https://wikimd.org/index.php?action=history&feed=atom&title=ScyphozoaScyphozoa - Revision history2026-04-26T03:30:56ZRevision history for this page on the wikiMediaWiki 1.44.2https://wikimd.org/index.php?title=Scyphozoa&diff=5648188&oldid=prevPrab: CSV import2024-04-22T07:58:22Z<p>CSV import</p>
<p><b>New page</b></p><div>[[File:Cauliflour_Jellyfish,_Cephea_cephea_at_Marsa_Shouna,_Red_Sea,_Egypt_SCUBA.jpg|Cauliflour Jellyfish, Cephea cephea at Marsa Shouna, Red Sea, Egypt SCUBA|thumb]] [[File:Stranded_Cambrian_scyphozoans.jpg|Stranded Cambrian scyphozoans|thumb|left]] [[File:Schleiden-meduse-2.jpg|Schleiden-meduse-2|thumb|left]] '''Scyphozoa''' is a class within the [[phylum]] [[Cnidaria]], a group of primarily marine animals noted for their distinctive jelly-like appearance. The members of this class are commonly known as the true [[jellyfish]], distinguishing them from other cnidarian classes such as the [[Hydrozoa]] (which includes Portuguese man o' war, a colonial organism mistaken for a jellyfish) and the [[Anthozoa]] (which includes corals and sea anemones). Scyphozoans are found in every ocean, from the surface to the deep sea, and are an important part of marine ecosystems.<br />
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==Characteristics==<br />
Scyphozoans are characterized by their gelatinous, umbrella-shaped bodies called [[bell]]s, through which they propel themselves by rhythmic contractions. They have a central mouth located on the underside of the bell, surrounded by tentacles that bear specialized cells called [[cnidocytes]]. These cells contain nematocysts, which are capable of delivering stings to capture prey or defend against predators. The lifecycle of scyphozoans includes two main stages: the free-swimming [[medusa]], which is typically the sexual stage, and the sessile [[polyp]] stage, which can reproduce asexually.<br />
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==Lifecycle==<br />
The scyphozoan lifecycle is complex and includes both asexual and sexual phases. It typically begins with a fertilized egg developing into a free-swimming [[planula]] larva. The planula eventually settles onto a suitable substrate and develops into a polyp. This polyp may then reproduce asexually to produce more polyps or bud off free-swimming medusae through a process known as [[strobilation]]. The medusae grow, mature, and eventually reproduce sexually by releasing sperm and eggs into the water, where fertilization occurs, starting the cycle anew.<br />
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==Diversity==<br />
The class Scyphozoa includes several orders, such as the [[Semaeostomeae]] (which includes many of the larger jellyfish seen near beaches), the [[Rhizostomeae]] (notable for their complex mouth structures), and the [[Coronatae]] (which live in deeper waters). Each order encompasses a variety of species adapted to different ecological niches. Some species, like the [[lion's mane jellyfish]] (''Cyanea capillata''), are among the largest invertebrates in the world.<br />
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==Ecological Role==<br />
Scyphozoans play a significant role in marine ecosystems. They are predators, feeding on a wide range of small fish, [[zooplankton]], and other jellyfish. They are also prey for a variety of larger marine animals, including certain species of [[turtles]], [[fish]], and [[birds]]. Additionally, their presence in large numbers, or blooms, can significantly impact marine environments and human activities, sometimes clogging cooling intakes of power plants and desalination facilities, or stinging swimmers.<br />
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==Conservation==<br />
While jellyfish are abundant in many parts of the world, the health of scyphozoan populations is closely tied to ocean conditions. Changes in temperature, salinity, and the availability of prey can affect their numbers. Overfishing and habitat destruction also pose threats by disrupting the delicate balance of marine ecosystems. Monitoring and research are essential for understanding the complex dynamics that govern these creatures and their habitats.<br />
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[[Category:Cnidaria]]<br />
[[Category:Scyphozoa]]<br />
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