<img style=“float:right; margin:10px 10px 10px 10px;cursor:pointer; cursor:hand;” src=“http://www.marinebio.com/upload/05/Sphyrnatiburo1.jpg” width =150 height=100 alt=right>Last year, shark biologists jumped into a frenzy when they found out that a virgin female bonnethead shark (on right) ‘miraculously’ gave birth to a female pup. Demian Chapman of the Institute for Ocean Conservation Science at Stony Brook University in New York, stated afterwards that he thought the asexual reproduction “only happens as an occasional fluke.”

Well, then make that one occasional fluke a year, because a female blacktip shark (on left) at the Virginia aquarium has given another unconsummated birth to a female pup. Chapman now thinks, “It’s definitely more common and widespread than we think.”

<img style=“float:left; margin:10px 10px 10px 10px;cursor:pointer; cursor:hand;” src=“http://farm1.static.flickr.com/121/307203688_10600eb392.jpg?v=0” width =150 height=100 alt=right>Last year, researchers Mahmood Shivji of the Guy Harvey Research Institute of Nova Southeastern University in Dania Beach, Florida, and his colleagues thought it was a case of stored sperm until DNA fingerprint analysis showed there were no male contributions. The newest miracle baby’s tests are the same- no male involved, as reported in the newest issue of The Journal of Fish Biology.

Shivji and his colleagues think the pregnancy occurred through an asexual reproductive process called parthenogenesis, which is when the mother’s chromosomes split during egg development and pair with a copy of themselves.

While this discovery is by no means takes shark fisherman ‘off the hook’ when it comes to overfishing — both sharks produced only one female pup, as opposed to average litters of four to six pups, so it won’t boost struggling populations any time soon — it does show that there is a lot more interesting work to be done on shark reproductive biology. “I think in the next five years we will be able to show many species of sharks — if not all — [can undergo parthenogenesis],” hypothesized Chapman.

Chapman is currently testing to confirm another reported case of parthenogenesis in a white spotted bamboo shark with Kevin Feldheim of the Field Museum in Chicago. If all sharks are capable of parthenogenesis, the question becomes to what extent this behavior occurs in the wild and how much it contributes to their populations. Either way, it’s a very exciting discovery, which will definitely lead to a lot more research on species which we currently know so little about.