Mass culture of microalgae as an inherent part of hatchery operation- Winter School on Recent Advances in Breeding and Larviculture of Marine Finfish and Shellfish

Microalgae are microscopic unicellular phytoplankton which have less than 10 μ size. These floating planktons being the predominant component of the first tropic level in the aquatic food chain has got immense value as an aquaculture live feed and as a result the production of unicellular algae has gained importance in several countries due to their wide use as food in the hatchery. Most micro algae are rich sources of essential fatty acids; vitamins such as B12, B6, B1, biotin, riboflavin, nicotinic acid, pantothenate, C, E and A; chlorophyll ‘a’ and ‘b’ and carotenoids and these plankton plays a vital role in aquaculture to meet the nutritional requirements of the larvae as well as for bio-encapsulation. It is, therefore, its culture is an inherent part of aquaculture operation. The successful rearing, growth and survival of larvae in the hatchery depends upon the provision of suitable strain of these microalgae during their critical stages of life cycle. The algal species may vary in size, shape and nutritional quality, and are also used for generating “green water” system in many hatcheries. Inspite of all efforts to replace micro algae by artificial feeds, aquaculturists are still depending on the production and use of micro algae as live food for the fishes during their different stages of life cycles. In addition to these, micro algae together with bacteria have an important role in oxygen balance in fish culture system.