Dinoflagellida

Dinoflagellida /Di·no·fla·gel·li·da/ (-flah-jel´ĭ-dah) an order of minute plantlike, chiefly marine protozoa, which are an important component of plankton. They may be present in sea water in such vast numbers that they cause a discoloration (red tide), which may result in the death of marine animals, including fish, by exhaustion of their oxygen supply. Some species secrete a powerful neurotoxin that can cause a severe toxic reaction in humans who ingest shellfish that feed on the toxin-producing organisms.