Slugs, snails, and squid, oh my!
Over two sold-out days during the April 2021 school holidays, budding malacologists were hosted by Australian Museum staff in the ever-popular Scientist for a Day (SFAD) program.
Parents or carers drop off their children in the morning and pick up a scientist in the afternoon.
The program kicked-off at 9:30am, where children were welcomed by Australian Museum (AM) hosts Dale, Naomi, and Kaitlyn who explained what the jam-packed day of activities entailed.
Children received a ‘field journal’ and pencil. Throughout the day, these are filled with fascinating facts, scientific drawings, and other content that our SFAD participants would like to record.
Exploring the Museum
Just before the Museum opens to the public, our group are the first to explore some of the Museum's amazing exhibitions. Children searched Wild Planet, Garrigarrang, Surviving Australia and 200 Treasures of the Australian Museum for answers to the clues given in the Scavenger Hunt activity sheet, such as, ‘Find a fossil mollusc that sounds like, “I am a knight”?’ The answer to which is of course, an ammonite.
They discovered dangerous cone shells, blue-ringed octopus, and that the local Aboriginal word for fish hook, such as those made from filing conch or turban shells, is bara. These shells are heavy and iridescent “mother of pearl”, making them excellent lures.
What is Malacology?
Jaever Santos from the Australian Musuem Research Institute (AMRI) explained that malacology is the study of molluscs. Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda.
Molluscs are animals that have:
- an unsegmented soft body
- an internal or external shell (most species but not all)
- a mantle (fold in the body wall that lines the shell)
- a muscular foot and/or tentacles
Our collection of molluscs includes chitons, clams, mussels, snails, nudibranchs (sea slugs), tusk shells, octopus, and squid.
Jae spoke about the effect climate change and increased carbon dioxide (CO2) is having on our oceans. Ocean acidification is impacting the thickness and strength of mollusc shells which are made mostly of calcium carbonate. This can make them more susceptible to predation and decrease their chance of reaching maturity and reproducing.
Children used paper straws to blow carbon dioxide into water (in bio-cups) that contained purple cabbage indicator. After a few minutes, the purple colour changed to a light pink indicating it had become more acidic.
The group also guessed whether common household materials were acidic, neutral, or alkaline by adding the purple cabbage indicator solution and comparing the colours to the pH scale.
Our young malacologists then dived deeper into understanding squid anatomy by performing a squid dissection. A deeper understanding of the structure and function of these fascinating molluscs can lead to a greater appreciation of these ancient creatures.
After examining the external anatomy of the squid, children used scissors to cut open the mantle to examine the internal anatomy. Instead of teeth, it has a sharp beak. Each of its two feather-like gills has its own heart to pump blue-coloured blood. It also has a central heart. This means it has thee hearts in total!
The ink sac was gently removed and cut open. Children used the ink to write with or make a fingerprint. Squids use their ink (made of a dark melanin pigment) to evade predators by discolouring the water. Humans use squid ink in food and medicine.
Rare behind-the-scenes opportunities with our Malacology Collection Manager, Mandy Reid, and Research Scientist, Don Colgan, allowed children to view the Malacology Collection which is the largest of its type in Australia and encompasses marine, freshwater, and terrestrial molluscs, comprising an estimated 11 million individual specimens.
Why is the room cold? Not to preserve the dry shells, but to prevent small insects from eating the labels (they cannot live and reproduce in those conditions).
Why don’t we have larger shells here? They are stored offsite in Castle Hill as they take up so much room. They have been collecting them for so long that the collection is huge!
Here we are in the wet collection area or “Spirit” Store.
What does a giant cuttlefish look like in real life? We ventured into the wet storage lab and Mandy put on some thick gloves then opened a draw containing a perfectly preserved cuttlebone, used for buoyancy control, as well as several pristine wet specimens of giant cuttlefish that are native to Sydney. They are preserved in a special type of alcohol. If any parents read the following comment in their child’s field journal, this drawing and other shelves in the wet collection help explain this.
Staff explained how they are slowly digitising the collection to make things easier to find on a computer.
We talked about specimen donations from the public: what makes a good one worth adding to the collection? Lots of information about its discovery: where, when, how it was discovered, whether it still had a living animal in it. This was a great time to ask lots of questions and find out if you would like to be a malacologist one day.
What do snails need to survive? Garden snails (Helix aspersa) are air-breathing snails, which have a single lung. They like eating plant matter. Their shell can protect them and prevent them drying out. They are mainly active at night or very early in the morning, but if it rains during the day, they usually come out. To observe our snails in action, they were sprayed with water and encouraged by the nearby food source of cabbage. ‘Squidward’ and ‘Snail’ were the first to make it to the perimeter.
Time to relax and paint an ammonite fossil plaster cast. Museums make plaster casts of fossils to preserve the original for study. Copies are used for display when the original is too fragile, heavy, or rare.
The Australian Museum has an incredible collection of opalised fossils from Lightening Ridge, NSW. These 110-million-year-old fossils are from a period of time called the Cretaceous when a shallow sea covered what is now inland Australia. Many animal groups including dinosaurs, marine reptiles, fish, early mammals, molluscs, as well as fossils of parts of plants have been found here.
Opal is formed from a solution of silicon dioxide and water. As water runs down through the earth, it picks up silica from sandstone, and carries this silica-rich solution into cracks and voids, caused by decomposing fossils. As the water evaporates, it leaves behind a hard silica deposit. Like a prism, silica spheres, diffract white light to create the rainbows of shimmering colour. Children were offered iridescent paints to add flashes of colour and make their ammonites appear opalised.
Jenny from Creative Science presented a Slime Show. Many molluscs produce slime to prevent desiccation or drying out of exposed soft tissues, glue or adhesion so they can climb surfaces or make tunnels, and as a lubricant to help them move. Slime is also known as mucous and is formed by adding water to very long molecules of protein. A very small quantity of the protein can make very large quantities of slime.
Time for hands-on activities exploring different types of slime and polymers such as psyllium husk slime, cornflour slime, gelatine slime, tapioca slime.
A snail made from bouncing silly putty that could be pulled slowly to make it flow like a liquid or snap it quickly to break like a solid.
Goodbye from Winny
Finishing the day off in Prehistoric Playground meeting Winny – a life-sized Muttaburrasaurus puppet.
At 4pm, our Scientists for a Day were picked up by parents and carers and had lots to share! Thanks again to our hosts and special guests.
Subscribe to our newsletter
Subscribe to our eNewsletter to find out when the next school holiday events are open for bookings!