Sydney’s famous funnel-web spider splits into three!

Reports of unusually large Sydney Funnel-web spiders from around Newcastle led an international team of scientists to take a fresh look at the Sydney Funnel-web, Atrax robustus. Expecting one new species, they instead ended up splitting the species into three!

Big, with a glossy black or dark brown carapace, these iconic spiders are simultaneously feared and revered. The venom of male Sydney Funnel-webs can kill an adult, and thirteen deaths have been attributed to this species between 1927 and the early 1980s. Then life-saving antivenom was introduced and there have been no deaths since.

Reopening the case

Former Australian Museum scientist and funnel-web expert, Dr Mike Gray was aware that the Sydney Funnel-web was quite a variable species, including some giant specimens found in the Newcastle area, but it was difficult to pin down whether this variation meant anything and when he redescribed the species in 2010 Dr Gray decided to keep it as one. But when our international team of researchers from the Leibniz Institute for the Analysis of Biodiversity Change in Hamburg, Germany (LIB), the Australian Museum and University of Sydney in Sydney, and Flinders University in Adelaide ‘reopened the case’ on the Sydney Funnel-web, we looked at gene sequences in combination with fine morphological details from specimens across the region and we found the species split into three distinct groups. This gave us the information we needed to understand which characters allowed us to tell them apart. We have now characterised these three and designated each as a separate species. But if we have three species, are they all just as dangerous? And does the same antivenom work?

The good news is that the current antivenom is already effective against a wide variety of funnel-web spider bites, not just our Sydney funnel-webs, but also other related species that can cause serious envenomation in eastern Australia. Our new findings may help to make the antivenom even better. Each species is likely to have a different composition of venom peptides and now we have recognised the three species, venom researchers will be able to characterise the venom of each one separately. This is a pivotal opportunity for scientists to gain new understanding of these venoms and in the future, it may allow ‘fine tuning’ of antivenom production.

Where are they found?

So where are our three species found? Starting with the ‘true’ Sydney Funnel-web, Atrax robustus, we first had to know which of the three this name belonged to. The reference, or type, specimen — the ‘name-bearer’ for this species — is a female spider stored in the Natural History Museum in London. Our team were allowed to dissect this unique specimen so we could match it to our newly examined and genotyped specimens based on fine internal details. Now we can say that Atrax robustus occurs from the Central Coast south to the Georges River, extending as far west as Baulkham Hills near the southern end of its distribution. Although a few records are also known from the Blue Mountains and Wollongong, the heartland for the Sydney Funnel-web’s distribution really is where we always thought, in the leafy northern suburbs of Sydney — no name change there thankfully!

Next is the Southern Sydney Funnel-web, Atrax montanus. This species was described in 1914 but was later considered to be the same species as Atrax robustus. The distribution does overlap with A. robustus and the two species look extremely similar, explaining why genetics backed up with fine internal details were needed to sort out which is which. This species co-occurs with the Sydney Funnel-web in some areas but overall has a much wider distribution, from the Watagans south west of Newcastle south to Bowral in the Southern Highlands and west to the upper Blue Mountains.

The rarest of the split species has never had a scientific name before, the Newcastle Funnel-web, Atrax christenseni. You may recall some news stories of ‘giant’ Sydney Funnel-web spiders handed in to the Australian Reptile Park for the venom milking program. Well, those so called “Big Boys” are this new species. The Newcastle Funnel-web seems to be restricted to an area within about 25 km of the City of Newcastle, 110 km to the north of Sydney. Unlike the other two species, male A. christenseni spiders can be distinguished with a good photograph by the extra-long male mating organs, or pedipalps. The species is named in honour of Kane Christensen for his dedication to documenting aspects of funnel-web behaviour and collecting specimens for our study.

We infer from distribution data that each of these three Atrax species has been associated with serious envenomation in the past—and the currently produced antivenom works for an even wider variety of funnel-web spiders than these three species. Importantly, there is no change to the first aid message — if you think you may have been bitten by a funnel-web spider it is a potential medical emergency — do your first aid and urgently seek medical attention. The need to collect male spiders for antivenom milking at the Australian Reptile Park has not changed — if you know you can safely collect, please carry on as before! Locality data for any funnel-webs was always important and has just got a lot more so.

Our icon has been silently declining

While the safety messaging surrounding funnel-web spiders has not changed, our research has also uncovered a worrying reduction in the range of the iconic ‘real’ Sydney Funnel-web that is strongly linked to loss of habitat. Densely populated areas of Sydney where our museum records show there used to be funnel-webs are now curiously devoid of recent records. Widespread decline is almost certain, and local extinction of some populations is highly likely. Citizen scientists on iNaturalist and amateur spider experts have done superb work in recording exciting creatures like funnel-web spiders. Intriguingly, those records now show significant blank areas when compared with the maps that include historical Australian Museum specimens in our paper.

Illegal trafficking

The new Newcastle Funnel-web may also be of conservation concern. There is a huge and largely unregulated trade in Australian invertebrates. The Newcastle Funnel-web is a relatively large species, newly described and has a restricted distribution — just what unscrupulous collectors might target. For this reason, we have avoided giving detailed data for collecting sites in our paper.

Why worry about decline in funnel-webs? Why not be glad that there are fewer, possibly lethal, creatures? Funnel-webs are amazing creatures whose ancestors have been around for millions of years — far longer than humans, or even human-like apes have graced the planet. Do a bunch of settlers from overseas, unwittingly setting up their major township in the epicentre of the distribution of the deadliest spiders on earth, really want to destroy these extraordinary species?!

Seriously though, funnel-web spiders are an important part of our ecosystem. They are both predators and prey, little cogs in that complex machine of life that we still don’t fully understand. It is easy to avoid being bitten, and the invention of antivenom that has prevented deaths since its invention is a proud achievement. Millions of Sydneysiders enjoy seeing wildlife in their gardens and in the bush, including the exhilaration of observing a potentially deadly spider from a safe distance. We can celebrate that we can thrive whilst living alongside our notorious but thrilling spider neighbours. Cool!

• Funnel-web spiders factsheet
• Sydney Funnel-web spider factsheet
• Southern Sydney Funnel-web Spider factsheet
• Newcastle Funnel-web Spider factsheet
• Gray, M. 2010. A revision of the Australian funnel-web spiders (Hexathelidae: Atracinae). Records of the Australian Museum 62: 285-392. D.o.i. 10.3853/j.0067-1975.62.2010.1556
• Loria, S.F., Frank, SC., Dupérré, N. et al. The world’s most venomous spider is a species complex: systematics of the Sydney funnel-web spider (Atracidae: Atrax robustus). BMC Ecol Evo 25, 7 (2025). https://doi.org/10.1186/s12862-024-02332-0

• Drs Danilo Harms and Bruno Buzatto are indebted to National Geographic Society who generously provided an Exploration Grant that enabled this research. Dr Buzatto also thanks the Australian Geographic Society for sponsoring some of the field work and Dr Harms the Australian Museum for a Research Institute Visiting Research Fellowship that allowed for collections and field work.
• Lead author, Dr Stephanie Loria was supported by the German Science Foundation.
• Thank you to Kane Christensen for his part in collecting and informing the team, Dr Matt Shaw for facilitating identification of the type of Atrax montanus and Cynthia Chan, Harry Leung and the late Ron Lovatt for assisting with photography of this same specimen.