Abstract
The complete mitochondrial control regions (CR) of three mackerels (Rastrelliger spp.) were examined and analyzed. The CR contained three domains, in which three termination-associated sequences (TAS-I, TAS-II and TAS-III), two central conserved sequence blocks (CSB-E, CSB-D), three conserved sequence blocks (CSB-I, CSB-II, and CSB-III) and a putative promoter were detected. Molecular indices analyses of the aligned complete CR sequences showed high level of haplotype diversities and genetic divergences among the three species. The intraspecific divergence among species of this genus ranked from 0.25% to 1.62% and interspecific divergence from 1.90% to 4.30%. The phylogenetic tree shows monophyly with R. brachysoma as a basal species of Rastrelliger. Applying the average divergence rate for fish control regions, the results suggest that the time of separation among Rastrelligers could have occurred in the middle Pleistocene era.
Acknowledgements
The authors are grateful to Bob Harwood for his help in the evaluation of the manuscript as well as to two anonymous reviewers for providing helpful comments on an early version of the manuscript.
Declaration of interest
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. This study was supported by a grant from the Kasetsart University Research Development Institute, Bangkok, Thailand.