For balancing the ecosystem. Cnidarians are important in balancing the ecosystem, as all other organisms are. If there were a decrease in numbers, other living things which rely on cnidarians would also have problems.
Cnidarians are classified into four main groups: non-moving (sessile) Anthozoa (sea anemones, corals, sea pens); Cubozoa (box jellies);swimming Scyphozoa (jellyfish); and Hydrozoa, a broad group that includes all the freshwater cnidarians as well as many marine forms. There are about 10, 000 species of Cnidarians. There are two major body forms among the Cnidaria-the polyp and the medusa. Sea anemones and corals have the polyp form, while jellyfish are typical medusae. When you look at them, you can see that these body forms are the same except that one is upside down. Cnidarians. Cnidarians are a group of invertebrates that includes jellyfish, corals, sea anemones, and hydras. There are between 8,000 and 9,000 species of cnidarians alive today. The articles listed below provide information about the characteristics, classification and evolution of c Class ANTHOZOA Geologically the anthozoans are the most important of the cnidarians because their polyps often produce calcitized skeletons that are readily preserved as fossils. They can be either solitary or colonial. Common forms of anthozoans include corals, sea-anemones, and sea-pens. The phylum Cnidaria (Coelenterata in some texts) includes both solitary and colonial organisms that have radial and/or bilateral symmetry. Typical cnidarians alternate each generation between a fixed polyp stage and a free living medusoid stage. Cnidaria: Life History and Ecology. Cnidarian ecology is a complex subject indeed, because it is cnidarians, in particular corals, that are the builders of some of the richest and most complex ecosystems on the planet, coral reefs. Other cnidarians are important as predators in the open ocean. Cnidarians generally occupy two major niches. They may use their cnidocysts to trap prey items. On the other hand, many cnidarians, anthozoans in particular, depend on zooxanthellae, symbiotic dinoflagellates within the tissues, to survive. Cnidaria is a phylum containing over 9,000 species found only in aquatic and mostly marine environments. All cnidarians have radial symmetrical. There are two major body forms among the Cnidaria-the polyp and the medusa. Sea anemones and corals have the polyp form, while jellyfish are typical medusae. When you look at them, you can see that these body forms are the same except that one is upside down. Making the world better, one answer at a time. Cnidarians are important in balancing the ecosystem, as all other organisms are. If there were a decrease in numbers, other living things which rely on cnidarians would also have problems. For example, when a jellyfish kills a fish for food, it is actually helping the other populations of fish that would need to compete with the one slain for food, territory, etc. Yes, many species of cnidarians have powerful stinging cells and potent venom strong enough to cause injury and or death to humans. These include the Portuguese man of war, th … e sea wasp, lion's mane jellyfish, fire coral, and the carpet sea anemone. Cnidaria is one of the more primitive animal phyla. It includes aquatic organisms such as jellyfish, sea anemones, corals, and hydras. Most cnidarians are marine, although a few, such as the well-known hydra, are freshwater species.  cnidarians, such as jelly fish, sea anemones, hydra, and corals, have tentacles surrounding their mouth. they are a hollow-bodied animal with two celled layers that are organ … ized into tissues. the inner layer forms a digestive cavity where food is broken down. A jelly fish. Yes, many species of cnidarians have powerful stinging cells and potent venom strong enough to cause injury and or death to humans. These include the Portuguese man of war, th … e sea wasp, lion's mane jellyfish, fire coral, and the carpet sea anemone.
http://www.mesa.edu.au/cnidaria/default.asp http://animals.about.com/od/cnidarians/ http://paleo.cortland.edu/tutorial/Cnidarians/cnidarians.htm http://www.ucmp.berkeley.edu/cnidaria/cnidarialh.html http://www.mesa.edu.au/cnidaria/default.asp http://www.answers.com/Q/Why_are_cnidarians_important_to_humans http://www.encyclopedia.com/topic/Cnidaria.aspx http://www.answers.com/Q/Why_are_cnidarians_important_to_humans
why are cnidarians important