THE’antechinea small Australian marsupial, invests enormous energies to mate to come to compromise his health, a behavior that may seem bizarre, but makes sense from an evolutionary point of view. Twelve hours of uninterrupted sexfor three weeks in a row, which culminate almost certainly with the death. Despite being very rare in vertebrates, this reproductive strategy, called semelparityhas evolved by Maximize fertilization chances. The continuous effort and the loss of hours of sleep, however, trigger the release of corticosteroids in the bloodstream of these animals, leading to a immune deficit And lethal gastric ulcers, a bit like us when we are stressed. Exhausted and deployed, the male tends to die shortly after the end of the coupling period, while usually the females die after giving birth to a single litter and rarely survive after the second.
What an animal is the antechine and how it reproduces
Antechini are a kind of small marsupy mammals of the Dasiurid family similar to mice, which inhabit trees inhabitants. 15 species are known, all natives of Australia and all with an unusual reproductive behavior. During the coupling season, which can go from July to September, all females of the same species of antechine synchronize their flair e they go into heat at the same time. Here begins a period of three weeks during which almost all energies are dedicated to mating. In this phase, the male doors also sacrifice several Hours of sleep: A small effort for animals that normally need up to 15 hours a day of rest, during which they enter torpor to save as many energy possible.
The males mate with more females and the females mate with multiple malesbringing the same litters to have different fathers. Females can keep the cum of multiple males inside their ovidotti and release it later.
Curiously, many species of antechine they live in the same places but they reproduce in different periods Based on daily lightingwith the larger species that reproduce before. This selective reproduction per size has given rise, in the long term, to a reproductive isolation and the so -called species Sympatricity specification. All species need some kind of reproductive separation To differentiate itself from the progenitor species, but while in other cases the separation is geographical, for example due to a physical barrier of some kind (allopatric specification), in this case the separation was temporal type.
The males of this Australian marsupial die from the effort after mating
The energy efforts necessary to mate for so long and with so many individuals have enormous consequences on the body of the antechini. Their body experiences very high levels of corticosteroidshormones involved in many physiological mechanisms including metabolism, the immune system and the inflammatory response. This excess of corticosteroids for long periods, combined with thoroughness, leads to a immune deficit and the onset of serious gastrointestinal ulcers.
Exhausted males meet one mass of masswhile the females carry out gestation and take care of the litter (which also reaches a dozen children) for a month, while breastfeeding lasts about 100 days. When the little ones become independent, often Even females succumb to effortand only in a few species are they able to perform two or three reproductive cycles during their life. In a species, Antechinus mimeteswere also observed rare cases of cannibalism by females towards the deceased males, a source of protein that is easy to access.
Because the antechines reproduce like this
Invest all their energies In a single reproductive act to the point of dying it may seem like a counterproductive survival strategy, but which assumes meaning in an evolutionary perspective if we consider that the goal of a life form is the Passage of the genetic heritage to subsequent generations.
Most of vertebrates, insect molluscs and even perennial plants use a reproductive strategy, called Hyeroparity: Multiply the number of reproductive events to have more chances than the offspring survives. Depending on the species, the procedure requires an energy investment in terms of courtship, parental care or greater production of gametes.
With the opposite strategy, the semelparity all energy expenditure is concentrated on reproduction, in a the only act during life, even at the expense of one’s personal survival. In short, it must be “Good first”. They are Semelpari, for example annual plants, as well as kind of insects and arachnids, notes to die after mating such as butterflies, ephemeral and spiders. However it is very rare in vertebratesand it can be found in the salmon and in a few species of reptiles and marsupials, including the antechine.
