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.
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.
During the mating frenzy, some pairs mate for up to 14 hours at a time. In those species that have completely adopted the shorter mating system, all males die: Elevated stress levels cause a fatal immune system collapse and death by hemorrhaging and infection. (Related: "3 Mammals That 'Choose Their Babies' Sex.")
The poster child for this phenomenon is the male antechinus, a tiny, short-lived Australian mammal. The critter goes on a mad mating spree (sometimes as long as 14 hours), after which it suffers a fatal immune system breakdown and dies a ragged wreck.
The praying mantis, black widow spider, and jumping spider are among a number of species that devour their mates. Sexual cannibalism is also found in other invertebrates, including a relative of the praying mantis, the Chinese mantis, and scorpions.
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.
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.
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. Seahorses are members of the pipefish family.
However, if a kangaroo rat drinks water, the necessary bodily liquids and vitamins are flushed out, and it dies as a result of dehydration.
Coercive mating is very common in water striders (Gerridae) because in most of the species, the female genitalia are often exposed and easily accessible to males. Without any courtship behavior, males initiate by forcefully trying to mount the females.
A half man/half dog wouldn't get very far past a single cell (assuming the egg and sperm could even come together!). This is because dogs and people have very different sets of instructions in their DNA. Their genomes are simply too different to come together and make something that will live.
But octopuses aren't the only ones who kill their sex partners. Female praying mantises often kill their mates, especially if they're hungry, and within certain species of spiders, the males will actually offer themselves as a meal for their newly-impregnated partners.
They react differently when external stimuli are applied while sleeping and while awake. But the bullfrog, Lithobates catesbeianus show the same reaction in both situations. This indicates that bullfrogs do not sleep. Lithobates catesbeianus is an animal that cannot sleep.
What may not be so well known, though, is that kangaroos cannot walk backwards. Their hopping movement is called saltation. During saltation, kangaroos push off with both large feet at the same time, and they use their tails for balance.
Brachiopods have black blood. Octopuses have a copper-based blood called hemocyanin that can absorb all colors except blue, which it reflects, hence making the octopus' blood appear blue.
The swamp wallaby is the only mammal that is permanently pregnant throughout its life according to new research about the reproductive habits of marsupials. Unlike humans, kangaroos and wallabies have two uteri. The new embryo formed at the end of pregnancy develops in the second, 'unused' uterus.
Most animals that procreate through parthenogenesis are small invertebrates such as bees, wasps, ants, and aphids, which can alternate between sexual and asexual reproduction. Parthenogenesis has been observed in more than 80 vertebrate species, about half of which are fish or lizards.
Also knows as Platypus frogs, the female amphibian, after external fertilization by the male, would swallow its eggs, brood its young in its stomach and gave birth through its mouth.
Could we mate with other animals today? Probably not. Ethical considerations preclude definitive research on the subject, but it's safe to say that human DNA has become so different from that of other animals that interbreeding would likely be impossible.
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.
Lifelong attachment
In native birds that form long-lasting bonds, including butcherbirds, drongos and cockatoos, differences between the sexes are small or non-existent – that is, they are “monomorphic”.
Australian wildlife mating is not all rough animal behaviour; some natives also display a range of gentler traits. The vulnerable species the black glossy cockatoo pairs for life, which can be up to 80 years. "During that time they will stay monogamous to one another," Ms Eccleston said.
While mammals and birds possess the prerequisite neural architecture for phenomenal consciousness, it is concluded that fish lack these essential characteristics and hence do not feel pain.
Why Do Snails Sleep So Long? Snails need moisture to survive; so if the weather is not cooperating, they can actually sleep up to three years.
Jellyfish, starfish, and even corals manage very well without hearts. Starfish do not even have blood, so this explains why no heart is required. Instead, they use small hair-like structures called cilia to push seawater through their bodies and they extract oxygen from the water.