Scientists accidentally create Paddlefish-Sturgeon hybrid

The latest accidental invention in the world of science is the sturdlefish, a lab-created cross between an American paddlefish (Polyodon spathula) and a Russian sturgeon (Acipenser gueldenstaedtii).

On the surface, parental units form an unlikely pair. On the one hand, they’re not exactly neighbors – as the name suggests, sturgeon are native to Russia and surrounding areas, and paddlefish are found throughout the Mississippi Valley in the United States. Their diet also differs; Carnivorous sturgeon hunt crustaceans and small fish along the bottom of lakes and rivers, while paddlefish work to filter zooplankton from the water.

But they do have some things in common. As The New York Times reports, paddlefish and sturgeons are both large, slow-growing, long-lived freshwater fish species. And they are both considered “fossil fish” because their bloodlines date back to the Mesozoic era. They are also both critically endangered due to habitat loss, overfishing and pollution.

To help support declining populations in the wild, scientists from the Hungarian Research Institute for Fisheries and Aquaculture have worked to breed the two species in captivity. Last year they used an asexual reproduction process called gynogenesis, which requires the presence of sperm, but does not use its DNA.

Only this time, a researcher mistakenly donated paddlefish sperm to sturgeon eggs. Scientists quickly welcomed hundreds of bouncy hybrid baby fish with their mother’s penchant for meat and various combinations of their parents’ physical attributes. A study of the hybrid was published in the July issue of the journal The genes.

“We never wanted to play with hybridization,” said Dr. Attila Mozsár, principal investigator at the institute and co-author of the study. The New York Times. “It was absolutely unintentional.”

About 100 hardy fish are still alive in the lab, but the researchers don’t plan to breed any further. If the fish, like many other hybrids, are sterile, they will not be able to produce caviar, which is why Russian sturgeons are mainly valued. In addition, the introduction of a new hybrid into the wild could threaten existing species.

Sturdlefish, ligers, and mules aren’t the only offbeat animal hybrids – check out polar bears, wholphins, and more here.

[h/t The New York Times]