Species Profile: Six-Spotted Fishing Spider

There are over 43,000 species of spiders across the globe, about 3,400 of which are found in North America, and 729 confirmed to be found in BC. Spiders are one of the smallest creatures to instil such great amounts of fear in people. The species of nursery web spider that will be the focus of this week’s Species Profile should be feared, and is rather quite fascinating!

Dolomedes triton is also known as the six-spotted fishing spider, so named for the spots on the underside of it’s body. It is also identified by a pale stripe running along each side of the grey or brown coloured body. As with many spiders species, the females are much larger than the males, up to 6 cm in length.

Dolomedes triton is considered semi-aquatic and appropriately named after the Greek god Triton, messenger of the sea. Common habitats include ponds, lake shores, and even slow moving streams. Other common names of this species include the “raft spider”, or “dock spider” as they are able to run on water, and are often found near vegetation, rocks, or structures on or near water (such as docks). Dolomedes triton is common throughout southern Canada, the US, and Central and South America.

The six-spotted fishing spider hunts by anchoring its rear legs to a surface and spreading its forward legs onto water where it awaits stimulation, similar to how other spider species might practice on a web. Dolomedes triton eats other invertebrate insects, as well as tadpoles and even small fish! They are also able to move under water by crawling along plant stems and leaves. This behaviour is for catching prey and escaping predators.

taken by our friends at the Creston Valley Wildlife Management Area
Photo taken by our friends at the Creston Valley Wildlife Management Area

Dolomedes triton is of the family Pisauridae, or the nursery web spiders, which characteristically build a nursery tent over and amongst vegetation to protect their egg sac. Another interesting fact about nursery web spiders is that, similar to most spider species, females are known to eat the male after mating. To prevent this act of cannibalism, male nursery web spiders often present the females with an insect gift to satisfy their mates hunger.

Here is a link to the photo by our friends at the Creston Valley Wildlife Management Area which inspired this Species Profile.

Here is a link to a neat video of a six-spotted fishing spider catching a small fish.

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Banner image taken from WikiCommons.

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