The Raft Spider
Spider of the Year 2020
from 01. January 2020
On display in hall 24.
With a body length of 10-22 mm, the Raft Spider, Dolomedes fimbriatus, is one of the largest native spiders. It occurs throughout Europe and lives mainly on the banks of still or slow-flowing water bodies, in swamp areas, but also on wet meadows. Raft spiders are lying in wait for their prey on the water surface, mostly under the cover of plants. They mainly feed on water insects and insects, but also tadpoles and small fish. They are active almost all year round, but at least from March to October.
Raft Spiders can easily be identified by the pale stripes along both sides of the body. The basic coloration of the strong and stocky body is yellow-brown to blackish-brown.
As the English name implies, the Raft Spider is a skillful hunter. When lying in wait for its prey, its underbelly touches the water surface. Thanks to its thick coat of body hairs it can rely on surface tension. In case of danger, or to catch prey, the spider can submerge, while an air bubble around the body keeps it dry.
Why was the Raft Spider selected as the European Spider of the Year?
As one of the largest native spiders inhabiting the banks of lakes and rivers, it is easy to detect; moreover it shows remarkable adaptations to its habitats, which are unfortunately increasingly threatened and in danger. It is therefore important for scientists to get data on the current distribution of the Raft Spider. Please, assist us with the documentation of this unique spider by sending your observations, locality records, and photographic documentation to christoph.hoerweg@nhm-wien.ac.at.
On display in hall 24.
