Hungarian researchers accidentally created a hybrid of two "living fossils," the Russian sturgeon and the American paddlefish, according to a new study. Researchers were trying to produce sturgeon offspring through gynogenesis, a system of asexual production that requires the presence of sperm but not the actual contribution of paternal DNA, according to the study published in the journal Genes. Paddlefish sperm was used on the negative control group when it "unexpectedly" fertilized the sturgeon eggs.
"We didn’t really want to make any hybrid of these two species," said Miklós Bercsényi, an aquaculture geneticist at the University of Pannonia who worked on the study. "It was unintentional."
The two fish began evolving separately more than 184 million years ago and have developed very different physical characteristics, feeding behaviors and preferred habitats.
As the fish grew, it became clear from their appearance they were not purely sturgeons or paddlefish.As the fish grew, it became clear from their appearance they were not purely sturgeons or paddlefish.
A DNA analysis revealed they were true hybrids. Some fish had equal amounts of maternal and paternal DNA while others had twice aA s much maternal DNA, causing their wide range of physical appearances.A year later, more than 100 hybrids, dubbed sturddlefish by some, have survived.
How did this happen?
Kovács said hybridization may be possible thanks to the sturgeons' slow evolution. The two fish are considered "living fossils" or species that have remained essentially unchanged over millions of years and have very few surviving close relatives.