Serious illness characterized primarily by diarrhea with rapid onset and resolution after \(\pu{24 h}\) that is a consequence of consumption of bivalve shellfish (mollusks) such as mussels, oysters, and clams that have ingested, by filter feeding, large quantities of dinoflagellates containing a group of high-molecular-weight structures with multiple ether linkages, such as okadaic acid, dinophysis toxins, pectenotoxins, and yessotoxin.