Formation of Dinophysis dens and D. diegensis from laboratory incubations of Dinophysis acuta and D. caudata

Abstract

Vegetative cells of several species ofDinophysisspp. have been found to produce “small cells,” different in size and shape, following a “reductionary division” under certain environmental conditions, as part of a polymorphic life cycle. Based on observations on fixed natural populations,Dinophysis densand D.diegensiswere hypothesized to be small forms of Dinophysis acutaand Dinophysis caudata,respectively. During autumn 2001, we were able to confirm these hypotheses after incubations, in cell culture chambers, of groups of individually picked cells from natural populations ofD.acuta and D.caudata.Eight to 10 days after inoculation, different life cycle stages of the two species were observed in vitroand contrasted with wild specimens from Dinophysisblooms in Galician and Catalan waters.