Jellyfish in aquarium? It's possible!
Updated: Oct 3, 2021
Almost certainly if you find yourself reading this article of from my blog you will have had an aquarium in your life. A reef? Or maybe a Guppy aquarium, but have you ever had a jellyfish aquarium? In recent years, thanks to specialized companies, the breeding in captivity of many species of jellyfish has taken hold.
Zoom on the Jellyfish
Jellyfish have been present on our planet for more than 600 million years. Long before there were fish. The long survival in the oceans was possible thanks to an extremely simple, 90% water-based anatomy. They have a symmetrical radius structure, featuring four main rays called perradi. The mouth of the jellyfish is situated in the concave, umbrella-shaped part of the body right at the end of the handle that connected with the gastrovascular cavity of the animal. The nervous system is simple and basic, yet these animals are highly complex: reproduction, nutrition, distribution on the planet are all hot topics and subject of research. They are able to move very efficiently through rhythmic contractions of the umbrella. The best known jellyfish are the Scifomedusas, which are equipped with batteries of stinging cells with neurotoxin action, especially the tropical ones (cubomedusas) rarely equipped with emolic liquid compounds, which are also deadly for humans.

Striped Compass Medusa Dotted (Phyllorhiza punctata) by Jellyfish farm
Which jellyfish can you breed?
Originally there were very few types on the market. The first to be marketed were: mangrove jellyfish and ear jellyfish. However, research and experience have brought about a dozen specimens to the market, bred and marketed directly on farms. The images below show the most commonly available types of jellyfish to breed and to find, curtesy of Jellyfish Farm.
Mangrove jellyfish (Cassiopea xamachana)

Moon jellyfish (Aurelia aurita)

Fried egg jellyfish (Cotylorhiza tuberculata)

Lagoon jellyfish (Mastigias papua)

Striped Compass Medusa Dotted (Phyllorhiza punctata)

(Chrysaora colorata)

Japanese compass jellyfish (Chrysaora pacifica)

All the images featuring jellyfish are courtesy of Jellifish fam under the copyright laws.
Kreisel aquaria
Very often on the market we find round shaped tubs with rounded corners, why? The reason is simple, these tanks are designed to ensure a rotational motion that prevents jellyfish from hitting the walls. In fact, the inside of these tanks is in extremely bare to prevent them from encountering possible obstacles. These aquaria are called Kreisel and have the additional advantage of ensuring that the specimens are not dragged near the drains.

The image shows my friend Alessio Fiorentino’s newly built jellyfish aquarium.
Technology and maintenance of a jellyfish aquarium.
For further information on the ordinary maintenance and set-up of these particular aquaria, we met with a friend who owns one: Alessio Fiorentino.
In jellyfish aquaria light is not essential, they are usually set up with rgb LED (purely for aesthetic reasons since they don't mind what colour and light intensity we provide them with) Jellyfish do not produce waste products like fish and other inhabitants of the sea, but they require extremely clean waters; therefore, a skimmer is always recommended. Alessio opted for a simple bubble magus q3 skimmer. In order to ensure a better stability of the system, Bio media and bioball can be added to the sump (for example Alessio uses those from Maxspect); finally a heater for the winter periods (ensuring a temperature ranging from 18 and 20°C).
Ordinary maintenance.
“Jellyfish must be fed often (ideally twice daily) with very fine zooplankton. I am hatching the artemia which I will then enrich and keep in the refrigerator to add daily to the tub. As regards the management of the parameters: the Salinity is around 31 PPM, they bear high values of nitrates and phosphates, but it is absolutely paramount to keep the nitrites down to. "
Conclusions
The breeding of these extraordinary animals is not something for everyone, the research behind it must push us to understand their fragility. Jellyfish are simple animals but with extremely specific needs. It is for this reason that we need to follow the experts’ advice and use specific equipment to ensure their correct and healthy breeding. I hope one day I will be able to breed them and admire their incredible charm.