Phylogeography of multiple lineages of black rats Rattus rattus Complex (Mammalia: Rodentia: Muridae) in Peninsular Thailand

In this study, we investigated phylogeography of the Rattus rattus Complex (=RrC) in Peninsular Thailand. A total of 945 base pairs of cytochrome b gene for 340 specimens were analyzed, including 46 specimens newly collected in this study. Phylogenetic inference using maximum likelihood and Bayesian Inference (BI) based on a partitioned substitution model showed that R. rattus Complex is grouped into 6 major lineages, with haplotypes from Thailand belonging to RrC Lineage II, RrC Lineage IV, and RrC Lineage VI. The haplotype diversity ( h ) and nucleotide diversity ( π ) were 0.958 and 0.03319 for the three lineages. The genetic distances were 0.78, 0.98, and 1.26 within RrC Lineage II, RrC Lineage IV, and RrC Lineage VI, respectively, and 5.93 between RrC Lineage II and RrC Lineage IV, 5.54 between RrC Lineage II and RrC Lineage VI, and 4.91 between RrC Lineage IV and RrC Lineage VI. This study elucidated that Peninsular Thailand and adjacent islands in Andaman Sea involve such 3 lineages. The overlapped distribution of multiple lineages in Peninsular Thailand and Andaman Sea islands may result from population exchange and dispersal with the northern Indochina in RrC Lineage II and RrC Lineage IV, and with southern Sunda RrC Lineage VI.