College Green Magazine – Eco-news From The Ground Up

A Dolomedes triton, or Six-spotted water spider in Emeriti Park pond. Photo by CG Photo Editor Elizabeth Linares.

By CG Editor Austen Verrilli

Arachnids usually fail to make people warm and cozy inside.  Spiders’ eight legs, venomous fangs and matrix of eyes cause some people to scream and run away in fear. But spiders aren’t around to waste their time scaring us. Instead they use our dwellings to their advantage as they feed on insects that feed on our leftovers. One scary spider keeps several more six legged bugs off kitchen floors and walls.

The Six Spotted Fishing Spider weighs in at less than a gram and stands a maximum two and a half inches in diameter, an educational website of Virginia’s Fairfax County Public Schools reports.  It prefers to keep away from dingy basements, drafty hallways, dusty couch-covered corners and showers.  The species instead lives by shallow slow-moving water sources like ponds, marshes and slow-moving streams. The spiders walk on water due to their light weight and hunt small minnows and insects.

The surface tension of water, which occurs because water molecules are attracted to each other, helps the Six Spotted Fishing Spider walk across the water. A Natural History journal article by Carl Zimmer explains that the a waxy coating on the spider’s legs and their light weight help keep the spider from breaking through the surface of water. The article also said that the spider’s long legs help to spread the spiders weight out more so it does not pierce the surface of the water. Check out this link to see a photo of Dolomedes titron jump on water.

Photo of the Six Spotted Fishing in Spider from Photobucket.com user russell888.

Fast Facts

•  According to the Fairfax County Public Schools website Dolomedes triton has two white stripes on the front of its body, 12 spots on the rear section of its abdomen and six spots on its bottom side.
• Six Spotted Fishing Spiders can row across water using some of their legs as paddles according Fairfax County’s site.
• The spiders hunt on land and water.
• Fairfax County’s site also reports that the Six Spotted Fishing spider can also dive into the water to hide or catch prey .
• The spiders can gather a bubble of air around their bodies and swim beneath the water for over a 30 minutes.
• Six Spotted Fishing Spider’s water repellant coating and tightly spaced hairs on its body help trap air around them under water.  Check out this MITnews article for a more detailed description.
• Female Six Spotted Fishing Spiders may eat a male approaching her to mate if she has already mated.
• Females stay with their egg sack until spiderlings emerge. 
• Dolomedes titron is found all across the United States.
• Six Spotted Fishing Spiders do not build webs.

Sources:

Fairfax County Schools Va.

http://issuu.com/ohioenviro/docs/oecvernalpoolguide

http://web.mit.edu/newsoffice/2008/underwater-0729.html