Toxicological Trivia from January 18, 2010: ‘Amnesic shellfish poisoning’was identified recently, has its origins in the toxic properties of the substance found in some shellfish and whose concentration is reduced only if they freeze these foods.This toxin is produced naturally by marine diatoms belonging to the genus Pseudo-nitzschia and, when accumulated in high concentrations by shellfish, can then be passed on to humans via consumption of contaminated shellfish This substance is: a) Domoic acid; b) Saxitoxin; c) Tetradotoxina