Glass squids (family Cranchiidae) live in the boundless waters of the twilight, or mesopelagic, zone. With no protective shell and nowhere to shelter, they need to get creative. Transparency is one way to thrive in a home with few places to hide. Like other cephalopods, glass squids are covered in tiny pigment sacs called chromatophores. They often keep their chromatophores closed so their skin is basically see through. This invisibility cloak hides them from both predators and prey. When the gl