Of the nearly 3200 known naturally occurring organohalogen compounds, more than 1600 contain bromine. These organobromines, which range in structural intricacy from the simple but enormously abundant bromoform (CHBr3) and bromomethane to the highly complex bryozoan bromine-containing indole alkaloids, are produced by marine and terrestrial plants, marine animals (sponges, tunicates, bryozoans, gorgonians, sea hares, nudibranchs), bacteria, fungi, some higher animals, and a few mammals including humans.