First successful culture of the marine dinoflagellate Dinophysis acuminata

The dinoflagellate genus Dinophysis includes several species that cause diarrhetic shellfish poisoning, none of which have yet been established in culture. We report on the maintenance of Dinophysis acuminata cultures that were established in December 2005 and also on its feeding mechanism, and growth rates when fed the ciliate prey Myrionecta rubra with and without the addition of the cryptophyte Teleaulax sp. D. acuminata grew well (growth rate of 0.95 d super(-1)) in laboratory culture when supplied with the marine ciliate M. rubra as prey, reaching a maximum concentration of about 2400 cells ml super(-1) at the end of the feeding experiment. In contrast, D. acuminata did not show sustained growth in the absence of the ciliate or when provided the cryptophyte Teleaulax sp. as prey (D. acuminata used its peduncle to extract the cell contents of the prey organism, M. rubra). Based on the prey- predator interactions occurring among D. acuminata, M. rubra, and Teleaulax sp. in this study, establishment of permanent culture of the dinoflagellate D. acuminata may facilitate a better understanding of the ecophysiology, biology, and toxicology of Dinophysis species, as well as the evolution of dinoflagellate plastids.