I get the chance to meet a lot of interesting people in this hobby. Most of the time these occurrences happen at random and with varying outcomes. But every once in a while you meet someone who really takes you in a direction you have either never been, or never thought you would go. I had another one of these encounters when Cameron Urban, of Jellyfish Art, who originally contacted us to discuss legislation related to the aquarium industry. I told him my thoughts on the subject, but the conversation eventually progressed into his specialty, jellyfish. Never passing up the opportunity for a good educational experience for the AquaNerd readers, I decided to ask him a few basic questions about jellyfish. Cameron replied in no time, and both our questions and his responses can be seen below.
The questions are very simple. I wanted to ask them from a beginner’s perspective, as most hobbyists don’t really know about jellyfish and their requirements. Cameron did a great job of answering each question, and I know I learned a few things.
AquaNerd: So, why jellyfish? What attracted you to them and what about them fascinates people?
Jellyfish Art: The first jellyfish exhibits opened in public aquariums several years ago when scientists first discovered how to display jellyfish in captivity using tanks with special water flow patterns. Since then, jellyfish exhibits have been wildly popular and now jellyfish are found in virtually all the public aquariums. It was clear people loved to watch jellyfish and their soothing and mesmerizing movements, but nobody had made the necessary tanks and food to allow people to have their own jellyfish. After some tinkering and experimenting, Jellyfish Art started selling jellyfish tanks, food, and jellyfish all online. It was immediately apparent that people had been wanting their own jellyfish as they started getting jellyfish tanks and pet jellyfish. That is when Jellyfish Art took off.
AquaNerd: Are jellyfish hard to care for?
Jellyfish Art: Jellyfish tanks are easier to maintain than many salt water tanks because jellyfish have such a low metabolism. In addition, our jellyfish tanks have very low evaporation rates, so maintaining salinity takes only a few minutes per month. Nevertheless, jellyfish do need to be fed once a day and follow similar cleaning procedures as other salt and fresh water tanks.
AquaNerd: What kind of water parameters are required for proper jellyfish care?
Jellyfish Art: Every 2 weeks, 25% of the tank water must be changed. You can leave the jellyfish in the tank during a water change. We discourage using tap water, so it is better to purchase salt water from your local aquarium store.
How does a jellyfish tank differ from a normal fish tank? The key differences are in the design and filtration. Whereas a normal fish tank is rectangular and has one direction of filtration, a jellyfish tank is circular allowing the filtration to keep the jellies suspended.
Jellyfish aquariums traditionally follow the kreisel design. By definition, a kreisel tank is circular, which helps the water to constantly flow in a cycle. Even the bottom of the tank is curved so that there are no obstacles or changes in the flow of the current. With its unique inlet and drain, the filtration system uses a special screen to prevent the jellyfish from getting sucked in and liquefied. Separate inlet and outlet chambers assist this operation helping the jellyfish to stay away from the sides of the tank. Combined, both the filter and tank design create an equilibrium in water pressure so the jellyfish don’t get stuck in one place but rather swim freely.
The kreisel tank is able to house most species of fish, however it is specialized for more delicate organisms such as jellyfish. If a jellyfish were to be placed in a normal fish tank there would be multiple barriers that would prevent the jellies from living a normal life span. As mentioned, the rectangular design would get the jellyfish stuck in corners most likely tearing their delicate tissue. It also wouldn’t be long before the jellyfish get sucked into the inlet of the filter. To house a jellyfish properly in a normal fish tank one would need to convert it. This takes a lot of money and free time, as well as a much more in-depth understanding of how a kreisel is constructed.
AquaNerd: What do jellyfish eat? Are some photosynthetic?
Jellyfish Art: For the most part, jellyfish in the wild feed on plankton, which is made up of thousands of microscopic species of swimming animals. Some species of jellyfish, such as the Upside Down Jelly host symbiotic algae within their oral arms. This algae provides extra nutrition to the jellyfish by producing organic material through photosynthesis. Many species of jellyfish feed on other species of jellyfish. For example, the sea nettles feed on moon jellyfish
In captivity, jellyfish are fed frozen food specially formulated for jellyfish. Jellyfish Art provides a frozen jellyfish food specifically formulated for jellyfish. It is made from plankton high in HUFAs (Highly Unsaturated Fatty Acids), which are essential for proper nutrition. Jellyfish can also be fed live food, although this is very time consuming and messy. Public aquariums have a full time staff, so they often hatch their own Artemia (brine shrimp) to feed to jellyfish. Depending on the species of jellyfish, sometimes public aquariums feed the jellyfish rotifers, blended krill, chopped fish, and other foods.
AquaNerd: What kind of equipment is required to successfully keep jellyfish?
Jellyfish Art: The tank must have a kreisel design so that the jellyfish don’t get stuck in any corners. The kreisel design will also ensure that the jellyfish don’t get liquefied in the filtration system and also so that they swim suspended above the bottom of the tank. The pressure of the filtration system must be fairly light and must be composed of biological, mechanical, and chemical components.
AquaNerd: I know there are countless species of dangerous jelly, but can the ones in captivity sting us? Are they dangerous to unsuspecting aquarium hobbyists?
Jellyfish Art: Most jellyfish can sting us. However, Jellyfish Art uses moon jellyfish, a species that is harmless to the human touch.
AquaNerd: Any crowd favorites? Which jellyfish are the most popular and why?
Jellyfish Art: There are definitely a few crowd favorites when it comes to jellyfish. After the movie Seven Pounds came out everyone wanted a box jellyfish. But more realistically, our customers will ask for either pacific sea nettles or moon jellyfish. Unfortunately, pacific sea nettles are a species that will only work in our larger custom tanks. Most people like the moon jellyfish because they become illuminated under LED lighting.
We would like to thank Jellyfish Art for, not only participating in our interview, but also expanding our horizons.