Search results
Results From The WOW.Com Content Network
This type of reproduction had been seen before in bony fish, but not in cartilaginous fish such as sharks. [27] In the same year, a female Atlantic blacktip shark in Virginia reproduced via parthenogenesis. [28] On 10 October 2008, scientists confirmed the second case of a "virgin birth" in a shark.
Asexual reproduction diminishes genetic diversity, which helps build defenses against threats to the species. Species that rely solely on it risk extinction. Asexual reproduction may have contributed to the blue shark's decline off the Irish coast. [79]
A form of asexual reproduction related to parthenogenesis is gynogenesis. Here, offspring are produced by the same mechanism as in parthenogenesis, but with the requirement that the egg merely be stimulated by the presence of sperm in order to develop. However, the sperm cell does not contribute any genetic material to the offspring.
Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change ... the sharks had reached sexual maturity in captivity in the ...
As with all types of asexual reproduction, there are both costs (low genetic diversity and therefore susceptibility to adverse mutations that might occur) and benefits (reproduction without the need for a male) associated with parthenogenesis. Parthenogenesis in sharks has been confirmed in the bonnethead [35] and zebra shark. [36]
The pregnancy of a stingray living in a tank without male rays has stirred a sudden interest in parthenogenesis, a scientific term that essentially means virgin birth.
The blacktip shark (Carcharhinus limbatus) is a species of requiem shark, ... In the absence of males, females are also capable of asexual reproduction.
Parthenogenesis is a mode of asexual reproduction in which offspring are produced by females without the genetic contribution of a male. Among all the sexual vertebrates, the only examples of true parthenogenesis, in which all-female populations reproduce without the involvement of males, are found in squamate reptiles (snakes and lizards). [1]