Parthenogenesis (from the Greek παρθένος parthenos, "virgin", + γένεσις genesis, "creation") is the growth and development of an embryo or seed without fertilization by a male. Parthenogenesis occurs naturally in some species, including lower plants, invertebrates (e.g. water fleas, aphids, some bees and parasitic wasps), and vertebrates (e.g. some reptiles, fish, and, very rarely, birds and sharks). It is sometimes also used to describe reproduction modes in hermaphroditic species which can self-fertilize.