Meet Leonie, the sexually fluid shark

A zebra shark named Leonie, housed at Townsville’s Reef HQ Aquarium, has just made history, becoming the first shark ever recorded to change from sexual to asexual reproduction.

The case was documented by Dr Christine Dudgeon from The University of Queensland (UQ), who explained that while sharks can reproduce via parthenogenesis — a form of asexual reproduction in which embryos develop in the absence of fertilisation — none with a recorded sexual mating history have ever been known to make the change to asexual reproduction.

That was the case until April 2016, at least, when Leonie hatched three eggs — despite having been separated from her breeding partner at the aquarium three years beforehand.

“We thought she could be storing sperm, but when we tested the pups and the possible parent sharks using DNA fingerprinting, we found they only had cells from Leonie,” said Dr Dudgeon.

Reporting in the journal Scientific Reports, Dr Dudgeon and her study co-authors theorise that Leonie made the switch to asexual reproduction specifically because she lost her mate.

“What we want to know now is, could this occur in the wild and, if so, how often does it?” said Dr Dudgeon.

“One reason why we haven’t seen it before could be because we haven’t been looking for it.”

Dr Dudgeon said the breakthrough has big implications for conservation — especially given the zebra shark was recently listed as an endangered species. The ongoing survival of the species will be looking especially optimistic if Dr Dudgeon can use Leonie’s pups to answer the ultimate question: can asexually produced sharks have pups of their own with a male partner?

“You lose genetic diversity with generations of asexual reproduction, so we’ll be seeing if these offspring can mate sexually themselves,” Dr Dudgeon said.

Pictured: Leonie the zebra shark.