Recently, while cooling off in our natural swimming pond, I noticed a spider on the water’s edge. When I attempted to get close for a better look it ran away on the water and then went under the surface where it remained quite stationary on the tiles for several minutes. I returned to the pool several times with the camera before I managed to get this photo but unfortunately from that angle I couldn’t get a good view of the eye arrangement.
POST UPDATE: click to enlarge photo for clear image of eyes.
Our attempts at identification were unconfirmed until we just happened to have a spider enthusiast visit us a couple of days ago. Although unable to identify the species from the photo Greg was confident that the spider belonged to Dolomedes, a genus in the family Pisauridae, which is the nursery-web or water spider family. The female nursery-web spider carries her egg sac beneath her. Just prior to the eggs hatching she constructs a silken brood chamber, often suspended between reeds, where she guards her offspring until they are independent.
This photo shows the spider under water, not a clear shot but it does illustrate the spider’s position, the water surface is in the top right-hand corner. And to give you some idea of its size the tiles are approximately 50mm square.
The last photo shows a different and more common Dolomedes which has found the environment of our natural swimming pond very suitable judging by the numbers of young I have observed.
While the conversion of our regular inground swimming pool to a natural pool is probably not everyone’s dream….it is an interesting environmentally friendly project and I’m going to write more about it very soon!