Article Correctness Is Author's Responsibility: Male size advantage drives evolution of sex change in reef fish

(University of California - Davis) Some species of fish, notably parrotfish and wrasses living on coral reefs, change their biological sex as they age, beginning life as females and later becoming functionally male. New work from UC Davis shows that this sequential hermaphroditism evolves when bigger males gain an advantage in reproductive success -- for example by defending a permanent mating territory.