The Virginia Aquarium's got an interesting case on their hand; the case of a dead female shark who turned out to be pregnant, but without a male of her particular shark species in the tank.|
They're hoping for a new first; evidence of interspecies shark sex. Parthenogenesis (reproduction without needing a male) has already been found in a hammerhead.
He said the phenomenon is coming to light with the joint Northern Ireland-U.S. research that analyzed the DNA of a hammerhead shark born in 2001 in the Henry Doorly Zoo in Omaha, Nebraska. The study was published in the Royal Society journal Biology Letters on the day before Firchau was bitten.
Asexual reproduction among sharks is more likely to happen in captivity, when there is no other option for reproduction, than in the wild, Hueter said.
Crossbreeding, on the other hand, is not known to happen at all among sharks, said Heather Thomas, aquarist at the John G. Shedd Aquarium in Chicago.
"It's not natural," Thomas said. "If you've got a shark that needs to swim to breathe and cross it with a shark that can lay on the bottom to breathe, what are you going to get? Are you going to get these weird mutations?"