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By: Dee, Aquarist at The Audubon Aquarium of the Americas
Like Brenda mentioned in her “Ordinary Animals” blog; all animals count on this planet, even the ones without brains.
Like the Zoo, the Aquarium has its own set of “super models.” Penguins and our two southern sea otters Buck and Emma often get the majority of the spotlight. One gallery that gets frequently overlooked at the Aquarium is the Jellyfish Gallery. Jellies may not be as cuddly as Buck and Emma but they are a captivating part of our animal collection.
The Jelly Gallery is home to eight specially designed exhibits called Kriesels. A Kreisel is a cornerless exhibit with circular water flow. Named after the German word for carousel, it’s designed to keep the jellies in the center of the exhibit and away from the walls. In the wild, jellyfish spend most of their time in open water and their soft bodies are easily injured by bumping into solid objects.
This unique aquarium design also encourages the growth of hydroids. Hydroids are colonial, plant-like animals that stick to the sides of the exhibit. They are close relatives of the jellyfish, feed on the same food, and thrive in the slow moving water of a Kriesel. Like jellyfish, they have stinging cells that they use for defense and prey capture. Their sting can be harmful to jellies and can kill them over time. Of course, this makes cleaning a priority for the jellyfish aquarist. In order to rid the Kreisel of hydroids, the jellies have to be moved out and the entire exhibit must be bleached. This may sound easy, but let me assure you it is very labor intensive and must be done every few weeks.
In addition to maintaining a hydroid-free environment a Jelly Aquarist must also grow food for them. Jellies eat a variety of foods in the wild; here at the Aquarium they eat newly hatched brine shrimp (nauplii). The brine shrimp hatch from small eggs in cone-shaped tanks full of saltwater. They grow for two days before being harvested and fed to our jellyfish. If you ever kept Sea Monkeys as a child, this is the exact same process, just on a larger scale. Some of the jellies in our collection are medusavores; this means they eat other jellies. In order to supplement the diet of our large sea nettles, we feed them tiny pieces of moon jellyfish.
One of my favorite species of jelly that we exhibit here at the Aquarium is the comb jelly (pictured). It’s not technically a ‘true’ jellyfish, but it is a close relative. The comb jelly’s most distinctive features are its "combs" that appear to glow and change color as they glide through the water. The combs are made up of groups of cilia. Cilia are tiny hair-like structures arranged in neat rows along the comb jellies body that beat rhythmically to propel comb jellies through the water, like a boat with hundreds of tiny oars. The color change is actually the prismatic effect of light hitting the cilia which produces a rainbow of seemingly electric color. They appear to light up as they swim; one day a visitor asked me “who decorated the jellies for Christmas?” In case you were wondering, unlike their jellyfish cousins, comb jellies do not have stinging cells and will not ruin your swim.
A quick tip for all you beach goers this summer: the Aquarists have found vinegar to be the best way to stop the pain from a jellyfish sting. However, if you prefer to appreciate the jellies from a safe distance don’t forget to spend a little extra time in the Jelly Gallery during your next visit to the Aquarium.