It was a huge, scary creature with eight legs and skunk like stripes that clung to the underside of the rock. It was completely submerged in the pool’s water and watching us carefully with its numerous eyes.
I needed to know what it was and why it was in my daughter’s mini ecosystem project. We started with an assumption that it was a spider. The eight segmented legs, two body regions and the fact that it looked a lot like a Wolf Spider were other clues that helped us decide it was probably a spider.
Yet, I was skeptical. A spider living underwater was something I did not even wish to consider and had never seen before.
In trying to identify this spider, I took the easy way. Meaning, I used the Internet and Googled for water spider pictures.
After sifting through hundreds of pictures we finally identified this spider as Dolomedes triton, known more commonly as a Fishing Spider.
Interesting Facts about Dolomedes triton the Fishing Spider:
These large spiders (up to 3 cm in length) eat insects, larvae, tadpoles and small fish and the females may even eat the males if they are hungry enough.
My daughter wasn’t aware of this but now knows why all her guppies died in her mini ecosystem. The spider and the turtles are fine.
According to Animal Diversity Web, to catch its prey, Dolomedes triton spiders may tap the water surface to lure fish closer. The concentric surface waves help the spider locate its prey. The spider then goes below the surface and heads towards the prey. These fishing spiders can stay underwater for up to 45 minutes, if necessary.
To stay underwater for long periods of time, fishing spiders use air trapped in their body hair to breathe.
The female Fishing Spider will spin a silk sack and carry her eggs around in her front jaws. When it is time for the eggs to hatch, the female Dolomedes triton Fishing Spider will put the sack in a leaf shelter and she will guard the sack until the eggs hatch and the hatchlings go out on their own.
The Fishing Spider has eight eyes and really good vision.
Other names it is known as include: Fishing Spider, Shore spider, Six Spotted Fishing Spider, Shoreline spider or Dock Spider
Found near marshes, ponds, slow streams, on docks, and shorelines and apparently in mini ecosystems of curious children.
In closing, I can’t pass up sharing a small quip that the information about these fascinating fishing spiders has inspired; I hope you find it amusing.
Her many eyes noticed, she responds, “The better to see you with my little minnows.”
She dives under the water and snatches her prey from underneath. The Jaws of the insect world strikes again. Cue eerie music.
Lane, L. 2002. “Dolomedes triton” (On-line), Animal Diversity Web. Accessed June 10, 2009 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Dolomedes_triton.html.