Saxitoxin

noun

1. A potent neurotoxin produced by certain dinoflagellates that accumulates in shellfish feeding on these organisms and consequently causes food poisoning in humans who eat the shellfish.
2. A neurotoxin, produced by some dinoflagellates, that can accumulate in mollusks and cause subsequent food poisoning in humans
3. a powerful neurotoxin produced by certain dinoflagellates found in red tides; it can accumulate in mollusks that feed on the dinoflagellates and cause food poisoning to humans