Differences between Pagrus major and Pagrus auratus through mainly mtDNA control region analysis

抄録

The magnitude of intraspecific and interspecific genetic differentiation in Pagrus major collected from two Japanese areas, the East China Sea (ECS) and the South China Sea (SCS), and Pagrus auratus, collected from Australia (AUS) and New Zealand (NZ), was estimated using restriction fragment length polymorphism (RFLP) analysis and DNA direct sequencing of the mtDNA control region. The RFLP haplotypic diversities in P. major samples were high (0.88-0.93); in contrast, these diversities were relatively lower (0.58-0.65) in P. auratus samples. The relative relationships among samples that resulted from RFLP analysis were almost the same as those from DNA direct sequencing, except that values from the former were less sensitive and were one-third to one-fifth lower than those from the latter. A significant heterogeneity was observed in the distribution of RFLP haplotypes between samples from P. auratus and P. major, and between samples from AUS and NZ. The difference of the nucleotide substitution by direct sequencing in the control region between P. auratus and P. major was 3.48%. Based on the substitution rate, the division time between samples from P. auratus and P. major was assumed to be 2-6 million years ago. With regard to morphological aspects, there was a significant difference in the bump between NZ and ECS samples, although there were no other significant external morphological differences. From these results, we suggest that the relationship between these ‘species’ is at the level of a subspecies. Accordingly, P. major might be renamed P. auratus major and P. auratus renamed P. auratus auratus.