Vitamin A (VA) is an essential dietary nutrient for fish and plays an important role in a range of physiological processes including vision, reproduction, embryogenesis, growth and differentiation and maintenance of epithelial cells. Knowledge of effects of VA on aquatic organisms is limited, but new information continues to be published. The aim of the present review is to present an overview of the dietary requirements and functions of VA in fish of commercial importance in aquaculture production. The effects of VA on reproduction and early embryonic development are described, and the estimated dietary requirements for VA of several species of fish are discussed. New research findings on how VA requirements vary with the life stages of fish are explored that will expand understanding of the complex role of VA. Sources of VA in feeds are described, and the potential need to consider how changes in fish feed formulations towards higher use levels of sustainable ingredients may affect dietary VA supplementation recommendations is discussed.

中文翻译：

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鱼中维生素A的功能和需求

维生素A（VA）是鱼类必需的饮食营养素，并且在一系列生理过程（包括视觉，生殖，胚胎发生，上皮细胞的生长，分化和维持）中起重要作用。VA对水生生物影响的知识是有限的，但是新的信息仍在继续发布。本综述的目的是概述在水产养殖生产中具有商业重要性的鱼类中VA的饮食需求和功能。描述了VA对生殖和早期胚胎发育的影响，并讨论了几种鱼类对VA的估计饮食需求。探索了有关VA需求量如何随着鱼的生命阶段而变化的新研究发现，这将扩大对VA的复杂作用的理解。