Not Your Average Aquarium
Written by Betty Trummel
One of my favorite places inside of Crary Lab is the aquarium where many of the marine biologists work. I wandered down to the aquarium at Crary Lab today…just to see what new creatures were in the tanks. Take a look at the interesting shapes and adaptations of these marine critters.
Beyond what you see in the photo above are large round tanks. I peered into the first one on my left and saw two pretty big fish swimming slowly around the tank. These are Antarctic toothfish. Several of the large round tanks held toothfish.
These fish are caught on or near the bottom of water that can be up to about 2000 meters deep. They can live for 50 years, and the largest one ever caught near McMurdo was 202 pounds.
The Antarctic toothfish is a unique creature because its blood contains a natural protein “antifreeze” which allows it to live in freezing seawater. This fish will eat anything it can sink its sharp teeth into and fit in its mouth. It mostly preys on small-medium fishes. Commercial fishing in the Ross Sea region began in the late 1990’s, but in recent years these fish have been more difficult to catch in the McMurdo area.
My favorite is the touch and feel tank…with its crazy looking marine life. I stuck my hand in the tank to touch a sea star and realized just how COLD the water is for these creatures. I’m used to tidepooling (looking in the little pools of water on a rocky shore during low tide) in New England (mostly Maine and Massachusetts) or the Pacific Northwest (Washington; Oregon; British Columbia, Canada), where the water is significantly warmer than Antarctica.
This little fish below is called a rockcod. They are well-adapted to the extremely low and stable temperatures on the McMurdo area. They live on the seafloor. They will eat prey that is both sedentary (still; not moving) and moving. Sometimes they will ambush prey and other times they will kind of peck at it. They are versatile fish indeed.
In the photo below there is a type of sea star (with curled arms) which is so unusual. I’ve not seen anything like it before when in Crary Lab here in McMurdo. To the left of it is an Antarctic scallop. This scallop lives on the seafloor. It has a swimming escape response to predators and disturbances. Scallops are filter-feeders and eat tiny plants (diatoms) and animals (foraminifera).
The photo below shows a much larger sea star and then clockwise from the sea star you will see a bright yellow-green gastropod. Gastropods do not have a shell for protection from predators. They can grow to be 1.4 to 7 centimeters long. Scientists have found that they appear to be protected from predators by a chemical that deters (discourages or prevents) some animals from feeding on them. I wonder then, what predators does this gastropod have?
Continuing clockwise you’ll see a longer, sort of oval creature. That’s a chiton. It has bony armor on its shell. A chiton is a mollusk that most often lives near the edge of the ocean. They move along very slowly on their muscular feet and cling to rocks. They have really interesting shells made up of eight overlapping plates.
In the “six o’clock position” (bottom) there is a small scallop. To the left of the scallop is a delicate sea spider.
The sea spider is amazing to me. It seems so fragile, yet it lives in such cold water. I couldn’t keep my hand in that water for longer than a few seconds, yet this creature has adapted to live here. Some of the species that live in Antarctic waters are deep-sea dwellers, while other species prefer shallow water. They can be quite large, with some having leg spans as wide as fifty centimeters. That’s half of a meter stick! Sea spiders are mostly bottom dwelling (benthic) creatures.
Another view of the touch and feel tank…
I took the photo below when I was here in 2006; it shows a beautiful sea anemone (I couldn’t get a good shot in the tank today). This cluster of three shows how they can change in shape depending on the situation. Often they look like flowers as the largest one in the middle looks in the photo. The rounded one above it to the left is in the closed position for protection. The one just under the main anemone is half way open/closed. Sea anemones are carnivores (eat other animals) and catch their food using their tentacles, which have poisonous stingers. Notice how they attach to the rocks in the touch and feel tank.
It’s amazing to see so many different creatures in one little tank. I often wish I had studied to be a marine biologist. I love ocean creatures and their unique adaptations. Whether its color, shape, size, bony plates, stinging tentacles, teeth, or some other feature, these creatures are special and amazing in their ability to survive in the cold water of this region. I know I haven’t seen all of the marine life in this area, but these critters demonstrate some pretty cool adaptations. This truly is not your average aquarium.
If you live near an aquarium at home, I would encourage you to spend time there and learn all you can about ocean life. I know one of my favorite places in Chicago is the Shedd Aquarium. When I visit the Shedd I can see examples of many creatures similar to what I saw today. I’ve always loved studying ocean life, and having a small aquarium here in McMurdo is great.
Write and tell me which creatures are your favorites. Have a great day!