Observations on the opisthonephric kidney of the sea lamprey of the Great Lakes, Petromyzon marinus L., at various stages during the life cycle

Abstract

The kidneys at all stages consist of renal corpuscles, tubules, and an archinephric duct. The kidney of the ammocoete does not contribute to the formation of the adult kidney for at transformation a new kidney is formed. Degeneration of kidney tissue occurs at four stages: in the anterior regions throughout larval life; in the entire ammocoete kidney at transformation; in the anterior regions throughout adult life; in the entire kidney during the spawning migration. Large quantities of amorphous material appear in the interstitium during anterior degeneration of the adult. The other stages involve necrosis followed by the invasion of phagocytes.