Meeting Abstract

24.2  Wednesday, Jan. 5  Just because the shoe fits doesn’t mean you should wear it: complex evolutionary patterns in the reef fish genus Naso HORNE, John B*; VAN HERWERDEN, Lynne; CHOAT, J Howard; James Cook University; James Cook University; James Cook University john.horne@jcu.edu.au

Some Indo-Pacific coral reef fish species have been reported to have multiple sympatric lineages sometimes called non-geographic or temporal clades. To date, these patterns are only found in non-recombining mtDNA but occur across different taxa in several families. They appear to belong primarily to widespread species with high dispersal potentials. However, notwithstanding the number of recent case studies that feature non-geographic clades, the biological significance of this pattern is still unclear. At one extreme, these parallel lineages may be previously isolated populations that are currently admixed, or cryptic species existing in sympatry. At the other extreme, the divergence between these lineages could be no more than what is expected to arise in a large panmictic population over time. Here I present a comparative phylogeography of five unicornfish congeners, all exhibiting non-geographic population structuring, and conclude that one explanation does not fit all.