Azadinium spinosum

Azadinium spinosum is a species of dinoflagellates that produces azaspiracid toxins (toxins associated with shellfish poisoning), particularly AZA 1, AZA 2 and an isomer of AZA 2.

Description
It measures 12–16 μm in length and 7–11 μm wide, is a peridinin-containing photosynthetic dinoflagellate with a thin theca. Its large nucleus is spherical and present posteriorly, whereas its single chloroplast is parietal, lobed, and extends into the epi- and hyposome.