Your Guide to Keeping Jellyfish as Pets
Jellyfish are one of the most mesmerizing creatures on Earth — and yes, you can actually keep them at home. Once reserved for public aquariums like the Monterey Bay Aquarium and the Georgia Aquarium, pet jellyfish have become increasingly accessible thanks to purpose-built tanks and captive-bred species that thrive in home setups. If you have ever stood transfixed in front of a jellyfish exhibit, the good news is that experience can now live in your living room.
At ItsyBitsyPets, we cover the fascinating world of jellyfish keeping — from choosing your first species to maintaining the specialized equipment these ancient animals require. Jellyfish are not your typical aquatic pet, and that is exactly what makes them so captivating.
Best Jellyfish Species for Home Aquariums
Moon jellyfish (Aurelia aurita) are far and away the most popular species for home keeping. They tolerate a wider range of temperatures than most jellyfish, grow to a manageable size of 6 to 12 inches in diameter, and are commercially bred by suppliers like Sunset Marine Labs and Jellyfish Art. Their translucent bells pulse with an almost hypnotic rhythm, and under LED lighting they take on stunning blue, purple, and pink hues.
Other species gaining popularity include Atlantic sea nettles, blue blubber jellyfish, and spotted lagoon jellyfish. Each has different temperature and salinity requirements, so research your chosen species carefully before purchasing. The jellyfish keeping community on r/Jellyfish is a helpful starting point for species-specific advice and troubleshooting.
Jellyfish Tank Requirements
Standard rectangular aquariums are not suitable for jellyfish. These delicate animals drift with currents and will get sucked into filtration intakes or trapped in corners, causing tissue damage and stress. Jellyfish require a kreisel tank — a circular or pseudo-circular design that creates a gentle, laminar flow pattern keeping the animals suspended in the water column without ever hitting a wall or getting stuck.
Purpose-built jellyfish tanks from companies like Jellyfish Art and Cubic Aquarium Systems range from desktop nano units holding two to three moon jellies up to larger display systems for serious hobbyists. Expect to invest between 200 and 500 dollars for a quality starter setup. You will also need a chiller if your room temperature exceeds 77°F, since most jellyfish species prefer cooler water between 62 and 72°F.
Feeding Your Jellyfish
Jellyfish are carnivores that feed on zooplankton in the wild. In captivity, the standard diet is freshly hatched baby brine shrimp (Artemia nauplii), which you can hatch at home from cyst eggs using a simple hatchery setup. Most keepers feed their jellyfish once or twice daily, dispensing the brine shrimp directly into the tank where the current carries the food past the jellyfish oral arms.
You can tell if your jellyfish are eating properly by looking at their stomachs — in moon jellyfish, you can see the four horseshoe-shaped gonads through their transparent bell. After a good feeding, these structures and the gut canals will appear orange or pink from the brine shrimp. If your jellies look completely clear after feeding time, they may not be catching enough food and you should increase the amount or adjust the flow rate.
Water Quality for Jellyfish
Jellyfish are extremely sensitive to water quality — more so than most saltwater fish. Ammonia and nitrite must stay at zero at all times, and nitrate should remain below 20 ppm. Regular water changes of 10 to 20 percent weekly are essential. Use a quality marine salt mix and match the salinity to your species requirements — moon jellyfish do well at 1.023 to 1.025 specific gravity.
One unique challenge with jellyfish tanks is micro-bubble management. Air bubbles can become trapped under the jellyfish bell, causing them to float unnaturally and potentially damaging their tissue. Make sure your filtration system does not introduce air bubbles into the tank, and avoid using airstones or protein skimmers inside the jellyfish enclosure.
Jellyfish Lifespan and Health
Most pet jellyfish species live between 6 and 18 months in captivity, depending on the species and care quality. Moon jellyfish typically live about one year. This shorter lifespan compared to fish is something to consider before getting started — you will likely need to purchase replacement jellyfish periodically if you want to maintain a display.
Common health issues include bell shrinkage from poor water quality, tentacle loss from mechanical damage, and bacterial infections visible as cloudy patches on the bell. The best prevention is pristine water quality and proper tank design. Our care guides cover jellyfish health monitoring and troubleshooting for the most common issues keepers encounter.
Why Jellyfish Make Unique Pets
Jellyfish are not cuddly and they will never learn your name, but they offer something no other pet can — a living piece of the deep ocean in your home. Research published in the journal Environment and Behavior has shown that watching aquatic animals reduces anxiety and lowers heart rate, and jellyfish tanks are increasingly used in therapeutic settings for exactly this reason. They are silent, allergen-free, and require no walks. For apartment dwellers, busy professionals, and anyone who appreciates the alien beauty of marine life, jellyfish are a genuinely fascinating choice. Explore more unusual aquatic species in our invertebrates and saltwater pets sections.