Somehow, the mermaid Mary got pregnant on her own and gave birth to a baby who survived after giving birth.
A small stickleback fish (scientific name for Gasterosteus aculeatus) nicknamed “Mary” jumped through a large spawning stage in an evolutionary tree. Like most females, sticklebacks lay eggs that are not fertilized. Then the male fertilizes the egg. But somehow she bet that Mary got pregnant on her own and gave birth to a baby that survived after childbirth.
This is the third time that scientists have discovered a fish carrying embryos developing in the abdomen, the researchers report in an article published on February 20 in the journal Nature Science. But this is the first time that these embryos have been born and transformed into healthy fry.
Andrew MacColl, evolutionary biologist and team member at the University of Nottingham in UK, said: “Although this is an extremely rare phenomenon, it can help us see change., Evolution really is. important on the tree of life. In addition to laying animals, most mammals and very few species of fish keep their eggs inside the body and give birth to offspring. While it may seem difficult to achieve with evolution, this little stickleback seems to have passed the process on its own. “
Researchers aren’t sure exactly how she got pregnant this way. They speculated that it did not mate, but cloned itself. Another possibility that scientists put forward is that Mary is a hermaphrodite fish, thus fertilizing her own eggs. But the results of the genetic analysis revealed that Mary’s child had two separated parents.
Scientists’ most plausible theory is that Mary accidentally swam in a nest filled with sperm from a male fish that had just fertilized a bunch of normal eggs. Somehow, some sperm moved up Mary’s oviduct and fertilized the unborn eggs in the mermaid’s body.
Although the embryo develops well, this process leaves the mother with many problems. When researchers found Mary while studying the stickleback in Scotland, she was swollen because the babies were so small they were almost dead.
Researchers gave Mary euthanasia with an animal welfare prescription. They then dissected Mary and extracted her eggs. Of these eggs, 56 survived to adulthood in the laboratory aquarium. Twenty children are still alive three years later.
What makes the discovery so remarkable, the researchers said, is that under normal circumstances, in addition to providing sperm, the male stickleback plays a vital role in egg development. After having had eggs, the male sticklebacks create a suitable environment, stimulating the healthy development of the eggs. And Mary’s interior environment seems to have done just that, too.
One of two cases of fish with an unfertilized embryo was also in sticklebacks in the 1950s, but their embryos did not develop and the fry did not live. These researchers are currently actively searching for many sticklebacks with similar situations during their expeditions in Scottish waters, the statement said.
If they find more than one case, it would be a big hit. Many animals, including some fish, are known to have developed the ability to independently produce offspring. Presumably, it’s a window into how this evolutionary leap came about.
