Characterization of toxin-producing strains of Dinophysis spp. (Dinophyceae) isolated from French coastal waters, with a particular focus on the D. acuminata-complex

Dinoflagellates of the genus Dinophysis are most prominent producers Diarrhetic Shellfish Poisoning (DSP) toxins which have an impact on public health and marine aquaculture worldwide. In particular, acuminata has been reported as major DSP agent in Western Europe. Still, its contribution to events regions English Channel Atlantic coast France, role others species community these areas not clear. addition, identification within D. complex proven difficult due their highly similar morphological features. present study, 30 clonal strains dominant isolated from French coasts including (3 sites), Ocean (11 sites) Mediterranean Sea (6 sites). Morphologically, were identified three species: acuta, caudata, tripos, well acuminata-complex. Sequences ITS LSU rDNA confirmed identifications revealed no genetic difference Using mitochondrial gene cox1, two groups differing by only one substitution found acuminata-complex, but SEM analysis various showed a large range variations. Based geographical origin morphology, subclade A ascribed ‘D. acuminata’ while those B sacculus’. Nevertheless, distinction into separate remains questionable was supported our data. The considerable variations observed cultured suggest that physiological factors might influence cell contour bias identification. Analyses cultures coastal waters using liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) species-conserved toxin profiles for acuta (dinophysistoxin 2 (DTX2), okadaic acid (OA), pectenotoxin (PTX2)), caudata (PTX2) tripos (PTX2), irrespective (Atlantic or Sea). Within different observed: (subclade A) contained OA sacculus’ B) Sea/Atlantic PTX2 toxin, with C9-esters also being present, albeit lower proportions. same between several studies Galicia (NW- Spain). This consequences terms health, consequently monitoring programs. While profile could appear reliable feature separating both Spanish coasts, this does seem consistent observations broader scale complex, possibly frequent lack characterization.