Hydrothermal: (adj.) relating to the action of heated water in earth's crust Hydrothermal Vents: a fissure in earth's surface through which geothermally heated water erupts Hydrothermal vent animals are a variety of species which have adapted to survive in an extremely inhospitable environment, which high levels of sulfur and gas in the water. These organisms vary in size, physiological form, and survival mechanisms.
Planktonic: (adj.) of or relating to plankton Planktonic species are small or microscopic organisms that drift in the pelagic regions of the sea, oceans, or freshwater habitats. Organisms include bacteria, diatoms, jellyfish, and various larvae. Planktonic animals either passively float or have limited motile function and drift throughout their environments.