Isolation of Some Carotenoid Rich Floral Bioresources for Preparation of Diet Additives in Aquaculture

A major input in terms of cost in aquaculture is feed and consequently, the aim of the most aquaculturist is to converting the feed into live fish with maximum efficiency and minimum cost. Though in many cases the feed supplied contains the optimal levels of ingredients, still the crucial factor is that it has to be consumed by the target species. If the feed is not readily consumed it would lead to wastage and poor feed conversion ratio (FCR) as well as pollution of the water body. To increase the acceptability or palatability of feeds and to reduce such pollutional problems, use of diet additives in fishery sector is relevant. Diet additives perform several functions. They act as nutritional supplements, colouring agents, flavouring agents, preservatives, moisture content controller, pH controller, physiocolgical activity controller, etc. Carotenoids are very commonly used as fish feed additives in different parts of the world. Carotenoids are a class of hydrocarbons and their oxygenated derivatives are characterized by a system of conjugated double bonds. Currently more than seven hundred carotenoids including their geometrical isomers are known. On the other hand, astaxanthin is a naturally occuring carotenoid pigment that has a unique antioxidant property. It is available from several biological species.