Final report
Farmers receive higher prices per kilo for large yabbies. Yabby farmers have reported that the majority of yabbies trapped from farm dams are below market size (< 30 g) and therefore of no economic value. In addition, farmers also report that while dams produce large yabbies when first harvested, after a number of years the proportion of large animals gradually decreases.
To identify why yabbies in farm dams stunted and how farmers could increase the size of small yabbies the project had three main experimental areas: Research station experiments, industry farm dam recording system, and Genetics and Reproduction Laboratory.
This project has shown that population control methods to increase the proportion of marketable yabbies are required. This study has also shown that it is possible to convert yabbies below market size (< 30) to high value animals by improving feeding and management practices. The application of these results will produce larger yabbies and directly result in increased returns to farmers. In addition the increase in market-sized yabbies from farm dams will provide a higher catch rate per unit of trapping effort. Consequently, the harvesting of yabbies from more isolated dams will become economically viable.
Keywords: Cherax albidus, crayfish culture, pond culture, aquaculture techniques, feeding, stocking density, reproduction, hybrid culture.