Give you some example of jawless fish?

Most fish are not jawless. There is a small group of very primitive fish called Jawless fish (Agnatha). However, they make up a very small proportion (<1%) of the fish species on earth. Jawless fish are things like lamprey and hagfish. All other fish, like trout, salmon, tuna, sharks, rays, cichlids, goldfish, etc, etc, have jaws.

See the related link for more information on the primitive jawless fish.