ABSTRACT
Numerous marine organisms produce substances that are poisonous. Some are toxic only when ingested by other animals, while others possess an anatomical apparatus for injecting venom. Marine zootoxins are among the most highly toxic substances known. Biologists have not unraveled all of the mysteries, but much is known about the role of toxins in predator/prey relationships, food gathering, and defense mechanisms. Dinoflagellates are marine plant protozoa and are major components of the phytoplankton that forms the food base for millions of marine organisms. Shellfish are resistant to dinoflagellate toxins. Whether a given species of shellfish becomes toxic depends on the feeding behavior of the shellfish, the concentration of toxic dinoflagellates in the water, and the duration of bloom. Marine fish contain numerous toxins or venoms. Categories of fish toxins are still changing as new toxins are isolated and identified.
