The Aurelia aurita, also known as moon jellyfish, is a common species of jellyfish, which can be found in oceans around the world. They are hardy, and capable of living in acidic, polluted or poorly oxygenated water. Life Cycle of Moon jellyfish
The polyps are the first stage of their life, hatching from eggs. The polyps undergo a process called strobilation, to enter the strobila stage, and then the juvenile stage, which are called ephyra. They then mature to enter the adult stage, known as medusa, over the period of one month, under laboratory conditions, which include abundant sources of food.
Anatomy of Interest
The ephyra stage of the species, which is the one of interest to this experiment, have a disk shaped body and 8 symmetrical…show more content… 5- ethynyl-2′-deoxyuridine (EdU) was used as the stain. However, there was no dramatic increase in the size of the stain during symmetrization, proving that theory wrong.
The theory that programmed cell death on the cut side of the void, created a negative pressure to pull the arms to the other side was tested. Sytox, a DNA-binding dye that does not cross intact cell membranes and therefore only stains cells with compromised membranes, indicating cell death, was used. This theory too was proven false.
This seemed to indicate that it was not proliferation or death that caused it but reorganization of the cells. Muscular reconnection on the cut side could pull the arms to the cut side. To block muscle reconnection, we treated the cut ephyrae with cytochalasin D, which inhibits it, after the cuts healed sufficiently. The observation was that the muscle reconnection was inhibited, but a percentage of them continued to undergo the process. However, it was also seen that an increase in concentration of cytochalasin D seemed to decrease the number of symmetric…show more content… In such a system, if a section of the arms were cut, the forces would become unbalanced, leading to an inability to maneuver. In an amputated jellyfish, the total angular push, due to elastic repulsion is not cancelled out, and causes a stretching resultant force along the disc. The repetition of this cycle, causes the arms to move to a more stable state, in turn causing the symmetrization. It was found that if a substance that increases muscle contraction, such as magnesium, was introduced, the rate of symmetrization increases as well. Thus, the correlation between pulsation rate and symmetrization speed supports the idea that muscle contraction plays a dominant role in driving