New Dietary Information: Zeaxanthin
Posted: Sat Nov 19, 2005 4:23 pm
I'm reading Crustacean Nutrition by the World Aquaculture Society. It's a hard slog, let me tell you. But I have finished the chapter on carotenoids. I will be writing an article on all the information found in that chapter, but I think for the time being, it's very important that people are aware of a couple of things.
Astaxanthin is the critical carotenoid as far as crustacean health is concerned. It is 10 times more potent than the next most powerful carotenoid, and that is the form that crustaceans can use most efficiently. They can convert other carotenoids into astaxanthin, but it costs them in efficiency. It turns out that beta carotene is actually one of the weakest carotenoids as they affect crab health and biology. Zeaxanthin is a better substance if you cannot get astaxanthin, it is the quickest to convert biologically to astaxanthin. Beta carotene requires time and several oxidative steps to achieve the same end.
Krill, krill oil, copepods, spirulina (even more than you serve already), capsicum (red bell pepper), and xanthophyll-containing foods such as oats, wheat and corn are very important in crustacean diet. Crayfish are high in astaxanthin as well. "Biosynthesis or deposition of carotenoids may be adversely affected by poor lipid nutrition." More oily foods -- fresh seafood would be better than dried. It appears that good feed ratios of astaxanthin are about 1% - 100 mg/100 g of diet. This is for prawns, but can be applied to our crabs as well. They should have constant access to low levels of astaxanthin, or at the least, slightly higher levels of zeaxanthin.
I just compiled a list of zeaxanthin-containing foods. Refer to:
http://epicureanhermit.com/index.php?op ... &Itemid=25
Astaxanthin is the critical carotenoid as far as crustacean health is concerned. It is 10 times more potent than the next most powerful carotenoid, and that is the form that crustaceans can use most efficiently. They can convert other carotenoids into astaxanthin, but it costs them in efficiency. It turns out that beta carotene is actually one of the weakest carotenoids as they affect crab health and biology. Zeaxanthin is a better substance if you cannot get astaxanthin, it is the quickest to convert biologically to astaxanthin. Beta carotene requires time and several oxidative steps to achieve the same end.
Krill, krill oil, copepods, spirulina (even more than you serve already), capsicum (red bell pepper), and xanthophyll-containing foods such as oats, wheat and corn are very important in crustacean diet. Crayfish are high in astaxanthin as well. "Biosynthesis or deposition of carotenoids may be adversely affected by poor lipid nutrition." More oily foods -- fresh seafood would be better than dried. It appears that good feed ratios of astaxanthin are about 1% - 100 mg/100 g of diet. This is for prawns, but can be applied to our crabs as well. They should have constant access to low levels of astaxanthin, or at the least, slightly higher levels of zeaxanthin.
I just compiled a list of zeaxanthin-containing foods. Refer to:
http://epicureanhermit.com/index.php?op ... &Itemid=25