Jul 21, 2020 12:30:00

Researchers inadvertently cross-link two endangered species to produce 'endangered hybrid fish'

There are many cases where many plants and animals are endangered or even become extinct due to climate change and human activities, but researchers have been able to reproduce endangered species by various means. I'm trying.

The research team, which was conducting an experiment using two endangered species of Russian sturgeon and spatula sturgeon , inadvertently reported that they produced ``hybrid fish of endangered species'' by crossing two endangered species. did.

Genes | Free Full-Text | Hybridization of Russian Sturgeon (Acipenser gueldenstaedtii, Brandt and Ratzeberg, 1833) and American Paddlefish (Polyodon spathula, Walbaum 1792) and Evaluation of Their Progeny | HTML
https://www.mdpi.com/2073-4425/11/7/753/htm

Scientists Accidentally Bred a Bizarre Hybrid of Two Endangered Fish
https://www.sciencealert.com/scientists-create-a-strange-hybrid-between-two-very-different-kinds-of-fish

Scientists Accidentally Bred the Fish Version of a Liger-The New York Times
https://www.nytimes.com/2020/07/15/science/hybrid-sturgeon-paddlefish.html

Both Russian sturgeon and big-billed sturgeon are endangered species due to the decrease in population due to overfishing, etc., both belong to the order Sturgeon Sturgeon, but different species are divided into sturgeon family and spatula family, respectively. is. In addition, Russian sturgeon inhabits the bottom of the sea, ponds, and rivers in Eastern Europe, Serbia, and the Middle East to eat crustaceans and small fish, while sturgeon inhabits North America and strains zooplankton. There are also differences in habitat and diet.

Each species is believed to have diverged about 184 million years ago and has evolved in isolation on completely separate continents. Therefore, even though they belong to the same sturgeon eye, there is a big difference in appearance. The following images are pictures of a typical young Russian sturgeon.

The picture below shows a young sturgeon sturgeon. At first glance, you can see that there are great morphological differences in fins and nose.

A research team at the Hungarian Institute of Aquaculture used these two species of fish to try to breed the

female sturgeon of Russian sturgeon. Gynogenesis is a type of asexual reproduction in which an individual develops only based on the nucleus of an egg derived from a female, although sperm induces division of the egg but does not fertilize. Although female development often causes various disorders, it is said that in some animals such as gimpuna , individuals develop normally even in female development.

In 2019, the research team carried out an experiment to place the sperm of a spatula sturgeon near the egg of a Russian sturgeon and to stimulate the female development of the egg by stimulating the sperm. Because the two species diverged 184 million years ago and they looked quite different, the research team thought the egg would never fertilize.

However, contrary to the researchers' expectations, sperm of the sturgeon were successfully fertilized with the eggs of the Russian sturgeon, and hundreds of 'endangered hybrid fish' were unintentionally born. “We never wanted to make a hybrid. This was not intentional at all,” said Attila Mozsár, a research team.

This fish, which was created unintentionally, is called ' sturddlefish ' by combining the names of 'Russian sturgeons' and ' sparrow sturgeons (American paddlefish)'. Sturddlefish has a very strange form like two species mixed in half, has fins and noses like Russian sturgeon, has mouth-like carnivorous sturgeon and carnivorous eating habits. .. In the image below, the top is a Russian sturgeon, the bottom is a sturgeon, and the two types in the middle are the sturddle fish that were born this time. As a result of DNA analysis, it was found that there are two types of sturddlefish, 'individuals that inherited half the DNA of Russian sturgeon and spatula sturgeon' and 'individuals that inherited twice the DNA of mother's Russian sturgeon'. The research team is reporting.

The sturddlefish that was born this time seems to have decreased to about two-thirds one month after it was born, but about 100 animals are still alive at the time of writing the article, and the research team will continue to take care of it in the future. The research team says that they are not planning to create new hybrids of Russian sturgeon and spatula sturgeon, but this discovery is a valuable thing to show that sometimes hybrids are born even at a seemingly distant species It can be said to be a case.

'I was unbelievable when I first saw this, I thought, 'Mating sturgeon with sturgeon? Shouldn't I?', says Solomon David, an ecologist at Nicole State University in the United States. Commented. However, the sturgeon family members, who are also called 'living fossils', have a very long lifespan and a slow evolutionary rate, so they pointed out that the time of 184 million years did not hinder the crossing. It's very cool that living fossils still surprise us.'