It might sound counterintuitive, but according to a new study published Thursday in PLOS Genetics, it's true, at least for parasitic worms. Although nearly all animals reproduce sexually, there's a small percentage that's managed to procreate without sex and the root-knot nematode is one of them.
Bdelloids are microscopic animals that live in freshwater and damp habitats across the world. Despite their apparent lack of sex, we know they have evolved for tens of millions of years into more than 500 species.
Liu has spent years studying cell fate decisions and cell signaling pathways in Caenorhabditis elegans, a transparent nematode that was the first multicellular organism to have its whole genome sequenced. "An adult C. elegans hermaphrodite has a fixed number of somatic (nonreproductive) cells—exactly 959,” Liu says.
Ghost Worms were large, snake like worms that lived in the Caves of Doom on Planet Doom and always moved together in groups. Like many ghosts, they were under the command of Prime Evil.
Really wild orgasms Not only do animals enjoy the deed, they also likely have orgasms, he said. They are difficult to measure directly but by watching facial expressions, body movements and muscle relaxation, many scientists have concluded that animals reach a pleasurable climax, he said.
We're sure some of these are bound to surprise you! Beavers are one of the few mammals that mate for a lifetime, only choosing to find another mate if their original mate dies. But here's where it gets interesting: there are two types of beavers, European beavers and North American beavers.
The primary function of sex is to reproduce, so it would make sense that nature would incentivise animals to mate by rewarding them with a pleasurable experience. We don't know how many animals experience sexual pleasure, but we have evidence for it in a number of species.
Oral sex has been observed throughout the animal kingdom, from dolphins to primates.
Unlike humans, animals can't tell us they're having orgasms, so we can't truly know what their experience is like. For the most part, we assume that male animals orgasm because there's an ejaculation–though one can happen without the other, they usually go hand-in-hand.
For males belonging to some species of the Dasyuridae family of marsupials, sex is a fatal, frenzied final act. After intercourse, the immune systems of these palm-sized, mouselike creatures collapse and they die soon afterward.
Animals that mate for life: beavers
Not much is known about how beavers find their mates, but once they do, they stick with that partner for life. A genetic study by Charles University in Prague even found that beavers stay faithful to their mates. Granted, this only applies to European beavers.
Not only do animals enjoy the deed, they also likely have orgasms, Bekoff said. They are difficult to measure directly but by watching facial expressions, body movements and muscle relaxation, many scientists have concluded that animals reach a pleasurable climax, he said.
In fact, such human-animal hybrids are often referred to as “chimeras”.
2. -Polygamous mating system: females each copulate with both males; males each copulate with all four females.
Swamp wallabies have two uteruses, so they can conceive a new baby before birthing another, scientists have discovered.
Mother octopuses never meet their babies, as they stop eating and die of starvation before the young hatch.
Octopuses are semelparous animals, which means they reproduce once and then they die. After a female octopus lays a clutch of eggs, she quits eating and wastes away; by the time the eggs hatch, she dies.
Unlike many other animals, dolphins do not mate purely for procreation. Rather, these highly social and intelligent animals have sex for pleasure as well. Further, this means they can have sex throughout the year, rather than being limited to a mating season.
Animals that don't need sleep (bullfrogs and dolphins)
The nutrients gained when a female praying mantis eats her suitor benefit her offspring as they grow. Sexual cannibalism — when the female of a species consumes the male during or after mating — is also known among spiders, such as the black widow, and scorpions.
Squirrel monkey infants have such large heads compared to the size of their mothers' pelvises that they face a very high rate of birth complications. Perhaps the most horrifying birth is that of the spotted hyena.
The length of gestation varies from species to species. The shortest known gestation is that of the Virginian opossum, about 12 days, and the longest that of the Indian elephant, about 22 months. In the course of evolution the duration of gestation has become adapted to the needs of the species.
Seahorses and their close relatives, sea dragons, are the only species in which the male gets pregnant and gives birth. Male seahorses and sea dragons get pregnant and bear young—a unique adaptation in the animal kingdom.