Jellyfish are beautiful but extremely harmful creatures of the deep. Jellyfish strike a lot of fear into the minds of people who portray them as blobs floating around in the ocean that go around stinging people at the beaches
but yet jellyfish are much more than that. Jellyfish are ferocious predators of the sea but not everyone portrays them that way.
Jellyfish are actually very simple creatures when you take a look at them on the inside. Jellyfish belong top the phylum cnidaria which include hydras, hydroids, jellyfish, sea fans, sea anenomes, corals. They can range in s
ize from peas to seven feet in diameter. This is the only phylum to withhold only two layers of cells. Jellyfish have two layers: the first is the ectoderm or outer skin, the second is the endoderm or inner skin. Between these two layers is a jelly
like substance called mesoglea which jellyfish get their name from. A jellyfish has no respitory, circulatory, or excretionary organs. It also is lacking a well developed head and a nervous system.
The only opening in a jellyfish is the mouth which everyone sees when they look at the umbrella of the jellyfish. Right under that umbrella is the mouth which hang feeding tentacles. In the feeding tentacles there are tiny
little capsules which hod the poison to catch food. They are called nematocysts. When prey touches the tentacle automatically poison is injected into the animal via a spear. The animal then becomes paralyzed and the tentacles bring it up to the mout
h were the body absorbs it.
The upside-down jellyfish is one exception to how most jellyfish actually feed. Believe it or not but the upside-down jellyfish is actually more like a like a plant. In the Tentacle region right before you
get to the mouth there is a big bush there well in those layers of skin there is something called zooanthalle which make these jellyfish photosynthetic, they make their own food from light energy.
Most of the jellyfish we know of
are asexual. This means that it has both male and female organs or the
power to reproduce by itself. In the life process of a jellyfish an
adult fertilizes an egg and drops it on the sea floor. the egg turns into a polyp. In this polyp tiny jellyfish are stacked on top of each other to form a cylinder of jellyfish. After they mature one by one the top leaves and becomes free swimming.
For the jellyfish movement is quite hard. There is a ring of muscles around the base of a jellyfishes umbrella. In order to move the ring of muscles have to contract squeezing the water out of the umbrella which propels the
jellyfish forward.
Even though on the inside they are very simple creatures jellyfish are varicose beauties of the deep they are not to be taken lightly and demand the utmost respect.
Since the project is strictly on how to keep jellyfish safely in captivity without having to buy any special tank systems our data is how they were kept. There are two species that are currently being kept. The two species
that are being kept is the moon jellyfish (Aurelia aurita) and the upside-down jellyfish (Cassiopeia).
The moon jellyfish are a little harder to keep though because they require a special tank design to mimic the ocean. At first we needed to devise a system were water could come in and out without hurting the jellyfish in an y way. The tanks at the Waikiki aquarium were used as a model to build the tank. What was needed to be done was to create an unlimited current in the tank. From doing some research a kreisel tank (it was used for plankton research, German for spinni ng top) was also used as a model because it created this current. We made it by cutting strips of acrylic plastic a little less than the width of the tank and about one and a half times the height of the tank. We cut two of those and then placed one i n the tank by bending it into a curve and did the same to the other sheet. We created a circle in the middle of the tank with two other compartments on the sides. The circle part is what is going to be holding the specimens. Next the holes were nee ded in the acrylic so that we can accomplish a water flow that will support both the jellyfishes keeping them suspended in the water column and creating a current so that they wonÕt be siphoned out. Using a propane flame torch we heated a nail to the po int that it could melt the acrylic. We then made a four pointed star or a cross with three holes on each arm so that the siphoning power wonÕt be to strong in one area. A filter was made by placing a five gallon bucket in a sink drain with the pump si tting on the bottom and filter floss on top then charcoal then another layer of filter floss. The pump pumps the water up from the filter to a tee which then dispenses the water to both tanks.The moon jellies tank the water comes through a tube and we h ave tried to aim it at were the water exits the system so that none of the jellyfish get sucked away instead they are pushed away by gentle jets of water which circulates the tank as if they were riding the currents of the ocean.
The upside down jellyfish needed just a few things to flourish. One thing is that they needed a lot of light because they were photosynthetic so light was needed to sustain life. A regular set up of a twenty gallon tank was
dedicated to keeping them alive. The hook up to the filter and other tanks was not complete so there was no flow of water to or from the tank.
The experiment was basically to find a safe way to maintain two species of jellyfish found on the island of Oahu alive in captivity. The two species selection were the moon jellyfish (Aurelia aurita) and the upside-down jellyfi
sh (Cassiopeia). The tanks used were a modified version of the Kreisel, which was used successfully in Germany for plankton research, and was found to support the moon jellyfish quite effectively (Worbel, David; ÒPlanet of the JelliesÓ; Aquarium Fish: Fe
bruary, 1994). The upside-down jellyfish were placed in a regular set-up, twenty gallon tank. Within a period of less than two weeks the entire population died. Shortly afterwards, the population of moon jellyfish started to decrease from twenty-eight
to three.
The research showed that there is no safe way to keep them, but improvements to the jellyfishesÕ habitat by better preparation of the water. Additionally, the living conditions were not correct, as they were placed in the tank
over a period of just a few hours. This may have caused them to suffer toxic shock due to temperature differences, an ammonium spike, and possibly the wrong kind of bacteria producing harmful effects. Another attempt will be made, but more cautious ste
ps will be taken to properly prepare the water, and more attention given to the chemicals present in the water before introduction of the jellyfish to the tanks. With hard work, diligent preparation procedures, and a little luck these jellies from the se
a can be placed in the tanks, survive, and thrive for everyone to enjoy.
Being disappointed with the results I called an employ from the jellyfish section of the Waikiki Aquarium tried to clear a few things up. The mucus that was in the upside-down jellyfishes tank is a reaction they give off when
being stressed. He said that it could of been overcrowding because if you had too many jellyfish for one area then there could of been an ammonium spike in the water. Ammonia is a waste product they give off and if there are too many giving off at the
same time then you get an ammonium spike in the water. The layer of black sand that was found on the bottom of the tank is actually a waste product a certain bacteria gives off. The waste product or the black sand is actually hydrogen sulfide which i
s toxic to the jellyfish. So it was a combination of things that made them die.
The moon jellyfish died of the same thing itÕs just that there was less ammonium in the water and probably less of that bacteria. Since the jellyfish in this tank were not as large as the other ones were they were not giving off as much ammonuium.
The next time if we try it again I want to try to monitor chemical rates and try to control what is in the tanks and how many jellyfish are in the tanks to try to keep the losses down and the success rate up.
PLEASE E-MAIL ME IF YOU HAVE ANY OTHER QUESTIONS. THANKYOU!!!!!!