Patterns of genetic diversity in Notropis girardi in the Canadian River and Pecos River, New Mexico.

Authors: Tracy A. Diver, Megan J. Osborne, Thomas F. Turner

Year: 2009 (xli)

Abstract

The Pecos River in New Mexico hosts a diverse community of pelagic spawning cyprinids. Relatively high alpha diversity results from the presence of an intact native fish fauna coupled with non-native species that have been introduced from other rivers. Using the protein-encoding mtND4 gene, we first assessed genetic diversity of six species within this community. There was no evidence of introgression between species, and, contrary to expectations of genetic theory, mtDNA diversity (as measured by Á¨) was higher for recently introduced species Notropis girardi and, Hybognathus placitus compared to native Macrhybopsis aestivalis and Notropis jemezanus and endemic species Notropis simus pecosensis. Non-native species were presumably introduced into the system by bait bucket release (Bestgen et. al. 1989), and high levels of genetic diversity of non-native populations may result from multiple introductions from genetically divergent sources. In this study, samples from the introduced Pecos River population of N. girardi were compared to samples collected in the native range in the Canadian River, NM. Nucleotide sequence data from the mtND4 were compared among groups to determine whether the Canadian River, NM is the likely source population of the introduced population. Future work will focus on genetic assessment of other potential source populations via analysis of mtDNA and nuclear-encoded microsatellite DNA markers.