List of taxa that use parthenogenesis
Parthenogenesis is a form of asexual reproduction in which the embryo develops directly from an egg without need for fertilization.
[3] No males of Epiperipatus imthurni have been found, and specimens from Trinidad were shown to reproduce parthenogenetically, making it the only velvet worm known to use parthenogenesis.
At least in one normally cyclical parthenogenetic species obligate parthenogenesis can be inherited: a recessive allele leads to loss of sexual reproduction in homozygous offspring.
[citation needed] A related phenomenon, polyembryony is a process that produces multiple clonal offspring from a single egg cell.
[11] Among species with the haplo-diploid sex-determination system, such as hymenopterans (ants, bees, and wasps) and thysanopterans (thrips), haploid males are produced from unfertilized eggs.
Thus, in a relatively short period, all the worker bees die off, and the new drones follow if they have not been able to mate before the collapse of the colony.
These include a honey bee subspecies from South Africa, Apis mellifera capensis, where workers are capable of producing diploid eggs parthenogenetically, and replacing the queen if she dies; other examples include some species of small carpenter bee, (genus Ceratina).
[18] Offspring are genetically identical to the parent, indicating it reproduces by apomixis, i.e. parthenogenesis in which the eggs did not undergo meiosis.
The Journal of Fish Biology reported a study in which scientists said DNA testing proved that a pup carried by a female Atlantic blacktip shark in the Virginia Aquarium & Marine Science Center contained no genetic material from a male.
[31] A female round stingray (Urobatis halleri) held in captivity from all males for eight years was reported pregnant in 2024.
[33] In June 2023, discovery was made at a zoo in Costa Rica, where researchers identified the first documented case of a self-pregnant crocodile.
This female American crocodile, housed at Parque Reptilania, produced a genetically identical foetus, with a 99.9% similarity to herself.
The scientists speculate that this unique ability might be inherited from an evolutionary ancestor, suggesting that even dinosaurs could have possessed the capability for self-reproduction.
[52] In 2012, facultative parthenogenesis was reported in wild vertebrates for the first time by US researchers amongst captured pregnant copperhead and cottonmouth female pit-vipers.
These lizards live in the dry and sometimes harsh climate of the southwestern United States and northern Mexico.
[citation needed] An interesting aspect to reproduction in these asexual lizards is that mating behaviors are still seen, although the populations are all female.
Lizards who act out the courtship ritual have greater fecundity than those kept in isolation, due to the increase in hormones that accompanies the mounting.
[58] Some lizard parthenogens show a pattern of geographic parthenogenesis, occupying high mountain areas where their ancestral forms have an inferior competition ability.
[59] In Caucasian rock lizards of genus Darevskia, which have six parthenogenetic forms of hybrid origin[37][38][60] hybrid parthenogenetic form D. "dahli" has a broader niche than either of its bisexual ancestors and its expansion throughout the Central Lesser Caucasus caused decline of the ranges of both its maternal and paternal species.
[62][63] The first description of parthenogenetic development in a passerine was demonstrated in captive zebra finches, although the dividing cells exhibited irregular nuclei and the eggs did not hatch.
[62] Parthenogenesis in turkeys appears to result from a conversion of haploid cells to diploid;[63] most embryos produced in this way die early in development.
[65] In 2021, the San Diego Zoo reported that they had two unfertilized eggs from their California condor breeding program hatch.
