The mechanism by which echidna erects only 2 out of 4 penises is revealed

Animals of the order Monotreme, such as platypus and echidna, have a very different ecology from other mammals, such as the temperature fluctuating depending on the temperature and being born from eggs, and one of the strangest ones is 'male platypus'. There are four penis. ' Male echidna are known to erect only two of the four penises during mating, but new research has revealed the mechanism.

The Unique Penile Morphology of the Short-Beaked Echidna, Tachyglossus aculeatus --Abstract --Sexual Development --Karger Publishers

Solving the mystery of the four-headed echidna penis

Solving mystery of the four-headed echidna penis | EurekAlert! Science News

Australian researchers discover why only two of echidna's four penis heads become erect at one time | Australia news | The Guardian

50 echidnas that have been injured in a traffic accident are brought to the Karambin Animal Hospital, an Australian wildlife hospital, every year, but many of them have no chance of recovery and must be euthanized. Therefore, a collaborative research team of biologists at the University of Melbourne conducted a study by scanning the corpse of a echidna that died in an accident to investigate the reproduction of the mysterious echidna.

Microscopes and micro- CT scans were used in the study. A normal CT scan can only scan hard tissues such as the skeleton, but the research team succeeded in scanning the genital organs of echidna by staining soft tissues with iodine.

When the research team made a 3D model of the internal structure of the echidna's penis from CT scan data and investigated its function, the blood vessels of the echidna's penis were first divided into two, and each branched into two, which was 4 It turned out that it was branched into one. Furthermore, it was found that the corpus cavernosum that erects the penis is also divided into two, and by controlling which one concentrates the blood flow, it is possible to erect only two out of four. ..

by Jane Fenelon

It's unclear why echidna causes only two penises to erect at a time, but the research team speculates that it may be related to the race for breeding. This is because it is known that captive echidna males can ejaculate 10 times in a row without a break. In this way, echidna is thought to erect two penises at a time and ejaculate alternately into the uterus of two females to efficiently mate and increase the chances of leaving their own offspring.

Although it is not new to this study, the male echidna is used only for ejaculation because the echidna excretes in the cloaca. Also, since the testes of the echidna are inside the body, there seems to be no shadow.

'This is the first time we've seen this morphology in mammals,' said Jane Feneron of the University of Melbourne, the lead author of the paper. Studies of other animals that have it have shown that the common reason for acquiring these reproductive organs is the 'fight between males over females.' '

in Science,   Creature, Posted by log1l_ks