Temperature-dependent growth and sexuality of the ciguatoxin producer dinoflagellate Gambierdiscus spp. in cultures established from the Canary Islands.

Benthic dinoflagellates of the genus Gambierdiscus produce ciguatoxins, compounds that when metabolized in fish and consumed by humans cause ciguatera poisoning (CP). This syndrome, which is widespread in tropical and subtropical regions, has recently been reported also in subtropical-temperate latitudes such as the Canary Islands where CP events have been regularly detected since 2004. This study examined the effect of temperature on the growth of Gambierdiscus isolated from Canary waters: G.

Ciguatera-Causing Dinoflagellate spp. (Dinophyceae) in a Subtropical Region of North Atlantic Ocean (Canary Islands): Morphological Characterization and Biogeography.

Dinoflagellates belonging to the genus produce ciguatoxins (CTXs), which are metabolized in fish to more toxic forms and subsequently cause ciguatera fish poisoning (CFP) in humans. Five species of have been described from the Canary Islands, where CTXs in fish have been reported since 2004. Here we present new data on the distribution of species in the Canary archipelago and specifically from two islands, La Palma and La Gomera, where the genus had not been previously reported.

The life history of the toxic marine dinoflagellate Protoceratium reticulatum (Gonyaulacales) in culture.

Asexual and sexual life cycle events were studied in cultures of the toxic marine dinoflagellate Protoceratium reticulatum. Asexual division by desmoschisis was characterized morphologically and changes in DNA content were analyzed by flow cytometry. The results indicated that haploid cells with a C DNA content occurred only during the light period whereas a shift from a C to a 2C DNA content (indicative of S phase) took place only during darkness.

"Canary Islands (NE Atlantic) as a biodiversity 'hotspot' of Gambierdiscus: Implications for future trends of ciguatera in the area".

In the present study the geographical distribution, abundance and composition of Gambierdiscus was described over a 600km longitudinal scale in the Canary Islands. Samples for cell counts, isolation and identification of Gambierdiscus were obtained from five islands (El Hierro, Tenerife, Gran Canaria, Fuerteventura and Lanzarote). Average densities of Gambierdiscus spp.

Divinyl chlorophyll a in the marine eukaryotic protist Alexandrium ostenfeldii (Dinophyceae).

Here it is reported the first detection of DV-chl a together with the usual chl a in the marine dinoflagellate Alexandrium ostenfeldii from the Baltic Sea. Growth response and photosynthetic parameters were examined at two irradiances (80 and 240 μmol photons m(-2) s(-1)) and temperatures (15 °C and 19 °C) in a divinylic strain (AOTV-OS20) versus a monovinylic one (AOTV-OS16), using in vivo chl a fluorescence kinetics of PSII to characterize photosynthetic parameters by pulse amplitude modulated fluorescence, (14)C assimilation rates and toxin analyses. The divinylic isolate exhibited slower growth and stronger sensitivity to high irradiance than normal chl a strain.

Yessotoxins profile in strains of Protoceratium reticulatum from Spain and USA.

Seven strains of Protoceratium reticulatum isolated from Spain and the USA were cultured in the laboratory. Yessotoxins (YTXs) quantification and toxin profile determination were performed by LC-FLD and LC-MS/MS. The four Spanish strains were found to produce YTX and known YTX analogs, however, YTX was not detected in any of the three USA strains.