Application of a Quantitative PCR to Investigate the Distribution and Dynamics of Two Morphologically Similar Species, and (Dinophyceae) in Korean Coastal Waters.

Species of the marine dinoflagellate genus are known to produce various potent biotoxins and can form noxious blooms that cause mass mortalities of fish and shellfish. To date, harmful blooms of the species have been reported in Korea, but was recently recorded off the southern coast of Korea. Here, we developed a quantitative real-time PCR (qRT-PCR) assay with specific primer pairs for the accurate detection and quantification of these two similar-looking unarmored species, and and investigated their distribution and dynamics in Korean coastal waters. Overall, had not only a wider distribution, but also higher cell abundances (15-2553 cells L) than (3-122 cells L) in surface waters. Of 18 sampling sites, the two species were found to coexist at two sites. During monitoring at a fixed station (S5), was generally predominant over ; however, the two species exhibited similar dynamics and occasionally co-occurred. Both species showed similar physiological responses to temperature and salinity, requiring similar conditions for optimum growth. These results suggest that blooms of the two species may co-occur and induce a synergistic adverse effect on marine environments.