JELLYFISH FAQs.


Useful information to help you care for your jellyfish aquarium.

Q: How long do jellyfish live for?

A: The average life expectancy of jellyfish varies significantly depending on the specific species. The most commonly available species to be kept as a pet jellyfish are Moon Jellyfish (Aurelia Aurita). Moon Jellyfish typically live about 12 to 15 months, provided they are kept in an appropriate aquarium. Other jellyfish such as blue blubber jellies have a shorter lifespan at around 6 to 9 months whilst Sea Nettles can sometimes survive for many years.


Q: Is it difficult to keep jellyfish?

A: We get asked this question a lot. Keeping any animal requires you to learn about the basic requirements to keep it healthy and jellyfish are no different. As a somewhat delicate saltwater creature, jellyfish requires a little more effort than a standard goldfish, however they are easier to keep than many other saltwater fish.


Q: How much work is needed in maintenance?

A: Once setup, it's actually quite simple.  Outside of daily feeding, you should perform a small clean once once per week along with changing 10% of the water once per week. Every 6 months a deep clean should be performed, rinsing the internal filter sponge.


Q: What do Jellyfish eat?

A: In the wild, jellyfish feed on plankton. For home jellyfish aquariums, there are a number of jellyfish specific powdered foods available from aquarium stores. We recommend the food produced by our livestock partner Exotic Aquaculture which should be available from most Cubic stockists. In addition, Jellyfish feed well off hatched baby brine shrimp and many more experienced hobbyists use this as a supplement along with the powered food.


Q. How often do jellyfish need to be fed?

A: Your jellyfish will need to be fed at a minimum of once per day however we find frequent small feeds works best.


Q: What about the environmental impact of collecting jellyfish from the oceans?

A: Firstly, very few of the jellyfish sold through high street retailers have come from the ocean, the majority of them are excess jellies cultured for public aquariums and other commercial jellyfish aquariums. Even when jellies are taken from the wild it has almost zero effect on wild populations. Jellies in the wild reproduce extremely quickly and can be seen in swarms of millions at certain times of year. Scientists are currently trying to understand why the numbers of jellyfish in our oceans has increased so much in recent years, getting to the point where they are causing problems with fish stocks by out competing juvenile fish for planktonic food.


Q: Is it cruel or unfair to keep jellyfish in an aquarium?

A: Jellyfish have no central nervous system i.e. they have no brain and are not aware of them selves or their surroundings. In this way it makes sense to think of jellies as being more like plants than fish. If the aquarium you keep the jellies in does a good enough job of replicating the jellyfish’s natural environment (good water quality, no sharp edges or surfaces which they can damage themselves on) then there is no reason to believe your jellyfish will even know they are not in the ocean. Keeping jellyfish in an aquarium is no crueler than keeping a plant in a plant pot. In the wild mortality rates are exceedingly high with only a few jellies in every thousand reaching maturity due to natural predation and beaching. In an aquarium jellyfish are not at risk of these problems and have been known to live for up to double the lifespan of their wild counterparts.


Q: Some of the inhabitants of my aquarium are looking unwell,

what should I do?

A: For us to help you with this question we first need some basic information from you including the size and type of your aquarium, what you are keeping in your aquarium, water quality, temperature and feeding/maintenance routine. Try posting in the advice section on our forum.


Q: Can I mix jellyfish species?

A: We do not recommend mixing more than one jellyfish species in the same aquarium. Some species of jellyfish eat others in the wild and even the ones that don't eat each other seem to irritate each other if they are different species. We have found that although some species (moons, flames, spotted lagoons) can be mixed together in the short term, over long periods it negatively effects their health and growth.


Q: Can I mix jellyfish and fish?

A: It is not recommended to keep jellyfish with fish in the same aquarium. This is because jellyfish have stinging tentacles that can harm or even kill fish. Additionally, fish may harass or try to eat jellyfish, which can be stressful for the jellyfish and disrupt their feeding and swimming behavior.