Benthic dinoflagellates from the coral reef lagoon of Mayotte Island (S-W Indian Ocean); identification, toxicity and preliminary ecophysiological study.

The community of benthic dinoflagellates of Mayotte Island is similar to those of other regions. Four clones of Gambierdiscus toxicus and of other benthic dinoflagellates species (Prorocentrum spp., Ostreopsis sp., Amphidinium spp.) have been isolated and screened for their crude toxicity using mouse-test. The toxigenic reservoir seems moderated. One toxic clone of G. toxicus has been studied for factors governing growth and photosynthetic activity of this species: salinity, temperature, light intensity and nutrients with bioassays.