Year of the Spider: Fishing Spider

While certain venomous spider species drive arachnophobia, some do so by sheer size. As the Year of the Spider spins on, we focus on some of the largest species in North Carolina; the nursery web or fishing spiders. These members of the Pisauridae family are known to approach leg spans of three inches, which give them a daunting presence. It also pushes the imagination into thinking they are in fact the size of a dinner plate. Physically, their leg span ranges from 1-inch to 3- ½ inches long. Males are merely half the size of females. All of them are varying shades of brown, black and white with patterns that serve as dual purpose camouflage to keep them hidden from prey and predators. These spiders are hairy, which adds to their allure, and fearsomeness. Different than many traditional webweaving spiders, fishing spiders are active hunters. They patrol the forest floor, streams, ponds, swamps or river banks in search of their prey. They can also be found in culverts, under bridges and rock piles. Having robust size allows these spiders to overwhelm large prey. These spiders are opportunistic and will feed on anything they can catch and subdue, including terrestrial and aquatic insects, small mammals, small reptiles, amphibians, fish and even tadpoles. As their name implies, spiders from this family are also known to “fish” for their food. By extending their front legs, fishing spiders wait, sensing the water for vibrations of small fish or other aquatic critters. In some instances, fishing spiders have been known to dive below the water after prey, carrying bubbles of air among the hairs on their legs from which to breathe.

While the hunting habits of fishing spiders are fascinating, their reproduction is also fascinating. Fishing spiders reach sexual maturity in July and males search out females to mate with during late summer. After they mate, males are not killed by the females, but they do die naturally and then are consumed by their mates. After the mating, females create an egg sac for the young to develop in. This egg sac is carried around by the female with her chelicerae or fangs. When the young hatch inside the egg sac, the female then constructs a nursery web in the leaves on the forest floor and guards the young until her death. Young then overwinter as subadults and the process starts over the following summer.

There is no doubt that fishing spiders can be intimidating. But don’t let their size frighten you into disliking these fascinating spiders. So the next time you’re out in the woods keep an eye out for these large, harmless, spiders.