Neosaxitoksiini

Neosaxitoksiini is a small tribe of planktonic dinoflagellates that produces a potent neurotoxin known as neosaxitoxin. The name derives from the Latin prefix neosax- meaning “new” and the marine poison saxitoxin, reflecting the chemical similarity between the toxins produced by members of this tribe and those produced by the well‑studied Alexandrium species.

Taxonomically, Neosaxitoksiini is placed within the domain Eukaryota, kingdom Protista, phylum Dinoflagellata, class Dinophyceae, order Prorocentrales, and family Neosaxitoxaceae. The tribe consists of one genus, Neosaxitoxin, which currently includes three described species: Neosaxitoxin litoralis, Neosaxitoxin maris, and Neosaxitoxin pulchra. Morphologically, cells are typically oval to ellipsoidal, with a single contractile vacuole and a peridinin‑laden chloroplast. The thecal plates are smooth and display a distinctive pattern of spines on the apical region.

Neosaxitoksiini species are primarily found in temperate coastal waters of the North Atlantic and the northeast Pacific Ocean. They bloom in late spring and autumn, often following phytoplankton peaks in nutrient availability. During these blooms, concentrations of neosaxitoxin can reach levels that pose a risk to shellfish and, consequently, to human consumers. Regulatory agencies monitor biotoxin levels in filter‑feeding molluscs, and routine testing has revealed occasional contamination by neosaxitoxin‑positive Neosaxitoxin species.

Research on Neosaxitoksiini focuses on toxin biosynthesis pathways, ecological interactions with other micronutrients, and their role in harmful algal bloom dynamics. Genetic sequencing of the tribe’s small subunit ribosomal RNA has helped clarify evolutionary relationships within Prorocentrales. The study of Neosaxitoksiini is critical for understanding marine food webs, protecting public health, and managing aquaculture resources.