Population genetic structure and taxonomy of the common dolphin (Delphinus sp.) at its southernmost range limit: New Zealand waters

Authors

  • Karen A. Stockin,

    1. Coastal-Marine Research Group, Massey University, NSMC, Auckland, New Zealand
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    • Authors contributed equally to this work.
  • Ana R. Amaral,

    1. Universidade de Lisboa, Faculdade de Ciências, Centro de Biologia Ambiental, Campo Grande, Lisbon, Portugal
    2. Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
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    • Authors contributed equally to this work.
  • Julie Latimer,

    1. Allan Wilson Centre for Molecular Ecology and Evolution, Massey University, NSMC, Auckland, New Zealand
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  • David M. Lambert,

    1. Allan Wilson Centre for Molecular Ecology and Evolution, Massey University, NSMC, Auckland, New Zealand
    2. Griffith School of Environment, Griffith University, Nathan, Queensland, Australia
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  • Ada Natoli

    Corresponding author
    1. Biology Department, United Arab Emirates University, Al Ain, United Arab Emirates
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Abstract

New Zealand is the southernmost limit of the common dolphin's (genus Delphinus) distribution in the Pacific Ocean. In this area, common dolphins occur in both coastal and oceanic habitats, exhibit seasonal and resident occurrence, and present high morphological variability. Here we investigated the population structure and the taxonomic identity of common dolphins (Delphinus sp.) within New Zealand waters using 14 microsatellite loci, 577 bp of the mtDNA control region, and 1,120 bp of the mtDNA cytochrome b gene across 90 individuals. We found high genetic variability and evidence of population expansion. Phylogenetic analyses conducted to clarify the taxonomic status of New Zealand common dolphins did not show any clustering reflecting geographic origin or morphotypes. The microsatellite analysis showed genetic differentiation between Coastal and Oceanic putative populations, while mtDNA revealed significant genetic differentiation only between the Hauraki Gulf and other putative groups. Our results suggest that differences in habitat choice and possible female site fidelity may play a role in shaping population structure of New Zealand common dolphins.

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