The Blue-spotted angler fish is a common predator that lives in the dark zone of the ocean. The blue flashing part that hangs off its head is used for luring prey. It does not use the flash to see, as it can smell and hear well, and sense the change in the water pressure. This is one of the over 200 species discovered so far. Most anglerfish consist of pretty much only the mouth and teeth, obviously with certain organ systems that help it survive. Their stomachs can expand to hold large meals, and some anglerfish are even considered tasty!