Zebra shark in Dubai zoo reproduces without male

A zebra shark has reproduced without a mate at an aquarium in of one of Dubai’s most iconic buildings, the sail-shaped Burj al Arab. Scientists are shocked because the process of reproduction without a mate, known as parthenogenesis, is not often observed in sharks, according to the BBC.

Zebe, the shark, came to Dubai in 2001 and has laid eggs on her own for the past four years, producing healthy offspring each time. Scientists are baffled since parthenogenesis is usually seen in much simpler organisms.

“We were actually moving the eggs and one of our guys felt something move inside the egg. And there were babies inside,” said David Robinson, assistant aquariums manager at Burj al Arab, according to the BBC. “We weren’t looking for it but I don’t think we ever expected to find it,” he went on. “It just goes to show how little we know about sharks,” he said.

Parthenogenesis is a process where one egg impregnates another by acting as the sperm. It has been observed in sharks only five times over the past ten years, according to The National. Scientists believe it may be part of the reason why sharks – whose ancestors go back millions of years – have survived several mass extinctions that others, like dinosaurs, have not.

"It was already known that a shark had done this before, but they were of a totally different lineage than zebra sharks; so, this is very exciting,” Robinson told The National. The eggs have hatched, and the babies are “pretty” according to Robinson.

The shark has produced 21 offspring over the years, but only eight are still living. There is one drawback to this type of reproduction: the babies are likely sterile. The National reports: "These animals are clones, more than actual offspring, so I'm unsure whether they will actually be able to reproduce. They are born sterile, basically," Robinson said.

But when the eldest pup reaches sexual maturity, the aquarium staff still plans to try to introduce a sterile male – just to be sure.