鱼类早期资源的发生和生长决定种群的年际补充强度。洞庭湖是重要的鱼类基因库，渔业资源已严重衰退。河湖复合生境是很多鱼类完成早期生活史的重要场所，支流-湖泊区鱼类早期资源的发生和生长直接关系着补充到洞庭湖鱼类的幼鱼数量，但相关的研究很少；支流上严重的水电开发对洞庭湖鱼类早期资源发生和生长的影响亟待分析和了解。沅水是洞庭湖最长的支流，本研究拟在沅水-西洞庭湖区采集鱼卵和仔鱼，采用形态学和分子生物学相结合、耳石微结构分析等方法；比较不同生境不同发育期、不同生态类型仔鱼数量和比例组成以及仔鱼的种类组成；比较不同生境优势鱼类仔鱼的丰度、生长率和摄食强度的差异；分析环境因子和仔鱼群聚、生长率之间的关系。揭示支流-湖泊区不同生境在鱼类早期资源补充过程中的作用和关键的影响因子，阐明支流-湖泊区对种群补充的重要性，分析电站对鱼类产卵和生长的影响，并提出保护策略，对洞庭湖渔业资源的保护和修复具有重要的价值。

Occurrence and growth of fish resources of early life history stages determine year-class strength of population. Fishery resources have been heavily declined in Dongting Lake, which is an important gene pool. Many fishes in Dongting Lake spend the early life history stages in lakes and its tributaries. River-lake ecosystems play a crucial role in determining the survival rate of fish juveniles into Dongting Lake by influencing fish occurrence and growth in the early life history stages. But information about the process of fish recruitment is scarce. Many dams have been established in the tributaries, and its effects on occurrence and growth of fish in early life history stages are not known. Yuanhshui River is the longest tributary. In this study, ichthyoplankton will be collected in lotic, slow water-flows and lentic habitats in the Yuanshui River and West Dongting Lake. The morphological methods and molecular biological technique, otolith microstructure will be utilized to identify species and analyze growth. The density and the proportion of eggs and larvae in different developmental stages, and larval fish of different ecotypes will be compared among the three habitats. Larval assemblage will be determined in each habitat. The density, growth rate and feeding intensity will be compared for larvae of dominant fish among the three habitats. The influence of abiotic and biotic factors on larvae occurrence, growth and feeding will be analyzed. The results will reveal the contributions of the three habitats to the spawning and nursing of fish, and the crucial environmental factors. The importance of river-lake ecosystems to the recruitment of population and the effects of the dams on fish resources will be elucidated. These results will guide conservation and restoration of fish resource in the Dongting Lake.