Discrimination of natural and cultured Oplegnathus fasciatus populations in Zhoushan sea area based on otolith morphology
To effectively distinguish natural and cultured populations of Oplegnathus fasciatus,we used both tradi-tional statistical analysis and neural network methods to compare six shape indices and twenty-one truss indices from otoliths of 174 randomly selected specimens(100 from a natural population and 74 from a cultured population).The results showed that among the six shape indices,ellipticity,roundness,and aspect ratio exhibited significant differences between the two populations.Twelve out of the twenty-one truss indices displayed significant differences.Results of discriminant analysis indicated that traditional statistical analysis and neural network methods achieved correct discrimination rates of 57.5%and 81.4%for shape indices,while for truss indices were 69.5%and 85.4%,respectively.These findings indicated that neural network technique is more effectively than traditional statistical method to distinguish natural and cultured populations of O.fasciatus.