5 minutes with Dr Robert Raven, Arachnology

Today’s #CouchCurator is Head, Terrestrial Biodiversity & Senior Curator, Chelicerata, Dr Robert Raven. With a wide knowledge of invertebrate groups, including earthworms and snails, as well as some frogs, Robert heads the most active arachnological unit in Australia. In 2010, they celebrate that since 1976, staff and honorary associates have described over 1000 new species of spiders.

What is your favourite object/species in the collection and why?

Favorites with me change with each published paper. Bear in mind that spiders are quite unimpressive in the wet state that I normally work on them. At present, the residuum is a new species of Marine spider that lives on reefs in North Queensland and only tastes air about 4 times a year when the tides drop below 0.3 metre and the offshore reef at Port Douglas becomes exposed. We named it after Bob Marley for his song “High Tide, Low Tide” and that gave it series media attention: Desis bobmarleyi. It was also named one of the 10 legendary marine species for 2019.

At present, I am working on several projects. When one gets stuck for inability to access the collection or get loans, I switch to another project. Amongst those are the Australian tarantulas, the biggest of our spiders. A quandary exists among the giants on the north-east coast. Despite their size, several species look very similar and two that are challenging differ only the whether there is a third claw on the fourth leg. Amazing, given that two spiders of the other group holding my present attention, a new genus of Prowling spider containing 50 + new species, would comfortably fit in the leg of one tarantula and the differences between those species are many: big things don’t have to have big differences.

The tarantulas are exciting for a number of reasons not the least being their size and the challenges they present. Adding to this challenge, the spiders differ in subtle differs of coiffure to which I seem blind. Thus, I need to have photographs of lots of the live spiders and match them to their morphology. The only way we can do this is using their shed skins which present a perfect replica of their living morphology. So the exciting aspect of the “collection” then are the live tarantulas. We can also test our understanding of the species by seizing one by the leg with forceps; she will twist and break off the leg giving us fresh DNA and it will immediately start regrowing inside the spider reach its original size after 3 moults (3 years).

The applied importance of these spiders is that the venom is already under development for a more humane treatment of breast cancer; the venom molecules binds the cancer cells stopping them from dividing. Of course, like many of the spiders I am working on at present, their important role in conservation is especially significant as the animals are being taken in large numbers from the wild each year. Equally, the spiders themselves are capable of killing and partially eating cane toads without apparent poisoning. So the standouts in the pending collections (because unregistered, they are not part of the State Collection), are the living tarantulas.

Do you have any interesting facts about your specialty area?

I think the mens Magazine GW has a full list but as a WA Colleague once announced, “A good day is one spent looking at male genitalia (of spiders)”. The males of most groups (not tarantulas!) have different shaped genitalia for each species. In the spiders, the sperm transfer organ (palp) is indirect but is special for each species and is a modified claw on the very first pair of appendages. In some species of Daddy-long legs spiders, the male palp is bigger than the rest of the body.

Superlatives. We have the largest collection of Jumping spiders and tarantulas in Australia. Other superlatives are covered in the previous section.

Rarity is just a function of access, collection timing, season and rainfall. Probably one of the most sought after species belong to the funnel-web spider which I named Hadronyche anzses. These spiders are found at a highly remote site (over 1000 metres high) in North Eastern Queensland, so remote that a WWII plane was only discovered there in 1995. Our highly intrepid former curator and entomological legend, Dr Geoff Monteith, assaulted the climb and obtained some males while trapping insects. These spiders represent the most remote and isolated species of funnel-web with the nearest species being found 1000km to the south just west of Gladstone. The highly isolated location implies that the spider will have a very exciting venom and some years ago the BBC wanted to do an expedition back up there. My conservative estimate for the complex logistics then (basically impossible now), was that they needed to advance us a deposit of $25,000 to organize it; they begged our apologies and recanted.

I estimate that there are ____ species waiting to be formally described in my area…

A formally computed estimate is that the Australian spider fauna is only about one third known, about 3800 species of a likely 10,000. An indication of that untapped diversity is that at least 10 new species of spiders are known in the Greater Brisbane Area in 2020.

As I said, I have many new species on the production line, including tarantulas, funnel-webs,  and Prowling spiders.

Tell us a little bit about your area and why do you love working in this specific research area?

My focus groups are trapdoor, tarantula and funnel-web spiders, as well as a number of free-hunting “Modern” ground hunting groups including Prowling spiders (family Miturgidae). Finding new species is getting a bit passé at present; the real excitement for me lies in sorting out the ones that are named but “lost”. A large part of the original Australian spider holotypes are stored in the Hamburg museum, which through the almost unique foresight of the curator before WWII, were transferred to underground rail tunnels and thus survived. Some were lost and some were mislabelled and sorting out these mysteries. For example, one species (holotype lost) was listed as coming from King George Sound, SW WA but nothing resembling it has since been found there. However, similar species are found near King Sound, near Broome; thus it is assumed “George” was incorrectly added and it near Broome that we must focus our efforts in looking for a replacement holotype (neotype). These mysteries abound and there really is no greater pleasure in my research than figuring them out.

What is your favourite thing about your role at the museum? Why?

We are a focal point of knowledge. Having the skills we do, people contact us with their diverse discoveries (like Cane toad killing Prowling spiders and Wolf spiders) and thus we are like a powerful magnifying  lens, focussing the knowledge, greatly extending our eyes with the many inquirers, and feeding that knowledge back through our social media channels and the media.

What is one of the most interesting facts you have discovered through working at the museum?

A lady rang me about being bitten by a Flower spider; she was already very sick and wheel-chair bound, she could not walk. For the following two nights, the venom worked its way through her system generating slightly more exaggerated results because of her condition. On the third morning, she rose and could walk and her health was normal; a Lazarus effect. She was medically documented as being in full remission, albeit for 6 weeks. On checking with a pediatric specialist, Queensland Museum associate and former Honorary, Professor John Pearn, reported such things were not uncommon with ant bites; effectively, the autoimmune system does a full reset in response to the novel foreign protein. She kept the spider alive and got it to bite her again when the remission passed but alas she got no joy: it has to be a novel venom.

What is your favourite gallery/exhibition at the museum (current or past) and why?

A number of our natural history displays get remarkable responses and one of the one spectacular, apart from Spiders – The Exhibition, was Insects Alive. It was a free display of living insects and spiders built by a number of government departments and universities: in 6 weeks, it brought through 70,000 visitors. Our most surprising perhaps was BIG, a display cobbled together quickly to fill a gap in the program. It had animals ordered from small to big and was an amazing parade of our magnificent selection of mounted animals. The public love what we show them about natural history and Spiders rather upturned my understanding of how much.

Learn more

Interested in learning more about Dr Robert Raven? View his profile here.

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