Chinese mitten crabs, an invasive species of crustacean, have been spotted in regions of Cambridgeshire, prompting concern for the local environment.
The crabs, which are native to East Asia, have been pictured around busy roads and parks in Peterborough, much to the surprise of residents.
Chinese mitten crabs were actually introduced to North America and Europe over the past 200 years and have since been spotted in locations such as the River Thames.
While not threatening to humans, the crabs — often identifiable by their furry, mitten-like claws — are thought to be a risk to local biodiversity, and river banks.
So what do you need to know about the critters?
What are Chinese mitten crabs?
Chinese mitten crabs, also sometimes referred to as Shanghai hairy crabs, get their name after their furry claws. Although they’re a non-native species, they’ve been around the UK since at least 1935.
These creatures can grow to around 10cm in size, and efforts to remove mitten crabs have so far been very difficult.
While they are not dangerous to humans or pets, they are known as burrowing creatures, meaning they can embed themselves and potentially erode river banks.
They also potentially pose a threat to local fishing, either feeding on local marine life or damaging fishing nets.
Where else are they found?
Chinese mitten crabs have actually been located in a lot of regions across North America and Europe. They can live everywhere from canals to rivers.
The crabs have a complex reproductive cycle, meaning they’ll move between freshwater and saltwater depending on their age and sexual maturity.
While they’re originally from Korea and China, British Sea Fishing claims that they may have made their way over to Europe via commercial ships.
They’re now considered an invasive species in the UK, parts of Europe, and the US.
Are they dangerous?
Apart from an annoying nip from their claws, mitten crabs don’t pose a danger to humans or your pets.
In fact, in some parts of China, mitten crabs are actually seen as a local delicacy, but they can’t be sold for human consumption in the UK.
Environmentalists are more concerned about the danger that they might pose to UK biodiversity, especially the erosion of riverbanks and riverbeds.
What should I do if I find a mitten crab?
According to the Natural History Museum, there have been more than 800 records of mitten crabs in the UK. There are also some studies by UK scientists that you can help with if you locate a mitten crab.
If you spot one, the museum also suggests that you make a note of where it was and take a picture. You can submit sightings through an online form or by sending an email to recording@mba.ac.uk.
