It has been shown that fishing pressure can change when the switch from male to female occurs, since fishermen usually prefer to catch the larger fish. The populations are generally changing sex at a smaller size, due to natural selection. Protogyny: Where the organism is born as a female, and then changes sex to a male.Example: Wrasses (Family Labridae) are a group of reef fish in which protogyny is common. Wrasses also have an uncommon life history strategy, which is termed diandry (literally, two males). In these species, two male morphs exists: an initial phase male and a terminal phase male. Initial phase males do not look like males and spawn in groups with females. They are not territorial. They are, perhaps, female mimics (which is why they are found swimming in group with females). Terminal phase males are territorial and have a distinctively bright coloration. Individuals are born as males or females, but if they are born males, they are not born as terminal phase males. Females and initial phase males can become terminal phase males. Usually, the most dominant female or initial phase male replaces any terminal phase male when those males die or abandon the group. Bidirectional sex changers: Where an organism has female and male reproductive organs, but act as either female or male during different stages in life.Example: Lythrypnus dalli (Family Lythrypnus) are a group of coral reef fish in which bidirectional sex change occurs.
The film focuses on Louws attempts to understand why he was born with extra nipples, a condition he shares with the likes of Mark Wahlberg, Lily Allen, and Tilda Swinton, as well as well known TV and film characters such as the Bond villain Scaramanga and Chandler Bing. Fascinated and confused by this seemingly pointless mutation, Louw sets off on a personal journey of discovery to try and unwrap "the riddle of the triple nipple". He starts out by consulting the man in the street and even a renowned teratologist, an expert in physical mutations. After testing the notion that extra nipples could be a sign of fertility, he discovers that they are actually an atavism, or evolutionary holdover – a sign of how humans evolved. See also
Accessory breast
Grace Sherwood, sentenced to jail for witchcraft partly on the basis of having "two things like titts on her private parts of a black coller [color]"
Polydactyly

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