medusa dalam siklus hidupnya. Genus ini berada dalam filum Cnidaria, yang semuanya akuatik dan terutama hidup di laut yang strukturnya relatif sederhana. Transcript of Filum Cnidaria (Coelenterata). Nama Anggota: 1. Fadhil Nurrohman (06) 2. Fika Pebianti (07) 3. Lilastika Cattri (13) 4. Hydrozoa adalah kelas dari anggota hewan tak bertulang belakang yang termasuk dalam filum Cnidaria. Sebagian besar hewan Hydrozoa hidup di laut dan.
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These lack tentacles and contain numerous buds from which the medusoid stage of the lifecycle is produced. In addition to these two kasifikasi types of polyps, a few colonial species have other specialized forms. Especially the presumed phylogenetic distinctness of the Siphonophora is a major flaw that was corrected only recently.
WoRMS – World Register of Marine Species – Anthozoa
The arrangement and type of these reproductive polyps varies considerably between different groups. A few genera cnidara this class live in fresh water. Hydrozoans are related to jellyfish and corals and belong to the phylum Cnidaria. This page was last edited on 16 Decemberat In hydrozoan species with both polyp and medusa generations, the medusa stage is the sexually reproductive phase.
The polyp contains a central cavity, in which initial digestion takes place. The mouth leads into a central stomach cavity.
Some examples of hydrozoans are the freshwater jelly Craspedacusta sowerbyifreshwater polyps HydraObeliaPortuguese man o’ war Physalia physalischondrophores Porpitidae” air fern ” Sertularia argenteaand pink-hearted hydroids Tubularia. Cubozoa box jellyfish Hydrozoa hydrozoans Scyphozoa true jellyfish Staurozoa stalked jellyfish Polypodiozoa Polypodium. Medusae of these species of Hydrozoa are known as “hydromedusae”.
In some species, the reproductive polyps, known as gonozooids or “gonotheca” in thecate hydrozoans bud off asexually produced medusae. An additional shelf of tissue lies just inside the rim, narrowing the aperture at the base of the umbrella, and thereby increasing the force of the expelled jet of water.
Some species of hydromedusae release gametes shortly after they are themselves released from the hydroids as in the case of fire coralsliving only a few hours, while other species of hydromedusae grow and feed in the plankton for months, spawning daily for many days before their supply of food or other water conditions deteriorate and cause their demise.
For example, Hydra has no medusoid stage, while Liriope lacks the hydroid klasifokasi. Hydrozoa Owen In any case, according to this classification, the hydrozoans can be subdivided as follows, with taxon names emended to end in “-ae”: From Wikipedia, the free encyclopedia.
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Zygotes become free-swimming planula larvae or actinula larvae that either settle on a suitable substrate in the case of planulaeor swim and develop into another medusa or polyp directly actinulae. In some species, this extends upwards to also enclose part of the polyps, in some cases including a closeable lid klasifioasi which the polyp may extend its tentacles.
Cnidarka tiny, new medusae which are either male or female mature and spawn, releasing gametes freely into the sea in most cases. Where the hydrocaulus runs along the substrate, it form a horizontal root-like stolon that anchors the colony to the bottom. Although most hydrozoans have a medusoid stage, this is not always free-living, and in many species, exists solely as a sexually reproducing bud on the surface of the hydroid colony.
Retrieved from ” https: Some of the more widespread classification systems for the Hydrozoa are listed below. Stinging cells are found on the tentacles and around the mouth.
As far as can be told from the molecular and morphological data at hand, the Siphonophora for example were just highly specialized “hydroids,” whereas the Limnomedusae —presumed to be a “hydroid” suborder —were simply very primitive hydrozoans and not closely related to the other “hydroids. Striated muscle fibres also line the rim of the bell, allowing the animal to move along by alternately contracting and relaxing its body. An introduction to Hydrozoa. Hydrozoan systematics are highly klasifikas.
These have a more or less cylindrical body with a terminal mouth on a raised protuberance called the hypostomesurrounded by a number of tentacles. The body consists of a dome-like umbrella ringed by tentacles.
Most hydrozoan species include both a polypoid and a medusoid stage in their lifecycles, although a number of them have only one or the other. In jlasifikasi projects Wikimedia Commons Wikispecies.
Articles with ‘species’ microformats Commons category link from Wikidata CS1 maint: The nervous system is unusually advanced for cnidarians. The colonies of the colonial species can be cnidarua, and in some cases the specialized individual animals cannot survive outside the colony. They may have a tree-like or fan-like appearance, depending on species.
The hollow cavity in the middle of klasifikadi polyp extends into the associated hydrocaulus, so that all the individuals of the colony are intimately connected. The hydrocaulus is usually surrounded by a sheath of chitin and proteins called the perisarc. The colonies are generally small, no more than a few centimeters across, but some in Siphonophorae can reach sizes of several meters.
Two nerve rings lie close to the margin of the bell, and send fibres into the muscles and tentacles. In some, defensive polyps are found, armed with large numbers of stinging klaslfikasi. Four radial canals connect the stomach to an additional, circular canal running cnidwria the base of the bell, just above the tentacles.