To reproduce their own kind, it is necessary that males and females take part in mating. However, in nature there are examples of the immaculate conception, and we are not only talking about single-cell organisms. The name of this phenomenon is parthenogenesis. Animal and plant organisms can reproduce without the participation of males. We offer you to get acquainted with the most striking examples of parthenogenesis.
Bright representatives of living creatures that support the population through year-round cloning of themselves. This happens by laying eggs. One adult is capable of reproducing twelve of its kind per day. The rate of parthenogenesis of aphids depends on the number of nearby natural enemies – ladybugs. The more predators, the faster the process of increasing the number of aphid colonies.
For many years, nothing was known about the parthenogenesis of crustaceans. Only by the mid-nineties of the twentieth century, scientists discovered marble crayfish, which for reproduction does not require males. To obtain healthy offspring, these creatures do not need to have males nearby. These representatives of the crustacean family are the first and so far the only ones who use parthenogenesis for reproduction.
Male marble crayfish are sterile. However, after intercourse, which does not carry fertilization, in females there is a change in the hormonal background, which contributes to the division of the egg. Gradually, this species of crustaceans, due to this feature, displaces other species of relatives and other animals from water bodies.
Male bees are large in size compared to workers, they have better developed sense organs. Bee males are called drones. They exist for a single purpose – copulation with the uterus. The queen of bees copulates once in her life. In the process of copulation, the queen bee collects the necessary amount of sperm inside the testis – a special organ that exists specifically for this purpose.
Then, throughout life, lays fertilized and unfertilized eggs. Worker bees appear from the fertilized, and drones from the unfertilized. This method of reproduction helps with the death of a large number of members of one bee family, the queen will quickly restore the population, in which there will be enough working individuals and drones.
In the males of these snails, the genitals are atrophied. For this reason, males are not able to participate in the fertilization of females. Namely, the female individuals of the snails melania have taken responsibility for the continuation of the genus. Due to the rapid population growth, these snails are popular with aquarists. Their ability to eat algae from the walls of the aquarium makes them in demand among lovers of decorative fish.
To rapidly increase the population, it is enough to maintain a high water temperature and provide snails with additional feeding. In countries with a hot climate – Cuba, America, South Africa and the Dominican Republic, in certain years snail melania became the causes of natural disasters. Scientists and ecologists were involved in solving the overpopulation by snails of local reservoirs.
These unknown creatures in wide circles are breaking all records in the matter of survival. Individuals of these microscopic creatures were found beneath the ice, in the waters of hot springs. Tardigrades are multicellular creatures that have a nervous, digestive and excretory system. In the event of an unfavorable period, they fall into a prolonged state of suspended animation, out of which after its completion.
The females of these creatures can do without males. They reproduce regardless of the presence, absence of a sexual partner. When fertilized by the male, the female lays no more than fifteen eggs, in his absence – more than thirty-five.
Daphnia or flea aquatic
The natural habitat of Daphnia is the reservoirs of Australia, Europe and America. Water fleas are able to reproduce offspring through cyclic parthenogenesis. Cyclic parthenogenesis involves obtaining offspring through and without sexual intercourse. After lengthy observations by Daphnia, scientists concluded that these creatures use parthenogenesis under favorable conditions – high water temperature, enough food.
Subject to the presence of nearby males, the female Daphnia mates, in the absence of a male, recreates offspring similar to herself. In the clutch obtained during parthenogenesis, all young individuals will be females with the same genetic code.
Due to this feature, the population of daphnia females capable of parthenogenesis is growing.