Fishing spiders, also known as dock or wharf spiders, are semi-aquatic arachnids that are prevalent in fresh bodies of water in Georgia and the Southeastern United States. They can also be found throughout North America. Most species live at least part of their lives in water, but there is a species of fishing spiders in the Southeastern US that lives in trees. Can you imagine that thing dropping out of a tree?
Despite their startling appearance, females can reach about an inch long with a four-inch leg span, while males are about half that size—they are not a major foe. They do bite and inject venom, but they aren’t usually aggressive towards humans. And the venom is not harmful unless you are specifically allergic to it. The hairy, spiny legs of fishing spiders add to their intimidating appearance but are in fact very useful for them to adapt to their environment. The hairs can be used to sense vibrations in the water and are hydrophobic, which means that they repel water because of a waxy covering. This allows the spider to walk on water, so they can live partially submerged and on the surface of the water.
They have fascinating hunting practices compared to run-of-the-mill web hunting spiders that wait for their web to do the trapping for them. Fishing spiders hunt on foot and pounce on their prey to bite it and inject venom to incapacitate. Web-building spiders often have poor vision and use the vibrations from their web to find their prey, but some fishing spiders have good vision and hunt by sight. Fishing spiders spend their time hunting mayflies, other insects and even small fish. The hairs on their legs also allow fishing spiders to sense vibrations of their prey in the water, making them a formidable predator.
The mating practices of the fishing spider are also very interesting. Directly after mating, the male dark fishing spider becomes immobile and either dies a few hours later or is eaten by the female. While deadly to the male, sticking around to the end ensures that his sperm will fertilize the female, ensuring the survival of his genes into the next generation—even if he won’t live to meet his offspring. The female fishing spider is in that sense, somewhat of a “man-eater”.
Fishing spiders are an important part of their ecosystem. They help to keep the insect population under control and play a role in many aquatic and terrestrial ecosystems. They may look scary, but they are not bad guys. Don’t feel bad if you don’t want to meet one face-to-face, but you’ll likely come out of it unscathed!
