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Age and growth of two newly established invasive populations of Tilapia mariae in northern Australia

Authors

  • D. J. Russell,

    Corresponding author
    1. Invasive Animals Cooperative Research Centre, University of Canberra, Canberra, ACT, Australia
    • Northern Fisheries Centre, Department of Agriculture, Fisheries and Forestry, Cairns, Qld, Australia
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  • F. E. Thomson,

    1. Northern Fisheries Centre, Department of Agriculture, Fisheries and Forestry, Cairns, Qld, Australia
    2. Invasive Animals Cooperative Research Centre, University of Canberra, Canberra, ACT, Australia
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  • P. A. Thuesen

    1. Northern Fisheries Centre, Department of Agriculture, Fisheries and Forestry, Cairns, Qld, Australia
    2. Invasive Animals Cooperative Research Centre, University of Canberra, Canberra, ACT, Australia
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Author to whom correspondence should be addressed. Tel.: +61 740573717; email: johnru2001@hotmail.com

Abstract

Sagittal otoliths were used to age the samples of Tilapia mariae collected from a coastal river and an impoundment. Validation of sagittae checks was achieved using both quantitative marginal increment analysis and by tetracycline marking of the otoliths of fish kept in tanks and in a farm dam. The annulus pattern on the otoliths was generally clear and their formation appeared to be temperature related and largely completed in the Austral spring around September and October. Male T. mariae grow faster and larger than females and the maximum ages of fish from the coastal river and impoundment was 9+ and 4+ years, respectively. Past fish surveys and the absence of older age classes in the impoundment population would suggest that this population was only very recently established.

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