Collected reprints: Abstract 2567
Collected reprints
Abstract
Coutteau, P.; Hadley, N.H.; Manzi, J.J.; Sorgeloos, P. (1994). Effect of algal ration and substitution of algae by manipulated yeast diets on the growth of juvenile Mercenaria mercenaria. Aquaculture 120: 135-150
The development of a cost-effective algal substitute would greatly reduce the operating costs of bivalve hatcheries. Previous work has resulted in the development of a yeast diet with improved digestibility and nutritional composition. The use of this yeast product as a partial algal substitute for the culture of juvenile hard clams Mercenaria mercenaria was investigated in a series of growth experiments. Juveniles of the hard clam (1 mg live weight) were batch cultured in a 1 8 1 recirculating system for 2 or 3 weeks. The optimal weight-specific daily ration for a mixture (50/50 on dry weight basis) of Isochrysis galbana (clone T-Iso) and Chaetoceros gracilis was found to be 1.5 to 2% dry weight per wet weight of seed. Replacing 50% of the algal ration by yeast did not result in a significant decrease in growth rate relative to the algal-fed controls. The substitution of 80% of the algal diet resulted in growth rates reaching 90% compared with those obtained for the algal-fed controls. The incorporation in the yeast diet of fat-soluble vitamins, rice starch, or an extract from macro-algae did not improve its nutritional value. However, the addition of kaolin occasionally resulted in a significantly higher growth rate. The present results are compared with previous reports on the use of yeasts for nursery rearing of bivalves.
Back to list of volumes
Back to table of contents of volume 24