19. Hermaphrodite

A hermaphrodite is an organism that exhibits both male and female reproductive organs. Hermaphroditism is a characteristic common among fish and gastropods. Those known as sequential hermaphrodites are born a certain sex but can change into the opposite sex either one or multiple times, depending on the species. The earthworm seen here is an example of a simultaneous hermaphrodite, which has both male and female reproductive parts for its entire life. Because they produce both sperm and eggs at the same time, simultaneous hermaphrodites have the ability to mate with any other member of their species and some can even self-fertilize.