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Tuesday, February 9, 2010

Sun Jellyfish

The Sun Jellyfish a member of the marine life species that is very unique. It is different from other fish based on its shape and other factors making it one of the most individual water forms in the world. The Jellyfish is a species belonging the scyphozoan class of marine life in the invertebrates. The name of scyphozoan is derived from the Greek name "skyphos" meaning "a drinking cup" and is used to describe the jellyfish based on their shape.

The jellyfish are located in the ocean around the world. They have a lifetime about three to six months. There are two forms of bodies for the jellyfish, the polyp stage occurs when they are in the sessile stalk form. During this stage, they have their mouths and tentacles facing upwards. This is how they catch their food that is passing them in the water. The second stage is the normal body structure and the most popular stage for the jellyfish. During this stage, they are in the umbrella shape referred to as the bell shape. The body structure of the jellyfish is known as the medusa and tentacles since the jellyfish hang from the border of the bell shape. The jellyfish's body consists of 90 -94% water.

The body of the jellyfish is made up of gastrodermis, an epidermis, and mesoglea. They do not have a central nervous system, respiratory system, an osmoregulatory system or a circulatory system. They use the same orifice to take in food and expulse of wastes since they have an incomplete digestive system. Jellyfish does not have any sensory organs or a brain. They have a small sensory organ located near its bell. This organ is called the rhophalia. They use the rhophalia and to identify odor and light. Jellyfish use their nerve net for detection of other organisms and it is located in the epidermis region.

Groups of jellyfish are referred to as a smack. They feed on large metazoan, other small fish, and small protozoa in the water. They typically trap the food in their tentacles yet there are some jellyfish that do not have any tentacles. To reproduce, the male jellyfish release their sperm into the water and the sperm travels to the female's mouth. This is how the females' ova are fertilized. Jellyfish lodge their eggs in their oral armpits where a chamber is formed for fertilization.

The most important defense mechanism of the jellyfish is the tentacles. The tentacles are covered with stinging cells called cnidocytes. Since the jellyfish do have any motion in water, they are hampered and not considered hydrodynamic. The lack of motion affects their swimming speeds so it is important for them to create water currents, which reaches their tentacles. To generate the current, the jellyfish flex their bells in an open and close simulation in a rhythm. To swim, jellyfish contract and expand their bodies. They do not have shells or scales so when they are exposed to the sun they seem to disappear, leaving only a filmed circle. Due to their invisibility in the sun, jellyfish are toxic and can cause death to humans. Generally, the sting of the jellyfish is extremely painful and attributed to various allergies in humans.

Jellyfish have a difficult life in captivity in comparison to other marine animals. They are not accustomed to the bound aquariums since they require the natural currents for their means of transportation.

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