Sturddlefish
The sturddlefish is a hybrid of the American paddlefish (Polyodon spathula) and the Russian sturgeon (Acipenser gueldenstaedtii), accidentally created by researchers in 2019 and announced in 2020. Obtaining living hybrids through breeding individuals from different families is unusual, especially given that the two species' last common ancestor lived 184 million years ago. The hybrids were created accidentally during attempts to induce gynogenesis, a type of parthenogenic reproduction where a sperm cell must be present to trigger embryogenesis but does not genetically contribute to the offspring. Hundreds of hybrid fish were created, of which about two-thirds survived over one month, and about 100 survived for one year. As of July 2020, all living hybrid fish are living in captivity at the research lab in Hungary. There are no further plans to create new sturddlefish. Background Both the American paddlefish and the Russian sturgeon are endangered species. Researchers in Hungary conducted experiments designed to test if either species could be bred in captivity. As part of these experiments, an attempt was made to induce gynogenesis with each species. During the course of the experiments, the researchers used sperm from paddlefish fathers instead of sperm from sturgeons to act as a control in