Fen Raft spider, Dolomedes fimbriatus
The raft spider, Dolomedes fimbriatus, is a European spider Found only in or near damp places, raft spiders are the largest in Britain. They are can of move across water and submerging themselves for periods of time to protect themselves from predators.
Adult females are the larger of the species with bodies measuring 22 mm long and with a leg span of about 70 mm.
Raft spiders are semi-aquatic and live their lives around acidic bogs. They are dark brown or black in color with a large stripe of white or cream along their sides.
A second similar species of raft spider, Dolomedes plantarius, occurs in Britain as well. Though less particular about its habitat, which tends to be neutral to alkaline, unpolluted water, it is far rarer. They like to stay in warmer places and also eat dead things.
The Raft spider is Britain's largest spider aka Fishing or Bog Raft Spider, Females reach more than 22 mm in length the males only 10-13mm The spiders need water in their habitats, bog pools and ditches on wet heath land in southern England are the best places to look. Despite their size they are able to move across the water surface as these photos show, if threatened it is also able to submerge under water for minutes at a time.
Habitat: Marshes, swamps and ponds
IMAGE D2925 (C) 2008 COLIN DUKE
IMAGE D2928 (C) 2008 COLIN DUKE
IMAGE D2935 (C) 2008 COLIN DUKE