''Megadolomedes'' is a genus of

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

in the family

Pisauridae Nursery web spiders (Pisauridae) is a family of Araneomorphae, araneomorph spiders first described by Eugène Simon in 1890. They resemble wolf spiders (Lycosidae) except for several key differences. Wolf spiders have two very prominent eyes in ad ...

. The genus contains only one species, ''Megadolomedes australianus'', commonly known as the giant water spider. It is one of Australia's largest spiders, with a legspan of up to 18 cm. Found near creeks and ponds, it is capable of running on water. Food includes small fish, tadpoles and aquatic insects. Air is trapped on body and leg hair, allowing them to stay underwater for long periods of time. German naturalist

Ludwig Carl Christian Koch Ludwig Carl Christian Koch (8 November 1825 – 1 November 1908) was a German entomologist and arachnologist. He was born in Regensburg, Germany, and died in Nuremberg, Germany. He studied in Nuremberg, initially law, but then turned to medic ...

described the giant water spider as ''Dolomedes australianus'' in 1865, from a specimen collected in Wollongong.

References

Pisauridae Spiders of Australia Monotypic Araneomorphae genera {{Pisauridae-stub