长江水系四大家鱼种质资源的保护和合理利用

四大家鱼是我国淡水养殖和捕捞的主要对象，本文从影响长江水第四大家鱼种质资源的主要因素出发，对目前鱼类养殖场普遍存在的四大家鱼种质退化的原因进行了分析，提出了保护长江水系四大家鱼天然产卵场，利用长江故道保护和合理利用长江四大家鱼种质资源，保护四大家鱼人工养殖群体的遗传性能，建立长江水系四大家鱼种质资源监测体系等对策。

PROTECTION AND RATIONAL UTILIZATION OF THE GERMPLASM RESOURCES OF THE FOUR MAJOR CHINESE CARPS IN THE YANGTZE RIVER SYSTEM

The four major Chinese carps, i.e, the black carp (Mylopharyngodon piceus),the grass carp (Ctenopharyngodon idellus), the silver carp (Hypophthalmichthys molitrix) and the big head carp (Aristichthys nobilis) are the main species for freshwater aquaculture and fishing in China. Based on the main factors influencing the germplasm resources of the carps in the Yangtze River system, this paper deals with the analysis of the phenomena of the degradation of the germ lines that are ubiguitously present in fish farms and the analysis of the causes of the sustaining degradation of the fish resources, and puts forward the strategies such as the protection of thespawning grounds, the use of the obsolete course of the Yangtze River for the protection and rational utilization of the germplasm resources, the protection of the genetic properties of the cultured stocks and the establishment of the monitoring system of the germplasm resources in the Yangtze River system.