Scientists have discovered why such a cute animal, the echidna, has a four-headed penis – all for one purpose

There are four species of equidists, which, along with ducklings, belong to a unique group of animals, also known as cloaca, they are the only mammals that lay eggs like birds and fish, but feed their young. Not much is known about them, so all discoveries by scientists are welcome.

One of the most interesting riddles related to the cloaca is the male echidna penis. It is unique because it has up to four heads. As if that wasn’t enough just yet, only two are used during an erection, and a male echidna can choose which penis heads to use this time.

“How the male does all of this has been a mystery for a long time. Only for the first time in history have we been able to find out how things are going anatomically, “the statement said.

Why is it so unique?

Not to mention its unique shape, the echidna male penis is also unique in that, unlike other mammals, it is used only for reproduction and not for urination. For the latter purpose, echidns are used by the cloaca, a multifunctional opening used for urination, defecation, and females for laying eggs. The unused echidna multi-headed male penis retracts and protrudes through the cloacal opening during erection. The testicle, which does not have a scrotum, hides within the body of the echidna and does not appear on the outside.

The exclusive and echidna sperm and sperm do not fight each other by themselves, but rather work as a team for a common goal.

“In the ejaculated sperm samples, we count up to a hundred gametes, which fuse into one compound and form a kind of spherical derivative. Those compounds, as we have managed to discover, are moving in an aggressive and coordinated way towards the goal. In addition, larger compounds swim better than individual swimmers or smaller formations, ”explains Jane Fenelon, a research and reproductive biology expert at the University of Melbourne. As far as scientists know, only a few animal semen are capable of doing this.

3D Modelis

To better understand the principle by which the equidistant penis actually works, researchers led by J. Fenelon decided to study the anatomy of the short-eared equididian (Tachyglossus aculeatus) that lives in the Australian Wildlife Sanctuary. Unfortunately, the rescued echidnas living there had suffered various injuries, mainly from cars, and many echidnas had to be put to sleep. Fortunately, it turned out that the pens of the sleeping equidist are in good condition and suitable for research, says J. Fenelon.

Experts have developed 3D equidistant penis models, specialized and process-based computed tomography examinations. Routine CT scans look at hard tissues like bones, so the researchers had to stain the equidist’s sex organs with iodine to see soft tissues as well.

“This means that we have been able to create a 3D model of the entire penis, of all its internal structures, because only then is it possible to know how it works,” say the researchers.

The evolution of the erection

The 3D computer model showed that the urethra, the tube through which the seed flows, divides into two separate tubes before branching off the equidistant penis heads, which further divide accordingly, thus ensuring that the seed reaches to the four heads. This all sounds logical, but this discovery by the scientists does not explain why only two heads are used during a meeting.

“Initially, we thought we had found some kind of valve mechanism that was responsible for the use of the heads,” the researchers wrote. The only thing they found was not a valve, it turned out to be a penile tissue solely responsible for the process.

Mammalian penises consist of two types of erectile tissue, the corpus cavernosum and the corpus spongiosum. Both tissues fill with blood during an erection, but the main function of the corpus cavernosum is to give the penis a firm shape, and here the corpus spongiosum ensures the passage of the urethral tube for semen to drain.

Both tissues start at the base of the penis. In most mammalian cases, the two spongy bodies fuse into one, while the corpus cavernosum remains separate. In short, the situation is different: the corpus cavernosum fuses here and the corpus spongiosum remains separate, which is what allows the echidna to separate the erection of the individual heads.

“We are not sure why this is beneficial for male echidna,” says Fenelon. “But I think it could be an advantage for the males to compete with each other for the females.”

In another experiment with a live but drug-suppressed echidna, experts found that by changing penis head combinations, a man can ejaculate ten times in a row without major interruptions. This can be useful for competing with competitors, but more experimentation is needed to substantiate such a hypothesis.

The study findings were published in the journal “Sexual Development” on April 29.