GONADECTOMY EXTENSION. “For example, lifespan of semelparous annual plants can often be artificially extended by removing reproductive structures. Optic gland removal in O. hummelincki causes cessation of brooding, reinstates normal feeding behavior, and extends life. In fishes, removal of the gonads (Pacific salmon, lampreys) or of the pituitary gland (lampreys) and prevention of mating (eels) can substantially increase life span.”