Marvellous Molluscs – Part 2

Dr John Healy is Curator of Molluscs at Queensland Museum and is actively involved with research on molluscs (malacology).

Dr John Healy

As John notes, the role of Curator of Molluscs covers many and varied activities. This includes taxonomic work on the collections, field work, identification of samples, public inquiries and even work on cultural and historical aspects of shell use and art through the ages. John has been extensively involved in taxonomic work on Australian Molluscs, and has named over 80 species new to science, including numerous bivalves and tusk shells.

In association with the Dr Nerida Wilson of the Australian Museum, John is also working on the evolutionary relationships and classification of volute snails – a family of marine molluscs that has no planktonic stage in their life cycle. (The eggs of many other marine molluscs hatch into a planktonic stage that can move with the currents and establish the species in other areas.) Volutes are direct developers and as such are vulnerable to local extinctions if they are over-collected or if their habitat is substantially damaged. There are few individuals from other areas than can come in and re-colonise the area.

Beautiful bivalve, Spondylus versicolor

Many molluscs are named by the structure and colour of their shell alone, especially if the shell is distinctive enough. John notes that this can give rise to a bit of a dilemma: some species may be named but they could in fact be extinct. There have been some species of molluscs discovered and named in the recent past, for which no living specimen has ever been seen – only their shell!

The Argonaut ‘shell’ looks a little bit like a fossil ammonite – John draws attention to some similarities to true shells of the ammonite genus Scaphites – and some scientists believe that octopods may even be ammonites. However, the differences in shell structure are profound, suggesting the Argonaut ‘shell’ has developed independently of the chambered ammonite (and nautilus) true shells.

To learn more about the marvellous world of Molluscs, visit the Mollusc page of our QM website.

To learn more about the work that John does, visit his Biography page.

To learn more about animal adaptations, view our Animal Adaptation Videos.

Marvellous Molluscs – Part 1

Darryl Potter is the Collection Manager for both Molluscs and Crustaceans at Queensland Museum.

Darryl is involved in collecting, identifying, labelling, and storing specimens from the animal groups of Molluscs (snails, bivalves, chitons, squid and octopuses) and Crustaceans (crabs, shrimps, lobsters, barnacles, etcetera). He also maintains the database that stores information about these collections.

Darryl Potter

Darryl has accompanied other QM scientists, such as Peter Davie (Senior Curator of Crustacea), Jeff Johnson (Collection Manager of Ichthyology) and Dr John Healy (Curator of Molluscs) on many expeditions that involved inter-tidal trips and scuba diving in the beautiful waters off the Queensland and northern New South Wales coasts.

Over recent months, Darryl and QM scientists have been busy compiling the revamped QM publication, Wild Guide to Moreton Bay and Adjacent Coasts, Vol 1 & 2. The book is authored by Peter Davie and several other QM scientists, and includes magnificent photography from QM photographers Gary Cranitch and Jeff Wright.

To purchase the book, follow this link to Wild Guide to Moreton Bay and Adjacent Coasts.

Darryl’s area of expertise includes land snails and marine gastropods (one-shelled molluscs such as snails and slugs). Darryl and three other colleagues have recently published the first volume of a guide to Australian land snails which is based on 20 years of fieldwork conducted across Queensland, coastal New South Wales, Cape York and the Torres Strait. The second volume is under production and will be based on snails found in the more arid and semi-arid zones of Australia. Already there are 800 species that have been documented for inclusion in this volume.

Follow this link to purchase Australian Land Snails Volume 1: a field guide to eastern Australian species.

Last week, Darryl was collecting specimens from Nudgee Beach and some of the specimens are shown below. He is now in the process of identifying, labelling and cataloguing these species.

Specimens from Nudgee Beach checked against Wild Guide book

An interesting recent QM acquisition is the Diamondback Squid that appears in the image below.

Diamondback Squid, Thysanoteuthis rhombus

This squid is the largest cephalopod species to be collected from the waters off Moreton Bay. Its name comes from the characteristic diamond-shaped fin which extends along the length of the body. The arms have two rows of suckers and there are wide protective webs along their length. They can grow up to a metre in length and weigh as much as 30 kilograms.

To find out more about magnificent molluscs and crustaceans, visit the Mollusc and Crustaceans section of our website.

To read more about Darryl’s work, visit his Biography page.

Displaying Insects

Now that the weather is getting a bit warmer, some creepy crawlies will be emerging from their period of winter inactivity. Teachers and students may like to engage in a schoolyard safari to collect, identify, and display some of our amazing Australian insects.

Cicada, Birrima varians

On Queensland Museum’s Wild Backyards site you can find out how to trap insects using pitfall traps, malaise traps, and beating and netting. Instructional videos show you how to Plan a Study, Collect Insects, Identify Insects using a CSIRO Invertebrate Key, Display Insects, and Summarise Data using spreadsheets. The Backyard Explorer Leader’s Guide and User’s Guide that are on the Wild Backyards site are suitable to use with mid-primary to senior Biology groups. EEIs (Extended Experimental Investigations) and ERTs (Extended Response Tasks) can be designed around biodiversity assessments. A study of changes to flora and fauna over time and space is one way of exploring changes to biodiversity.

The Displaying Insects video has recently been added to QM’s suite of instructional videos. In this video Noel Starick, who was an entomologist at CSIRO for many years, shows some of the techniques and ‘tricks of the trade’ to help budding insect-lovers produce an eye-catching insect display.

Insect Collection

Insect trays can be kept from year to year and used to teach classification (Yr 7 of the Australian Science Curriculum) and adaptations (Yr 5), as well as classification at a senior Biology level.

An insect tray with specimens classified down to Order level, is included in the new QM Loans kit, Micro Marvels. This kit will be available for borrowing from 2012.

Micro Marvels kit

Booklets that assist with teaching these themes were uploaded on a previous blog; see the one on New Primary Science Loans kits trialled in the Classroom.

Exploring the Deep

Dr Merrick Ekins is the Collection Manager of Sessile Marine Invertebrates at Queensland Museum. He collects Sponges, Cnidarians (Hard, Soft and Black Corals, Anemones, Jellyfish, Zooanthids), Ascidians (sea squirts), Bryozoans, Brachiopods and Hemichordates.

Sessile animals are ones that are fixed in place, at least in the adult stage, and don’t tend to move around from place to place. Merrick is responsible for collection, storage, transport and maintenance of over 50 000 specimens.

Dr Merrick Ekins with specimens

Part of Merrick’s job involves deep-sea scuba diving to collect these specimens. He has a Dive Masters certificate and is a qualified Cave Diver. On such dives he may collect fish, sponges, octocorals, ascidians, and hard and soft corals for other QM scientists. For example, specimens may be collected on behalf of or in conjunction with Jeff Johnson (ichthyologist); Dr John Hooper (sponge expert); Dr Monika Schlacher (octocorals researcher); Pat Maher (ascidian researcher); and Dr Carden Wallace (coral expert); and for other international projects such as the Deep Down Under expedition.

Merrick collecting underwater specimens

Merrick says it is best to preserve the specimens as quickly as is possible on the dive boat. For example, sponges are frozen and octocorals are placed in ethanol. Other animal such as sea anemones and ascidians require more steps such as ‘relaxation’ prior to preservation. Menthol crystals are added to salt water to make these specimens ‘relax’. That is, the tentacles that were previously withdrawn into the central body cavity become everted i.e. they spread out.  Then the sea anemones are fixed in formalin, stored in alcohol, and labels attached to the jars. Data about the specimens is entered then into QM’s sessile marine invertebrate database.

The image below shows an ROV (Remotely Operated Vehicle) beginning its dive on Osprey Reef to photograph and grab samples of new species of sponges and octocorals from depths of up to 600m. This device had three video cameras and lights attached to the framework.

ROV (Remotely Operated Vehicle) collecting specimens

Sponges are placed in nitric acid to dissolve the organic material and this leaves the silicone spicules which are essential for identification. The spicules are viewed under the SEM (Scanning Electron Microscope) to help with the identification and classification of the specimen. Sponges are rarely identified on their morphology (body structure) alone.

Sponge spicules under the SEM

Identification of octocorals involves dissolving them in bleach which leaves the sclerites. These are then view under a microscope or SEM in a similar fashion to sponges.

Octocoral sclerites under the SEM

Merrick particularly loves diving amongst ocotocorals, gorgonians (sea fans and sea whips) and Bryozoans (lace corals). These can make up fantastic underwater forests, and with all these beautiful bright colours, it’s really like visiting another world. It’s one of those moments of exploring that Merrick loves about science.

Underwater garden

Currently Merrick is researching the population genetics of deep-sea sponges found on sea mounts in New Caledonia. A sea mount is an island that didn’t quite make it to the surface and can be as much as 4 kilometres deep. These sponges are found about 200-500 metres below sea level. Merrick is collecting specimens from different sea mounts in the ocean to see if they are related. DNA technology helps with this process.

Merrick with deep sea sponge

On our QM website you can find out more about sessile marine invertebrates. Visit our resource Biodiscovery and the Great Barrier Reef to find out about the different types and uses of sponges. Learn more about how genetics and DNA technology help with the identification of species by viewing our Disease Detectives resource.

Merrick has a PhD in the field of molecular genetics in plant pathology, and worked in many varied fields of science before moving to the area of Marine Biology.

To learn more about the jobs that Merrick does, visit his Biography page.