Introducing the Nadgee Funnel-web

November 10, 2021 Kerri-Lee Harris & Paul Whitington

Having first sighted this strange little spider during the Winter of 2018, it now has a name:
Hadronyche nadgee Whitington & Harris 2021

This is an exciting find, both for us personally and for Australian spider taxonomy. The Nadgee Funnel-web is so different to its 35 cousins that it redefines what it means to be an Australian funnel-web.

We have recently published a formal description of the species in the scientific journal Records of the Australian Museum.

The paper is based on the nine male spiders that we collected here in the forest during the winters of 2020 and 2021.

CLICK TO DOWNLOAD PAPER FROM THE AUSTRALIAN MUSEUM

We named the species in recognition of the nearby Nadgee Nature Reserve, a very special wilderness that holds particular significance for us.

Nadgee Wilderness Area. It was at the end of a hike north from Victoria and through Nadgee in 2003 that we settled on the place we wanted to live in retirement … just a few kilometres north from the hilltop where we took this photo in 2013.

There is something wonderful about describing a new species. The sense of discovery. The satisfaction of piecing together a puzzle. The knowledge that this is a small but lasting legacy.

It is safe to say that this spider has been here for tens (perhaps even hundreds) of thousands of years – so no doubt it has been seen before. Indeed, it may have long been known to the region’s First Peoples. Now, with a globally-recognised name and description, we can share and build our collective knowledge of the species. And this particular species may prove pivotal in understanding the evolution of Australian funnel-web spiders. It is a privilege to contribute to the story.

1: the spider

What do they look like?

Up close, Hadronyche nadgee is recognisably a funnel-web. Those massive, downward thrusting chelicerae. That shiny, wide carapace with a transverse groove. The tight cluster of small eyes. Two pairs of short spinnerets. And a reared pose when disturbed, fangs exposed and dripping venom.

But in comparison with its infamous cousin Atrax robustus, Hadronyche nadgee is small, pale, and delicate.

This is the smallest atracid species described to date. The carapace is less than 5mm long – Atrax robustus is more than twice that. But then again, most funnel-web species are small compared to Atrax robustus. Of particular relevance are several small, northern species, with which Hadronyche nadgee shares some other characteristics.

We don’t yet know exactly what the female Hadronyche nadgee looks like. So far we have found only males. Females don’t wander and so we will need to seek them out. They are likely to be similar to the males in most key features, but will probably be a bit bigger. Among the atracids, females are typically larger than their male counterparts.

Are they dangerous?

A bite is certainly best avoided. The Sydney Funnel-web Atrax robustus is said to be the most venomous spider in the world. Bites by funnel-web spiders resulted in 14 reported deaths between 1927 and 1980, when an antivenom was developed for clinical use.

All of those fatalities were attributed to bites from Atrax robustus. However, it is almost certain that other Atrax and Hadronyche species are as venomous as Atrax robustus. Bites from at least 5 Hadronyche species have caused serious illness in humans with a similar envenomation syndrome to Atrax robustus.

A single molecule has been shown to be responsible for the envenomation effects of funnel-web spiders. It is a short protein (a peptide) dubbed delta-hexatoxin (δ-HXTX). δ-HXTX exerts its effects by binding to sodium channels in nerve cell membranes. It inhibits the closing of those channels, which is a normal part of the conduction of electrical signals in nerve cells. As a result, nerve cells fire for longer than normal.

The sequence of amino acids in δ-HXTX has been determined for 10 species of funnel-web spiders and it is surprisingly similar across all of those species. So it’s likely that Hadronyche nadgee has a very similar peptide.

The lethal effects of δ-HXTX appear to be restricted to primates, including humans. Non-primate vertebrates such as rodents, dogs and cats only show symptoms when injected with massive doses of the spider’s venom. The reason for this is unknown. It’s probably just an unfortunate (for us) evolutionary accident. Certainly funnel-web spiders didn’t evolve their venom to kill humans or other primates! For a start, funnel-webs evolved millions of years before primates, let alone humans, made an appearance on earth.

While it isn’t venomous to small rodents, recent work suggests that the funnel-web δ-HXTX may act to deter these animals if they’re looking to make a meal of the spider. The peptide elicits a specific pain response - mice flinch and lick the hind limb following a shallow subcutaneous injection of the peptide into the footpad.

δ-HXTX isn’t even particularly venomous to insects such as flies and cockroaches. A range of other peptides in the venom are however deadly to the spider’s insect prey.

How long do they live?

Many years, even decades. Mygalomorph spiders, the ancient lineage to which funnel-webs belong, are famously long-lived. The average lifespan of pet tarantulas is 20-30 years. An identified female trapdoor spider in Western Australia, living in the wild, recently died at the age of 43 years!

Female funnel-web spiders can also live at least 20 years, and a very large, log-dwelling female Hadronyche found near Jervis Bay in 2015 was estimated to be 25-30 years old. It may be that with sufficient food, a stable environment, and no predatory attack, a female could live even longer. In contrast, Atrax males mature at 5 years and then die within 9 months. Other atracids are probably similar.

So the Hadronyche nadgee males we collected were almost certainly several years old, and would not have lived too much longer – particularly if they were lucky enough to find a female. However, we are guessing to some extent. There are remarkably few studies into the life histories of funnel-web species, and of course nothing has been written about Hadronyche nadgee. This might be something we undertake in the future … it could be time to adopt some new pets!

Where do they live?

In burrows, but precisely where remains a mystery. The males we found were wandering, and so we don’t yet know where they came from. Based on what is known about other atracids, they would have lived in silk-lined burrows in the soil (as do Atrax species), within rotting logs (as do some Hadronyche), or perhaps within the crevices of standing trees (as do two Hadronyche species). Following their final moult, at sexual maturity, they would have abandoned their burrows to live as vagrants while seeking mates. They’d need temporary daytime retreats to avoid desiccation and to hide from predators, perhaps under rocks or logs.

In contrast, female atracids never venture far from their burrows and they never move house. Throughout their long lives they simply remodel their burrows to accommodate their increasing girth. Again, this is based on observations of Atrax … we know nothing at all about female Hadronyche nadgee, as we have yet to see one!

Are all funnel-webs Australian?

The family Atracidae is only found in Australia. While the most famous of these is Atrax robustus, the Sydney Funnel-web, there are (now) 36 named species currently grouped into three genera: Atrax, Hadronyche and Illawarra.

Confusingly however, there are other mygalomorph spiders called funnel-webs … highlighting the problem with common names. Macrothelidae is a family of spiders found mostly in Asia but with a couple of European species too. So while the Macrothelidae are called ‘funnel-web spiders’ and superficially resemble Australian funnel-web spiders, they are not the same. Detailed morphological studies and recent molecular research show that the Macrothelidae are quite distinct from Atracidae. Indeed, Australia’s mouse spiders, the family Actinopodidae, are now believed to be the atracids’ nearest cousins.

Atracids are largely restricted to south-eastern Australia with just a couple of exceptions: one species from far north Queensland and three from South Australia. Most have quite a limited distribution. For example, Atrax sutherlandi is only known from south-eastern NSW and the north-east corner of Victoria, while Hadronyche modesta seems restricted to Melbourne and the Dandenong Ranges region.

Is this the only local funnel-web?

There are two funnel-web species already known from our local area – Atrax sutherlandi and Hadronyche nimoola. Now Hadronyche nadgee makes three!

Hadronyche cerberea, a relatively widespread species, has been found in the southern highlands but has not been recorded here near the coast.

2: the discovery

How did you find it?

Totally by chance. We’re interested in all forms of life here in the forest. We are constantly on the lookout, usually with cameras in hands. Most of our observations are made during the day, opportunistically as we wander about. But now and then we venture out after dark, particularly in the region close to the house where moths and other insects gather at lights.

It was on such a night, during the Winter of 2018, that we first spotted the Nadgee Funnel-web. At the time it was one of several mygalomorph spiders out and about – including another funnel-web (Hadronyche nimoola) and several spiny trapdoor spiders (Arbanitis sp). All were males, suggesting conditions were perfect for mygals seeking a mate. Raining and cold, so no risk of dessication … low humidity spells death for these spiders.

Back then we didn’t realise the significance of the sighting. We couldn’t readily identify him and so he remained our ‘mystery mygal’. The sighting did, however, further encourage us outside on wet winter nights. In May 2020 we were again in luck. Four little males, all alike. We collected them for study – and at that point we realised it was indeed something special. In June of 2020 and 2021 we found another five – all males, all in the same area and always on rainy nights.

How did you know it was a new species?

It did not match any published descriptions. With the spiders in the hand we could take a closer look at the key features used to distinguish the various mygalomorph spiders. We were able to exclude all other mygal families (such as the trapdoors, tarantulas and mouse spiders) based on obvious differences. This convinced us we had a funnel-web, family Atracidae. It matched the family level description in all but one key feature … it was missing one of the two cheliceral teeth rows diagnostic for Atracidae. All known atracids have two rows of teeth on the underside of each chelicera – but all nine of our little spiders had just a single row. The species was clearly unique, the difference both unambiguous and significant. The sparse cluster of cuspules on the labium (‘lower lip’) is also a distinguishing feature.

How long have they been here?

A very, very long time. Judging by studies of other funnel-web spiders, this species probably evolved hundreds of thousands of years ago! It has seen ice ages come and go, forest environments change, and almost certainly predates humanity in this part of the world.

How have they remained undiscovered for so long?

Funnel-web spiders are cryptic, rarely leaving their burrows. Few people live in this region so there is small chance of an accidental encounter. Forestry workers are perhaps the most likely to disturb the spiders in recent times, but they probably don’t notice. The spiders are really quite small.

Other people will have seen these spiders before us – although perhaps not very many people, and not often.

We are confident that this species has rarely been collected. Museums contain hundreds of funnel-web spider specimens, some dating back to the 1920s and 1930s, deposited by scientists, collectors and the wider public. Researchers familiar with these collections alerted us to just a single, unusual, unidentified male specimen they considered a candidate … we can now name it Hadronyche nadgee. It was collected in 2006 from forests near Brogo, 70km to our north.

Did you have to kill them? Did this concern you?

We believe it was justified – it was certainly necessary in order to describe the species.

Our general philosophy is to tread lightly on the environment. But we also believe that knowledge of biodiversity is important. Living in such a natural environment we have quite a unique opportunity to document the plants and animals that surround us, their interactions, and responses to events such as wild fire. We photograph everything and aim for minimal disturbance – but sometimes a photo in the field is not enough.

It was necessary to collect these few spiders in order to show that they are indeed a new species. We needed to have them under the microscope, and it was important to have several animals to gain a sense of individual variability in features such as size and number of spines.

We treated them sensitively and trust that they didn’t suffer. After taking various live shots the spiders were housed in humid, dark containers for a few hours observation, before being euthanised. We placed them in the freezer for at least 24 hours before submersion in 100% ethanol. There is no consensus in the research community on the most ethical way to euthanise invertebrates. However, lowering the body temperature before chemical preservation is a widely accepted method.

And their remains have not gone to waste. Whenever a new species is published, it is a requirement that the individual animals upon which the description is based (the ‘type’ specimens) are deposited with a reputable scientific institution. Having completed our studies, the nine preserved specimens are now lodged with the Australian Museum in Sydney and the Queensland Museum in Brisbane. They are ‘held in trust for science’ (ICZN), and remain available for researchers into the future, whether for morphological comparison or genetic analyses.

Why does the accurate identification of species matter?

How can we effectively monitor or predict our impact on ecosystems without first knowing what animals, plants and other organisms are out there?

Healthy ecosystems are critical to life on earth, including human life, and ecosystem health is dependent upon its myriad organisms. So if we are to live sustainably on this planet, humanity must understand the effects our activities have on the natural environment.

Australia is wealthy, scientifically advanced, biologically rich – and yet 70-80% of Australian insects and arachnids remain undescribed.

That’s why we believe the study of biodiversity matters. It’s one of the reasons we do what we do.

3: describing a new species

Is it common to find an undescribed species?

Yes, particularly in Australia. It is estimated that as few as one in three of Australia’s spiders have been formally described and named. The ratio for several mega-diverse insect groups – beetles, flies, wasps – is even lower, at around 20-25%. So finding an unnamed spider or insect is not unusual, but the next steps involve considerable effort … plus a whole lot of luck.

Can anyone describe a new species?

In principle, yes. However, this involves much more than simply choosing a name. The species must be described in sufficient detail to prove that it is different to all other species, and that documented proof must convince recognised experts in the field. This means publication in a credible, peer-reviewed, scientific journal.

To prove a species is new, and to identify its closest relatives, requires considerable detective work. The scientific literature holds the key, but unlocking that can be daunting for those new to scientific research. It demands a fearless approach to technical language, an appreciation of discipline-specific conventions, and an understanding of the very nature of the scientific process itself.

We drew heavily upon our scientific training and experience in biological research, yet were unfamiliar with the intricacies and norms of taxonomic study and writing. The past few months have taught us much – knowledge that we are sure to put to use again.

There is also a good deal of luck involved. To be confident a species is novel relies upon information about other, related species. For many types of insects and spiders there is simply too little known. It isn’t possible to describe just one species in isolation … you need to study the entire suite! All similar, unnamed species must be examined and described collectively. Related, previously named species may also need to be redescribed and reordered. It can be a huge task, and one that is definitely the province of specialist taxonomists.

We were indeed lucky. Not only are Australian funnel-web spiders a relatively small group, but they have undergone a thorough and recent taxonomic review. In 2010 Michael Gray published a complete revision of the family. He examined hundreds of unnamed funnel-web spiders from museum collections and described 21 new species in the process. Gray’s 112-page treatise gave us the confidence that our spider was indeed new … none of the other funnel-webs have just a single row of cheliceral teeth. Gray’s work also provided us with a template for describing our spider … what features to measure, count and photograph.

How do you choose a name?

Despite what is popularly assumed, not by naming it after yourself! Although not strictly prohibited under the International Code for Zoological Nomenclature (ICZN), honouring yourself with a species name is generally considered rather poor form.

The inspiration for a name can be commemorative, descriptive, geographic – or even nonsense.

Authors have taken a variety of approaches to naming Australian funnel-web spiders. Below are a few examples.

Of the 21 new species described by Gray (2010) in his landmark revision of the family, 8 are geographic. It therefore seemed appropriate to name our species after a relevant location. We chose to recognise the nearby Nadgee Wilderness.

And remember that other novel species we found here? The tiny wasps that emerged from a caterpillar? Although we didn’t describe that species ourselves, the authors kindly invited us to suggest the name. Again, we chose one based on geographic location of the type specimen. Cotesia wonboynensis Fagan-Jeffries & Austin 2020 … meaning ‘from Wonboyn’.

But inspired creativity alone is not enough. The ICZN specifies the principles and rules that guide and govern the naming of animals. A similar but distinct code applies to plants.
In essence, the ICZN states that:

The two-part name must be unique. No two animals can have the same ‘full’ (Genus species) name. For example, there are other Hadronyche …. that is the nature of a genus. And there are other animals with nadgee as the second part of the name, the ‘specific epithet’. There is even a spider named Nosterella nadgee. But there was no other animal called Hadronyche nadgee … until now.
The name must be ‘Latinised’. The alphabet used must be Latin, which is the alphabet in use today for some languages (e.g. English, French) but quite different to that used by much of the world (e.g. Chinese, Arabic, Greek). As Latin is an inflected language, word meaning is determined by varying the ending, and the gender of the species epithet must match that of the genus. This can all be a bit intimidating, so we are very glad that Paul studied Latin and is fluent in German, another inflected language.
We were able to use the name nadgee, without modification, by applying it as ‘a noun in apposition’, rather than as an adjective.
The specific epithet is all lower case, must be more than one letter and have no hyphens etc. That’s simple.
Ideally, the name should be ‘appropriate’. The ICZN recommends that “as far as possible, they are appropriate, compact, euphonious, memorable, and do not cause offence” (Article 25). We believe nadgee is all of these.

Authorship

This is another aspect of the species name worth mentioning. In scientific publications the binomial species name should attribute the original author. For example, the Eastern Grey Kangaroo is properly named Macropus giganteus Shaw, 1790.

In the first paper describing a species it is designated ‘new species’ or a Latin equivalent such as ‘species novum’. So, in our paper we write Hadronyche nadgee sp. nov. – but in all subsequent works the species will be referred to as Hadronyche nadgee Whitington & Harris 2021. In posterity!

4: what next?

The obvious next step is to find the female. And to learn more about the site of their burrows … are they in soil, under rocks, in rotting logs, or standing trees? And how widespread are they? Perhaps photos online will uncover sightings previously unidentified, or misidentified.

The publication of the species description is simply the first step in learning more about the Nadgee Funnel-web.

Our thanks

The realisation that we had discovered a new species of funnel-web was exciting, but undertaking to write the paper brought a complex mix of emotions. Neither of us trained as taxonomists. The challenge was enticing, and we believed it was important, but could we do this? Early on, the support and enthusiasm of three experienced taxonomists encouraged us to follow through. We thank Dr Erinn Fagan-Jeffries, Dr Michael Rix, and Dr Robert Raven for welcoming us into the taxonomic community.

Life in a Southern Forest