They have claws, 10 legs, can produce hundreds of clones of themselves and have escaped from confinement to potentially run amok across the United States. The ecological threat posed by the marbled crayfish has now prompted prosecutors to wield invasive species laws in an attempt to curb the spread of the peripatetic crustaceans.
An Ohio woman who sold hundreds of marbled crayfish online has pleaded guilty to offenses under the Lacey Act, a US law preventing the transport of certain wildlife across state lines, after raising the crayfish in a huge tank in her home and selling them to people across 36 different states.
Allison Spaulding used eBay and Craigslist to sell various species of guppies and crayfish bred in her aquarium in Mount Vernon, Ohio and faces a maximum penalty of a year in prison and up to $100,000 in fines, although a federal judge is set to consider a lesser penalty under a plea deal.
The case is understood to be the first such enforcement action aimed at stemming the advance of the marbled crayfish, which has already exploded in huge numbers across countries as diverse as Germany and Madagascar. Wildlife officials fear the creature is now threatening to gain a claw hold in the US, where it is banned in several states but not nationally. Spaulding was prosecuted after Ohio introduced a state rule in 2020 naming the crayfish as an injurious species.
“We are trying to keep them off the landscape as they have the potential for serious environmental damage,” said Justus Nethero, wildlife investigator at the Ohio department of natural resources. “I hope this will be the springboard to this crayfish being federally listed as an invasive species, because these things have to start somewhere. I’d like to think this will change something.”
Nethero said he was “shocked” at the scale of Spaulding’s crayfish enterprise, which involved a 50-gallon tank of water with sand in it, filled with approximately 400 to 500 marbled crayfish. During a visit in May 2021 that Nethero said was cordial, investigators saw the tank. “Allison was very friendly,” he said. “This wasn’t like (the TV show) Cops. It was pretty smooth. We are talking about crayfish here, after all, not cocaine.”
Prosecutors allege that Spaulding was selling the crayfish via the internet at prices from $17 for two juveniles to $52 for a group of 40 crayfish to people who kept them in aquariums as pets or, due to their prodigious ability to clone themselves, as a reliable, self-perpetuating food source for other kept animals.
The species has spread across waterways in Europe as people have dumped them into rivers, lakes and toilets. Their tiny eggs can also inadvertently get washed down drains when emptying aquarium tanks, which Nethero said could be a pathway for the species to establish themselves in the US.
The marbled crayfish, also known as marmokrebs, self-cloning, or virgin crayfish, is at first glance relatively unremarkable – measuring around five inches in length, sporting a reddish or blue mottled shell and surviving off an omnivorous diet of algae, plants and amphibians.
But the species is parthenogenetic, meaning that it can asexually reproduce itself. All known marbled crayfish are female – no males have been discovered – and each animal can lay up to 700 unfertilized eggs that develop into genetically identical offspring. This prodigious cloning ability allows the marbled crayfish to quickly dominate any aquatic ecosystem it finds itself in, outcompeting, or consuming, any native species already there.
Experts have compared the spread of the species to the way that cancer develops in the body. “This crayfish is a serious pest,” said Gerhard Scholtz, an evolutionary biologist at Humboldt University in Berlin. The origin of the crayfish is murky – it was first recognized at a pet fair in Germany in 1995 before escaping into the wild – but it is now banned from being kept or distributed within the European Union and several other places, such as Japan.
No such ban yet exists in the US, a country that is already grappling with the environmental impact of a raft of introduced species that have upended landscapes, from feral hogs to Asian carp.
