Creating and destroying species: the ‘new’ biodiversity and evolutionarily significant units among New Zealand's galaxiid fishes

Authors

  • N. Ling,

    Corresponding author
    1. Centre for Biodiversity and Ecology Research, Department of Biological Sciences, Waikato University, Private Bag 3105, Hamilton, New Zealand
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  • D. M. Gleeson,

    1. Ecological Genetics Laboratory, Landcare Research N.Z. Ltd, Private Bag 92170, Auckland, New Zealand
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  • K. J. Willis,

    1. Centre for Biodiversity and Ecology Research, Department of Biological Sciences, Waikato University, Private Bag 3105, Hamilton, New Zealand
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    • Scottish Association for Marine Science, P.O. Box 3, Oban, Argyll, PA34 4AD Scotland.

  • S. U. Binzegger

    1. Ecological Genetics Laboratory, Landcare Research N.Z. Ltd, Private Bag 92170, Auckland, New Zealand
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¶Author to whom correspondence should be addressed. Tel.: +64 7 856 2889; fax: +64 7 838 4324; email: nling@waikato.ac.nz

Abstract

Morphological and genetic analyses of populations of two non-diadromous galaxiid species, the black mudfish and Neochanna heleios, the dwarf inanga Galaxias gracilis confirm the presence of a cryptic species, Neochanna heleios, within the geographic range of N. diversus, and indicate three distinct evolutionarily significant units (ESUs) in the latter species. Comparisons between G. gracilis and its parent taxon, G. maculatus, reveal that the former is not monophyletic and derives from three separate founding events. Significant morphological divergence between these two species is the result of ontogenic shifts in landlocked lacustrine populations and long-term morphological convergence in populations of G. gracilis.. Corresponding incipient changes are recognized in other younger landlocked populations of G. maculatus in New Zealand. These populations and the three groups within G. gracilis should be given the status of ESUs and managed accordingly by conservation agencies.

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