Traumatic insemination , also known as hypodermic insemination , is the practice of mating in some invertebrate species in which a man pierces a woman's stomach with aedeagus and injects sperm through a wound into her abdominal cavity ( hemocoel). Sperm spreads through the female hemolymfa, reaching the ovaries and producing fertilization. The process is detrimental to women's health. This creates an open wound that damages the female until it heals, and is susceptible to infection. Injection of sperm and ejaculatory fluid into the hemocoel can also trigger an immune response in women. Bed bugs, which are breeding only by traumatic insemination, have evolved a pair of sperm containers, known as spermalege. It has been suggested that spermalege reduces direct damage to female bed bugs during traumatic insemination. However, statistical experiments do not show conclusive evidence for the hypothesis; in 2003, the preferred explanation for such organs was the hygienic protection of bacteria.
The origin of the evolution of traumatic insemination is debated. Although it evolves independently in many invertebrate species, traumatic insemination is most often adapted and thoroughly studied in bed bugs, notably Cimex lectularius . Traumatic insemination is not limited to a male-female clutch, or even a coupling of the same species. Both traumatic and homosexual traumatic insemination have been observed.
Video Traumatic insemination
Mekanika
In humans and other complex life forms, blood and lymph are circulating in two different systems, the circulatory system and the lymphatic system, which is covered by capillary, venous, arterial, and glandular systems. This is known as a closed circulation system. Insects, however, have an open circulatory system in which blood and lymph is circulated unenclosed, and the mixture to form a substance called hemolymph. All the insect organs are bathed in hemolymph, which provides oxygen and nutrients for all the insect organs.
After traumatic insemination, sperm can migrate through hemolympha into the female ovaries, resulting in fertilization. The exact mechanism varies from taxon to taxon. In some orders of insects, the male genitalia (paramere) enters the female genital tract, and the spine ends through the female copulatrix bursa wall. On the other hand, men penetrate the outer body wall. In both cases, after penetration, men ejaculate into women. Sperm and ejaculatory fluid spread through female hemolympha. Insemination works if the sperm reaches the ovary and fertilises the egg.
Women's resistance to traumatic insemination varies from one species to another. Women of several genera, including Cimex , passive before and during traumatic insemination. Females in other genera refuse to marry and try to escape. This resistance may not be an aversion to the pain caused by insemination, since the observational evidence suggests that insects do not feel pain.
The research into the hereditary father produced by traumatic insemination has found the last precedent-the "significant" sperm. That is, the last man who traumatically inseminated women tended to make the most of his offspring as women.
Maps Traumatic insemination
Evolutionary adaptation
Many reasons for the evolutionary adaptation of traumatic insemination as a mating strategy have been suggested. One is that traumatic insemination is an adaptation to the development of a mating plug, a reproductive mechanism used by many species. After a man has finished copulating, he injects a sticky secretion into the female reproductive tract, thus "literally sticking the genital tract closed". Traumatic insemination allows the next man to bypass the sexually transmitted female genital tract, and inject sperm directly into his circulatory system.
Others argue that the practice of traumatic insemination may be an adaptation for men to avoid female opposition to marriage to eliminate courtship time, allowing one man to inseminate multiple partners when contact between them is brief; or that it evolved as a new development in sperm competition as a means to store the sperm as close to the ovary as possible.
This peculiar method of insemination may have evolved because male bed bugs compete with one another to place their sperm closer and closer to the mother egg layer, the ovary. Some male insects evolved long with a penis that enters the vagina but passes through a woman's storage bag and stores their sperm closer to the nearest ovary. Some men, especially among the bedbugs, develop traumatic insemination instead, and eventually this strange procedure becomes the norm among these insects.
It was recently discovered that members of the plant genus Coridromius (Miridae) also practiced traumatic insemination. In this insect, the male intromitent organ is formed by a left aided clutch with left paramed, as in bed fleas. Women also exhibit paragenital modification at the site of intromission, which includes grooves and invagination mating tubes to guide male parameters. The evolution of traumatic insemination at Coridromius represents the third independent appearance of this form of marriage in the actual bug.
Health reactions
While beneficial for individual male reproductive success, traumatic insemination imposes a cost on women: reduced lifespan and decreased reproductive output. "These [costs] include (i) wound repair, (ii) blood leakage, (iii) increased risk of infection through stab wounds, and (iv) immune defenses against sperm or accessory gland secretions introduced directly into the blood."
The male bed bug aedeagus has been shown to carry five pathogenic microbes (human), and female nine bed bug exoskeleton, including Penicillium chrysogenum , Staphylococcus saprophyticus , Stenotrophomonas maltophilia , Bacillus licheniformis , and Micrococcus luteus . A blood-agar test has shown some of these species to survive in vivo . This suggests an infection of this species may contribute to an increase in maternal mortality due to traumatic insemination.
Successive cuts each require energy to heal, leaving less energy available for other activities. Also, injuries provide a possible point of infection that can reduce the lifespan of women. Once in hemolymph, sperm and ejaculatory fluid can act as antigens, triggering an immune response.
There is a tendency for dense colonies of bed bugs kept in laboratories to become extinct, starting with adult females. In such an environment, where mating frequently occurs, the high mortality rate of adult women shows traumatic insemination is very detrimental to women's health. The damage done, and the high rate of squirrel lice (unnecessarily), has been shown to cause a mortality rate 25% higher than that required for women.
Bed bug adaptation
The effects of traumatic insemination undermine women. Bed bug females have evolved a pair of special reproductive organs ("paragenitalia") at the site of penetration. Known as ektospermalege and mesospermalege (referred to collectively as spermaleges), these organs function as sperm containers from which sperm can migrate to the ovaries. All reproduction of bedbugs occurs through traumatic insemination and sperms. The genital tract, although functional, is only used to lay fertilized eggs.
The ectospermalege is a swelling in the abdomen, often folded, filled with hemosite. The ectospermalege is seen externally in most species of bed bugs, giving the target man through which to pierce the female with the paramere. In species without ectospermalege that are seen externally, traumatic insemination occurs on various body surfaces.
Exactly why men 'obey' the aspect of women's control on this marriage site is unclear, especially as the P. cavernis man seems to be able to penetrate the stomach at some point independent of the presence of the ektospermalege. One possibility is that the marriage outside the ectospermalent reduces female fecundity in such a way that the marriage of the male mating is significantly reduced... the ektospermalege seems to act as a mating guide, directing the interest of the male marriage, and therefore destructive, to the forbidden area of ​​the woman's abdomen.
Mesospermalege is a sac that attaches to the inner abdomen, under the ektospermalege. Sperm is injected through the male aedeagus to the mesospermalege. In some species, the ektospermalege is directly connected to the ovary - thus, sperm and ejaculation never enter the hemolymph and thus never trigger an immune response. (Proper spermalege characteristics vary greatly in different species of bed bugs.) Spermalau is commonly found only in women. However, men in the Afrocimex genus have an ektospermalege. Sperm remains in the spermalege for about four hours; after two days, nothing is left.
Bed bugs in males have evolved chemoreceptors in their aedeagi. After the women, men can "feel" if a woman has just been married. If he does, he will not copulate longer and will ejaculate less fluid to the woman.
Use in animal kingdom
Although traumatic insemination is most widely practiced among heteropteran (typical bugs), this phenomenon has been observed in a variety of other invertebrate taxa. These include:
- Oxyurida (nematodes) - Traumatic insemination has been observed in the genus of pinworm including Auchenacantha , Citellina , Passalurus , and "possibly" Austroxyris.
- Acanthocephala (parasite, horn-headed worms) - The presence of a mating plug on the Pomphorhynchus bulbocolli side shows traumatic insemination occurring in this species. Because these parasites can not move after tethering themselves to the host's intestine, traumatic insemination may have evolved to compensate for their immobility.
- Rotifera (wheel animalcules) - In the genus Brachionus , men penetrate syncytial integuments (equivalent to skin) and inject sperm; in Asplanchna brightwelli men secrete enzymes that break female integuments and inject sperm through holes.
- Turbellaria (free live worms) - hermaphrodite flat worms multiply with "penis fence". Individuals "fence" with a penis, try to use their penis to penetrate the other skin and inject sperm. The 'losers' are flatworms that are inseminated and must bear the cost of reproductive energy. One study of Pseudoceros bifurcus found "Most inseminations are unilateral, even when reciprocal penis insertion can be achieved by the second pair, the first for insemination gets longer injection time than the second." In other species, Macrostomum hystrix , the worm can also inject its own sperm into its head if another pair is not available.
- Gastropod slug
- Strepsiptera (parasite with winged wings) - In Xenos vesparum , fertilization can occur either through the extragenital duct, or by traumatic insemination to the hemocoel.
- Drosophila (fruit flies) - Ejaculation is injected through the body wall to the genital tract, not the stomach.
- Opisthobranchia (sea slug) - Characterized by "repeated small injections to the dorsal surface of the partner, disturbed by synchronized circular motions", reaches its peak in standard genital insemination.
- Harpactea (spider) - The male of the spider species Harpactea sadistica penetrates the female body cavity and isolates the ovaries directly.
Homosexual traumatic insemination
Traumatic insemination is not limited to male-female clutches. Male homosexual traumatic insemination has been observed in the flower bugs Xylocoris maculipennis and sleep insects from the Afrocimex genus .
In the Afrocimex genus , both species have well-developed ectospermaleges (but only females with mesospermalege). The male ektospermalege is slightly different from that found in women, and remarkably, Carayon (1966) found that the Afrocimex man bugs suffered actual homosexual traumatic insemination. He found that male ektospermalege often exhibits typical marriage scars, and histologic studies show that "foreign" sperm are widespread in males who are homosexualized. Other male sperm cells, however, are never found in or near the male reproductive tract. It therefore seems unlikely that sperm from other men can be inseminated when a man has suffered a traumatic self-inflicted female pair with a female. The costs and benefits, if any, of homosexual traumatic insemination in Afrocimex remain unknown.
Klaus Reinhardt of Sheffield University and colleagues looked at two different morphologically different types of spermalegens in Afrocimex constrictus, a species in which both men and women are traumatized inseminated. They found women using sexual mimicry as a way to avoid traumatic insemination. In particular, they observed men, and women who had a male spermalege structure, were inseminated less frequently than women with female spermalege structures.
In Xylocoris maculipennis , after another male inseminatic traumatic male, injected sperm migrate to the testes. (The seminal fluid and most sperm are digested, giving men inseminated nutrient-rich foods.) It has been suggested, although there is no evidence, that when male ejaculation is inseminated into females, females receive both male sperm.
Interspecies traumatic insemination
The case of traumatic insemination between animals of different species will sometimes provoke a potentially deadly immune reaction. A Cimex lectularius woman traumatically inseminated by a man with C. hemipterus will swell in place of insemination because the immune system responds to male ejaculation. In the process, the lifespan of women decreases. In some cases, this immune reaction can be very large to almost fatal. A woman of Hesperocimex sonorensis will swell, blacken, and die within 24-48 hours after being traumatically inseminated by a male H. cochimiensis .
Similar mating practices
In the animal kingdom, traumatic insemination is not unique as a form of coercive sex. Research shows that in the genus of water-beetle Acilius there is no dating system between men and women. "This is a system of rape, but women do not take things quietly, they develop counter weapons." The culled marriage behavior includes men strangling the females underwater until they run out, and only allow occasional access to the surface to breathe for up to six hours (to prevent them from breeding with other males), and females that have different body shapes (to prevent males from getting a handle). Foreplay is "limited to women who try desperately to drive men away by swimming in panic".
"Rape behavior" has been observed in a number of duck species. In the blue-winged teal, "male male rape can occur at any time during the breeding season." The reasons mentioned above are that it is useful for paired males including successful reproduction, and expels intruders from their territory. Flocks of bottlenose dolphins occasionally gang up a woman and force her to have sex with them, by swimming nearby, chasing her if she tries to escape, and makes a sound or physical threat. In the world of insects, male water striders can not penetrate their sex shields, will attract predators to females until they copulate.
See also
- race of evolutionary weapons
- Sexual conflict
- sexual cannibalism
References
External links
- The BBC article on traumatic insemination on Harpactea sadistica spider, with video
Source of the article : Wikipedia
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