Here are two examples of the sturddlefish hybrid of the Russian sturgeon and American paddlefish.
Attila Mozsar/Genes
The American paddlefish and Russian sturgeon were never fated to mate. But when scientists accidentally bred a new hybrid of the two, the sturddlefish was born.
Most people know the Russian sturgeon for its eggs, which are sold as high-end caviar. The American paddlefish has a long snout, and can only be found in half of the US. Both species are referred to as “fossil fish” because of their ancient lineage and slow evolution.
Unfortunately, both sturgeon and paddlefish are critically endangered, according to the International Union for the Conservation of Nature. Because both fish species are in danger of dying out, scientists are understandably curious if sturgeon and paddlefish can be bred in captivity.
Using gynogenesis (a method of asexual reproduction that requires the presence of sperm without the contribution of their DNA for completion), the researchers accidentally used paddlefish sperm to fertilize the sturgeon eggs. Remarkably, the hybridization worked.
Hybridized fish hatched from the eggs, and the researchers separated them into two groups. Some of the sturddlefish that had twice as much maternal DNA looked more like sturgeon than paddlefish. The second group, which had the same amount of maternal and paternal DNA, looked like an equal mix of the two species.
Scientist Attila Mozsár from the Research Institute for Fisheries and Aquaculture in Hungary, in addition to the other scientists responsible for the new fish hybrid, revealed their findings in a study published in the scientific journal Genes this month.
The study marked the first successful hybridization between these two species — Russian sturgeon (Acipenser gueldenstaedtii) and American paddlefish (Polyodon spathula) — and between members of the Acipenseridae and Polyodontidae families.
“We never wanted to play around with hybridization,” Mozsár told The New York Times. “It was absolutely unintentional.”
While the sturddlefish offer a fascinating look into the hybridization of two species that weren’t necessarily meant to mate, don’t expect an influx of sturddlefish to invade waters anytime soon.
Most human-made hybrids like these sturddlefish are sterile and can’t reproduce in the wild. So for now, these sturddlefish are a mere scientific oddity.