Lampreys are ancient, jawless, eel-like fish with a cartilaginous skeleton, known for their round, sucker-like mouths with teeth used to attach to and feed on other fish. They are primitive vertebrates, more closely related to sharks than eels, and have survived for millions of years, with some species being parasitic and others non-parasitic filter feeders as larvae. They breathe through seven gill pores on each side and have a unique life cycle that includes a long larval stage (ammocoete) before metamorphosis.
