鱼类蛋白氨基酸的研究与进展.pdfVIP

Aquaculture 177 1999 201–216 Fish larval nutrition: a review of recent advances in the roles of amino acids Ivar Rønnestad a, , Anders Thorsen b , Roderick Nigel Finn a a Department of Zoology, Uniersity of Bergen, Allegt 41, N-5007 Bergen, Norway ´ b Department of Marine Enironment, Institute of Marine Research, Nordnesgt 50, N-5024 Nordnes, Bergen, Norway Accepted 1 October 1998 Abstract Marine pelagic fish eggs from various latitudes contain up to 50% of the total amino acid pool as free amino acids FAAs . The FAA pool is established during final oocyte maturation and seems to derive from the hydrolysis of a yolk protein. During yolk resorption, the FAA pool is depleted and reaches low levels at first feeding. The FAA are predominantly used as metabolic fuel, but they are also utilized for body protein synthesis. Amino acids are also important catabolic substrates after the onset of first feeding and may account for 60% or higher of the energy dissipation. Since growth is primarily an increase in body muscle mass by protein synthesis and accretion and fish larvae have very high growth rates, they have a high dietary requirement for amino acids. Fish larvae that develop stomachs late in development have a low proteolytic and absorptive capacities of the digestive systems at first feeding. In vivo studies have shown higher absorption of FAA than peptides and protein bound amino acids from the larval gut in the early stages of marine fish larvae. In the ocean, marine fish larvae obtain a large supply of FAA by consuming plankton after first feeding. The F