Female mutant crayfish clones have landed, but government recommends you not buy one

While there’s nothing illegal about importing a marbled crayfish, the government is suggesting people not own these female mutant crayfish.

'We do not recommend Canadians keep these animals as pets,' says Fisheries and Oceans Canada

The all-female marbled crayfish reproduces by cloning — and while it's a relatively new species, there are already huge populations around the world. (Submitted by Wolfgang Stein)

Female mutant crayfish clones are being sold in Canada, but the government doesn't think you should own them as pets.

According to a new study published in Nature, Ecology and Evolution, the all-female marbled crayfish reproduces by cloning at a rapid rate, earning it comparisons to the fictional Tribble alien-species on Star Trek.

"If you have one animal, essentially, three months later, you will have 200 or 300," Wolfgang Stein, a neurophysiologist at Illinois State University and one of the researchers on the study, told CBC's As It Happens.

Stein said this specific species has only been around for about 25 to 30 years when a female descendant of two slough crayfish inherited an extra set of chromosomes .

And that meant she didn't need any male crayfish to reproduce.

"The whole species is essentially female," Stein said.

The population exploded when they became hot commodities in the pet trade, especially among German aquarium hobbyists in the 1990s, said Stein. Now thriving populations are found in Japan, in Madagascar and Europe, prompting the European Union to ban the species from being produced, distributed, or released in the wild.

Illegal to release

The Department of Fisheries and Oceans says there haven't been any reports of wild marbled crayfish, known as Procambarus virginalis, in Canada, but they're carried by some pet stores and a look around Kijiji.ca shows sellers offering the bizarre animal at cheap prices in Toronto, Ottawa, Montreal and Halifax.

"Within a few months you will have a very large colony of crayfish," reads one Toronto-area ad.

While there's nothing illegal about importing the marbled crayfish to Canada, the government is suggesting people don't own the cloning species.

"Based on what is known about the reproductive behaviour of the marbled crayfish, we do not recommend Canadians keep these animals as pets," said Becky Cudmore, regional manager with Fisheries and Ocean's aquatic invasive species program.

"Human release of animals is one of the ways invasive species are introduced and become established in new areas."

Cudmore said anyone who already owns marbled crayfish should ensure the pet is contained.

"Unauthorized release of any aquatic animal into a waterbody from which they did not originate is illegal under the regulations," she said.

Stein's team looked at the island country of Madagascar as a case study for what happens when the crayfish find their way to the wild.

An ad selling the marbled crayfish appeared on Kijiji in the Toronto area. (Kijiji)

When the species was spotted in Madagascar in 2007 they occupied an area the size of Rhode Island, explained Stein.

"In 2017, they occupy the area the size of Ohio. That's a hundred-fold increase in just a decade."

His team warned that the crayfish will have to be monitored to make sure the bubbling marbled crayfish population doesn't negatively impact other underwater communities. 

Brie Edwards, a research scientist at Laurentian University, said more study would be needed to figure out how the marbled crayfish could affect Canada's ecosystem if it was ever released in the wild.

Since the slough crayfish originates from the southern states, it's not certain the marbled crayfish could survive in Ontario waters, said Edwards, who also works for the Ontario Ministry of the Environment and Climate Change.

"The likelihood that establishment would have negative implications for native species or ecosystems requires research and proper risk assessment," she said.