5 minutes with Sue-Ann Watson, Senior Curator Marine Invertebrates

Sue-Ann is Senior Curator, Marine Invertebrates at the Queensland Museum Network, based at the Museum of Tropical Queensland campus in Townsville. Her position is co-appointed with the Australian Research Council Centre of Excellence for Coral Reef Studies at James Cook University.

What is your favourite specimen in the collection and why?

At Museum of Tropical Queensland we have a very large giant clam shell. This is my favourite specimen in our collection because of its large size and because giant clams are such unique animals. When we get the giant clam out for special events like World Science Festival Queensland people are amazed by its huge size and they often want to take a peek inside to see if there’s a pearl.

It’s even more fascinating to see giant clams in the wild in the ocean! The Great Barrier Reef is one of the world’s strongholds for giant clam species, which are fully protected here. In other areas of the Indo-Pacific region, giant clams are harvested for their meat and shells, and for the ornamental aquarium trade. Overexploitation has led to giant clams being listed on the IUCN Red List of Threatened Species and some species are extinct in former areas of their natural range.

True Giant Clam, Tridacna gigas.

Do you have any interesting facts about your specialty area?

I work on marine invertebrates (animals without a backbone) that make limestone (calcium carbonate) shells and skeletons. One of these groups of shelled marine invertebrate are molluscs, a diverse group that includes clams, snails and squid. Here are some facts about molluscs.

Did you know that just like you can age a tree by counting the growth rings in the tree trunk, you can age a clam by counting the bands on its shell? Some clams live to be hundreds of years old – in fact one cold-water clam holds the record for the longest lived non-colonial animal ever recorded at 507 years old.

Cuming’s Crassatellid Clam, Eucrassatella cumingii.

Shells are windows to an animal’s past, not only can they tell us how old the animal is, they also contain information about the environment in which the animal grew, such as the temperature and potentially the pH and carbon dioxide levels of the ocean. Examining shells can also tell us whether the animal has had any injuries, including if it’s been attacked by shell crushing predators, and when in its life this happened.

The largest shell in the ocean is made by the True Giant Clam, Tridacna gigas, which can weigh over 250 kg and grow to 1.3 m long. This species has a predicted maximum lifespan of about 100 years.

Did you know on the Great Barrier Reef we also have jumping snails? We’ve been tracking their responses to global change such as rising seawater carbon dioxide levels and subsequent ocean acidification. We found that ocean acidification alters behaviour, making them less likely to avoid their predators – venomous cone snails.

The world’s smallest squid are the Pygmy Squid. These charismatic little critters can be found in the waters around the museum in Townsville.

Tropical Pygmy Squid, Idiosepiu pygmaeus, eating shrimp.

I estimate that there are this many species waiting to be formally described…

There are potentially thousands, or even tens of thousands of new species of marine invertebrates to be discovered, especially in highly diverse tropical areas, less explored areas such as the deep sea, and where species are very small, such as micromolluscs (which can be the size of a grain of sand), so there is lots of work to do.

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

Marine invertebrates are incredibly diverse. Even closely related species have evolved many elegant solutions to life’s challenges including an array of specialised anti-predator adaptations (like jumping snails). The diversity of species and forms means there is lots of variety in the work, and researching across many different groups of marine animals is always interesting. Finding out new knowledge for the first time, like how certain species are likely to respond to a rapidly changing climate, is very exciting.

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

We have very unique collections of deep-sea marine invertebrates off the coast of Queensland. These waters, beyond the Great Barrier Reef, hold all sorts of weird and wonderful creatures. We have about 4000 deep-sea specimens, and just within this particular collection, there are many new species yet to be described. These are just a part of Queensland’s priceless state collection of specimens and objects. It’s a real privilege to look after them and work on them.

Deep Sea Angler Fish conserved as part of the Queensland Museum Network Biodiversity Collections.

What is your favourite exhibition at the museum and why?

Our “REDMAP Spot it. Log it. Then we’ll map it.” exhibition which ran until early 2020. This was an exhibition about citizen scientists tracking our changing climate. Queensland is a global warming hotspot, warming at twice the global rate. REDMAP (Range Extension Database & Mapping project) invites the Australian community to spot, log and map marine species that are uncommon along particular parts of our coast so we can track where species are moving with global warming and marine heatwave events. Animals we are tracking include Estuarine Crocodiles and various species of shark https://www.redmap.org.au/region/qld/

Anything else you would like to add?

We are very fortunate that we have just got a scanning electron microscope (SEM) at Museum of Tropical Queensland. This allows us to image very, very small specimens and undertake taxonomy and ecology that would previously not be possible by eye or with traditional light microscopes because detailed features of the animals are too small.

Read more about Sue-Ann’s work at Museum of Tropical Queensland here.