CULTURE OF THE AUSTRALIAN RED-CLAW CRAYFISH (CHERAX-QUADRICARINATUS) IN ISRAEL - II - 2ND GROWOUT SEASON OF OVERWINTERED POPULATIONS

Redclaw crayfish (Cherax quadricarinatus) were collected after a first growout season and held over winter in earthen ponds under a plastic covering. At the end of the winter, separate male and female populatio ns and mixed populations were stocked in earthen ponds for a second gr owout season of 226 days. The slight differences in weight between mal es and females at the end of the first growout season were substantial ly enhanced during the second growout season. After the second growout season, crayfish weighing over 100 g were significantly more abundant in the male-stocking ponds than in the mixed-stacking ponds and were scarce among the specimens harvested from the ponds stocked with femal es. Survival rates of the crayfish cultured for a second season were c alculated to be at least 78% in the all-male stocking and 86% in both the female and mixed-sex stockings. Crayfish weighing less than 15 g, representing in-pond reproduction during the second growout season, co mprised over 30% of the harvest in both the mixed-sex and female stock ings, and less than 7% in the male stocking. Growing male C. quadricar inatus for a second growout season thus seems promising. However, deve lopment of the appropriate aquaculture technologies for monosex popula tion formation and overwintering is needed.