PHYLOGEOGRAPHIC PATTERNS IN KINOSTERNON SUBRUBRUM AND K-BAURII BASED ON MITOCHONDRIAL-DNA RESTRICTION ANALYSES

We used restriction assays of mitochondrial (mt) DNA to estimate phylo geographic variation in two sister taxa of mud turtles in the southeas tern United States. Extensive mtDNA variation characterized Kinosterno n subrubrum and, to a lesser degree, K. baurii. Each of 26 mtDNA haplo types from the 83 assayed specimens was localized spatially. Collectiv ely these mtDNA haplotypes demarcated four major matrilineal assemblag es each with a well defined regional distribution: a western group (A) in Missouri and Louisiana, a central group (B) throughout the Gulf co astal states, an eastern group (C) along the Atlantic coastal states n orth of Florida, and a southern group (D) in peninsular Florida. All a ssayed samples of K. baurii belonged to the mtDNA C assemblage. The tw o species in Florida are thus highly distinct in mtDNA genotype, but t hey exhibit minimal mtDNA divergence along the Atlantic coastal states . These findings raise questions concerning the evolutionary history a nd taxonomy of these two recognized species, MtDNA phylogeographic pat terns in the baurii/subrubrum complex are remarkably similar to those reported previously for two other southeastern kinosternids, Sternothe rus minor and S. odoratus.