Tuesday, May 7, 2013

How to Keep Upside Down Jellyfish

Care for Upside Down jellyfish
Cassiopeia Sp.


Temperature preference: Always tropical
True Jellyfish: Yes
Food Preference: Upside Down jellyfish require strong lighting. They have zooxanthellae algae living inside their tentacles. This supplies a major source of food for them. As the algae photosynthesizes, it produces food that the jellyfish can utilize. Upside Down jellyfish should also be fed normal jellyfish foods, such as live brine shrimp or rotifers. I find that they will also eat decapsulated non hatching brine shrimp eggs. Upside Down jellyfish don't move often, so live food is best. That ensures that they get the food, and it doesn't settle next to them.

*For Lighting, I just use a shop lamp with a compact fluorescent bulb inside. Similar lighting set ups will work.

Tank Preferences: Upside Down Jellyfish actually prefer tanks other than the traditional kreisels. Since, they generally sit upside down on the bottom of their tank, they prefer flat tanks. Sand is generally not used in jellyfish tanks, but it can be used in Upside Down jellyfish tanks. A good tank set up is to take a 10 gallon glass or acrylic aquarium. Screen off a section of the tank for a filter or find a way to cover the intake of the filter really well. Add some sand or go with a bare bottom. Add some lighting, and its done. You could also screen off a section and then have a drain to a sump. The possibilities for Upside Down jellyfish tanks are very open. Feel free to add macro algae or mangrove plants. Upside Down Jellyfish live in swampy environments so having tanks that are more like a refugium is good. Water quality is still important, but the tank definitely doesn't need to be spotless.

Life Cycle: Embryo-planula-polyp-strobila-ephyra-metaphyra-juvenile-adult

Life Span: 1 year on to several more.

Description: As said above, Upside Down Jellyfish are generally found laying upside down on sand flats. They stick their tentacles up in the water facing the sun. Their tentacles often resemble algae or little island forests. I imagine this is to allow for camouflage and increased surface area for algae to grow. These jellyfish come in all sorts of colors, such as: Olive green, to various camo colors, blues, greys and yellows. Some have white spots on them. Some also possess longer and flat oral arm tentacles that emerge from the lower bushier tentacles. These are often colored solid green or blue.

Breeding: Upside Down jellyfish have been known to breed on their own in captivity. They actively form polyps. These polyps tend to be very invasive and proliferate.

Planula: Planula are fairly similar to Moon jellyfish planula. They tend to be of a larger size, however.

Polyps: Polyps are very large. They exist as fairly large buds on a long skinny stem. Compared to Moon jellyfish polyps, Upside Down polyps are alien. If disturbed, the polyps may twitch or move. The polyps reproduce by budding off. These buds are actively mobile and can be seen by the naked eye, moving on surfaces or in open water. The polyps like to hang from where they are attached. They also seem to be fine standing on their own as well. Hanging the polyps upside down or at and angle better mimics their natural environment and keeps them clean.

Strobila: Strobila produce one ephyra per event. Strobilation will occur in waves. The best way to cause this is too adjust the temperature in the tank and bring it up. This will mimic spring time, which causes them to strobilate. Strobilations can yield a fair amount of ephyra, as most polyps will strobilate simultaneously. Manual strobilation can occur about once a month. This will avoid over working the polyps.

Ephyra: Ephyra come off the strobila at a very large size. They don't require quite the care that Moon jellyfish ephyra require. A good setup for raising Upside Down ephyra is to get a dish or container and place them inside. I generally use a 8” culture dish. They can grow in there with standing water. Feed daily with live baby brine shrimp and change the water daily or every other day or so.

*I tried to grow ephyra in a 10 gallon tank. I assumed the larger volume would allow more jellies and faster growth. Unfortunately, they seemed to have issues finding brine shrimp in the large volume. I found growing the upside downs a little in dishes or smaller tanks will help them grow more successfully. They can be transferred to a bigger tank after they grow a little.

Juveniles and Adults: Juveniles and adults can coexist in the same tanks. Once the Upside Down infants reach about 1” they are set to be moved into their permanent home as juveniles. Adults can get fairly large at 10-14”. They generally stick around 4-5” in home aquariums.