Friday, July 07, 2006

Walking on water

I spent too long this evening trying to get pics of the water striders on the pond, before deciding I don't have the right equipment or enough patience, or both. I found this pic on an invasive species website (click on pic for link).

Water striders, also called Jesus bugs or pond skaters, are true bugs that can run across the surface of the pond because of lots of microscopic non-wetting hairs on their legs. The short front legs are used for grasping prey (of what type I'm not sure), the long middle legs are used like paddles to skate across the water, and the rear legs are used for steering and braking. I've read that they're sensitive to vibrations on the water's surface and use that skill to locate their prey. Fish and birds will dine on them, catching them because these bugs aren't able to detect motion from above or below the surface of the water. My trying to photograph them caused them to leap onto a lily leaf or amongst the water lettuce; I suspect because my being so near the water attracted the interest of the fish looking for a handout.

If you're interested in reading more about how water striders use surface tension to walk on water, an article describing a study by MIT researchers is available here. Neat pics from the study, done using dye, are available here.

The science behind it all is interesting, yet I'd much rather just watch and wonder, enjoy their skating and the dimples they make on the pond's surface when still. Wonder and curiosity about the natural world need not be satisfied or lost because of knowledge. For me, it seems that learning only leads to more questions and an even greater curiosity.

5 comments:

MojoMan said...

I didn't know water striders are true bugs! Are they an invasive species?

Isn't is amazing how pond life finds its way to an artificial pond in a backyard?

GreenmanTim said...

Captivating post, thanks!

Ontario Wanderer said...

Thanks for the information and links to the study and wonderful photos!

LauraHinNJ said...

Mojoman: Don't know if they're invasive - let me know if you find out!

It does sort of amaze me the things that turn up in my little pond - not sure how they find it, but guess the saying is true - if you build it - they will come.

lené said...

Thanks for posting the link to the MIT article. It was fascinating to read about how they "row" with their middle legs.