Scientists Resolve “Identity Crisis” for Australia’s Deadliest Spider

The research team used a combination of anatomical and molecular (DNA) comparisons to study different populations of Sydney funnel-web spiders, documenting distinctions indicating that three species should be recognised—the “classic” Sydney funnel-web (Atrax robustus), found from the Central Coast and throughout the Sydney Basin, the Southern Sydney funnel-web (Atrax montanus), which is most common in the Blue Mountains south and west of Sydney, and the Newcastle funnel-web, playfully dubbed “Big Boy” by spider lovers, the largest of the three, which occurs only in the vicinity of the city of Newcastle, north of Sydney.

“Our research uncovered hidden diversity among funnel-web spiders,” noted lead researcher Dr Stephanie Loria of the LIB. “The Newcastle funnel-web, Atrax christenseni -‘Big Boy’- is a totally new species. The ‘true’ Sydney Funnel-web, Atrax robustus centres on the North Shore of Sydney and the Central Coast, and the Southern Sydney Funnel-web, Atrax montanus is a resurrected species name from 1914,” Dr Loria said.” None of these insights would have been possible without the use of historical collections and international collaboration.”

Dr Helen Smith, an arachnologist (spider biologist) at the Australian Museum and one of the authors of the research, explained that though the Sydney Funnel-web was previously known to be variable in some of its characteristics, this variability had been difficult to analyse.

“When our international team of researchers ‘reopened the case’ on the Sydney funnel-web, we looked at fine morphological details and gene sequences across the region and found the species split into three distinct groups.”

“We can now say that Atrax robustus [the “true”, or original Sydney funnel-web] mainly occurs from the Central Coast, NSW, south to the Georges River, extending as far west as Baulkham Hills. The heartland for the Sydney funnel-web’s distribution really is where we always thought, in the leafy northern suburbs of Sydney,” Dr Smith said.

Arachnologists Dr Danilo Harms from the LIB, and Dr Bruno Buzatto from Flinders University, began these comparisons after learning that unusually large funnel-web male spiders had been brought to Mr Kane Christensen, who was then based at the Australian Reptile Park, NSW, as part of its Venom Program. These large spiders all came from Newcastle, a city 150 km north of Sydney.

Investigating further, the research team collected new specimens of funnel-webs from throughout the Sydney region, focusing on their DNA. They also compared newly collected spiders with older specimens in the Australian Museum collections dating back to the early 1900s.

Dr Danilo Harms, co-lead author, said the revised taxonomy for funnel-web spiders may have practical implications for antivenom production and biochemical studies on spider venoms.

“Since 1981, the Australian Reptile Park, situated in Somersby, NSW, has run a Venom Milking Program to gather venom from Sydney funnel-web spiders for antivenom production,” Dr Harms explained. “Although no human fatalities have occurred since the development of antivenom in the 1980s, the antivenom for Sydney funnel-web spiders might be optimised by considering biological differentiation at the species level,” Dr Harms said.

Nevertheless, the current antivenom remains effective not only against all Sydney funnel-web spider species, “but also other related species that can cause serious envenomation in eastern Australia”, Dr Smith said.

Director, Department of Clinical Toxicology, Calvary Mater Newcastle, Professor Geoff Isbister said that funnel-web envenomations are mostly from bites by male spiders that wander from their burrows in search of females during the mating season. “While funnel-web bites are the most severe among spiders, they are not very common. If you are bitten by a funnel-web spider, call an ambulance and go straight to the hospital,” Professor Isbister said.

Chief Scientist and Director, Australian Museum Research Institute (AMRI), Professor Kris Helgen said spiders are impressive animals with incredible adaptations, including keen senses, spun silk, and a highly effective venom injection system.

“Spiders are older than the dinosaurs. In more than 300 million years of existence, they’ve mastered nearly every environment on Earth and play a vital role across global ecosystems. And they are astonishingly diverse—there are about 52,500 known living spider species, and potentially many more to discover,” Professor Helgen said.

“The Australian Museum has one of the world’s great spider collections, and has supported generations of spider researchers. We have hundreds of thousands of spider specimens. About 4,000 of these are funnel-webs of one kind or another, including the original male Sydney funnel-web that was responsible for the first recorded fatality. This new research, which relies on these collections, showcases their scientific importance and the insights that come from studying museum specimens in a thoroughly modern way—through international scientific collaboration and with cutting-edge approaches,” Professor Helgen added.

Dr Smith suggested naming the newly identified species from Newcastle after Kane Christensen, a huge fan of spiders who brought the species to the team’s attention.

“Kane has been instrumental in the identification of this new species, collecting specimens so that we could do further analysis as well as shooting terrific photos of our ‘Big Boy’. To show how much Kane’s work meant to us, we have called it Atrax christenseni. We named it after him,” Dr Smith said.

Acknowledging this honour Mr Christensen said he was thrilled to have a funnel-web species named after him.

“Atrax christenseni is a superb and impressive funnel web. The sheer size of the males, compared to the males of the other Atrax species is simply astounding. I am very passionate about funnel-webs and there is no greater compliment than to have another scientist name a funnel-web species after me. I am deeply honoured and accept it with great pleasure,” Mr Christensen said.

“I would also like to offer my sincere thanks for the help and encouragement from the Australian Museum, and Dr Buzatto, as well as the Australian Reptile Park for the opportunity to work on their funnel-web antivenom program. It has been a privilege and a joy to help shine a light on one of Australia’s formidable species, our feared and revered, funnel-web,” Mr Christensen added.