Two new species of trapdoor spiders discovered in Western Australia

A team of scientists led by The University of Western Australia has discovered two new species of trapdoor spiders in the Kimberley region

A team of scientists led by The University of Western Australia has discovered two new species of trapdoor spiders in the Kimberley region, marking the first time members of the species have been found in northern Australia.

The newly identified arachnids - Kwonkan fluctellus and Kwonkan nemoralis - were described in a paper published this month in the Australian Journal of Taxonomy, expanding scientific understanding of Australia’s unique spider fauna.

Lead author Dr Jeremy Wilson, a postdoctoral research fellow in UWA’s School of Biological Sciences and research associate with the Western Australian Museum, was part of the group that found them during an Australian Government-supported Bush Blitz expedition to the remote northern Kimberley in 2022.

“We didn't discover these spiders in the typical dry savannah landscapes the Kimberley is known for, but instead the specimens we found of Kwonkan nemoralis, which grows to around the size of a 20-cent coin, were located deep within a gorge that shelters patches of richer forest,” Dr Wilson said.

Image: About the size of a 20 cent piece... the Kwonkan nemoralis. Photograph: Dr Jeremy Wilson

“These wetter forest patches are quite small and usually sheltered by the gorge so when you enter them, it’s a completely different environment - much more humid, with a different collection of plant species.”

According to Dr Wilson, what makes the spiders fascinating is their highly specialised burrow construction.

“Unlike most related species that build simple open entrances to their burrows, spiders of the Kwonkan genus create elaborate burrow entrances with unique features,” Dr Wilson said.

“We were exploring along a small creek when we noticed distinctive circular burrows in the sandy banks.

“The burrows constructed by the Kwonkan nemoralis had a little collapsible silken collar around the entrance, which had grains of sand embedded in it and were unlike anything we’d seen before - clever engineering that serves multiple functions.

Image: Master architect... the silken collar around the spider's burrow. Photograph: Dr Jeremy Wilson

“When disturbed, the collar around the burrow’s entrance collapses and seals the entrance, while the sand blends perfectly with the surrounding landscape, making it virtually invisible to predators.

“One question we’re particularly interested in is why they build these unusual, modified entrances and whether they may be adaptions to specific hunting strategies, or for defending against predators such as scorpions, centipedes and wasps, which we know hunt these spiders.”

Dr Wilson said the design may also protect the spiders during unexpected flooding events in arid areas.

The discovery of the two new species contributes to Taxonomy Australia, a national initiative under the Australian Academy of Science that aims to document Australia’s biodiversity within a generation.

Photograph at top of page: Rainforest found in sheltered regions of the gorge. Photograph: Dr Jeremy Wilson