Jellyfish Life Cycle

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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 arms. During this stage, the juveniles only measure 1cm in diameter, but they’re limbs look and behave just as in the adult stage. They have a central stalk-like structure, hanging from their underside, known as the manubrium. The manubrium opens into the gastrovascular cavity and is hence, key for the jellyfish to feed. Experiment Newly strobilated ephyrae were anesthetized and between one to six arms were amputated.…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
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