They have claws, 10 legs, can produce hundreds of clones of themselves, and have escaped containment to potentially run amok across the United States. The ecological threat posed by the marbled crayfish has now prompted prosecutors to enforce 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 species across state lines, after she raised the crayfish in a huge tank at her home and sold them to people across 36 different states.
Allison Spaulding used eBay and Craigslist to sell various species of guppies and crayfish bred at her aquarium in Mount Vernon, Ohio and faces a maximum sentence of one year in prison and up to $100,000 in fines, although a federal judge is about to consider a lesser sentence. penalty under a plea agreement.
The case is seen as the first such action to stem the advance of the marbled crayfish, which has already exploded in large numbers in countries as diverse as Germany and Madagascar. Wildlife officials fear the creature is now threatening to grab hold of the claws in the United States, where it is banned in several states but not nationwide. Spaulding was sued after Ohio introduced a state rule in 2020 designating crayfish as a pest species.
“We try to keep them away from the landscape because they have the potential to cause serious environmental damage,” said Justus Nethero, wildlife investigator with the Ohio Department of Natural Resources. “I hope this will be the stepping stone to getting this crayfish on the federal invasive species list, because these things have to start somewhere. I’d like to think that’s going to change something.
Nethero said he was “shocked” by the scale of Spaulding’s crayfish venture, which involved a 50-gallon water tank containing sand, filled with around 400 to 500 marbled crayfish. During a May 2021 visit that Nethero described as cordial, investigators saw the tank. “Allison was very friendly,” he said. “It wasn’t like (the TV show) Cops. It was pretty smooth. We’re talking crawfish here, after all, no cocaine.
Prosecutors allege Spaulding sold the crayfish via the internet at prices ranging from $17 for two juveniles to $52 for a group of 40 crayfish to people who kept them in aquariums as pets or, because of their prodigious ability to clone itself, as a reliable, self-sustaining food source for other bred animals.
The species spread to the waterways of Europe as people dumped them in rivers, lakes and toilets. Their tiny eggs can also be inadvertently washed down drains when draining aquarium tanks, which Nethero says could be a pathway for the species to become established in the United States.
The marbled crayfish, also known as the marmokrebs, autocloning or virgin crayfish, is at first glance relatively unremarkable – measuring about five inches in length, sporting a red or blue speckled shell, and surviving an omnivorous diet of algae, plants and amphibians.
But the species is parthenogenetic, that is, it can reproduce asexually. All known marbled crayfish are female – no males have been discovered – and each animal can lay up to 700 unfertilized eggs which develop into genetically identical offspring. This prodigious capacity for cloning allows the marbled crayfish to quickly dominate any aquatic ecosystem in which it finds itself, competing with or consuming any native species already present.
Experts have compared the spread of the species to how cancer grows 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 illegal to keep or dispose of it. distribute it in the European Union and in several other places, such as Japan.
No such ban yet exists in the United States, a country that is already grappling with the environmental impact of a range of introduced species that have upended landscapes, from feral pigs to Asian carp.