page_title: Parrotfish
section_title: Life cycle
hierarchical_section_title: Parrotfish / Life cycle
caption_attribution_description: Cetoscarus bicolor
context_page_description: Parrotfishes are a group of about 95 fish species regarded as a family, or a subfamily of the wrasses. With about 95 species, this group's largest species richness is in the Indo-Pacific. They are found in coral reefs, rocky coasts, and seagrass beds, and can play a significant role in bioerosion.
context_section_description: The development of parrotfishes is complex and accompanied by a series of changes in sex and colour (polychromatism). Most species are sequential hermaphrodites, starting as females (known as the initial phase) and then changing to males (the terminal phase). In many species, for example the stoplight parrotfish (Sparisoma viride), a number of individuals develop directly to males (i.e., they do not start as females). These directly developing males usually most resemble the initial phase, and often display a different mating strategy than the terminal phase males of the same species. A few species such as the Mediterranean parrotfish (S. cretense) are secondary gonochorists. This means that some females do not change sex (they remain females throughout their lives), the ones that do change from female to male do it while still immature (reproductively functioning females do not change to males) and there are no males with female-like colors (the initial phase males in other parrotfish). The marbled parrotfish (Leptoscarus vaigiensis) is the only species of parrotfish known not to change sex. In most species, the initial phase is dull red, brown, or grey, while the terminal phase is vividly green or blue with bright pink, orange or yellow patches. In a smaller number of species the phases are similar, and in the Mediterranean parrotfish the adult female is brightly colored, while the adult male is gray. In most species, juveniles have a different color pattern from adults. Juveniles of some tropical species can alter their color temporarily to mimic other species. Where the sexes and ages differ, the remarkably different phases often were first described as separate species. As a consequence early scientists recognized more than 350 parrotfish species, which is almost four times the actual number.
  Most tropical species form large schools when feeding and these are often grouped by size. Harems of several females presided over by a single male are normal in most species, with the males vigorously defending their position from any challenge.
  As pelagic spawners, parrotfish release many tiny, buoyant eggs into the water, which become part of the plankton. The eggs float freely, settling into the coral until hatching.
  The sex change in parrotfishes is accompanied by changes in circulating steroids. Females have high levels of estradiol, moderate levels of T and undetectable levels of the major fish androgen 11-ketotestosterone. During the transition from initial to terminal coloration phases, concentrations of 11-ketotestosterone rise dramatically and estrogen levels decline. If a female is injected with 11-ketotestosterone, it will cause a precocious change in gonadal, gametic and behavioural sex.
caption: The bicolor parrotfish (Cetoscarus bicolor) was described by Rüppell in 1829. In 1835, he mistakenly described the terminal phase, featured on this photo, as a separate species, C. pulchellus
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