The bathypelagic life zone is a euphotic zone that starts at about 4000 meters under sea level. The water temperature starts to become plummet, and the last colors to fade are green and blue. Photosynthesizing plankton begins to absent itself as darkness sets in, and modified creatures that don't solely eat plankton or need light habit this zone. The term can also refer to anything found at such a level or area, or related to it by some condition i.e. a bathypelagic organism.