Saxitoxin
Saxitoxin : The parent compound of a family of chemically related neurotoxins. In nature they are predominantly produced by marine dinoflagellates, although they have also been identified in association with such diverse organisms as blue-green algae, crabs, and the blue-ringed octopus. The natural route of exposure to these toxins is oral. In a biological warfare scenario, the most likely route of delivery would be by inhalation or toxic projectile. It could also be used in a confined area to contaminate water supplies