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A hermaphrodite (/ h ər ˈ m æ f r ə ˌ d aɪ t /) is a sexually reproducing organism that produces both male and female gametes. [1] Animal species in which individuals are either male or female are gonochoric , which is the opposite of hermaphroditic.
Hermaphrodite species include the common earthworm and certain species of snails. A few species of fish, reptiles, and insects reproduce by parthenogenesis and are female altogether. There are some reptiles, such as the boa constrictor and Komodo dragon that can reproduce both sexually and asexually, depending on whether a mate is available.
Lythrypnus is a hermaphroditic fish that is able to change sex. Depending on its size and shape, Lythrypnus Dalli is able to have both male and female reproductive function. Species
A sequential hermaphrodite produces eggs (female gametes) and sperm (male gametes) at different stages in life. [2] Sequential hermaphroditism occurs in many fish, gastropods, and plants. Species that can undergo these changes do so as a normal event within their reproductive cycle, usually cued by either social structure or the achievement of ...
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 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.
XO sex determination can evolve from XY sex determination within about 2 million years. [clarification needed] It typically evolves due to Y-chromosome degeneration.As the Y-chromosome is not paired (though see pseudoautosomal region), it is susceptible to decay by Muller's ratchet.
In ovoviviparous fish the eggs develop inside the mother's body after internal fertilisation but receive little or no nourishment directly from the mother, depending instead on a food reserve inside the egg, the yolk. [10] Each embryo develops in its own egg. Familiar examples of ovoviviparous fish include guppies, angel sharks, and coelacanths.