Shark at Chicago aquarium hatched pups with no father

Dec. 20 (UPI) -- The Shedd Aquarium in Chicago said researchers were stunned when they discovered a female zebra shark had hatched pups without any genetic material from a male.

The aquarium said the female shark, nicknamed Bubbles, hatched pups in the tank she shares with multiple other adult zebra sharks, and the babies were originally believed to have been fathered by a male shark in the tank.

Genetic testing was performed on the pups as part of research related to a breeding program for the species and the researchers were stunned to discover Bubbles was the sole parent of the baby sharks, having reproduced via parthenogenesis, or "virgin birth," where a female will fertilize eggs with her own genetic material.

The aquarium said zebra sharks have been known to reproduce asexually on rare occasions, but it was believed to be a response to a lack of available male mates.

"This discovery throws a wrench in what we thought we knew about how and why parthenogenesis happens, and it illustrates a key aspect of science: we're continually learning," Kevin Feldhim, a researcher at Chicago's Field Museum, said in a Shedd Aquarium news release.

Feldhim co-authored a study on the case, published in the Journal of Fish Biology.