Upside down jellyfish stings?

[fishoholic]

Came real close to buying an upside down jellyfish today, until the girl at the LFS told me that they can sting and kill other fish and should be kept in a tank of their own. Anyone know anything about them? Was originally thinking of adding one to the 230g FOWLR tank. However I do not want my fish getting stung or hurt by one as well as I do not want my king angel or lunare wrasse hurting the jelly either.

[fishoholic]

Just finished reading up on them and they sound like a bit a a PITA to care for plus they can sting fish and corals if they get to close.

More info if anyone is interested:

The Upside Down Jellyfish, also called the Cassiopeia Jellyfish, is so named because its flattened bell (head) rests on the bottom. It extends its frilly tentacles up into the water column where they capture planktonic food and absorb light that is used by photosynthetic algae that are housed in its body.

It also prefers a wide sandy bottom to the aquarium and requires high intensity light for photosynthesis to occur. It will not tolerate copper or high nitrates in the water, and since its body is composed of 95 to 98% water, sudden changes in salinity or pH can have radical consequences.

Its sting is mildly toxic; humans very rarely notice the sting. Care should still be taken though when handling it or while doing maintenance on the aquarium.

It will require daily supplemental feeding with zooplankton substitutes.

Another popular Jelly fish is the Upside Down Jelly fish, Cassiopea, which comes from the western Pacific Ocean around the Philippines and has been introduced to Hawaii (probably by ships around World War II). Cassiopea grows to about 8 inches / 20 cm in diameter. They are interesting because they often lay on the bottom of sandy flats in shallower water, but they are also capable of floating around. The Upside Down Jelly fish carries symbiotic algae for food and swimming upside down allows that algae to catch the rays of the sun necessary for photosynthesis. Cassiopea also feeds on micro plankton like most other Jelly fish.

Keeping Cassiopea jellyfish in captivity is comparatively common and this species is by far the most frequently kept jellyfish species among aquarists. It can occasionally even be found in ordinary pet stores. To keep Cassiopea jellyfish you will need an upwards water flow to allow the jellyfish to stay suspended close to the surface.

The filtration demands of the jelly fish will resemble those of a reef tank. The water quality must be very good for your jellyfish to live well. Multiple skimming (surface and protein) is strongly suggested. Very effective biological filtration is important and ammonia content should be kept at the lowest levels humanly possible. Ammonia is known to neutralize the poison of a jellyfish’s sting, and is believed to harm a lot more than just the venom in a jellyfish. You will also want decent mechanical filtration when keeping jellyfish in an aquarium.

The next big hurdle is feeding your jellyfish. They eat live plankton and a few other things in the wild. Again, you will have little luck on good supply from the local fish store. One thing often used (though not as good as their natural diet) is baby brine shrimp (1-2 days old) which can be hatched in large quantities. Plan on a second hobby in raising Brine shrimp.

And the final note, LIGHTING! Your Upside Down Jellyfish fish depends on strong rays for its symbiotic algae to photosynthesize. Metal Halide, and/or VHO lighting are highly recommended.

Now, if you are not discouraged from keeping jellyfish in your aquarium, good luck. Just remember that it will be more challenging (and rewarding) than most other marine life.

On a safety note… If stung, there are a number of means suggested to cool the sting, including ammonia and vinegar. If this does not help or you feel other effects that are above a “sting,” seek immediate medical attention. While the two species suggested above are condsidered “safe” for humans, it is possible to have an allergic reaction that is much worse than the normal symptoms. Always handle your jellyfish with great care to keep both of you happy and healthy!

The best aquarium setup for these jellyfish is an aquarium with a wide sandy bottom. The sand layer should be thin. An external wet/dry filter is best but the water intake should be protected to prevent the jelly from becoming trapped. Protein skimmers should be used to keep the water quality up.

[fishoholic]

More info on the sting

Most people do not have an adverse reaction to such a sting, although some people may experience pain or swelling after contact. The main purpose of these nematocysts seems to be feeding; the frilly tentacles where the stinging nematocysts are located are on the underside near the mouth. Nematocysts are highly specialized cells which fire a tiny dart when disturbed. This is what gives the tentacles a "sticky" feeling. These darts will attach to the prey (or other intruder) and pump toxins into them. Nematocysts also occur in anemones and many corals and are an effective method of capturing prey and discouraging predators.

Good info. link

http://www.centralpets.com/animals/fish/saltwater_inverts/swi1782.html

[Nihoa]

i was never bothered by the sting but my gf said she could feel it. whenever a hermit would try and crawl over it you could tell the hermit felt it cus they would do a little dance and run away. that said, the sting didnt seem to bother our chocolate chip star who ate the jelly without much worry. frigger.

as far as hurting fish goes id be much more worried about some of the anemones than the jelly. you cant really put the jelly in the dt anyway cus they cant handle high flow or powerheads as they get sucked in pretty quick. you need a quiet area in the sump with a sandy bottom and no rock or sharp objects that it would rip itself on. i think you pretty much need a similar setup to a seahorse tank.

[fiorano]

i heard they prefer a cylindrical tank as well

[justinl]

a couple of corrections/additions I feel I need to make:

- upwards flow isn't really necessary. just low flow.

- they rely mostly on photosynthesis so lighting has to be bright; food doesn't have to be daily though they will eat it and would probably enjoy daily feeding.

-sandbed depth is irrelevant. just has to be oolitic (fine grained). don't feed brine shrimp.

-sandbed must be extensive. these can be kept in standard aquariums if you plan it right. you don't need a kreisel because they are benthic.

[fishoholic]

i heard they prefer a cylindrical tank as well

That is for regular jelly fish (which have to have a cylindrical tank or they could crash into a tank wall and die) the upside down ones do not need a cylindrical tank although they do need their own specialized tank, or a good sized refugium area that is lighted with MH.

(on a side note) Neither of which I had or wanted to set up so personally I decided against getting one.

[fishoholic]

a couple of corrections/additions I feel I need to make:

- upwards flow isn't really necessary. just low flow.

- they rely mostly on photosynthesis so lighting has to be bright; food doesn't have to be daily though they will eat it and would probably enjoy daily feeding.

-sandbed depth is irrelevant. just has to be oolitic (fine grained). don't feed brine shrimp.

-sandbed must be extensive. these can be kept in standard aquariums if you plan it right. you don't need a kreisel because they are benthic.

Agreed +1