Lampetra appendix

The American brook lamprey ("Lampetra appendix") is an endangered lamprey.

Identification

Blind and wormlike as ammocoetes (pronounced ammo-seat) or larvae, the american brook lamprey metamorphoses (changes) into a brown cylinder, almost 8 inches long. Adults have a dark back, pale belly, yellowish fins and a dark blotch at the end of the tail.