Michel Roggo / Brook lamprey (Lampetra planeri) showing sucker, Europe

Michel Roggo / Brook lamprey (Lampetra planeri) Europe

Juan Manuel Borrero / Illustration of diagram of ammocoetes or lamprey larvae (Petromyzontiformes) and Myxine hagfish (Myxine sp). Pencil and watercolor painting.

Willem Kolvoort / Split level view of Brook lampreys (Lampetra planeri) underwater in brook preparing a nesting place, Holland

Willem Kolvoort / Brook lampreys (Lampetra planeri) underwater in brook preparing a nesting place, Holland

Willem Kolvoort / Underwater view of Brook lampreys (Lampetra planeri) in brook preparing a nesting place, Holland

Norbert Wu / Lamprey (Petromyzon marinus) in parasite phase feeds on fish by rasping through their skin, Salmon River at Lake Champlain, New York