liquefied food for 10 to 15 minutes. Feed once or twice a day and add food little by little if there is not enough. The digestive system and oral arm taking on the color of the food signifies that the jellyfish is full. Pick it up gently with a glass container just large enough to hold the entire jellyfish and put it back into the tank. The water and food in the feeding vessel should be thrown away after feeding. Control the amount of ood each time you feed jellyfish to reduce unnecessary expense and to prevent water quality problems. It’s best to feed jellyfish this way, but if you have a great number of jellyfish to feed, you might have to feed them directly in the tank.
Tentacles develop around the rim of the bell in a juvenile A. aurita.
There are zooxanthellae in the bodies
of photosynthetically active jellyfish that
supply them with nutrition while jellyfish
supply the zooxanthellae with nitrogenous
waste. As they depend on each other, light
is important to these jellyfish, as with many
sessile reef invertebrates.
Courtesy of National Aquarium, Baltimore
Blue blubber jellyfish Catostylus mosaicus, photographed at the Jellies Invasion exhibit at the
National Aquarium in Baltimore.
average temperature is higher than this, so
a water-cooling system is necessary for a
jellyfish tank, as high temperatures will kill
the animals. Raising jellyfish in the winter is
another option if you live in a hot climate.
Rarely can jellyfish be kept with
tankmates. Most fish will eat up all of
the food or even attack the jellyfish. Most
invertebrates, including corals, will kill
and eat the jellyfish. So it is best to keep
jellyfish in a species tank.
Jellyfish live on plankton in the wild,
which is almost impossible to provide in
an aquarium. The most common food used
is grated shrimp. You can also add some
dry food for the jellyfish to capture with
Today there are many manufactured foods
that are especially intended for baby fish.
They contain advantages such as being
great tasting and full of protein, remaining
suspended in the water column, lacking the
risk of parasites or pathogens, and being
very convenient. These foods are also rich
in amino acids and are easy for baby fish
to take. It’s easy to feed jellyfish with these
artificial foods, and the size of these foods is
quite suitable for the tentacles of jellyfish.
To avoid water pollution, it’s best to use a
separate feeding vessel. Pick up the jellyfish
and some tank water with a container. Feed
a medium-sized jellyfish with 5 cc (
Jellyfish are capable of getting sick just
like any other animal. Besides predation,
which is likely to occur when they are kept
with tankmates, jellyfish can fall victim to
other problems. Food of poor quality can
contain parasites, and it is important to be
vigilant about keeping parasites out of the
tank. As mentioned earlier, bubble damage
can occur if one is not careful when setting
up the filter or changing the water. Objects
or decorations in the tank can also cause
serious harm to the jellyfish. A corner-less
(round) tank with no equipment, substrate,
or other objects in the tank itself is best.
Do not allow food to fall to the bottom of
the tank, and if any does, siphon it out to
make sure the tank is clean. Jellyfish are very
sensitive to dissolved nitrogenous wastes.
If jellyfish shrink in size, it is probably due
to a lack of food or poor nutrition. Jellyfish
can use their protein and fat reserves to stay
alive, which is why the body shrinks. In fact,
jellyfish can go more than two weeks without
any food. It is necessary to pay attention to
their size, movements, and reaction to food so
you can properly adjust their feeding.
Although jellyfish are not the easiest
animals to keep in the home aquarium,
they make fascinating specimens, and, with
the right care, they can thrive and delight
you and your family with some of the
wonder of ocean life. D