Fishing Spider

Photo by Stan Tekiela

by Stan Tekiela
© NatureSmart

July 15, 2019

I’ve been spending a lot of time out on my boat photographing loons, grebes, pelicans and other birds this spring. So, it was fun when I came across something else that was just as photogenic but perhaps not as endearing. It doesn’t have any feathers and has considerably more legs. It was a Fishing Spider (Dolomedes tenebrosus).

Fishing Spiders are large brown and tan spiders with dark markings on their legs. Of course, it has eight legs, as do all spiders. But what really is remarkable about these spiders is the size. Or more accurately, the size of the female, which can be over 1 inch in length. Males are about half the size of the females. In southern states these spiders can be even larger. In many regions, the Fishing Spider is the largest species of spider.

They are called “fishing” spiders because they are often found near shallow pools of water where they fish for minnows and aquatic insects. They are also called dock and wharf spiders because of their association with water. They have also been called raft spiders in the mistaken belief that the spider constructs rafts to move around the surface of the water. In many parts of the country, Fishing Spiders are also found in woodlands, far away from water, where they would be more accuracy called Tree Spiders because they live in trees.  

Unfortunately, they can often found in homes and other buildings where they can scare the heck out of the residents. However, these are harmless spiders and don’t have a strong venom so there is no need to panic if you come across one of these spiders in your basement. Their bite is equivalent to a bee sting but usually only bite if harassed or threatened.

Fishing Spiders don’t build webs like other spiders but rather actively go out and hunt down their prey. They are ambush hunters. They wait at the water’s edge with their front legs dipped into the water. The hairs that cover their legs feel even the slightest vibrations under water. So, they wait patiently for any aquatic insect or small fish to venture by before springing into action and grabbing their prey and delivering a bite.

Occasionally they “walk” out onto the water’s surface. Being so light weight, they use the surface tension of water to move about anywhere. When they dive into the water, the hairs that cover their body trap a thin air bubble around their body which allows them to breath underwater. Their lungs are located beneath their abdomen. Once they catch something, they return to land to feed. When they emerge from the water, they pop out and are completely dry.

When hunting they will bite their prey and inject a venom with their hollow jaws. The venom will both kill or immobilize the prey and also start breaking it down so the spider can “drink” its dinner later.  

I watched this Fishing Spider grabbing small aquatic insects right out of the shallow water and quickly bring everything it caught to its mouth. Its reflexes are lightning fast. I also watched it jump nearly 12 inches. Just about everything is amazing about the Fishing Spider. Until next time…

Stan Tekiela is an author / naturalist and wildlife photographer who travels the U.S. to study and capture images of wildlife. He can be followed on www.facebook.com and twitter.com. He can be contacted via his web page at www.naturesmart.com.