Some hermaphroditic groups have simultaneous hermaphroditism, whereas some sequential hermaphroditism. Intersex people were categorized as either having true hermaphroditism, female pseudohermaphroditism, or male pseudohermaphroditism. Gonochorism stands in contrast to other reproductive strategies such as asexual reproduction and hermaphroditism. Tantawy seems to have associated the concept with hermaphroditism or intersex individuals. These areas include an all-male society, promiscuity, monastic celibacy, hermaphroditism, and bisexuality. Common model organisms for this type of sequential hermaphroditism are wrasses. However other patterns of ontogeny exist, with one of the commonest being sequential hermaphroditism. The sexes are usually separate in bivalves but some hermaphroditism is known. Arisaema is a plant genus which is commonly cited as exercising sequential hermaphroditism. There is molecular and histological evidence suggesting the occurrence of hermaphroditism in "Acanthaster" cf. "solaris". Sequential hermaphroditism in plants is very rare. Some GSP are prone to epilepsy, hip dysplasia, and hermaphroditism. This process is called Sequential hermaphroditism. Many fish change sex over the course of their lifespan, a phenomenon called sequential hermaphroditism. Ovotesticular disorders are a family of disorders which includes true hermaphroditism.