Cnidaria



Biodiversity in the Cnidarian Phylum Randall Rhodes T here are over 9 thousand different species within this phylum. A specific example is a hydra, a marine species of cnidarians. A hydra is a marine organism, like all animals in this phylum. The hydra has a regenerative ability. They can develop back parts of themselves if they have been removed or damaged. The hydras also do not seem to age or die over a course of time. [5] Another commonly known cnidarian is a sea jelly or jellyfish. Sea jellies are commonly thought of as jellyfish, but the proper term is sea jelly. There are actually many different varieties of sea jellies in the cnidarian phylum like true jellyfish, box jellies, and other classes of jellyfish.3 Other species in phylum cnidaria include sea anemones and coral, as well as jellyfish. [2] Characteristics of the Cnidaria Phylum Randall Rhodes  T he many animals that fall under the phylum cnidaria all share some similar features. Three of the main features are: <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; text-indent: 0.5in; vertical-align: auto;">
 * <span style="background-color: transparent; color: #ff5050; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">Radial symmetry [<span style="background-color: transparent; color: #ff5050; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">6]
 * <span style="background-color: transparent; color: #ff5050; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">Tissue level organization [<span style="background-color: transparent; color: #ff5050; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">5]
 * <span style="background-color: transparent; color: #ff5050; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">Nematocysts [<span style="background-color: transparent; color: #ff5050; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">4]

<span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; text-indent: 0.5in; vertical-align: auto;"><span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">Something that all of the species of cnidarians have is a radial symmetry. Radial symmetry means that the when the animal is cut on several cutting planes the pieces are identical to one another. In other words, any way that the animal is rotated will look the same. An organism with radial symmetry exhibits no left or right sides. They have both a top and bottom only. [<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">6] <span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">Another characteristic they all show is tissue level organization. The animals therefore have many cells that contribute to a certain action, making them a more complex organism. These cells are organized into different tissues, and the tissues work together in the body. This means that these tissues are responsible for performing tasks, instead of organs. [<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">5] <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; text-indent: 0.5in; vertical-align: auto;"><span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">A type of cell that all cnidarians have is stinging venomous cells that helps them catch food and protect themselves. The organelle that also comes with the venomous cell comes with a physical structure, nematocysts, which come in many different varieties. Whether it is a large harpoon like barb, a sticky surface to trap prey, a lasso like string used to rope in preys, or a special type of nematocyst found on burrowing anemones, which create a tube in which the animal lives in, they all help cnidarians survive. [<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">4] <span style="background-color: transparent; color: #17365d; display: block; font-family: Times New Roman; font-size: 20px; line-height: 115%; text-align: center; text-decoration: none; vertical-align: auto;">Common Classes in the Cnidarian Phylum <span style="background-color: transparent; color: #5f497a; display: block; font-family: 'Lucida Handwriting'; font-size: 19px; line-height: 115%; text-align: center; text-decoration: none; vertical-align: auto;">Julie Perkins <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; text-indent: 27pt; vertical-align: auto;"><span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 35px; line-height: 115%; text-decoration: none; vertical-align: auto;">T <span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">he phylum cnidaria is generally broken down into four classes. Each class is a group of animals that share traits or attributes. For example, all cnidarians have a sting cells called nematocysts. <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; line-height: 115%; text-decoration: none; vertical-align: auto;">The four classes of cnidarians are: <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; line-height: 115%; text-decoration: none; vertical-align: auto;"> <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; text-indent: 27pt; vertical-align: auto;"><span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">Class anthozoa is thought to be the first class of phylum cnidaria. Anthozoans are symmetrical, and have aflowerlike appearance. This class includes coral and sea anemones, as well as sea fans and sea pens. Coral and Sea anemones help to provide environments for underwater creatures. Coral houses thousands of fish, as well as plants. Sea anemones can house small fish if they are immune to their nematocysts. [<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">2] <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; text-indent: 0.5in; vertical-align: auto;"><span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">Another class is class scyphozoa. This class of cnidarians are the typical kinds of jellyfish, not to be confused with the cubozoan jellyfish or class hydrozoa. This class of jellyfish can be either small or large, and are different from the other classes because they are shaped differently. [<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">3] <span style="background-color: transparent; color: #17365d; display: block; font-family: Times New Roman; font-size: 20px; line-height: 115%; text-align: center; text-decoration: none; vertical-align: auto;">Body Cavities in Cnidarians <span style="background-color: transparent; color: #5f497a; display: block; font-family: 'Lucida Handwriting'; font-size: 17px; line-height: 115%; text-align: center; text-decoration: none; vertical-align: auto;">Heather Vautrin <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: #000000; font-family: Algerian; font-size: 32px; line-height: 115%; text-decoration: none; vertical-align: auto;"> <span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 35px; line-height: 115%; text-decoration: none; vertical-align: auto;">T <span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">he phylum cnidaria is a branch of marine animals. This phylum includes sea jellies, sea anemones, box jelly fish corals and hydra.Cnidarians do not actually have a body cavity at all. An example of what the cnidarians have as a body is a sea jelly. A sea jelly is composed up of two layers of cells. Those cells are separated by a gelatinous substance called mesogloglea. Also sea jellies have little to no attributes. They have one hole from which they excrete and eat. [<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">8] <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; text-indent: 0.5in; vertical-align: auto;"><span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">This makes cnidarians acoelomates because acoelomates are defined as an organism without a body cavity. They do not possess a body cavity like coelomates. They are not pseudocoelomates because even though they are invertebrates, they still don’t contain a body cavity. [<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">7] <span style="background-color: transparent; color: #17365d; display: block; font-family: Times New Roman; font-size: 20px; line-height: 115%; text-align: center; text-decoration: none; vertical-align: auto;">Symmetry of Cnidarians <span style="background-color: transparent; color: #5f497a; display: block; font-family: 'Lucida Handwriting'; font-size: 17px; line-height: 115%; text-align: center; text-decoration: none; vertical-align: auto;">Heather Vautrin <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; margin-left: 4.5pt; text-align: left; text-decoration: none; text-indent: -4.5pt; vertical-align: auto;"><span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 35px; line-height: 115%; text-decoration: none; vertical-align: auto;">P <span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">hylum Cnidaria includes marine animals. These marine animals are sea jellies, box jellyfish, coral and hydra. These animals have radial symmetry which is when they are symmetrical from all angles. If you drew an imaginary line threw the top of a sea jelly you would see radial symmetry. The line would go through the body and if you turned it around on its axis it would roughly be the same from every angle. Sea Jellies can usually be divided into four equal parts because most sea jellies have four tentacles that hang down. The corals and sea anemones have six or eight fold symmetry. So all in all cnidarians have radial symmetry, although not in all the same ways. [<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">6]
 * <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: #ff5050; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">- Cubozoa
 * <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: #ff5050; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">- Scyphozoan
 * <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: #ff5050; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">- Anthozoa
 * <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: #ff5050; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">- Hydrozoa [<span style="background-color: transparent; color: #ff5050; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">1]

<span style="background-color: transparent; color: #17365d; display: block; font-family: Times New Roman; font-size: 20px; line-height: 115%; margin-left: 4.5pt; text-align: center; text-decoration: none; text-indent: -4.5pt; vertical-align: auto;">Evolutionary Success of Cnidarians <span style="background-color: transparent; color: #5f497a; display: block; font-family: 'Lucida Handwriting'; font-size: 17px; line-height: 115%; margin-left: 4.5pt; text-align: center; text-decoration: none; text-indent: -4.5pt; vertical-align: auto;">Julie Perkins <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; margin-left: 4.5pt; text-align: left; text-decoration: none; text-indent: 0.5in; vertical-align: auto;"><span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 35px; line-height: 115%; text-decoration: none; vertical-align: auto;">C <span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">nidarians can be seen as an evolutionary successful phylum because there are still many of them alive today. It is successful because of several factors. One of these factors is that this phylum has evolved greatly throughout the ages and has undergone the process of natural selection. For example, class anthozoa has suffered extinctions of species. This may seem like a sign of weakness; however, this means that the species that survived are successful because they were strong enough to survive natural selection. Now this class is an important part of the marine environment, and includes organisms like coral and anemones. [<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">2] <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; margin-left: 4.5pt; text-align: left; text-decoration: none; text-indent: 0.5in; vertical-align: auto;"><span style="background-color: transparent; color: #0070c0; font-family: Times New Roman; font-size: 17px; line-height: 115%; text-decoration: none; vertical-align: auto;">Another reason this class is evolutionarily successful is because of their nematocysts. These are the stinger cells that all creatures in the phylum possess. This gives all these organisms extra protection against predators. It allows them to render the oncoming threat impossible, and gives them time to escape. These cells can also help the cnidarians catch their prey [<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">1]

<span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: center; text-decoration: none; vertical-align: auto;">Works Cited <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; margin-left: 4.5pt; text-align: left; text-decoration: none; text-indent: -4.5pt; vertical-align: auto;">
 * 1) <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">Myers, Phil, and John B. Burch. "Class Anthozoa, Sea Anemones and Corals." //<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">Animal Diversity Web //. University of Michigan, 2001. Web. 16 May 2011. <span style="background-color: transparent; color: #800080; font-family: Times New Roman; font-size: 16px; text-align: left; vertical-align: auto;">__[]__ <span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">.
 * 2) <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">The Virtual Fossil Museum. "Phylum Cnidaria." //<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">The Virtual Fossil Museum //. Web. 16 May 2011. <span style="background-color: transparent; color: #800080; font-family: Times New Roman; font-size: 16px; text-align: left; vertical-align: auto;">__[]__ <span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">.
 * 3) <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">Waggoner, Ben M. "Introduction to the Scyphozoa." //<span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">UCMP //. Regents of the University of California, 22 Nov. 1994. Web. 16 May 2011. <span style="background-color: transparent; color: #800080; font-family: Times New Roman; font-size: 16px; text-align: left; vertical-align: auto;">__[]__ <span style="background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">.
 * 4) <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: black; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">Fenner, Bob. "Cnidarians." //<span style="background-color: transparent; color: black; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">Wetwebmedia, Aquarium, Pond, Marine and Freshwater Fish, Reef Tanks, and Aquatics Information //. Marine and Reef, Aqarium Livestock Weekly Specials. Web. 23 May 2011. <span style="background-color: transparent; color: #800080; font-family: Times New Roman; font-size: 16px; text-align: left; vertical-align: auto;">__[]__ <span style="background-color: transparent; color: black; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">.
 * 5) <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: black; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">Bellarmine University. "Cnidarians." //<span style="background-color: transparent; color: black; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">Bellarmine University //. Web. 23 May 2011. <span style="background-color: transparent; color: #800080; font-family: Times New Roman; font-size: 16px; text-align: left; vertical-align: auto;">__[]__ <span style="background-color: transparent; color: black; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">.
 * 6) <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: black; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">Klappenbach, Laura. "Radial Symmetry - Radial Symmetry in Cnidarians." //<span style="background-color: transparent; color: black; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">Animals Wildlife - Animal Facts, Animal Pictures, Habitat Facts, Evolution and Zoology //. New York Times Company. Web. 23 May 2011. <span style="background-color: transparent; color: #800080; font-family: Times New Roman; font-size: 16px; text-align: left; vertical-align: auto;">__[]__ <span style="background-color: transparent; color: black; font-family: Times New Roman; font-size: 16px; text-decoration: none; vertical-align: auto;">.
 * 7) <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: black; font-family: 'Times New Roman','serif'; font-size: 16px; text-decoration: none; vertical-align: auto;">Gregory, Ph.D, Michael J. "Introduction to Animals." //<span style="background-color: transparent; color: black; font-family: 'Times New Roman','serif'; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">The Biology Web //. Web. 23 May 2011. <span style="background-color: transparent; color: #800080; font-family: Times New Roman; font-size: 16px; text-align: left; vertical-align: auto;">__[]__ <span style="background-color: transparent; color: black; font-family: 'Times New Roman','serif'; font-size: 16px; text-decoration: none; vertical-align: auto;">.
 * 8) <span style="background-color: transparent; color: #000000; display: block; font-family: Times New Roman; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;"><span style="background-color: transparent; color: black; font-family: 'Times New Roman','serif'; font-size: 16px; text-decoration: none; vertical-align: auto;">Morris, Matthew. "Phylum Cnidaria - Cnidarians." //<span style="background-color: transparent; color: black; font-family: 'Times New Roman','serif'; font-size: 16px; text-align: left; text-decoration: none; vertical-align: auto;">Animals! Animal Information Center //. 15 May 2003. Web. 23 May 2011. <span style="background-color: transparent; color: #800080; font-family: Times New Roman; font-size: 16px; text-align: left; vertical-align: auto;">__[]__ <span style="background-color: transparent; color: black; font-family: 'Times New Roman','serif'; font-size: 16px; text-decoration: none; vertical-align: auto;">.