabolic energy, and decreasing ranges of fat and energy density were smaller than that of general fishes