鹰爪虾 1. Based on the Logistic equation as a model,curves about the selectivity of the three codends to the target species,Palaemon gravieri,were obtained. 使用Logistic曲线作为选择性模型,求得不同网目大小的网囊对鹰爪虾的体长选择性曲线,并运用极大似然法对渔获数据进行处理,同时估算选择性参数。