Sciences

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Sciences

Natural history - from animals to minerals, fossils to sea slugs. MV's scientists use the state's collections in important research.

Catalogue of cephalopods completed

Author
by Kate C
Publish date
4 June 2014
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Everyone loves a happy ending. And everyone loves octopuses. The recent completion of the third and final volume in the revised FAO Catalogue of Cephalopods of the World nails it on both fronts. 

Cephalopods of the World Volume 3 Cover of the new FAO Cephalopods of the World Volume 3.
Image: Emanuela D’Antoni
Source: Food and Agriculture Organization of the United Nations
 

This is a brilliant – and free – resource designed to assist people working in fisheries to identify the cephalopods that we humans are most aware of, namely the ones we've identified, that we eat, or can cause us harm. Volume 3: Octopods and Vampire Squids was co-authored by MV's Dr Mark Norman and Dr Julian Finn. They are also are two of the four series editors.

'Octopus’ berrima Spot the 'Octopus’ berrima in the sandy substrate! (The inverted commas signify that this species is provisionally placed in the genus Octopus.)
Image: Julian Finn
Source: Museum Victoria
 

Years of work and drawing from cephalopod researchers worldwide sees FAO Catalogue of Cephalopods of the World summarising descriptions of species for practical use by non-specialists. "We've distilled it down to diagnostic characters that will allow people on research or fishing vessels to identify species," says Julian. "It's a review of all the taxonomic work that's out there, for people who don't have immediate access to the literature." The species descriptions focus on traits that are easily measured, which is no mean feat for animals famous for changing their shape and form at will. Says Julian, "everything is based on characters that survive preservation and are consistent across members of a species, such as numbers of suckers, presence or absence of structures, and relative lengths of body components."

Julian and Mark also note that this project would not have been possible without significant financial and moral support from the Australian Biological Resources Study and the Hermon Slade Foundation. This allowed them to do the work on octopus taxonomy that was required for this new edition of the Catalogue. 

Argonauta argo The beautiful female Argonaut, or Argonauta argo.
Image: Julian Finn
Source: Museum Victoria
 

So, if you have an interest in, as Ze Frank calls them, 'the floppy floppy spiders of the sea', head to FAO and download a free copy of FAO Catalogue of Cephalopods of the World Volume 3 (PDF, 25.77Mb). And in case you need a reminder about why you love octopuses, here's a video showing how they can open jars from the inside (while we humans sometimes struggle to open them from the outside).

 

Eltham Copper Butterfly update

Author
by Kate Phillips
Publish date
13 May 2014
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Comments (1)

Once thought extinct, the Eltham Copper Butterfly was rediscovered in 1986 in Eltham, in a small patch of bush that was going to be bulldozed to build houses. A campaign to save the butterfly’s habitat began and the local council, State government and local community raised the money to buy the land and make it a conservation reserve. Since then other sites have been reserved in other parts of Eltham, Greensborough, Castlemaine, Bendigo and Kiata.

Eltham Copper Butterfly Eltham Copper Butterfly (Paralucia pyrodiscus lucida) perched on Sweet Bursaria, Bursaria spinosa.
Image: Andrea Canzano
Source: Andrea Canzano
 

Over time, butterfly numbers in the Eltham reserves went down. People from the nearby houses would walk through the reserves, let their pets in and local kids couldn’t resist building cubby houses. Active trampling wasn’t the only problem. The reserves weren’t being grazed by native fauna or cleared by periodic burns any more. Vigorous native plants and weeds started to crowd out Sweet Bursaria, the butterfly's sole food. The habitat was no longer ideal for the larvae or butterflies which need patches of sunlight and clear flight-paths.

Eltham Copper larva with ants Eltham Copper larva being tended by Notoncus ants on a Sweet Bursaria bush. The Eltham Copper Butterfly can only live in habitats where this plant and these ants are present.
Image: Andrea Canzano
Source: Andrea Canzano
 

A couple of years ago I ventured out one cool September night to help with the larvae count at an Eltham reserve. While it was exciting to be in the bush at night we didn’t find a single larva where they had been numerous a few years earlier. Results like his made people realise that it was not enough to fence off reserves and expect the butterflies to flourish.

In 2012 the Friends of Eltham Copper Butterfly in partnership with Nillumbik Shire Council, Parks Victoria, Friends of Diosma Road, Friends of Woodridge Linear Reserve and Eltham East Primary School obtained a Communities for Nature grant to protect and enhance the habitat of the Eltham Copper Butterfly.

The habitat restoration involved skilled workers selectively weeding the reserves and planting more Sweet Bursaria, other butterfly-attracting native grasses and daisies to bring the vegetation back to an ideal mix for the Eltham Copper Butterfly.

And the result? Already, only 12 months later, there has been a significant increase in the number of Eltham Copper Butterflies recorded in the counts in this summer (2013-14). It is an encouraging start, and supports the idea that active management can make a decisive difference for an endangered species. Ongoing community involvement and education is the other vital component. This takes many forms from festivals, to butterfly-friendly garden courses, to education in the local schools.

Children and performer Eltham East Primary School children have planted a butterfly garden. Here they're learning about the Eltham Copper Butterfly.
Image: Alison Bayley
Source: Alison Bayley
 

So it looks hopeful for the Melbourne Eltham Copper populations but what about the butterfly in Central Victoria?

In 2009 there were only three known butterfly sites in Central Victoria but in the last five years a small team surveyed 3,000 hectares of public land looking for the right habitat features for the butterfly – a combination of enough Sweet Bursaria bushes in an open forest habitat. Having identified promising areas, they went back at the right time of year to see if they could find the adults. With great excitement they found seven new sites bringing the total in the region to ten.

Julie Whitfield in butterfly habitat Julie Whitfield, a leader in Eltham Copper butterfly conservation in Central Victoria, at a site where a colony of butterflies was found at Big Hill, Bendigo.
Image: Kate Phillips
Source: Museum Victoria
 

However at the same time these new butterfly colonies were being discovered, the risk of fire was brought into sharp focus and fuel reduction burns given greater priority.

Areas surrounding regional towns such as Castlemaine and Bendigo are set aside to be burnt each year. Many of these overlap with the newly-discovered Eltham Copper butterfly habitat. The fuel reduction burns are designed to be ‘thorough’. While this is seen as good fire risk management it endangers fire-sensitive species such as rare orchids; a fire in Eltham Copper Butterfly habitat could wipe out one of its populations. However when on-the-ground knowledge is used to guide fuel reduction burns, important habitat pockets can be excluded. It is not a case of conservation versus safety, but a balancing of the two needs.

Thanks to Andrea Canzano, Karen Borton, Anne Fitzpatrick and Julie Whitfield for their contributions to this post.

Bugs within bugs, part 2

Author
by Patrick
Publish date
7 May 2014
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Comments (5)

Like any group of animals (or people), populations of bugs are susceptible to disease, pathogens and parasites. At Live Exhibits we keep our populations free from parasites, but sometimes new bugs from the wild turn out to be Trojan horses filled with unwanted guests.

Tachinid fly pupae Tachinid fly pupae, newly emerged from the abdomen of a Rainforest Mantid (Heirodula majuscula), collected from Cairns, North Queensland. These flies are always fatal to the mantid.
Image: Patrick Honan
Source: Museum Victoria
 

The parasites not only kill the bugs themselves, but could get into captive populations and cause havoc. Most of them are easily controlled once identified, and occasionally we can even operate to remove the parasite and allow the host to lead a long and fruitful life.

parasitic wasp larva A parasitic wasp larva being successfully removed from the abdomen of a living Olive-green Katydid (Austrosalomona falcata) collected from the wild.
Image: Alan Henderson
Source: Museum Victoria
 

But often this is not so successful and the first sign of something wrong is the presence of two different species within an enclosure rather than just one. When you get to recognise the signs of parasitism, it’s often difficult to find individual insects in the wild that are not parasitised.

tachinid fly larva A tachinid fly larva emerges from a wild-caught Robust Fan-winged Katydid (Psacadonotus robustus). The only indication of infection was the abnormally large abdomen of the male katydid.
Image: Melvin Patinathan
Source: Museum Victoria
 

One of the most insidious is the Gordian worm, named after the Gordian knot of mythology. These are long, hair-like worms up to half a metre long which begin their lives in freshwater streams attacking aquatic insects. When the aquatic host, such as a dragonfly or mayfly nymph emerges into adulthood, it leaves the stream and is caught and eaten by a spider, cricket or beetle. The worm grows within its new host, filling up the entire body cavity until the host is 95 per cent Gordian worm.

Gordian worm emerging A Gordian worm emerging from an Olive-green Katydid (Austrosalomona falcata).
Image: Alan Henderson
Source: Minibeast Wildlife
 

When fully fed, the worm causes its host to become thirsty to encourage it to seek out water where the worm emerges and continues its life cycle, laying more than 10 million eggs. Earlier this year Live Exhibits staff collected eight huntsmans near Cape Tribulation, North Queensland, five of which produced Gordian worms over the next few weeks.

 

Video: A newly emerged Gordian worm and its host, Beregama cordata, from the #liveexhibits takeover of the Museum Victoria Instagram account.
Source: Patrick Honan/Museum Victoria

The relationship between parasites and their hosts is an evolutionary arms race – as hosts come up with more effective defences, the parasites evolve techniques such as behavioural modification to overcome them. This fascinatingly gruesome relationship can be the stuff of nightmares; inspiration for everything from zombies to the film Alien, proving that science is stranger than science fiction.

This is the second in pair of posts about parasites. Don't miss Bugs within bugs, part 1

References:

Askew, R.R., 1971, Parasitic Insects, American Elsevier, USA, 316pp

CSIRO, 1990, Insects of Australia, Volume 1 & 2, Melbourne University Press, Melbourne, 1137pp

Gauld, I.D., 1984, An Introduction to the Ichneumonidae of Australia, British Museum (Natural History), UK, 413pp

Matthews, E.G. & Kitching, R.L., 1984, Insect Ecology (second edition), University of Queensland Press, Brisbane, 211pp

Small(er) is beautiful

Author
by Wayne
Publish date
4 May 2014
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When we think of Ice Age land animals, we often add the word ‘giants’; certainly many of the mammals of the Pleistocene were very large  – including many here in Australia. In a previous post, we’ve defined megafauna, and looked at a few Australian examples from the Quaternary. There is a different way of looking at this, though – rather than thinking of the Ice Age megafauna as ‘ancient giants’, it is equally valid to study modern-day animals from the perspective of them being dwarf or pygmy forms of their Ice Age relatives.

The phenomenon of dwarfism in post- Ice Age mammals changes the question from “why were they so big back then?” to “why are they so small now?”

Before we go any further, we should keep in mind that not everything was giant-sized in the Pleistocene; there were many ‘normal’ sized animals (by today’s standards) living happily alongside the big guys – it was just that the big ones were really big. It’s also important to remember that many of the ‘pygmy’ forms lived alongside their ‘giant’ relatives, rather than replaced them – there’s no such thing as a succession plan in evolution.

Having said this, here are a few examples of ‘dwarf megafauna’ alive today that had gigantic skeletons in their closets.

An example of ‘miniature giant’ is the modern day Eastern Grey Kangaroo Macropus giganteus; certainly large for an Australian land mammal, but 40-something thousand years ago it was overshadowed by its immense relative Macropus titan by 30%.

  skull of Macropus titan Skull of the Giant Grey Kangaroo Macropus titan. The ‘giant’ part is correct, but the ‘grey’ part is speculative; the colour of the Giant ‘roo is unknown…
Image: Tim Holland
Source: Museum Victoria
 

Similarly, the largest living Goanna, the Perentie Varanus giganteus, impresses with its size….but is smallfry against the immense extinct evolutionary ‘cousin’ Varanus “Megalania” priscus, – estimated at over twice (some have said thrice) the size.  

­­This also holds true on the Tasmanian Devil Sarcophilus laniarus, which had an over-sized, mainland-resident relative at least 15% larger than its living subspecies. All of these animals are at least in the same genus as their megafaunal relatives, in some cases they are subspecies of their modern-day pygmy forms.

Tasmanian devil skull Skull of the Giant Mainland (rather than Tasmanian) Devil Sarcophilus laniarus
Image: Tim Holland
Source: Museum Victoria
 

So, whilst it is true to say that in broad terms, there was an extinction event about 45, 000 years ago that led to the ‘end of the Megafauna’, this event was complex - there were other patterns at play that saw downsizing as a successful survival strategy.

Obviously many Australian megafauna taxa became entirely extinct as well, inconveniently leaving no close descendants or relatives, but their story is for yet another blog…

Taking nature to the nation

Author
by Nicole K
Publish date
1 May 2014
Comments
Comments (2)

In 2011 Museum Victoria produced our first Field Guide app: the MV Field Guide to Victorian Fauna.

The app has since been downloaded by over 85,000 people and gets great reviews. But there has been a repeated request – a request from people who don't live in Victoria.

Where are the apps for the other Australian states and territories?

This wasn't something we could address on our own. To make apps for the other states and territories, we needed the shared expertise of natural history museums around the country.

In 2012, Museum Victoria was successful in applying for an Inspiring Australia Unlocking Australia's Potential Grant to produce seven new Field Guide apps in collaboration with:

  • Australian Museum
  • Museum and Art Gallery of the Northern Territory
  • Queensland Museum
  • South Australian Museum
  • Tasmanian Museum and Art Gallery
  • Western Australian Museum


For the past two years, scientists around Australia have been writing species descriptions, sourcing images and we have been tweaking the code. We have also worked with colleagues from the Atlas of Living Australia to source taxonomic names, conservation status and recorded observations of each species.

We are very excited to announce that the products of this nation-wide collaborative project are now available.

Field Guide to ACT Fauna app (iPhone & iPad) Field Guide to ACT Fauna app (iPhone & iPad)
Source: Museum Victoria
 

There are now eight apps – Field Guides to the Fauna of New South Wales, Northern Territory, Queensland, South Australia, Tasmania, Western Australia and the ACT – as well as a new version of the original Field Guide to Victorian Fauna.

Collectively the apps contain 2105 species, 7281 images and 270 audio files.

They are available for both Apple and Android devices. And are all absolutely FREE.

We hope you enjoy them!

Links to the App Store and Google Play can be found via our National Field Guide Apps webpage.

Field Guide to Victorian Fauna (Android) Field Guide to Victorian Fauna (Android)
Source: Museum Victoria
 

Bugs within bugs, part 1

Author
by Patrick
Publish date
28 April 2014
Comments
Comments (1)

To support our collection of almost 100 invertebrate species on display at Melbourne Museum, Live Exhibits staff must occasionally collect bugs from the wild, and some of these can hold unwanted surprises inside.

Chalcid w A Chalcid wasp, newly emerged from the cocoon of its host caterpillar.
Image: Patrick Honan
Source: Museum Victorai
 

At least one in every ten insect species is a parasite on other insects. In Australia this adds up to several tens of thousands of parasitic insect species, all living their lives on the outside or, more commonly the inside, of other insects. Most of these parasites are wasps and flies, and most of their hosts are butterflies, moths and beetles.

Tachinid fly eggs on beetle Tachinid fly eggs on the outside of a doomed Leaf Beetle larva (Paropsis species).
Image: Patrick Honan
Source: Museum Victoria
 

Parasitic insects usually lay their eggs directly onto or into the body of their host, but may lay eggs on a food plant in the hope that they will later be ingested by a potential host. Once inside, the parasitic larva consumes the host’s internal tissues while the host continues to go about its business. The parasite usually avoids the vital organs until the last minute – then polishes these off and finally kills its host.

Aphid ‘mummies’ Aphid ‘mummies’ – aphids that have been parasitised and glued to the leaf by Braconid wasps. When fully developed, the wasps will cut a perfectly circular hole in the back and emerge as adults.
Image: Patrick Honan
Source: Museum Victoria
 

Parasitic wasps are able to find their hosts no matter where they might hide. In order to lay eggs on its host – Sirex Wood Wasp (Sirex noctilio) – Megarhyssa (Megarhyssa nortoni) can drill through 9cm of solid wood with its ovipositor (egg-laying organ). Megarhyssa females find their hosts using infrared detectors on their antennae; the outer bark of a tree is 0.5oC warmer where a larva lies underneath.

female Megarhyssa A female Megarhyssa (Megarhyssa nortoni) drills through a pine tree to deposit an egg on the Sirex Wood Wasp within.
Image: Patrick Honan
Source: Museum Victoria
 

A parasitic wasp will sometimes inject venom that paralyses the host but keeps it alive, allowing the wasp to hide it away for its offspring as a sort of living larder. A large wasp dragging a larger, paralysed, huntsman across open ground is a familiar sight during summer.

Pompilid wasp drags a huntsman A Pompilid wasp drags a huntsman (Isopeda species) from its hiding place under bark, before paralysing it and inserting an egg.
Image: Patrick Honan
Source: Museum Victoria
 

A caterpillar can sometimes dislodge a parasite’s eggs with its mandibles, but wasps usually lay their eggs just behind the caterpillar’s head where they can’t be reached. Many hosts are able to ‘encapsulate’ a parasite already inside their bodies, localising its damage and starving it of oxygen. When more than one parasite is laid inside a host, the larvae fight to the death within the host’s body for the rights to its organs.

wasp cocoons inside the empty shell of a Cabbage White Butterfly caterpillar Thousands of parasitic wasp cocoons inside the empty shell of a Cabbage White Butterfly caterpillar (Pieris rapae). Each cocoon will soon produce a tiny wasp that flies off to find other caterpillars to parasitise.
Image: Patrick Honan
Source: Museum Victoria
 

Parasites are themselves subject to attack from hyperparasites, insects that lay eggs inside an already-occupied host. The emerging larva seeks out the parasite in residence and burrows into its body. These in turn may be parasitised by superhyperparasites, and so on.

“Great fleas have little fleas upon their backs to bite 'em,

And little fleas have lesser fleas, and so ad infinitum…”

Augustus de Morgan (after Jonathan Swift)

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Updates on what's happening at Melbourne Museum, the Immigration Museum, Scienceworks, the Royal Exhibition Building, and beyond.

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