The opilio is the common name for the fish of the order Plaice, which are extremely laterally compressed, with the body of an adult individual being asymmetrical from side to side, with both eyes concentrated on the same side of the head, and with the mouth, teeth, and even fins showing asymmetrical features; the eyeless side lacks pigmentation. Because both eyes of this fish are on the same side, it is thought to swim in pairs and is also known as a flounder. Crowfish are widely distributed in the oceans around the globe, with many species living in coastal saltwater areas.