Meet the world's most selfless lover

The Madagascan Darwin's bark spider puts all other male species to shame. Photo / M. Gregori?

It's not often we think of spiders as superior to humans, but one particular species puts us males to shame.

The Madagascan Darwin's bark spider is not only known for its extreme web sizes and producing the world's toughest biomaterial, but it is a total stud in the bedroom.

A new study entitled 'spider behaviours include oral sexual encounters' discovered the species has a "rich sexual repertoire" and is keen to engage in marathon cunnilingus sessions with its female counterparts.

At first, this may not seem like strangest thing in the world, however scientists were quick to point out oral sex is an infrequent occurrence in the animal kingdom.

While mammals such as lemurs, lions, dolphins and bats are known to partake in such pleasures, the behaviour in spiders is exceedingly rare - only seen in widows.

Lead researcher Matjaz Gregoric said a two week study of the spiders discovered that the male species - who are 14 times lighter and 2.3 times smaller than the females - routinely took oral sex past foreplay.

"Oral sexual contact seems to be an obligate sexual behaviour in this species as all males did it before, in between, and after copulation, even up to 100 times," he said in a statement.

Despite acting selflessly towards their lady lovers, things aren't great for the lads with researchers observing they often fall prey to "sexual cannibalism" from the females.

Unfortunately, if the males can avoid being eaten after doing the deed, they are also known for engaging in "post-mating emasculation", which means they bite off a portion of their reproductive organs within 24 hours of intercourse.

It's not all bad news, with researchers discovering some males taking extra precautions and engaging in "mate binding" - the act of binding the giant female spider in silk to prevent her from gobbling up her lover during sex.

Uncertain with the exact reason why the spiders are so liberal with their bulk oral offerings, researchers first thought it may have been a function to avoid falling victim to cannibalism.

However, they were quick to disparage this hypothesis.

"This seems an unlikely function of oral sexual contact because males perform it with all females regardless of their aggressiveness, including the defenceless teneral ones," the researchers wrote inScience Reports.

After much deliberation the researchers came up with two likely reasons for the behaviour, although they admit more research will be needed to provide proof.

"Oral sexual contact may signal male quality. This would imply the existence of cryptic female choice mechanisms, where females may bias paternity in favour of better quality males," researchers wrote.

"Additionally, enzymes in the saliva could provide physiological advantage to the donor's over rival's sperm. This would be an adaptation for lowering sperm competition, and would function analogously to seminal toxins and aggressive sperm known in insects."

Oh and if you were wondering what oral sex with spiders might look like, there is a lovely YouTube clip of arachnid porn below, which should totally be safe for work.