The pelagic zone is split into five subzones, the epipelagic, mesopelagic, bathypelagic, abyssopelagic and the hadopelagic zone. All of these zones are classified by their ecology and depth range. The epipelagic is located from the surface to 200 meters down; this is the zone that has an abundance of sharks and tuna. As well as, all of the photosynthetic plants that requires light to live. The next zone is called the twilight zone, it is the next zone down located in the open ocean. It ranges from 200m to 1000m with very little light that appears down here. Some examples of what live here are the giant squid, blobfish and the prickly shark. From 1000m to 4000m down is the third level of the ocean and it is called the bathypelagic subzone. There is almost no light that is located here and many unique animals live here. Some examples of fish that live in the bathypelagic subzone are the humpback anglerfish, gulper eel and the phantom anglerfish. The next to last subzone is the abyssopelagic zone; it is at the very bottom of the ocean and ranges from 4000m to just above the ocean floor. This has no light peeking through at all and the animals that live here are blind. Examples of these animals are the black swallower, deep-sea angler and tripod fish. Finally, the last subzone is the hadopelagic zone; it is referred to as the water in the submarine trenches at the very bottom of the ocean. Some animals that are able to stand the extreme cold and pressure of this zone are deep water squid and some species of octopus.