Introgression of Luxilus cornutus mtDNA into allopatric populations of Luxilus chrysocephalus (Teleostei: Cyprinidae) in Missouri and Arkansas

Authors

  • D. D. DUVERNELL,

    Corresponding author
    1. Department of Biology, Saint Louis University, 3507 Laclede Ave., St. Louis, MO 63103, USA
      TeL +1 314 977 3902. Fax +1 314 977 3117.
    Search for more papers by this author
  • N. ASPINWALL

    Corresponding author
    1. Department of Biology, Saint Louis University, 3507 Laclede Ave., St. Louis, MO 63103, USA
      TeL +1 314 977 3902. Fax +1 314 977 3117.
    Search for more papers by this author

  • David Duvemell is a graduate student in the Ecology, Evolution, and Systematicsprogrammeatst. Louis university. For the last two years he has conducted research on fish hybridization. Nevin Aspinwall holdsa long-terminterest in fish hybridization and this subject has been the unifymg research theme in his laboratory. He recently completed a 26-year study in a British Columbian lake exploring the Isolating mechanismbetween, and the feeding ecologyof, two hybrfdizingminnows.

TeL +1 314 977 3902. Fax +1 314 977 3117.

Abstract

The cyprinid fishes Luxilus cornutus and Luxilus chrysocephalus hybridize extensively in a zone extending through the Great Lakes region with extensive introgression of L. cornutus mtDNA occurring in populations of L. chrysocephalus south of the present hybrid zone in Ohio. Western populations of these two species occur adjacent to one another in Missouri but hybridization has never been observed. In order to determine if hybridization has occurred historically in Missouri, allopatric populations of L. chrysocephalus were analysed for mtDNA introgression. Extensive introgression of L. ***cornutus mtDNA was observed in most populations of L. chrysocephalus in Missouri resulting in the elimination of L. chrysocephalus mtDNA in many populations. Luxilus cornutus mtDNA in L. chrysocephalus is found approximately 300 km south of extant L. cornutus populations in Missouri. Luxilus chrysocephalus mtDNA was replaced by four unique L. cornutus mtDNA haplotypes, with one particular haplotype becoming fixed in several L. chrysocephalus populations. The pattern of introgression suggests that historically L. cornutus occupied a more southern distribution in Missouri bringing it into contact with western populations of L. chrysocephalus and resulting in a hybrid zone.

Ancillary