Get access
Advertisement

Recent speciation between sympatric Tanganyikan cichlid colour morphs

Authors

  • CATHERINE E. WAGNER,

    1. Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
    2. Fuller Evolutionary Biology Program, Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA
    Search for more papers by this author
    • Present address: Department of Fish Ecology & Evolution, EAWAG Centre for Ecology, Evolution and Biogeochemistry, Seestrasse 79, 6047 Kastanienbaum, Switzerland.

    • Present address: Institute of Ecology and Evolution, Aquatic Ecology, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland.

  • AMY R. McCUNE,

    1. Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
    Search for more papers by this author
  • IRBY J. LOVETTE

    1. Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
    2. Fuller Evolutionary Biology Program, Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA
    Search for more papers by this author

Catherine E. Wagner, Fax: +41 (0)58 765 21 68; E-mail cew35@cornell.edu

Abstract

Lake Tanganyika, Africa’s oldest lake, harbours an impressive diversity of cichlid fishes. Although diversification in its radiating groups is thought to have been initially rapid, cichlids from Lake Tanganyika show little evidence for ongoing speciation. In contrast, examples of recent divergence among sympatric colour morphs are well known in haplochromine cichlids from Lakes Malawi and Victoria. Here, we report genetic evidence for recent divergence between two sympatric Tanganyikan cichlid colour morphs. These Petrochromis morphs share mitochondrial haplotypes, yet microsatellite loci reveal that their sympatric populations form distinct genetic groups. Nuclear divergence between the two morphs is equivalent to that which arises geographically within one of the morphs over short distances and is substantially smaller than that among other sympatric species in this genus. These patterns suggest that these morphs diverged only recently, yet that barriers to gene flow exist which prevent extensive admixture despite their sympatric distribution. The morphs studied here provide an unusual example of active diversification in Lake Tanganyika’s generally ancient cichlid fauna and enable comparisons of speciation processes between Lake Tanganyika and other African lakes.

Get access to the full text of this article

Ancillary