Lampreys (Petromyzontiformes)
Despite parasitic habits, lampreys are more ìadvancedî than hagfish in many respects
Larval stage (ammocoetes) lives as filter feeder in sediments; very amphioxus-like
Adults usually parasitize other fish; an introduced species wrecked the Great Lakes fisheries, beginning in the 1950s
Lampreys are probably descended from some early poorly armored jawless fish called anaspids (see slide 16)