Forty years living with Dinophysis: myths and realities

Forty years ago, Dinophysis forti was identified as the source of DSP and Dinophysis species targeted as potential toxins producers worldwide. Discoveries of their cryptophyte-like pigments, mixotrophic feeding on ciliate prey, and uncertainties about their life cycle made this genus an attractive topic of dinoflagellate biology, phylogeny and ecology. Within the dinoflagellate order, Dinophysis species constitute a unique group, the plastidic specialist non constitutive mixotrophs (pSNCM). Only the ciliate Mesodinium rubrum fed on Teleaulax/Plagioselmis/ Geminigera (TPG) clade cryptophytes has been used to grow Dinophysis, but alternative prey are being explored. Strains of each Dinophysis species exhibit site-specific functional traits in response to environmental change. Progress in modeling the population dynamics of these selective mixotrophs is hindered by the lack of adapted sampling to Dinophysis and their potential prey with a common appropriate spatio-temporal resolution. Are Dinophysis low density slow-growing dinoflagellates with no sexual life, unrelated to water discolorations and never the dominant component of the microplankton community? Are all members of the D. acuminata complex the same species? Can we have an early warning of Dinophysis bloom development? Are DSP events increasing in frequency, intensity and geographic distribution? These and emerging issues are discussed here on the light of past mistakes and recent progress in knowledge