Sea Lamprey

The sea lamprey (Petromyzon marinus) is a parasitic lampreyfound on the Atlantic coasts of Europe and North America , in the western Mediterranean Sea, and in the Great Lakes. It is brown or gray on its back and white or gray on the underside and can grow to be up to 90 cm (35.5 in) long. Sea lampreys prey on a wide variety of fish. The lamprey uses its suction-cup like mouth to attach itself to the skin of a fish and rasps away tissue with its sharp probing tongue and teeth. Secretions in the lamprey's mouth prevent the victim's blood from clotting. Victims typically die from blood loss or infection.

http://en.wikipedia.org/wiki/Sea_lamprey

http://www.dnr.state.wi.us/org/caer/ce/eek/critter/invert/lamprey.htm

http://www.science.mcmaster.ca/Biology/Harbour/SPECIES/SEALAMP/TITLE.HTM