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Finding a mate for humans is serious business that often results in a lifelong partnership. However, for many animals, mating is a matter of course and has no other emotion or meaning attached to it. In some cases, the very act of mating can have fatal results.
What are Semelparous Animals?
Pretty much all the animals on earth will reproduce, raise their young, and then go on to have another brood. However, there are some species, such as certain invertebrates, fish, and even some plants that will reproduce for the first time and die shortly thereafter.
This is known as semelparity and while it might sound a little intense, it’s actually beneficial for the species that behave this way. One of the most common reasons for this is that these species typically have very large amounts of young at once. What’s more, after this first bout of breeding, it’s highly unlikely that the animal would survive long enough for a second round.
Since the animal’s main aim in life is to reproduce, it can focus most of its energy on this which results in a larger clutch. The more young that are born, the better it is for the survival of the species. However, in certain males, such as the Pacific salmon, so much energy is put into the mating ritual that this lessens his immune system, which can cause conditions such as gastrointestinal hemorrhage and this is always fatal.
Animals that Die After Reproducing
For many creatures, their very reason for existing is for the continuation of the species. Once they’ve mated, it’s almost certain death. Let’s get to know some of these animals a little better.
Antechinus is a small marsupial of which there are 12 species. While they may be so small that they’re often referred to as marsupial mice, male antechinus save up all their energy for mating in sessions that can last in excess of 14 hours!
However, this is triggered by a stress hormone that massively escalates during the breeding season. Just before breeding season, when the males are around 11 months old, they will stop producing sperm. What’s already stored in their body is what they’ll use for the imminent mating.
Their stress hormones escalate so much during this time that other systems in the body are affected. But death isn’t quick. The males may develop ulcers and gangrene at the same time as losing their fur. Inside the body, systems such as the immune system start shutting down, and internal organs begin to hemorrhage. While they may still scrabble around for one last mating attempt, the males will usually die before the females give birth.
2. Praying Mantis
While marsupials will die from over-exerting themselves during sex, the male praying mantis enters into the agreement knowing that he’ll soon become a meal for his partner. That’s right, female praying mantises devour their mate during the act. This is known as sexual cannibalism and is more common than you might think.
Where the praying mantis is concerned, the female will begin by biting off the male’s head! This happens in as many as 25% of mating situations, but amazingly, eating the male accounts for as much as 63% of her diet while she goes through the breeding season.
It might seem a little unfair on the male but in reality, this actually boosts his chances of successful mating. In studies, it was shown that females who ate their partners, produced more eggs because as much as 90% of the male’s amino acids were being passed on.
That said, males will try to avoid being eaten and often go for females that are fatter and look as though they don’t need to feed, as well as approaching seemingly less aggressive females.
The phascogale is another species of small marsupial from Australia that’s also often called a marsupial mouse.
It’s only the males that will die after their first mating, whereas the females may live as long as three years, and it’s not uncommon for them to have several litters during their lifetimes.
So what happens to the males? Well, it’s a very similar story to the antechinus, with males stopping their sperm production shortly before mating. This usually happens when they are around a year old, and the stress of mating is what finishes them off.
However, it seems to be worth it for the survival of the species as a single female can have up to 15 young. Considering that these animals are now found only in a very small region of Western Australia, reproduction has never been more important.
There are two species of salmon; the Pacific salmon and the Atlantic salmon. It’s thought that as many as 90 to 95% of Atlantic salmon will die after they spawn. However, if they manage to survive, it is possible for them to spawn again. However, Pacific salmon always die after spawning.
Salmon are born in freshwater and they then go on the epic journey to the ocean. They will remain here for up to four years but for no less than one year, and when the time comes, they will return to their freshwater birthplace to spawn.
Females will dig out a nest called a redd, and then males will fight it out to mate with their chosen female. After a brief courtship, the pair will spawn before the female covers the fertilized eggs with gravel. It then doesn’t take much time for both males and females to die.
Cicadas are common insects that are responsible for those buzzing sounds you hear in late summer. There are more than 3400 species of cicada, and some of these will spend up to 17 years underground, patiently waiting for their time to shine.
When this time comes, mating occurs en masse, and millions of cicadas flood the local area. Some would say it’s akin to a biblical plague!
They’ll spend between four and six weeks engaging in mating rituals that involve a lot of loud calls. After this, pairs will mate, and it then only takes between two and six weeks for the male and the female to die.
6. Redback Spider
The redback spider is perhaps one of the most feared arachnids by humans thanks to the potency of its venom. However, there’s good reason for the males to fear their female counterparts, as these spiders are notorious for their sexual cannibalism.
Males will go in search of a female and are attracted by her pheromones. Upon meeting with her, he will attempt to copulate with her at the same time as somersaulting so that his abdomen is in line with the female’s mouthparts, essentially offering himself up as an in-mating meal! Two out of three mating sessions will result in the female completely devouring her mate.
It might sound worrying for the survival of the species if all males are eaten, but in reality, only around 20% of all males mate successfully. What’s more, males have been shown to select juvenile females that are less likely to eat them, and when they show significant courtship displays, their chances of becoming a meal are much lower.
With more than 300 species of octopus, you would think that they were easy animals to study. But the opposite is true because they’re very reclusive. However, we have managed to find out a little about their behavior, and it’s been discovered that females have a really hard time after they reproduce.
Once they have finished reproducing, female octopuses will stop eating and essentially allow themselves to wither away. In the study linked above, scientists have noticed that some females will even try to die faster by self-harming, including banging themselves into the tank walls.
But why do they do this? It’s all to do with their optic gland that secretes sexual hormones after mating as well as cholesterol. It’s almost as if their bodies are prepared to self-destruct once mating has occurred.
It’s also been observed that, in some cases, octopuses will eat one another after copulation. Although, there’s not a lot of evidence to see how frequently this happens.
8. Desert Spider
Another type of spider that risks its life when mating is the desert spider. These arachnids go above and beyond as parents, and the mother spider is devoured by her babies after the first few weeks of life.
She will carry her eggs on her back and, when the time comes, help her young out of their eggs and provide them with food. However, give it a couple of weeks, and the spiderlings start consuming their mother. But it’s not all in vain; eating the adult means better survival rates for the young spiders.
But it’s hard to even get to this point. If a male wishes to mate with a female that is already carrying eggs, he will predate the eggs in order to mate with her and have a new clutch. It’s a competitive world for spiders!
The mayfly is one of the shortest-lived creatures on the planet. While life expectancy varies by species, it’s not typically more than 24 hours once they reach their adult stage. There are some species where the adult females only survive for five minutes!
So, it’s a race to mate quickly. This happens above a body of water where the males and females will gather to mate. After the event, the female falls into the water to lay her eggs, and then she will lie there, not moving, before dying. But the males don’t get away with it that easily; they’ll also die, but they’ll often head to a quiet spot on land to take their final breath!
Bees within a hive have different jobs. Some are workers, some take care of the young, and the males, known as drones, are born to reproduce. When the queen takes her mating flight, she has a choice of hundreds of drones.
Those that are successful will mate with the queen and will ejaculate with such force that it causes their penis to be ripped from their body. This often remains inside the queen and must be removed by any other drones that come to mate with her. Of course, the gaping wound is always fatal for male bees, and it’s even been seen that drones can ejaculate themselves to death when they overheat. Even when there isn’t a queen in sight.
However, not all drones are successful in their mating attempts, but this still doesn’t bode well. You see, if they do not mate, they’ll be shunned by the colony, destined for a short-lived life alone.
11. Sea Lampreys
The sea lamprey is one of the oddities of the ocean. While they look like eels, they’re actually jawless fish and have large, sucking mouths filled with teeth that look like something out of a nightmare. However, they prey on cold-blooded creatures and are no real threat to humans; phew!
But a threat to the species itself comes in the form of mating. Sea lampreys, just like salmon, will return to their freshwater homes to make nests called redds. It’s thought that the males release a bile-based pheromone to attract females, but when they have mated, both parents will soon die.
12. Dark Fishing Spiders
It’s usually web-weaving spiders that will experience death after sex, but it has now been observed that the dark fishing spider, one that does not weave a web, also risks certain death in the name of reproduction.
As with many spider species, it’s the males that lay their lives on the line, and the reason for this is to do with how they transfer their sperm to the females. In studies, it has been observed that the moment the male transfers his sperm, his legs will curl up, and he becomes immobile, never recovering from this state. However, it can take several hours before the heartbeat stops and the spider dies.
If that wasn’t enough, once the male has died, it is not uncommon for the female to engage in sexual cannibalism. However, this is thought to be beneficial to the offspring, who tend to grow larger when the mother has eaten the father.
13. Labord’s Chameleon
It would seem that the only reason for a Labord’s chameleon to be born is to mate. These amazing animals spend up to nine months developing in their eggs only to be born, mate a few months later, and then die.
But even if they weren’t to mate, these chameleons wouldn’t last very long. It’s been shown that their rate of maturity is incredibly rapid. They’re ready to breed just two months after hatching and are already starting to show signs of old age at this point.
Mating usually occurs in January with the eggs being deposited in February or March. It’s rare that any adults would survive the hatching period so all of the population is always the same age.
14. Northern Quoll
The northern quoll, a marsupial native to Australia, is a pretty amazing little creature. They’re able to climb vertically and are aggressive predators, but their breeding rituals leave a lot to be desired.
The males put all of their energy into finding a mate. They’ll travel up to 6.2 miles (10 km) and fight off other males, all to get the girl. But as they do this, their physical condition rapidly deteriorates, so by the time it comes to mating, the act itself is enough to finish them off.
This happens annually with males mating before their first birthday. You might think that this was concerning since the northern quoll is an endangered species, and you’d be right. Less than 100,000 are left in the wild and even without the males dying after mating, these animals naturally have an incredibly short life span, and are also prey to many animals, including feral cats.
15. Brazilian Gracile Opossum
The Brazilian gracile opossum is only partially semelparous. This is because death isn’t guaranteed after mating, but it’s highly likely.
As with several other species, the males have to pit themselves against one another in a polygynous community in order to have the honor of mating with their chosen female. The stress of this along with the physical stress of sex itself can often take it out of the males who may die shortly after mating. But this isn’t always the case and some survive to breed a further one or two times.
16. Little Red Kaluta
The little red kaluta is a small, nocturnal mammal native to parts of Australia. While it is incredibly adorable, don’t get too attached because the males will die after mating.
It’s a story we’ve heard time and again; the males will literally mate themselves to death, copulating with as many females as they can in the short two-week breeding season in September. It’s a matter of exhausting themselves physically, passing on as much of the DNA as possible, and then having an eternal sleep to recover!
In some cases, these little critters can go for up to 14 hours a day, but all that testosterone isn’t good for the immune system, which is why the act is so fatal.