3 years ago

Dynamics of commercial size interval populations of female redclaw crayfish (Cherax quadricarinatus) reared in gravel-lined ponds: A stochastic approach

The objective of the present study was to establish the impact of monosex-female redclaw crayfish (Cherax quadricarinatus) culture in gravel-lined ponds, by using a stochastic approach to analyze production dynamics for the 40–60g, 61–90g and >90g commercial-size intervals. After growing female redclaw crayfish 17weeks in 2500m2 gravel-lined ponds stocked at 6femalesm2, mean final weight was 80.53±0.70g, survival was 76.2±1.7% and FCR was 0.82±0.10. Overall, yields averaged 0.26tha1, 2.12tha1 and 0.99tha1, respectively, for the 40–60g, 61–90g and >90g size intervals. This resulted in a mean total biomass of 3.39tha1 and a commercial biomass of 3.3tha1. Values of the coefficient of variation of total commercial biomass indicated a maximum certainty in production after 10weeks, when percentages of recruitment of the 40–60g and 61–90g size intervals were similar. The contribution of the >90g size interval was negligible, and the total composition of the commercial population was more homogeneous. The sensitivity analysis showed consistency of the simulation model. After 10weeks, variability of the commercial biomass is particularly influenced by the rate at which mean individual weight (w t.) changes from its initial value to its final value (k). In contrast, after 17weeks the variability of k was not relevant in determining the variance of commercial biomass, because the influence of k progressively diminishes as the final weight of crayfish is approached. Results from the Monte Carlo simulation indicated that, when increasing sample size from one pond to 100 ponds, variability in production forecasts was reduced 89.8%. The present study demonstrates the feasibility of monosex-female redclaw crayfish culture in gravel-lined ponds. It also shows that the stochastic approach used to analyze production dynamics for the 40–60g, 61–90g and >90g commercial-size intervals is an important tool to evaluate the impact of size classes on total production and commercial yields. According to our results, we recommend an initial stocking density of 6organismsm2 for commercial monosex grow-out of females in gravel-lined ponds.

Publisher URL: www.sciencedirect.com/science

DOI: S0044848616309656

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.