Harpaz, S., Department of Aquaculture, Agricultural Research Organization, Bet Dagan, Israel, Department of Aquaculture, Agricultural Research Organization, P. O. Box 6, Bet Dagan, 50250, Israel
Rise, M., Institutes for Applied Research, Ben-Gurion University of the Negev, Beer-Sheva, Israel
Arad, S., Institutes for Applied Research, Ben-Gurion University of the Negev, Beer-Sheva, Israel
Gur, N., Zemach Central Feed Mill, M.P. Jordan Valley, Israel

The effect of adding carotenoids from various sources to feed of juvenile freshwater crayfish Cherax quadricarinatus on pigmentation, growth and survival was examined under laboratory conditions. Juvenile crayfish were fed diets fortified with carotenoids at a level of 100 μg g-1 for a period of either 49 or 55 days. Carotenoid sources were: dried algal cells prepared from Dunaliella salina in which the main carotenoid is β-carotene; a synthetic carotenoid, astaxanthin (Carophyll Pink 8%, manufactured by Hoffman-La Roche) and alfalfa meal. Crayfish receiving feeds fortified with carotenoids exhibited better body colouration than those in the control group, which were fed a diet to which no carotenoids were added. Growth and survival of the crayfish were not affected by the addition of carotenoids to their diet. © 1998 Blackwell Science Ltd.