Intertidal trapdoor

Fact Box Species: Idioctis yerlata (QM) Family: Barychelidae Body length: female: uncertain; about 20 mm male: uncertain; about 18 mm Habitat: This species builds a burrow with a door in intertidal rock cavities on the northern coastline of Queensland. It presumably catches its prey only when the tide is out Toxicity: Uncertain; like other members of the same family this spider may have quite toxic venom so handle with caution

Burrow entrance Its habitat Above and below Some features

This spider is not easily identified by the non-expert and is likely to be misidentified as a 'true' trapdoor belonging to the Family Idiopidae. However, while it has a similar shape and colour as well as the short, stubby spinnerets of the Idiopidae it is distinguished from them by the presence on the end of each leg of a pair claw tufts, although these are not as obvious as they are on many other barychelids.

Another important distinguishing feature of Idioctis yerlata is its habitat. There are few, if any, other Australian mygalomorph spiders that construct burrows in intertidal marine habitats. I. yerlata depends on a neatly fitting door to keep the water out of its burrow when the tide comes in and submerges the burrow entrance. First discovered on the eastern coastlines of North Queensland it has now been found as far south as Airlie Beach and its range may therefore extend even further south than this.

Known Range: This unusual intertidal spider may be found on suitable beaches from Cairns to Rockhampton but is never present in large numbers.

Spider(s) with a very similar appearance: Some other barychelids but also idiopid trapdoors such as Euoplos species.