27 October 2012

Fishing Spider - Dolomedes stilatus

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Fishing Spider - Dolomedes stilatus

A widespread spider of well watered areas around Esperance and although a Fishing Spider, it will happily take to surrounding areas when ephemeral swamps dry out over summer. I had one that bred in my external laundry during January after all surrounding surface water had disappeared. She produced dozens of offspring that climbed to the roof and presumably ballooned away.

As the photographed spider is reasonably common, I have used the name Dolomedes stilatus as it is currently the only Dolomedes species listed for WA. The body length is around 2 cm (1") and the total span around 8 cm (over 3"). It is attractively marked with two bright orange stripes along the cephalothorax making it quite distinctive, so is unlikely to be confused with other spiders.

This fishing spider is active in, on and around small lakes, swamps and ponds where it hunts aquatic animals including small vertebrates like tadpoles and fish, but will also take land-based invertebrates. These spiders are also known as Nursery-web Spiders as the surrounds of the nest are clothed in silk strands, which the spiderlings use to get around and eventually to climb to a high position in order to balloon away. The mother is very attentive and will stay to extend the nursery-web strands and protect her young until they (en-mass) take their leave.