Concerning spiders, and where to find them

By: Dan Mead, the 25th Anniversary Sequencing Project Coordinator
Date: 14/12/2017

Fen Raft Spider on the water, courtesy of Dr Helen Smith (
Fen Raft Spider on the water, courtesy of Dr Helen Smith (

About spiders (specifically the Fen Raft spider, Dolomedes plantarius) and where to get them from.

After visiting the Fen Raft spider website I contacted the woman listed on the Fen Raft spider web site, a Dr Helen Smith. Dr Smith was incredibly helpful and, I discovered, is the ‘grandma’ to the spiders living in the ditch we’re planning to source them from. Helen raised them in her house as part of the translocation programme she has been running for the past few years.

Also, I found out, spiders hibernate for the winter, something I probably should have intuited. The thing is, no one knows how these particular spiders do it! When farmers clear out the ditches to keep the water channels clear and healthy, a whole bunch of these raft spiders pop to the surface. It’s assumed they are hibernating under the water, but do they burrow into the mud? And how do they breathe during this time? Do they even breathe?

My guess is that they trap air around their bodies and this sustains them over winter but they must also shut down their metabolism to virtually nil to avoid using it up. Also how to they anchor themselves underwater? Do they burrow? Grab onto something? Wedge themselves under a rock? It’s a mystery…

Helen is going to send me photos and, maybe, videos of the collection as well. I’m hoping to see spiders appearing all over the surface of the water like some kind of hidden marine corps about to go into action.

This should all take place next Tuesday, weather permitting, so another species should be sampled by Christmas.

About the author:

Dan Mead is the 25th Anniversary Sequencing Project Coordinator, for the 25 Genomes Project for the Wellcome Sanger Institute, Cambridge.

More on the 25 Genomes Project:

25 Genomes Project web page