Friday, 30 October 2015

Day 350 - Fabulously, Resplendently Special Fen Raft Spider

15 days to go!

Fen Raft Spider (Dolomedes plantarius) at Bird Fair
Hey everyone today's Day 350. Only 15 days to go! The countdown had now officially begun. Well, as it's such a special occasion, I thought I would write about a special species. Well, I chose the Fabulously Resplendently Special Fen Raft Spider. It's quite a rare species so I thought it deserved the spot of Day 350. We saw this at Birdfair, It was captive but it's such a beautiful species I felt like I had to cover it anyway.

Also, it seems fitting for Halloween Eve!

So, here are the facts:

  • Specifically, this spider is called the Fen Raft Spider, Raft Spiders is the family that it comes from.
A Spiders eye view - it has one leg holding onto a leaf
  • They are one of only two species of spider that are fully protected by the UK law. Don't worry, they had clearance to own them!
  • This is understandable as, in the UK at least, they have been branded as 'vulnerable to extinction'! 
  • Adding to this, you can see why, as they are only known to live at 3 sites across all of the United Kingdom. 
  • Not only are they a beautifully coloured and marked spider they are quite big at up to 7cm across. They will live for around two years.
With a big egg sac!
  • It is rather a caring mother, for 3 weeks it carries up to 700 eggs in a silk sack and then weaves a nursery web just before the eggs hatch.
  • This web, which looks sort of like a tent, is found between 10cm and a metre above the water.
  • Well, seen as they live right above water, they'll need some adaptations. This why their legs are kind of hairy and the hairs are very sensitive. 
  • Using the surface tension of the water they spread their legs over the surface of the water and detect vibrations with the sensitive hairs. They feel for their prey's vibrations on the waters surface like most spider do on their webs.
  • Also they have great eyesight and can see under the water and will pounce on fish and tadpoles that get close. I found a great video on youtube showing this - narrated by David Attenborough too!

  • Apart from fish they will eat tadpoles and insects like pond skaters.
A beautiful Spider!
  • They are seen, in the few places they are, from May until August. That is most commonly, they can be seen at other times.
  • The Males have a body length of between 13 and 18mm and the Females have a body length of between 17 and 22mm.
Here are some links to some more information:

ARKive - Fen Raft Spider

Another video here tells you about conservation work for this wonderful Spider.

Hope you enjoyed,


1 comment:

  1. Such amazing spiders Zach! What wonderful photos. - Tasha