class scyphozoa notes
Post on 16-Apr-2017
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Class Scyphozoa (Bell Shaped animals)- The JellyfishesScyph means bell and refers to the jellyfishs bell-shaped animal (body).
Class: ScyphozoaThe largest jellyfish has a bell that can measure up to 13 feet across. The Lions Mane Jellyfish has tentacles that may extend as many as 75 feet below the bell.
The jellyfish are characterized by a body that faces up and its mouth and tentacles face downward. This body form is called Medusa
They are free swimming and move by opening and contracting the bell.
Class Hydrozoa Hydras and the Portuguese Man of WarThese Cnidarians have specialized cells in their mesoglea layer that distinguish them from other Cnidarians.
Hydras look much like anemones and live in freshwater.
The Portuguese Man-of-War, however is quite unique. It is often mistakenly called a jellyfish but it isnt one. It is actually a colony of polyps.
This Portuguese Man-of-War was carried up onto the beach by heavy winds. It is not uncommon during such times to see thousands of them stranded on the beach. They can still sting and should be considered dangerous. The name comes from the colors of the uniforms worn by Portuguese marines during the 1500s when they were sailing to South America. They wore pink and purple and must have appeared dreadfully fearsome adorned in such colors!
Class Cubozoa Box JellyfishThe bell of this group is cube-shaped. The venom from the Box Jellyfish is so potent that it is considered to be the second most venomous animal in the world.
The box jellyfish inhabits the Great Barrier Reef off the east coast of Australia. Lifeguards protect themselves from the box jellyfish sting by wearing two pairs of panty hose. One is put on over their bathing suit and the second is slipped on over their head. A hole is cut in the crotch for the lifeguards head to stick through and his or her arms go into the legs. The feet are cut off of the hose and gloves are worn. The reason it is effective is that the box jellys stinging threads are shorter than the diameter of the panty hose fibers. Even if the cnidocytes fire and the stinging threads are released, they cannot penetrate the lifeguards skin to inject their venom.