Animal Biology Report, Essay Example

The scientific name of the moon jellyfish is Aurelia aurita. According to the scientific classification system, the kingdom of this organism is Animalia, the phylum is Cnidaria, the class is Scyphozoa, the order is Semaeostomeae, the family is Ulmaridae, and the genus is Aurelia, and the species is A. Aurita. This animal is the most studied species among members of its genus. As a consequence, scientists use their knowledge about this organism to gain a greater understanding of similar species. This particular jellyfish is translucent to light and typically measures 30-35 centimeters, although it could grow as large 40 centimeters (Pond 35). Compared to some other species of jellyfish, Aurelia aurita is considered small to medium sized. Researchers are able to readily identify Aurelia aurita based on some of its physical characteristics, including the fact that it has four gonads that appear to be the shape of horseshoes. These gonads can be observed through the top of the jellyfish, which is also known as the bell. The jellyfish is also marked by its tentacles, which it uses for hunting and limited swimming. Typically, Aurelia aurita drifts until it finds food and then uses its tentacles to stun its prey.

Aurelia aurita is found in a majority of oceans, independently of the climate that is characteristic of certain area. Specifically they can be found as far North as the point just before the arctic and as far South as the southern tip of South America. Thus, it appears that it is challenging for Aurelia aurita to live in portions of the ocean that have a very cold temperature. Otherwise, it is reasonable for the jellyfish to survive.  However, even though the species can live in the oceans, it is typically found in estuaries and harbors due to the increased availability of food in these areas. This organism can live in temperatures ranging from 6 to 31 degrees Celsius, indicating that to survive, Aurelia aurita can inhabit many diverse parts of the ocean. However, it prefers to live in temperatures that range between 9 and 19 degrees Celsius. Furthermore, even though the moon jellyfish is a saltwater organism, it can live in areas with low salinity. Another notable fact regarding Aurelia aurita’s habitat is that it prefers to live in areas in which the currents are consistent. However, because the jellyfish can live in many diverse areas and locations, there is not one specific place in which they can be found (Dawson et al., 11968). In order to continue competing for food, these jellyfish could reasonably travel far distances and still remain successful in its ability to thrive.

Water conditions that are ideal for the moon jellyfish have a sufficient level of dissolved oxygen in the water (Moen & Svensen 74). Specifically, jellyfish have trouble living in areas with very warm weather because the amount of dissolved oxygen in the water is typically the lowest in these locations. This is also an effect that is seen among the jellyfish during warmer months in areas with significant seasonal weather changes. Aurelia aurita prefer living in areas in which the dissolved oxygen concentration is below 2.0 mg/L. These organisms tend to change their location within the ocean to seek places with more ideal dissolved oxygen concentrations during these seasons.  Destinations that are ideal for the Aurelia aurita during summer months include Tokyo Bay in Japan and Seto Inland Sea. A large portion of reproductive activity occurs during summer months in these aforementioned locations.

The life cycle of Aurelia aurita consists of two main stages, the polyp stage, which involves asexual reproduction, and the medusa stage, which involves sexual reproduction. Asexual reproduction occurs through a process known as budding, in which DNA is shared evenly between two daughter cells, although the sizes of the resulting cells may differ. However, since these cells are genetically similar to the parent, this helps the jellyfish form a large group of polyps, known as a colony. Some of these polyps produce a structure known as the ephrya, which is the stage that exists after the budding of the polyp. These ephyra are small medusa, which are essentially immature jellyfish. These medusae swim away from the parent and develop over time before reproducing through sexual reproduction. At this point, a zygote is formed and this zygote then developed into a larva, also known as a planula. This larva then leaves the adult medusae and attaches to a fixed and shaded surface. Under these conditions, the adult is then able to produce new polyps, continuing the life cycle of Aurelia aurita.

Aurelia aurita has male and female members. The male is responsible for releasing the sperm, which is received by the female through the mouth. When the sperm joins with the egg, fertilization occurs and the zygote is formed. Once the eggs are fertilized, they develop in the “pockets in the arms that surround the mouth until they are ready to be released” (Mystic Aquarium). Scientists report that their courtship rituals appear to take the form of a “mating dance”. However, this ritual is not highly studied and has only recently been described. Interestingly, all jellyfish experience puberty at exactly the same time; during the spring season. The hormone that triggers this effect is released when the cold water that is typically present during winter seasons shift to the warmer weather experienced during spring and summer (Wolford, 2014).

Since jellyfish have the potential to lie up to 45,000 eggs each day, a single jellyfish can potentially have millions of offspring. Once they are born, they are typically left on their own for survival. Some females carry their young planulae for a short period of time before they are deposited in the water. Since the life cycle of jellyfish is relatively short, there is not sufficient time for jellyfish parents to reasonably care for their young and there are often too high a number of young for this to be possible. Thus, it is fortunate that Aurelia aurita are born with instincts that allow them to survive on their own and partake in the reproduction cycle the following season.

Typically, Aurelia aurita feeds on plankton in addition to mollusks, crustaceans, tunicate larvae, rotifers, protozoans, diatoms, eggs, fish eggs, and more. As long as the available food is small, it is possible for the moon jellyfish to consume it. Because the Aurelia aurita hunts smaller organisms, it could be said to be a predator, although it also has to defend itself from becoming prey due to the dietary needs of larger ocean animals. These organisms capture their food using their tentacles, which are effective in this process because they are coated with mucus. At this point, the food is brought to the gastrovascular cavity, which acts as the digestive system for this species. In this cavity, enzymes are recruited to help break down food. While this organism does not technically have a digestive system, it has digestive organs that allow the process to occur.

Currently, these jellyfish have no risk of becoming extinct. In fact, they are so prevalent that they are clogging the piping system of nuclear plants and are wiping out portions of the fishing industry due to their need to feed on some of the same food sources as humans (Guilford). The current environmental climate is causing the jellyfish population to rise, which is causing a series of problems around the world. It may be beneficial for scientists to find a way to work to reduce the current population problem before Aurelia aurita further alters the balance of the ocean ecosystem. Since a large number of jellyfish can be produced each mating season, it may be beneficial to increase the population of jellyfish predators in the Tokyo Bay in Japan and Seto Inland Sea because these are popular mating spots for the organism. Specifically, the leatherback sea turtle is a good candidate for this process due to its enhanced lifespan and potential for minimal ecological impact. It is possible that human action has upset the balance of the ocean, but we can reasonably reduce the amount of the moon jellyfish population by taking advantage of biology.

Works Cited

Dawson, M. N.; Sen Gupta, A.; England, M. H. Coupled biophysical global ocean model and molecular genetic analyses identify multiple introductions of cryptogenic species. Proc. Natl. Acad. Sci. USA, 102.34(2005): 11968–11973.

Guilford, G. 2013. Web. 28 Oct. 2015.  Jellyfish are taking over the seas, and it might be too late to stop them. <http://qz.com/133251/jellyfish-are-taking-over-the-seas-and-it-might-be-too-late-to-stop-them/>

Moen, F.E.; E. Svensen. Marine fish & invertebrates of Northern Europe. Southend-on-Sea: AquaPress, 2004.

Mystic Aquarium. 2015. Web 28 Oct. 2015. <http://www.mysticaquarium.org/animals-and-exhibits/species-of-the-month/664-moonjelly>

Pond, W.G. Encyclopedia of Animal Science. New York: Marcel Dekker, 2004.