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 celebrated that since 1976, staff and honorary associates have described over 1000 new species of spiders.

What is your favourite species in the collection and why?

Favourites 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, my favourite 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 Desis bobmarleyi after Bob Marley for his song “High Tide, Low Tide.”

At present, I am working on several projects. Amongst those are the Australian tarantulas, the biggest of our spiders.

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.

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.

How many species do you estimate are awaiting to be formally described?

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 with spiders?

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 is a lot of fun. 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.