A sea lamprey (pronounced LAM pree) is an eel-like water creature. It grows up to three feet long. Its mouth is a cuplike sucker lined with sharp “teeth”.
Fishermen dread the sea lamprey because of its destructive eating habits. It is a parasite—it eats other fish by attacking itself to the other fish with its strong sucker mouth.
It scrapes a hole in the fish with its teeth and tongue, which also has teeth, and then sucks the blood out of the fish.
A fish attacked by a sea lamprey usually will die.
Sea lampreys are normally saltwater creatures, but they swim up freshwater rivers and into lakes to spawn.
Sometimes they remain in the inland lakes and never go back to the sea.
When this happens, they can become serious pests. Sea lampreys have destroyed many important food fishes, such as trout and mackerel, in the Great Lakes.- Dick Rogers