Fishing Spider (Dolomedes spp.)
Detailing the physical features, habits, territorial reach and other identifying qualities of the Fishing Spider.
Updated: 4/6/2018; Authored By Staff Writer; Content ©www.InsectIdentification.org
The Fishing Spider is commonly found near bodies of water and, as any fisherman could tell you, it can grow to be 'this big'.
Fishing Spiders are typically found near bodies of water. They may also venture into nearby woods for terrestrial hunting. Fishing Spiders are large and look menacing. Their leg span can stretch to more than 75mm (3 inches), making some slightly bigger than the palm of an adult hand. Like nearly every spider in North America, it can bite and deliver venom, but its venom is not considered dangerous unless you happen to be specifically allergic to it.
As members of the Nursery-Web family, females will lay their eggs on a silken mat and then wrap them up into a small ball. She will then carry the egg sac in her jaws as she looks for a good place for them to hatch. She will build a web and attach her egg sac to it, then stand guard until the spiderlings emerge. Hundreds of spiderlings can hatch at once and they eventually disperse from the nursery on their own silken threads.
Fishing Spiders get their name from their hunting behavior and occasional food source. They are adept at ambushing insects and other food items on land, but they are also able to submerge their bodies just under the surface of calm water and hunt for small fish and tadpoles. The bristly hairs on their body trap air bubbles that they use to breathe while underwater and waiting for something to swim by. They have been known to stay submerged for more than 30 minutes at a time when hunting in water. They are also able to eat insects skimming or treading on the water's surface above them.
They are active during the summer months. Look for Fishing Spiders on or near boat docks and marinas. They may also be seen near shorelines and the banks of rivers and creeks. Keep an eye on still water to see if any are quietly hunting.