Which class of cartilaginous fish includes sharks, rays, and skates?

Which class of cartilaginous fish includes sharks, rays, and skates? The answer is Chondrichthyes.

Chondrichthyes is the class of jawed fishes whose skeletons are made primarily of cartilage rather than bone. It includes sharks, rays, skates, sawfish, and chimaeras. Sharks, rays, and skates are grouped mainly within the subclass Elasmobranchii, while chimaeras form the surviving group Holocephali.

Their cartilage-based skeleton is only one defining feature. Most chondrichthyans also have paired fins, multiple gill openings, and skin covered with tooth-like structures called dermal denticles or placoid scales. Unlike most bony fish, they do not have a swim bladder, so many species rely on lift from their fins, oily livers, and continuous swimming.

A frequent mistake is choosing Elasmobranchii for this question. That name is more specific: it covers sharks, rays, and skates, but not chimaeras. Because the question asks for the class containing the shark-and-ray groups, Chondrichthyes is the broader and canonical answer.