Baker’s yeast as a substitute for microalgae in the hatchery rearing of larval and juvenile tropical oyster (Crassostrea belcheri, Sowerby 1871)

ABSTRACT

In this study, baker’s yeast, Saccharomyces cerevisiae, was used as a partial substitute for microalgae in the hatchery rearing of larval and juvenile tropical oyster (Crassostrea belcheri). Dietary microalgae were replaced with graded levels (0%, 25%, 75%, and 100%) of untreated and treated yeast in the feed of oysters from the early umbo (6 days postfertilization) to the eyed larval stage (18 days postfertilization); then the same diets were formulated with untreated barker’s yeast and fed juvenile oysters for 3 weeks. The results showed that a partial substitution of microalgae with untreated or treated baker’s yeast is unsuitable for feeding oyster larvae up to the eyed stage. With juvenile oysters, there were nonsignificant differences (P > 0.05) in mean shell width and length during the study period. The replacement of 25% microalgae with baker’s yeast showed mean daily growth rates (DGR) as high as that obtained with 100% microalgae, while the other treatments showed lower DGR (P > 0.05). Nonsignificant differences were found among the treatments in terms of mean percentages of survival at the end of the experiment (P > 0.05). The percentage of juvenile oysters larger than 0.75 cm was highest (P < 0.05) when 25% microalgae was replaced with baker’s yeast, while the highest percentage of juvenile oysters smaller than 0.32 cm was observed with diet where 75% microalgae was replaced with baker’s yeast (P < 0.05). From the experiments, it was concluded that a partial substitution of microalgae with untreated or treated baker’s yeast was unsuitable for feeding oyster larvae, while a 25% substitution with untreated yeast could be used for rearing juvenile oysters.

KEYWORDS:

• Baker’s yeast
• Crassostrea belcheri
• juvenile oyster
• microalgae
• Saccharomyces cerevisiae

Acknowledgments

The authors thank Supatcha Dungjan and Thossaporn Klomkleing for their assistance in collecting the samples. We also wish to thank Barry Bendell for his assistance in editing the manuscript.

Funding

This study was funded by the Higher Commission of Education, Year 2012, Ministry of Education.

Additional information

Funding

This study was funded by the Higher Commission of Education, Year 2012, Ministry of Education.