What jawless fish special features?

Jawless fish, such as lampreys and hagfish, possess unique features that distinguish them from other fish. They have elongated, cylindrical bodies and lack true jaws; instead, they have a round, sucker-like mouth filled with rasping teeth. Their skin is typically smooth and covered in mucus, providing protection and aiding in movement through water. Additionally, jawless fish have a notochord for structural support and possess gill slits for respiration, reflecting their primitive evolutionary status.