Cnidarian

About Cnidarian

Most cnidaria have stinging cells attached to their bodies called nematocysts. They live in the oceans from the tropics to the Poles. There are four major groups of cnidarians: Anthozoa, Cubozoa, Hydrozoa and Scyphozoa. The Anthozoa include true corals, anemones and sea pens; the Cubozoa are the box jellies; the Hydrozoa is the most diverse group with siphonophores, hydroids, fire corals and medusae; lastly, the Scyphozoa are the true jellyfish.

Aurelia aurita

Aurelia aurita, also recognized as Moon Jelly, swim by pulsations of bell-shaped upper body parts of the animal. Their body is white and they're round which gives it the moon shape. Additionally, they are transparent and look just like the moon when the sun or moon shines on them.

They can be found near the coast; they generally travel in large groups in open warm and tropical waters in the Atlantic Ocean, Pacific Ocean, Indian Ocean. Aurelia aurita can be identified by the four moons' in the middle of their bells; these four moons are their reproductive organs.

With only limited ability to move, they move horizontally. They do not use much energy to swim around; they prefer water that has a constant currents. They keep their bell close to the surface; this allows the tentacles to spread for a better chance of capturing food. The tentacles are also used if they feel threatened by predators or are disturbed.

Aurelia aurita is carnivorous species that feeds on zooplankton such as molluscs, crustaceans, copepods, protozoans and diatoms.

Diploria strigosa

Diploria strigosa, commonly known as brain coral, are a unique species of coral. They are found in abundance in coral reefs of the Bahamas, Caribbean and Bermuda. This species of coral is also most often found in shallow waters of depths ranging from 1-30 meters. Brain coral are able to grow so long as they are receiving adequate sunlight and nutrients. Maximum energy consumption is allowed for when they are in an area with low sediment, that could cloud the water, thereby not allowing sunlight to pass through. Their rate of growth changes due to water temperature increase or decrease and also as the water becomes less clear.

Coral have a unique ecological niche in that they provide shelter for a multifarious amount of marine organisms, including plankton, fish, crabs and more. They have been compared to a city in the way that they provide a home for such a diverse group of organisms.

Coral can reproduce both sexually and aseually. Sexual reproduction occurs when gametes are released from male and female corals, which then become fertilized and grow into mature coral. Asexual reproduction is done in the form of fragmentation which is when a portion of coral breaks off, establishes itself in the sediment on the floor, and grows to produce a new colony. The release of the gametes, as shown in the picture above on the left, is called spawning. Spawning most frequently occurs at night and also tends to be more common depending on the season, which influences water temperature. For many species of coral, the temperatures where fertilization peaks is between 25 and 29 degrees Celsius.

One of the adaptations of brain coral is that it has evolved to allow peak fertilization to occur at lower temperatures . For example, average temperatures in Bermuda are about 20 degrees Celsius. That region also has very warm summers and cooler winters, which means that these coral have to be able to survive and reproduce in an area with a wider range of temperatures and a lesser amount of consistency.

Evans, Joseph . "Brain Coral, Diploria strigosa." Brain Coral, Diploria strigosa. Accessed January 27, 2017.

http://www.thecephalopodpage.org/MarineInvertebrateZoology/Diploriastrigosa.html.

http://www.ucmp.berkeley.edu/cnidaria/scyphozoa.html.

http://www.ucmp.berkeley.edu/cnidaria/cnidaria.html.

http://marinebio.org/species.asp?id=231.

http://www.bioexpedition.com/moon-jellyfish/.

http://eol.org/pages/203484/details.

http://tolweb.org/treehouses/?treehouse_id=3373

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