Raft Spider 1
A Raft Spider (Dolomedes fimbriatus). This early spring Raft Spider wasn't a fully grown adult, but nor would you call it a juvenile.
Dolomedes fimbriatus are Britain's largest spider, along with their cousin, the Fen Raft Spider (Dolomedes plantarius). Like all the Raft or Fishing Spiders, in the genus Dolomedes, they have an extraordinary ability to walk on water, or even leap from the surface, using the surface tension of water. However, they are also able to dive through the surface tension in an instant, so fast you cannot see it, to grab prey. So they are true masters of the surface film of water.
They don't spend all their time on the surface of the water, and spend much or most of their time in the vegetation beside the edge of the water. Especially when the females are carrying their very large egg sacs in their jaws. The time this species spends on water appears to be related to the breeding season and courtship. The juvenile spiders spend far more time resting on leaves, often some distance from any water, than they on the water's surface (although a few do rest on the surface of the water).
Raft Spider 1
A Raft Spider (Dolomedes fimbriatus). This early spring Raft Spider wasn't a fully grown adult, but nor would you call it a juvenile.
Dolomedes fimbriatus are Britain's largest spider, along with their cousin, the Fen Raft Spider (Dolomedes plantarius). Like all the Raft or Fishing Spiders, in the genus Dolomedes, they have an extraordinary ability to walk on water, or even leap from the surface, using the surface tension of water. However, they are also able to dive through the surface tension in an instant, so fast you cannot see it, to grab prey. So they are true masters of the surface film of water.
They don't spend all their time on the surface of the water, and spend much or most of their time in the vegetation beside the edge of the water. Especially when the females are carrying their very large egg sacs in their jaws. The time this species spends on water appears to be related to the breeding season and courtship. The juvenile spiders spend far more time resting on leaves, often some distance from any water, than they on the water's surface (although a few do rest on the surface of the water).