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Last week we met the spotted turtles that will soon be calling the water exhibit home. Now it’s time to meet the freshwater fish and the Pacific habitat fish…
The residents of the freshwater river habitat have presented a bit of a challenge for the Museum staff. This habitat will include a variety of fish species collected from the Ottawa and Rideau Rivers. Determining which species could coexist peacefully in the habitat has been a learning process. For example, the staff tried to keep a group of large- and smallmouth bass in a tank with a group of Bluegill fish. But the bass decided that the Bluegills would make better snacks than roommates – they ate half of the Bluegill population in one night. For now, the more aggressive species of freshwater fish are kept in separate tanks in the Animal Care Facility. When the fish go on display, these predatory species will be separated from the less aggressive fish by an invisible Plexiglass barrier that bisects the freshwater aquarium.
Some large- and smallmouth bass daydream about tasty Bluegill fish.
There may be conflict between the freshwater river fish, but the residents of the Pacific habitat are getting along just fine. The Pacific tank, which is already on display in the Museum’s cafeteria, is a biodiversity habitat, meaning that it contains many different species that can live in harmony. The water in their tank is kept at a cool 9 degrees Celsius. This relatively low temperature means that they don’t eat too much (and therefore don’t produce much waste), so a large number of animals can share the habitat. This tank includes a wide range of vertebrates (including a foot-long gunnel fish) and invertebrates (such as brightly-coloured starfish). Each day, these laid-back West Coast species receive their nutrition in the form of an “algae shake.” It’s not very appetizing-looking, but it seems to hit the spot.
Having a lengthy acclimation period is extremely important for both the animals that will be living in the exhibit and the staff who will be caring for them. It means that that there will be fewer surprises (and fewer conflicts between tank-mates) when the water exhibit goes live in May.
Homarus americanus
American lobster
This specimen is impressive, but it’s certainly not the biggest in a Canadian museum. The Huntsman Marine Science Centre in St. Andrews, New Brunswick may hold the contender for that award!
A lobster’s big claws are each specialized for a task, one for cutting and one for crushing. As it eats, lots of bits and pieces float in the water around the lobster’s head, offering a food source to the barnacles you can see hitchhiking on the surface of the claws. These are crustaceans, too, although they haven’t looked much like them since they settled here as tiny free-swimming larvae and traded their planktonic life for this permanent home next to the grocery store!
A big part of the Water Project is the new permanent gallery to be housed in Ottawa, and a big part of that gallery is a real, full-sized blue whale skeleton. This skeleton will be close to 20m (65 ft)! It’s going to be a truly amazing experience to be able to stand next to a giant. I can’t wait.
A. McDonald
When a big specimen comes in that needs a lot of work, the technicians often give it a pet name. This is a bit of a tradition in the museum world. The name that was given to our Blue Whale is Tallulah. No one knows why, but that name seems to have come to her and it stuck.
I thought I’d share with you where Tallulah came from and how she ended up at the museum. Here’s the official history:
The beached whale was found at Codroy, off the Cape of Anquille, Newfoundland and was flensed on the beach under contract between April 22 and May 10 1975. It was a less than mature female.
The skeleton was shipped by rail car to Ottawa along with the rest of the accessioned material. The oily bones were removed to the NMNS Catherine Street building and the wooden rail car was burned on the siding by the rail company with the cost reimbursed by the NMNS.
Whales have a lot of fat in their bodies and when a whale dies that fat begins to turn rancid. If you have ever smelled rancid fat it is not a pleasant experience! But the worst part is that the horrible smell sticks around! I can only imagine what that burning railcar smelled like – and wish I hadn’t!
It became abundantly clear to staff in the building that the skeleton, along with the others required attention and the lot was hastily buried in the NCC tree nursery on Russell Road, in a sandy clay soil, for eight years.
In order for the soil bacteria to do their job, there have to be some specific conditions. From what I understand these were not the conditions in the place they buried Tallulah. When they dug up the skeleton a lot of the oil and fat was still in the bones. This means that they still stunk! If we were going to put Tallulah on display we would have to find a way to clean them.
In preparation for potential exhibit in the Water gallery it was recognized that (…) the blue whale skeleton was unsuitable for public display in its current condition. The challenge of de-oiling the skeleton in a cost effective, WHMIS-acceptable and secure way pointed to the use of enzymes in house. The skeleton is currently in two tanks; one 1000 liter and the other 6000 liter; bathed or sprinkled with a commercial enzyme cleaner and lipase (pancreatic) enzymes held at 50-55 degrees C for several months. It is the fourth whale to be treated this way following two in London and one in Copenhagen. (This whale) is more challenging because it is the most sizable (three times the size) at 19.8 m and 2.3 tons and because the oil is now thirty-two years old. Other natural history museums are curious about our project and possible applications.
A. McDonald
Tallulah is now being submerged in huge vats of enzymes, which are breaking down the oils and will leave the bones clean and ready to be prepared for display. Stay tuned for updates on this project!
A. McDonald
Every now and then I take a trip down to the collections pods to see what neat specimens are being prepared for the gallery. Here’s my latest discovery.
Judith Price, Assistant Collections Manager for the invertebrate collection gave me some background on this fascinating specimen.
Cancer magister
Dungeness crab
CMNC 2004-6024
Although it can be found on menus as the Dungeness crab, this animal was given its scientific name in recognition of the zodiac sign Cancer, The Crab. This specimen was collected in 1908 in Departure Bay, near Nanaimo, British Columbia. Like many crustacean specimens prepared for museums at that time it was dried, stuffed with cotton fibre and wired into a lifelike pose. This makes it a good specimen for display, and may even be of more use to modern researchers studying DNA than a more modern animal prepared using formaldehyde or ethanol!
Producing a traveling exhibit has its own set of challenges, the biggest being that it travels! Set-up and tear down have to be easy, the components have to be crated and shipped, and the specimens have to be hardy. This leaves a big challenge for preserved wet collections – or pickled specimens as they are often called. The fluids used to preserve specimens require special treatment in shipping and including them in a traveling exhibit make for a very complicated shipping process. On the other hand, leaving them out means leaving out some of the most interesting specimens and losing some very powerful visitor experiences. So what to do?
Judith Price, Assistant Collections Manager for the invertebrate collection at the Canadian Museum of Nature may have found an answer. Recently she experimented with freeze drying some of the preserved wet specimens. The results were incredible. Despite a lack of colour from the pickling, the detail of specimen’s texture was amazing.
Here’s Judith’s explanation of what was done.
Most invertebrate specimens stored in scientific collections are “pickled” in alcohol or other fluids to preserve them for study. Unfortunately these fluids are usually flammable, so the fire department sets safety limits on how much we can use in a public space like our new Water gallery and traveling exhibit. We decided to try freeze drying some specimens to see if that would be a better way of exhibiting the diversity of aquatic life. Since preserved animals lose all the colours they display when alive and are left a dull pink, this would also let us tint the specimens to look more lifelike, and use them in dioramas.
Our freeze drier is mainly used by the researchers who study diatoms, single-celled plants with a shell made of silica. Paul Hamilton, one of our botanists, showed Jean-Marc Gagnon and I how to use the machine (which he thinks is simple but I beg to differ!)
For our first run, Jean-Marc selected from our collections a few invertebrates of various sizes and fragility: some small to medium sized crustaceans (the group that includes lobsters and crabs), a marine worm called a “blood worm”, a couple of small sea stars and two small sea cucumbers with their mouth parts exposed. These last are very fine and almost frilly, a good test of the stability of softer tissues.
We pinned the softer animals in a glass dish with wax in the bottom, then submerged them in water. This was intended to support them and to reduce surface shrinkage. Then into the freeze drier they went!
The freeze drier works by pumping out as much air as possible from a well-sealed container, allowing the water to more easily escape from the specimens inside. The air is then passed through a very cold chamber where the water vapour collects as an ice block so we can remove it later.
We made one miscalculation: the water around our specimens didn’t freeze as a block, it bubbled and boiled and when it finally froze it looked like a pile of snow! This is because as the air pressure lowered, so did the boiling point of the water (this happens as you go up in altitude for the same reason). Next time we will use a regular freezer to stabilize the samples before putting them in the freeze drier.
Although we had a scary day before the “snow” evaporated off the specimens, the experiment turned out very well. All the animals came through wonderfully, although not with “flying colours”. Our exhibit specialists will paint those back on before these specimens go into our new galleries!
These delicate little specimens can now be painted to reflect the natural colour. A few more experiments and the traveling exhibit may have its specimens after all!
I took a walk down to the collections pod today to see what specimens where being worked on for the gallery. When I entered the pod I got an extra special treat. Judith Price, the Assistant Collections Manager for the invertebrate collection, and Nicole Dupuis, the exhibition content developer for the water gallery, had laid out some of the specimens that will be placed on display around the blue whale in the final gallery. This is a part of the design process of figuring out what specimens best tell the story of the gallery and how they all fit together in the physical space available. It takes a lot of playing around to get everything right. Here’s a sneak peek at what we are likely to see in the final gallery.
C.Iburg
C.Iburg
C.Iburg
Coronula diadema
Whale barnacle
CMNPA 1999-0022
These egg to fist sized crustaceans are found on humpback whales (and reported from fin, blue, and sperm whales) especially on the lips, the long grooves of the throat and the genital region.
C.Iburg
Barnacles begin their lives as free-swimming larvae, but appear able to ‘smell’ a nearby whale when ready to settle down. They then develop the heavy calcium-rich plates that shield the barnacle’s soft body (now lost in this specimen). As the plates fuse together, the whale’s skin is drawn into the spaces between the plates, permanently stitching the barnacle’s shell to the whale. Even though the barnacle may only live for one to two years, the whale carries the shell around until it can find a way to scrape it off.
C.Iburg
Luckily, the barnacles only attach to the surface layer of the whale’s very thick skin and blubber layer. They don’t harm the whale, just hitchhike through the plankton-rich water that the whales enjoy.
Museums have their roots in the human desire to collect and study objects from the world around them. The early “Cabinets of Curiosity” used to hold the beautiful, the weird and costliest items their owner could afford, but today’s museums’ collections look very different indeed.
C.Iburg
An earlier shell collector would value this carved scallop shell, but our museum collects mollusc specimens as indicators of the place and time where they lived, and needs as much of the original characteristics of the specimen as possible to be available for scientific study.
C.Iburg
The new water gallery will of course include aquariums with live animals! If you’ve ever kept a pet goldfish you might think this is easy but housing aquatic species is not as simple as you might think. I learned this the other day in the live animal care facility at the museum. One aquarium that we want to show is something called a surge tank. This tank simulates the wave action of the inter-tidal zone. Our animal care technician, Stacey Tidman took a trip recently to learn about how these tanks work.
Recently I went to the New England Aquarium to spend some time with the aquarists who specialize in caring for live displays similar to those we are looking into setting up at our museum. While taking pictures of their surge aquarium I was caught off guard when the dump bucket came down and the splash got not only in the tank, but hit me and my camera with a fine, salty mist. I am now looking into acquiring live specimens that will thrive in that turbulent environment.
It’s going to be a real learning process. Let’s hope we don’t need our raincoats once we get our surge tank up and running!
Diplogonoporus balaenopterae (Lönnberg, 1891) from Balaenoptera acutirostrata (Minke whale)
CMNPA 1999-0008
c. Iburg
This is a tapeworm that is often found in the small intestine of minke and sei whales but can also infect dogs and people who eat uncooked infected whale meat or fish (which might carry the larval stages of many parasites.) Like many parasites, tapeworms use different members of a food chain to foster and pass along the various life stages of the worm. The eggs of Diplogonoporus, shed in the feces of the whale, are eaten and hatch within small crustaceans called copepods, which are then eaten by small fish, later sieved out of the water by baleen whales such as the minke.
C. Iburg
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