We travelled up to the Shropshire Mosses and Meres to see this beauty. There are two raft spiders in the UK, the very rare Fen Raft Spider, Dolomedes plantarius which is only found at a handful of sites in East Anglia and the South East and the widespread but very localised in distribution raft spider. Bizarrely the rarer of these two is quite well studied, however the ecology of fimbriatus is hardly understood at all. And they're not easy to find either in boggy landscapes, unless that is the big females are on water. And when I say big, I mean big.... they'd give the canny lasses in Newcassel on a Friday night a run for their money. Yep that big.
These are just stunning arachnids. And yes the female is huge, the biggest spider in Europe. The one below was about 7-8cm long from leg tip to opposite leg tip, the body about 3cm.
These photographs don't do this spider justice as the body was like chocolate brown velvet with a lemon curd go-faster stripe down each lateral side. As hunting spiders they spend a lot of time waiting for prey on water, using water tension to support their weight. However they are attached to a piece of vegetation using their hind legs and a tiny thread of silk.
One curious piece of this species ecology is that if a male approaches to breed and she thinks, nahh far too weedy, she just eats him. Not after mating as many spiders do, but before mating. Now that does have a slight ecological problem in that if the last female was on the planet, would she eat all the males and become extinct?
I'm glad we found some spiders as with this very dry spring we're currently experiencing the Moss we were visiting was almost dry. The two females we found were actually in puddles around an ancient tree stump, this was the only open water we found. We need rain, and lots of it soon.
If you want to find out more about these fascinating beasties, I'd recomment the Dolomedes website http://www.dolomedes.org.uk/