Fishing spiders constitute any species belonging to the Dolomedes genus of arachnids. Also known as dock spiders, these arachnids live in ponds, swamps, slow-moving streams, surrounding vegetation and any human additions to the natural environment, such as docks and canoes. Spiders of the Dolomedes genus live throughout the United States, from New England to Texas, Florida and the west coast. They are the biggest spiders in the upper Midwest and possess the ability to stand on and move across water and dive into it for brief periods. Fishing spiders eat tadpoles, small fish, various insects and other small vertebrate animals. They exhibit dark, brown or gray markings with some white.
Diving Bell Spiders
Diving bell spiders (Argyroneta aquatica) are unique among spiders in that they represent the only species to spend large portions of their lives underwater. They do this by spinning waterproof webs that act as exterior lungs, trapping an air supply for the spiders to bring underwater. Diving bell spiders derive their common name from an antiquated type of diving equipment. The spiders surface occasionally to capture more oxygen, though carry out most primary life functions, including eating and mating, beneath the surface of the water. These insects live throughout Europe, Asia and northern Africa.
Wolf spiders belong to the Lycosidae family of arachnids. They do not spin webs, but rather live in natural hallows and hunt prey actively. Wolf spiders don't trap moisture on webs as many spiders do and so must seek alternate water sources. Though wolf spiders don't occur commonly in and around water like diving bell or fishing spiders do, they may need to seek moisture from sources like ponds, particularly ponds in home gardens, as wolf spiders commonly live around homes. They feed on crickets, grasshoppers, ants, other spiders and various pest insects like aphids. Wolf spiders possess particularly large eyes, making them easy to identify.
None of the spider species commonly found around water possesses a particularly venomous bite and generally cause less damage to human skin than a bee sting. Fishing spiders avoid contact with humans at all costs. Wolf spiders prove beneficial to human society, as they feed on a number of damaging insects.
The issue of man-made ponds slightly confuses the notion of spiders living near such ponds. While fishing spiders and diving bell spiders always live in or around water, and while wolf spiders may seek a pond as a source of moisture, man-made ponds may end up in established spider habitats. As such, spiders not generally attracted to water or ponds may live around your pond because they or their ancestors lived there before the pond appeared.