Field observations of the dinoflagellate genus Azadinium and azaspiracid toxins in the Southwest Atlantic Ocean

FABRO, E.; ALMANDOZ, G. O.; KROCK, B.; TILLMANN, U.

MARINE AND FRESHWATER RESEARCH

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2019

1323-1650

Some dinoflagellate species of the genera Azadinium and Amphidoma (Amphidomataceae) produceazaspiracids (AZA), a group of toxins responsible for gastrointestinal disorders in humans following the consumptionof contaminated shellfish. In this study, we investigated the diversity, distribution and abundance of Azadinium and AZAfrom field plankton samples collected during four oceanographic expeditions that covered an extended area of theArgentine Sea during different seasons. Scanning electron microscopy analyses indicated the presence of five Azadiniumspecies: Az. dexteroporum, Az. luciferelloides, Az. obesum, Az. asperum and Az. cf. poporum. Azadinium-like cells werefrequently found and were even an abundant component of plankton assemblages, showing a wide latitudinal distribution,from,38 to,55.58S, and occurring in a wide temperature and salinity range. High cell densities (up to 154 000 cells L1)occurred in northern slope and external shelf waters during spring. AZA-2 was detected in net samples from the 20- to200-mm fractions by tandem mass spectrometry?liquid chromatography analysis, suggesting a transfer of AZA throughthe food web. Our results contribute to the knowledge of the worldwide occurrence of Azadinium species and AZA, andhighlight the importance of amphidomatacean species as a potential source of AZA shellfish poisoning in the south-westAtlantic Ocean.