Application of otolith shape analysis to species separation in Sebastes spp. from the Bohai Sea and the Yellow Sea, northwest Pacific

Shape descriptors of sagittal otoliths were applied to the identification of four sympatric species of the genus Sebastes (Sebastes schlegeli, S. hubbsi, S. nudus and S. thompsoni) inhabiting the coastal reefs of the Bohai Sea and the Yellow Sea, northwest Pacific. Canonical discriminate analysis of standard length-corrected otolith shape variables (a combination of shape indices and elliptic Fourier coefficients) was demonstrated to be a useful tool for species identification with a high overall classification success of 96.6 %. An otolith morphological tree based on hierarchical average linkage cluster analysis indicated the closest proximity was between S. hubbsi and S. nudus. The otolith morphological affinities coincide well with the phylogenetic relationships reported among these species, which indicates the potential to use otolith morphology to establish phylogenetic relationships in this genus. In addition, ecomorphological comparisons suggest that the otolith shapes might be influenced by several ecological and environmental components such as depth, body color and substrate type. Among the environmental factors, depth could be the most comprehensive factor associated with the inter-specific variations of otolith morphology.