Dr. Yew-Hu Chien of the Department of Aquaculture, National Taiwan
Ocean University, Keelung, Taiwan, reported in a recent nutrition and
disease seminar sponsored by Roche Aquaculture Centre, Far East, In
Bangkok, that astaxanthin has uses other than enhancing the
pigmentation in cultured kuruma shrimp (Penaeus japonicus). It can correct the "blue" disease in cultured tiger shrimp (P. monodon) and can enhance quality for a better price.
Besides pigmentation, other biological functions of astaxanthin have gained increasing attention recently. Survival improvement in kuruma shrimp and tiger shrimp by dietary astaxanthin supplementation was reported. It was postulated that astaxanthin in shrimp may serve as an intracellular oxygen reserve, allowing the shrimp to survive under the hypoxic conditions in pond bottom.
Astaxanthin has been shown to add tolerance to environmental stresses.
When subjected to sudden salinity drop, kuruma shrimp juvenile with higher astaxanthin consumed less oxygen. Under the condition of gradual decline of dissolved oxygen from saturation to depletion and remained depleted for a period of time, tiger shrimp juvenile fed high astaxanthin had significantly greater survival than those fed no astaxanthin supplement diet.
Instead of retinoids (vitamin A), astaxanthin was suggested as essential
growth factor in early development of bear shrimp (P. semisulcatus).
Significant positive correlation was found between dietary astaxanthin
supplementation and growth of tiger shrimp postlarvae, but not growth of kuruma shrimp juvenile.
Another study by G. Merchie of the Ghent University found that
astaxanthin enhances the physiological condition and disease resistance of postlarval P. monodon.
Meanwhile, Ms. Renee Chou, fish nutritionist with the Singapore Primary Production Department, included the role of carotenoids in nutritional prophylaxis in her review (at the VICTAM international feed and food industries show held in November in Bangkok) of recent developments in marine shrimp and fish nutrition in Asia, as follows: Asthaxanthin as Carophyll Pink improved FCR and yield in shrimp when given at 625 ppm in diet; improved egg number per female, improved fertilization rate and metamorphosis to protozoea, at 100 ppm in diet.
(excerpt from AQUACULTURE ASIA January-March 1997, Vol. II, 1: 45)
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