Rearing Britain’s Largest Spider For Release

For the last few weeks we have been playing a small role in the Fen Raft Spider Species Recovery Programme,  a partnership project led by Natural England,  to safeguard  the future of Britain’s largest spider. The fen raft spider (Dolomedes plantarius) is listed as a vulnerable species and is found on just two sites in England and one in Wales.

In July we received 200 spiderlings each in its own test tube. These were checked daily and the young spiders were fed fruit flies every four days. Whilst they were with us they shed three or four times and had grown from a body length of a couple of millimetres to around half a centimetre. By rearing the spiders individually in captivity for the first few weeks the survival rate can be improved by 90%.

Over 2000 spiders have been reared by ten BIAZA collections around the country and on Monday they were collected and have now been released into selected Fenland habitats.

Adult fen raft spiders have a leg span upto 8cm and are able eat small fish like sticklebacks. They mature when they are 3 years old so hopefully in 2014 some of the nature centre reared spiders will help to build up the British population of these spectacular arachnids.

To find out more about this project visit these:

Thanks to Ian Hughes for the photographs from release day.


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