This flatworm can self-inject sperm
A hermaphroditic flatworm will self-inject sperm into its head when no suitable partners can be found, says a new study published in the Proceedings of the Royal Society B. Researchers believe the Macrostomum hystrix may have evolved the ability to self-fertilize in order to survive.
Flatworm Hermaphrodite Can Impregnate Itself
Researchers studying a freshwater flatworm came to a startling conclusion about its reproductive abilities when they found out the Macrostomum hystrix can self-inseminate using its hypodermic-like penis. As odd as it seems, it’s true.
The researchers have published their findings about the creature, which is a hermaphroditic flatworm that possesses both male and female sexual copulatory organs as well as sperm and eggs.
Though the flatworm will and usually does find another mate when a suitable partner is not within stabbing reach, the strange little creature takes it upon itself to go along with the reproductive process.
Weird Sex Findings of the Flatworm Explained
Researchers from the Evolutionary Biology and Zoological Institute of the University of Basel conducted a series of experiments that isolated the offspring of 1,000 flatworms in order to observe the rather kinky sex phenomenon.
Their findings concluded the flatworms that were isolated had more sperm in their head regions, whereas the flatworm that lived in groups had more sperm in their tail regions. Upon further investigation, the researchers determined the preferred method of insemination between two flatworms was in the tail region.
So how did the isolated flatworms get so much sperm in their heads? Through the use of their hypodermic penis. The isolated flatworms are believed to have plunged the needle-like penis through their heads to inseminate themselves.
Previously, self-insemination (dubbed by scientists as “selfing”) was not believed to be possible in hermaphroditic species due to the sexual organs being both isolated and separated from the other.
However, thanks to evolution, the flatworm overcame this small detail by evolving the needlelike appendage, one that apparently has enough flexibility to allow it to stab itself in the head and have the weirdest sex on the planet. Researchers noted that this is the first example of evolutionary engineering of a sex organ for selfing.
Seriously, Nature? The Flatworms are Freaks
Even when the copulation isn’t solitary, the flatworm has found a way to make sex freaky.
When a flatworm is in its normal mating behavior with a partner worm, instead of taking the other worm out for a nice dinner, the two hermaphrodites break out into a duel of penis fencing.
Yes, it is exactly as it sounds. As both possess the hypodermic appendage, the individuals whip it out and proceed in an awkward, yet somehow elegant sword fight until one plunges its organ into the other one. Then, the winner proceeds to inseminate the other before going about its own way.
Warning: Too Much Selfing May Lead to Lack of Genetic Diversity
Steven Ramm, the lead author of the study, says the flatworm’s solo sexual habits may be a strange concept for us, though selfing does produce viable offspring. However, the lack of genetic diversity that occurs due to too much selfing can put the population at risk.
In essence, selfing is the best option for the flatworms if they must choose between not reproducing at all or making the time for a little self-love.
So whether it’s with a partner after a fight to the sex or it’s all by the lonesome and a rush to the head, the flatworm will continue to reproduce in its own bizarre, kinky ways, and we have no right to judge it.
