HermaphroditeA hermaphrodite (hərˈmæfrəˌdaɪt) is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are of different sexes, either male or female but not both, are gonochoric, which is the opposite of hermaphroditic. The individuals of many taxonomic groups of animals, primarily invertebrates, are hermaphrodites, capable of producing viable gametes of both sexes. In the great majority of tunicates, mollusks, and earthworms, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the female or male.
Sucker (zoology)A sucker in zoology is a specialised attachment organ of an animal. It acts as an adhesion device in parasitic worms, several flatworms, cephalopods, certain fishes, amphibians, and bats. It is a muscular structure for suction on a host or substrate. In parasitic annelids, flatworms and roundworms, suckers are the organs of attachment to the host tissues. In tapeworms and flukes, they are a parasitic adaptation for attachment on the internal tissues of the host, such as intestines and blood vessels.
FlatwormThe flatworms, flat worms, Platyhelminthes, or platyhelminths (from the Greek πλατύ, platy, meaning "flat" and ἕλμινς (root: ἑλμινθ-), helminth-, meaning "worm") are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates. Unlike other bilaterians, they are acoelomates (having no body cavity), and have no specialised circulatory and respiratory organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion.