A morphological study on ten parrotfish species from Xisha Islands, China

In order to investigate the main differences in the fish body morphology of parrotfish among their species and their important role in species identification, we had collected ten parrotfish species in the Xisha Islands waters from 2019—2022, and selected 24 morphological traits for measurements. Then we used multivariate analyses to discriminate the morphological differences among those species. One-way ANOVA results show significant differences among parrotfish species for all morphological indicators (P<0.05). Seven morphological indicators with eigenvalues greater than 1 had been extracted. The cumulative variance contribution was 66.86%, and the morphological differences among species mainly lay in the characteristics reflecting feeding and swimming abilities. Discriminant analysis was used to discriminate those samples, and the combined discrimination rate was 81.1%. The morphological clustering results of the ten parrotfish species were consistent with those of fish classification but differred significantly from those of evolutionary tree in previous study, which indicates that the phenotypic characteristics of parrotfish can be influenced by environmental factors in addition to genetic control.