Mitten Crabs

[rufus]

Went out to find some new marks for peeler collection today and tried a new spot at Rainham on the Thames Estuary. No peelers at all but plenty of little crabs with long legs that I had never seen before. Got home and did a search for crabs in the Thames and it seems the estuary is running alive with those that I had found...Chinese mitten crabs.

 

Now what I want to know is... can they be used as bait? I mean do they peel like a shore crab? Has anyone ever tried one out?

 

They are becoming an environmental nuisance it seems...what better way to reduce numbers than to put them on a hook and catch bass with them?

[Leon Roskilly]

Hi Rufus,

 

There's been Mitten crabs in the Medway for several years now.

 

They come down into the estuary in the spring to lay their eggs, then move back up into freshwater.

 

All crabs must peel off their hard shell to grow (I don't know whether mittens do their peeling in freshwater, I suspect they do).

 

I'm not sure that you have identified the crabs you have seen correctly.

 

Mittens are called mittens because they are covered in 'fur'.

 

I have a suspicion that the crabs you have found are young 'king' crabs.

 

I caught the tail-end of a news item on these several weeks back.

 

Another alien species, they have become established in East Anglia / Suffolk and are either like, or perhaps 'king crab' is another name for 'spider' crabs.

 

The presenter was talking about the need to establish a commercial fishery for them, to keep their numbers down, although it was admitted that once they had become established, it would not be possible to eradicate them from the area.

 

http://news.bbc.co.uk/1/hi/sci/tech/904323.stm

www.guardian.co.uk/Print/0%2C3858%2...57014%2C00.html

 

http://news.bbc.co.uk/1/hi/uk/264556.stm

 

Hmmm! Seems that King crabs are not spider crabs, but something else. I can't find a reference to them arriving in Suffolk though!

 

 

Tight Lines - leon

[Topecatcher]

Mitten crabs are in the Humber also they have a different shaped shell which incidently is very hard. The fur!! is on the crabs claws, hence the name mitten.

[rufus]

Leon

 

I'm not sure either..but they do look rather a lot like the mitten crabs in the pictures..the 'fur' you speak of was not apparent , but these specimens were very small juveniles. One interesting thing to note was that I saw not a single shore crab in this colony that I found....but a little further downstream, just three miles or so, at Grays, a healthy head of our good friend the common shore crab was found in numbers under every rock ( none in moult however, ggrr).

The king crab looks amazing ...fancy meeting one of those down a dark alley!!! What do they eat...COD?? The crabs get their revenge after all!!

I sent off a report to Roni Robbins @ the NHM so should get some detail here. Unfortunately I did not think to bring home a specimen for comparison so can't be sure as yet, but I'll go back soon as there are loads of maddy's under the same rocks, easy pickings.

[Leon Roskilly]

See:

 

http://www.dailymail.co.uk/sciencetech/art...riverbanks.html