A preliminary assessment of growth, survival, yield, and economic return of australian red claw crayfish, cherax quadricarinatus, stocked at three densities in earthen ponds in a cool, temperate climate

Juvenile (mean weight 8.1 g) Australian red claw crayfish, Cherax quadricarinatus, were stocked in July at three rates of 12,000/ha, 18,000/ha, and 24,000/ha into two, 0.02-ha earthen ponds in a cool temperature region of the United States (Kentucky) and grown for 70 days. Red claw were fed a pelleted marine shrimp diet twice daily. Ponds had continual aeration provided. Dissolved oxygen and temperature were measured twice daily (0900 and 1530 hours); total ammonia nitrogen (TAN), nitrite, and alkalinity were measured twice weekly; and pH was measured daily. At harvest, there were no significant (P > 0.05) differences in final individual weight, percentage weight gain, specific growth rate, feed conversion ratio, percentage survival, yield, and economic return among all treatments and averaged 58.4 g, 805%, 3.04%/ day, 7.47,42.7%,461 kg/ha, and -$2659/ha, respectively. There were no significant (P > 0.05) differences in the percentage of males and females harvested from the ponds among any stocking rate with males comprising 48.2% and females comprising 51.8%. Final individual weight of males and females was not significantly (P > 0.05) different among all treatments. These data indicate that there is no advantage to stocking red claw at rates below 24,000/ha in terms of growth, survival, yield, and economic return and that red claw can grow to marketable size in a cooler temperate region of the United States with a short (<110 days) growing season by stocking a larger-size (8 g) red claw.