Pisaura mirabilis is a species of arachnid in the family Pisauridae, the nursery web spiders. It has a palearctic distribution, being found all over Europe, and also inhabits the Canary Islands and Madeira, the Asian part of Russia, China and North Africa. It lives in all habitats but prefers wet environments, and inhabits all strata from the ground to the top of trees, at altitudes up to 1,100 metres (3,600 feet), but is not found under rocks or in caves. The spider has relatively long legs, the fourth pair being the longest, and a slender opisthosoma. Males are 10 to 13 millimetres (0.39 to 0.51 in) in length, while females are 12 to 15 millimetres (0.47 to 0.59 in). This photograph shows a female P. mirabilis spider carrying an egg sac, photographed at a lake near Wolvercote in Oxfordshire, England.

Photograph credit: Charles J. Sharp