Washed up on beach. Approx 8cm long.
No interactions present.
Female crab no idea what species.
All given ID's are subject to error/ommissions. Please seek independent verification before acting on ANY advice given. BE SAFE =)
I have difficulty understanding how this is a spider crab. It has a flexible segmented body with feathered legs underneath. This is more or less the complete creature. I don't think it is just the abdomen of a crab. It is much more like an isopod of some sort.
It is a bit hard to understand how this is spider crab related at first but if you look at this link and the first observation of Maja brachydactyla above in the carousel it should become clear. This link shows how the abdomen of a female Hyas araneus looks on the animal. Your object is larger than a female Hyas species can grow to so it is more than likely from a Maja species and there is only one to pick from in British seas. Hope this helps:
Check out the first and fourth pics in particular. The feathery leg like structures are to do with egg production and containment, I dont know what they are called.
Hi, Nightfly, I think you are correct, another image I found is http://www.naturalvisions.co.uk/ImageDetail.aspx?imdet=49913
Thats a good image there, it would have been useful some time back when a similar object to your one was posted, its the first pic in the carousel for M. brachydactyla when you are viewing your own observation.
The nearest pic I had to the object that time and in your observation was a view of the abdomen of a smaller relative of the Spiny Spider Crab- a smaller animal called Hyas araneus. Thanks for the link, very useful indeed.
Lat/Lng: 52.1443, -4.497
OS grid ref: SN292524