Parthenogenesis has been observed in many types of sharks and snakes, though often the offspring have very shortened life spans. After an observation of pathogenesis in a hammerhead shark in captivity (which sadly didn't survive), researchers at the Belle Isle Aquarium of the Detroit Zoological Institute decided to try to hatch the seemingly unfertilized eggs their white spotted bamboo sharks would leave around the tank.

They were able to rear two pups successfully, and they were confirmed clones of their mother. Some researchers hypothesize that the ability of sharks to reproduce via parthenogenesis is what allowed them to become one of the oldest species on the planet: When males were scarce, females could just make progressively younger copies of themselves to wait for Mr. Right Shark to come around. (Which might even be a good idea for our species.)

They made these clones by a process called automatic parthenogenesis: The egg is formed normally (with half the species' usual number of chromosomes), then fertilized by the "polar body," a cell that is created during oogenesis and contains the same gene copies as the egg, resulting in the shark having half the genetic variation of its mother. This is why often the pups don't survivethey can be missing critical genes that the mother only had one copy of.