Our oceans are filled with fascinating marine life. Of course, they're not all harmless. Avoid these venomous creatures while snorkeling, diving, or swimming.

The two most prominent types of plankton in the ocean are zooplankton, which are tiny animal organisms, and phytoplankton, which are plantlike. (Other forms of plankton include bacterial and fungal.

Learn about polar habitats and discover how animals have adapted to live in the cold icy conditions. What is an ocean habitat? Learn all about ocean habitats and the many different types of ...