Discrimination of natural and cultured Oplegnathus fasciatus populations in Zhoushan sea area based on otolith morphology.

Abstract

To effectively distinguish natural and cultured populations of Oplegnathus fasciatus, we used both traditional 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.