大鲵（Andriasdavidianus）是世界上珍稀名贵的两栖动物，已被列为国家二级保护动物和国际濒危物种。大鲵主要分布在我国长江中上游、珠江中上游及汉水上游的深山峡谷的石灰岩层结构的溪流中。一、大鳗的生物学及资源概况大钢为卵生，体外受精，属一年一次产卵动物。生殖季节在 Andrias davidianus is a rare and valuable amphibian in the world and has been classified as a national second class protected animal and an internationally endangered species. Dazhu are mainly distributed in the limestone layer of the middle and upper reaches of the Yangtze River, the middle and upper reaches of the Pearl River and the deep canyon upstream of Han River. First, the biology and resources of large eel Grand steel for oviparous, in vitro fertilization, is a spawning animal once a year. Reproductive season in