ISSN:
1365-2109
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
Notizen:
Stocking and harvest data from 45 grow-outs of the crayfish Cherax tenuimanus (Smith 1912) on a commercial farm were analysed to give predictive equations for survival, mean weight and individual weights of crayfish at harvest. Density dependence was a major factor influencing variation in survival and mean weight. Harvest mean weight decreased, and biomass increased, with density. The crayfish price ($ kg−1) employed to estimate the market value of harvested crayfish increased with individual weight from a minimum saleable weight of 40 g. For grow-out of 0+ year-olds for 1 year, the market value was a maximum at low stocking densities of 1.5-2.0 m−2. Further grow-out for 1 year of the unsaleable weight range (20-40 g) of 1+ year-olds, gave a harvest value which increased with stocking density. Comparison of predicted and actual cohort numbers and mean weights for a further 1 5 harvests showed no bias in prediction and a mean precision level of 16% for numbers and 11% for mean weight.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1365-2109.1995.tb00862.x
