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Trapdoor Spider

Antrodiaetus pacificus


It is a fairly large species, females ranging from 11 to 13 millimeters in length, males slightly smaller. They are generally dark brown to almost black in color with the abdomen purplish brown. Males are characterized by their long legs, slim bodies, and three tergites (hardened plates) on the abdomen. Females are more robust with only one tergite.


These spiders excavate burrows in the soil or in damp, rotten wood, digging with a row of spines on each chelicer, known as a ratellum. The six to ten inch deep vertical shafts are lined with silk. The webbing extends beyond ground level as a short collar of camouflaged silk. The turret’s two sides may be drawn in by the occupant, forming two "doors" which meet in the middle.


Information taken from "Tarantulas in the Pacific Northwest," Washington State University.

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1 Comment

NevilleBlack 11 years ago

We have trapdoor spiders?! đŸ˜²

Spotted by

White Rock, British Columbia, Canada

Spotted on Oct 31, 2012
Submitted on Dec 16, 2012

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