Growth and ageing of feral Xenopus laevis (Daudin) in South Wales, U.K.

Authors

  • G. J. Measey

    Corresponding author
    1. School of Biological Sciences, University of Bristol, Bristol BS8 1UG, U.K.
      All correspondence to current address: Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, U.K. E-mail: j.measey@nhm.ac.uk
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All correspondence to current address: Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, U.K. E-mail: j.measey@nhm.ac.uk

Abstract

A feral population of African clawed frogs Xenopus laevis from a small pond in South Wales was sampled continuously for 2 years to assess morphometric growth. Toe-clips taken at intervals over a 4-year period were found to contain lines of arrested growth (LAG) which corresponded to each consecutive winter. The first toe-clips revealed a population structure within the pond consisting of a dominant cohort of frogs with one LAG that metamorphosed in 1993, and a few older individuals. Subsequent toe-clips in 1996 and 1998 gave two and four more LAG, respectively. Morphometric growth was found to be restricted to a short growing season, significant differences in the growth rates of males and females being first detected in their third growth season. Reproductively active frogs were still within their initial period of growth, suggesting that Xenopus laevis does not conform to the standard energy resource allocation mechanisms of typical ectotherms.

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