Fishing Spider – Dolomedes

Fishing Spider – Dolomedes tenebrosus

Fishing Spider - Dolomedes tenebrosus*Size: 60mm (almost 2 ½ inches) from tips of back legs to tips of front legs
*Spider size is normally measured by body length only but I thought you might like to know how far across the legs too. Enjoy! This is a big spider.

Family Pisauridae – fishing and nursery web spiders.

This large spider was hunting on rocks semi-submerged in a creek, and appeared to be at home qually on a solid or liquid surface. The prey did not stand a chance against the sudden burst of speed ambush this gal mounted. These tiny micro-dramas are going on, all the time, all around us. You don’t have to go to Africa to see some of the most exciting hunters doing their thing!

Fishing Spider - Dolomedes tenebrosusFishing spider on the rocks in Mud Creek near Oregon, Illinois has caught a water strider


The semi-aquatic fishing or “raft” spiders of Europe and North America are quite large. The females can reach a body length of 30mm (over 1 inch). They hunt on the surface of still or slow-moving fresh water. They row themselves across the surface much like pond skaters, supported by the surface tension, and can also sail across on the wind.

Pond Skater

Here is a picture of the water strider species this big spider is feeding on. Fast as these bugs are, they don’t see well enough to detect the wait-and-pounce ambush the spider practices (below).

D. tenebrosus matures in the spring and will subsequently mate and produce egg cases that are carried around by the females until ready to hatch. The young are guarded by the female in a nursery web and may number 1,000 or more in each brood. See: nursery web spider.
North American Insects & Spiders
Explore over 3,000 close-up photos and information on over 700  arthropod species commonly found in North America.  Our live insects & spiders have been photographed unposed, in the wild, at various locations in Canada, Mexico and the United States.
Spiders Index | Spiders Main | Beetles | Butterflies | Stinging Insects