摘要
深海海鱼鱼卵中的游离氨基酸占鱼卵总氨基酸含量的近 5 0 % (干重 )。游离氨基酸库中的游离氨基酸似乎是卵黄蛋白的水解产物。仔鱼吸收卵黄内源营养的过程中 ,游离氨基酸库中的游离氨基酸逐渐减少 ,到仔鱼开始摄食时 ,库中的游离氨基酸已近枯竭。游离氨基酸不仅是代谢能源 ,而且是体蛋白合成的基本原料。仔鱼开始摄食后 ,氨基酸作为分解代谢的重要物质 ,可能有高达 6 0 %的能量由氨基酸提供。由于仔稚鱼的生长主要是通过合成蛋白质增加鱼体的重量 ,加之仔稚鱼的生长速度很高 ,因此 ,仔稚鱼需要其饲料中有较高的氨基酸含量。仔鱼开始摄食后 ,其消化系统对蛋白质的水解和吸收能力较弱。海水仔稚鱼的早期阶段 ,仔鱼的肠道对游离氨基酸的吸收要高于对多肽和蛋白质中氨基酸的吸收。仔鱼开始摄食后 ,由浮游生物获得大量的游离氨基酸。用微粒饲料培育仔稚鱼 ,微脂粒技术可能是向饲料中添加游离氨基酸的实用技术。
Nearly 50% of the total amino acid in marine pelagic fish eggs are free amino acids (FAAs). The FAAs seem to be the hydrolysis products of a yolk protein. The FAAs are mainly used as metabolic energy source, but they are also utilized for body protein synthesis. Amino acids are also important catabolic substrates and may account for 60% or higher of the energy consumption. Fish larvae have a high dietary requirement for amino acids and a low protein hydrolytic and absorptive capacities of the digestive systems at first feeding. Some studies have showed higher absorption of FAA than peptides and protein bound amino acids from the larval gut in the early stages of marine fish larvae. Marine fish larvae obtain a large supply of FAA by consuming plankton after first feeding in the ocean. While microdiets are used for fish larvae, it is possible that the high contents of FAA are added in microdiets by liposomes techniques.
出处
《海洋水产研究》
CSCD
2003年第1期75-79,共5页
Marine Fisheries Research
基金
国家自然科学基金 (38770 588)
关键词
海水仔稚鱼
氨基酸
营养生理
研究进展
Marine fish larvae Essential amino acids Nutrition physiology Research outline
