Is a lamprey a cartilagous fish?

No, a lamprey is not a cartilaginous fish; it belongs to a class of jawless fish called Agnatha. Unlike cartilaginous fish, such as sharks and rays, which have skeletons made of cartilage, lampreys have a cartilaginous structure but lack true jaws and paired fins. Instead, they have a sucker-like mouth and are known for their parasitic feeding habits.