azadinium spinosum 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. azadinium spinosum scientific classification domain: eukaryota (unranked): sar (unranked): alveolata phylum: dinoflagellata class: dinophyceae order: incertae sedis family: amphidomataceae genus: azadinium species: a. spinosum binomial name azadinium spinosumelbrächter et tillmann 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.