We were recently sent the following photo by Rick, a visitor to Anglers' Net. It appears to be of a mitten crab. Now, I've never seen one of these in the flesh before (or even in the shell!), or even spoken to anyone who has, so I wondered how widespread they are these days?
Here's what Rick had to say:
My daughter was fishing the Thames at night at Eton near Windsor, Berkshire and landed this monster.
I am 50 and been fishing the Thames most of life.
Can you tell me if this is native to the water, as I have never seen one before caught from the Thames?
I'll include a link to a thread in our coarse fishing forum below. If you have caught a mitten crab in the UK, please add details. It would be interesting to see just how quickly they are taking over our rivers.
To report a capture of a mitten crab in the UK, please click here.
Since first publishing this article, we have received the following helpful response from the Environment Agency:
The mitten crab is a very successful "invader" and is known to burrow into river banks and represents a hazard to river and other freshwater engineering projects, and generally out-competes many native species. The crab is capable of emerging from water and crossing dry land to enter new river systems. This invasion could eventually threaten freshwater habitats currently occupied by populations of our native crayfish.
The Natural History Museum are doing research and ask for the following information to be reported:
Where and when was the crab seen or caught?
Did you see any other crabs in the same area?
Were they alive or dead?
What was the approximate size?
Do you know what sex they were (males have a V-shaped abdomen and females have a U-shaped abdomen).
Information can be reported to:
Department of Zoology
The Natural History Museum
Tel: 020 7942 5272
It may also be advisable to contact us on 08708 506 506, so that we can notifiy our biodiversity team in the local area.