Effect of microalgae diet and culture system on the rearing of bivalve mollusks: Nutritional properties and potential cost improvements

Abstract

The application of microalgal diets in aquaculture is gaining more and more attention with the increasing demand of aquaculture. Literature reports of diet microalgae in rearing bivalve species have mainly focused on nutrient uptake of shellfish, and there is a lack of complete overview of nutritional composition and efficient microalgae cultivation methods for the purpose to improve shellfish production. This paper reviews the effects of microalgal composition for the rearing of bivalve mollusks, and analyzes the economic cost of microalgae culture for bivalve mollusk feeding. Artificial or natural feeds have not been proven to be effective substitutes for live microalgae in rearing bivalve mollusks. In our view, the effects of feeding diet microalgae to bivalve shellfish can vary depending on their different life stages. Mixing suitable microalgae diets can play a beneficial role in the growth of the bivalve mollusks. The content of fatty acids, sterols, and carotenoids in the microalgae are important factors affecting the nutritional value for the shellfish. Biofilm attached culture of some microalgae can increase the cell density of the algae. Studying the nutritional requirements of bivalve mollusks at different periods in their lifecycles, formulating the proper mixed feed according to the composition of lipids and sterols in the microalgae, and efficient microalgae culture systems, may improve the nutritional value and reduce the production costs of shellfish.