Research Commons
      • Browse 
        • Communities & Collections
        • Titles
        • Authors
        • By Issue Date
        • Subjects
        • Types
        • Series
      • Help 
        • About
        • Collection Policy
        • OA Mandate Guidelines
        • Guidelines FAQ
        • Contact Us
      • My Account 
        • Sign In
        • Register
      View Item 
      •   Research Commons
      • University of Waikato Research
      • Science and Engineering
      • Science and Engineering Papers
      • View Item
      •   Research Commons
      • University of Waikato Research
      • Science and Engineering
      • Science and Engineering Papers
      • View Item
      JavaScript is disabled for your browser. Some features of this site may not work without it.

      Growth and population dynamics of crayfish Paranephrops planifrons in streams within native forest and pastoral land uses

      Parkyn, Stephanie M.; Collier, Kevin J.; Hicks, Brendan J.
      Thumbnail
      Files
      Hicks - Growth and population.pdf
      524Kb
      Link
       www.royalsociety.org.nz
      Citation
      Export citation
      Parkyn, S. M, Collier, K. J. & Hicks, B. J. (2002). Growth and population dynamics of crayfish Paranephrops planifrons in streams within native forest and pastoral land uses. New Zealand Journal of Marine and Freshwater Research 36, 847-861.
      Permanent Research Commons link: https://hdl.handle.net/10289/1573
      Abstract
      Population dynamics of crayfish (Paranephrops planifrons White) in streams draining native forest and pastoral catchments, Waikato, New Zealand, were investigated from September 1996 to July 1998. Crayfish densities were generally greater in native forest streams because of high recruitment over summer, but varied greatly between streams in both land uses. Peak densities in summer were 9 crayfish m-2 in native forest and 6 crayfish m-2 in pasture streams, but peak biomass in summer was much greater in pasture streams. Mark-recapture data showed that crayfish, particularly juveniles, in pasture streams grew faster than in native forest streams, through both greater moult frequency and larger moult increments. Females reached reproductive size at c. 20 mm orbit-carapace length (OCL) after their first year in pasture streams, but after 2 years in native forest streams. Annual degree days >10°C appeared to explain the differences in the timing of life cycles. Estimates of annual crayfish production (range = 0.8-3.4 g dry weight m-2 year-1) were similar in both land uses, and P/B ratios were between 0.95 and 1.2. Despite deforestation and conversion to pasture, crayfish in these Waikato hill-country streams have maintained similar levels of annual production to those in native forest streams, although juvenile growth rates have increased and longevity has decreased.
      Date
      2002-11
      Type
      Journal Article
      Publisher
      RSNZ Publishing
      Rights
      Copyright New Zealand Journal of Marine and Freshwater Research. Used with permission.
      Collections
      • Science and Engineering Papers [3122]
      Show full item record  

      Usage

      Downloads, last 12 months
      37
       
       

      Usage Statistics

      For this itemFor all of Research Commons

      The University of Waikato - Te Whare Wānanga o WaikatoFeedback and RequestsCopyright and Legal Statement