Sharks, stingrays, manta-rays and chimaeras are fish with a cartilaginous skeleton. Cartilage is a flexible and strong substance, but less hard than bone. Cartilaginous fish have jaws and teeth that are usually hard and sharp. Sharks are cartilaginous fish that live in tropical waters. Although its skeleton is very flexible, its cartilage spine is firm. Manta-rays  and stingrays, have two large pectoral fins. Chimaeras are a species that lives without light at a depth of 1.500 meters. This infographic from the Ábaco collection belongs to the Amphibians and Fish series, which also includes those originally titled: What Is an Amphibian?, Metamorphosis, Fish Anatomy and Bony Fish.