VIDEO: A SPIDER THAT CAN FISH UNDERWATER...

Surely this is any arachnophobe's biggest nightmare, a spider that can swim underwater?

This spider catches fish underwater and is disturbingly well-adapted to its task. This includes walking on water and breathing underwater while it stalks its prey. Dolomedes is a genus of large spiders of the family Pisauridea; they are also commonly known as fishing spiders, dock spiders or wharf spiders. 

Almost all Dolomedes spider species are semi-aquatic, with the exception of the tree-dwelling D.albineus of the southwestern United States. Many of these species have a striking pale stripe down each side of the body, they hunt by waiting at the edge of a pool or stream, then when they detect the ripples from prey, they run across the surface using their foremost legs, which are tipped with small claws; like other spiders they inject venom with their hollow jaws to kill and digest their prey. 

They mainly eat insects, but the larger species eat small fish. Nature is amazing, watch the video: