Cleaning seafoods in many cases will not remove the toxins. Cooking does not destroy the toxins. Paralytic Shellfish Poisoning Toxins Certain one-celled organisms called dinoflagellates produce PSP toxins. PSP toxins accumulate in the dark digestive organs or viscera of most shellfish. PSP symptoms begin within a few minutes to a few hours after eating toxic shellfish.
Symptoms begin with tingling and numbness of the lips, tongue and fingertips.
Later symptoms are lack of balance, lack of muscle coordination, slurred speech and problems in swallowing. Complete paralysis and death can occur in severe cases. Certain one-celled plants called diatoms produce domoic acid. Bivalve shellfish and some finfish filter these diatoms from the water. In most cases, domoic acid accumulates in the viscera of these animals.