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Sexual dimorphism also occurs in hermaphroditic fish. These species are known as sequential hermaphrodites. In fish, reproductive histories often include the sex-change from female to male where there is a strong connection between growth, the sex of an individual, and the mating system within which it operates. [55]
The stoplight parrotfish is a protogynous hermaphrodite that shows full sexual dichromatism, meaning that it changes its sex from female to male during its lifespan, and its color changes with its sex change. [4] The sex change is most likely due to the control of hormones, in particular, 11-ketetestosterone (11-KT). [5]
As sex-determining mechanisms, TSD and genetic sex determination (GSD) should be considered in an equivalent manner, [8] which can lead to reconsidering the status of fish species that are claimed to have TSD when submitted to extreme temperatures instead of the temperature experienced during development in the wild, since changes in sex ratio ...
For example, in some species of cichlid fish from Lake Malawi, if an individual has both the XY locus (on one chromosome pair) and the WZ locus (on another chromosome pair), then the W is dominant and the individual has a female phenotype. [40] The sex-determination system of zebrafish is polygenic. Juvenile zebrafishes (0–30 days after ...
The larval period in oviparous fish is relatively short (usually only several weeks), and larvae rapidly grow and change appearance and structure (a process termed metamorphosis) to become juveniles. During this transition larvae must switch from their yolk sac to feeding on zooplankton prey, a process which depends on typically inadequate ...
The XY sex-determination system is a sex-determination system present in many mammals, including humans, some insects , some snakes, some fish , and some plants (Ginkgo tree). In this system, the sex of an individual usually is determined by a pair of sex chromosomes.
Striped maple trees (Acer pensylvanicum) have been shown to change sex over a period of several years, and are sequential hermaphrodites. [69] When branches were removed from striped maple trees [70] they changed to female or to female and male as a response to the damage. Sickness will also trigger a sex change to either female or female and ...
In cases of protandrous sex change, the immature ovarian tissues develop and the testicular tissues deteriorate due to changes in the activity of gonadal steroid hormones such as estrogen. [12] Bi-directional, or serial, sex change occurs when hermaphrodites are capable of changing their sex in either direction, possibly multiple times.