Abstract
A simple and rapid quantification system for zooxanthellae released from corals or existing in environmental waters was developed. Real-time PCR with a primer set designed to amplify the nuclear 18S rRNA gene of any genetic clade of Symbiodinium was used with intercalating dye SYBR® Green I to enable the low-cost, simple assay of Symbiodinium density in surrounding waters. With the combination of a simple DNA extraction method developed recently by another group that traps cells onto a filter, the utility of the qPCR system was tested by investigating both the diel release pattern of Symbiodinium from Acropora digitifera in an aquarium and the occurrence of cells in field waters. Results showed that the system was fast and could accurately monitor Symbiodinium densities released from coral, and could possibly be applied to the Symbiodinium occurring in the field water —an outcome that could never be matched by conventional microscopic counts.
