Divergent Pathways of Ammonia and Urea Production and Excretion during the Life Cycle of the Sea Lamprey.

Little is known about nitrogenous waste (N waste) handling and excretion (J_{N waste}) during the complex life cycle of the sea lamprey (Petromyzon marinus), an extant jawless fish that undergoes a complete metamorphosis from a filter-feeding larva (ammocoete) into a parasitic juvenile that feeds on the blood of larger, jawed fishes. Here, we investigate the ammonia- and urea-handling profiles of sea lampreys before, during, and after …