Culture techniques and growth characteristics of Dinophysis acuminata and its prey

The dinoflagellate Dinophysis acuminata Claparede & Lachmann is a toxic alga that causes diarrhetic shellfish poisoning. No Dinophysis species were maintained in culture for a long period of time until 2006 when Park successfully established D. acuminata in culture using a three-step feeding protocol in which the cryptophyte, Geminigera cryophila, is fed to Myrionecta rubra (=Mesodinium rubrum), a ciliate that is in turn fed to D. acuminata. In this paper, we present the details of culturing D. acuminata from the Northeastern United States. The protocols described herein can be adopted for laboratory studies of this species. The effects of temperature on the growth and ingestion rates of D. acuminata were also examined. The results show that D. acuminata growth rate was 0.23 /d at 10°C and 0.11 /d at 4°C when fed M. rubra prey. The maximum prey ingestion rate was 2.80 Dinophysis cell/d at 10°C, although the rate decreased slightly at 4°C. In overall, temperature showed a greater influence on growth rate of D. acuminata than on the ingestion rate under the study conditions, and the quantity of available food was also an important regulator to D. acuminata growth.