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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In some species, this extends upwards to also enclose part of the polyps, in some cases including a closeable lid through which the polyp may extend its tentacles. Sometimes, these medusoid buds may be so degenerated as to entirely lack tentacles or mouths, essentially consisting of an isolated gonad. Wikimedia Commons has media related to Hydrozoa. Most famous among these was probably the assemblage called ” Hydroida “, but this group is apparently paraphyleticunited by plesiomorphic ancestral traits.

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.

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Llasifikasi colonial hydrozoans also include some polyps specialized for reproduction. Unlike some other cnidarian groups, the lining of the central cavity lacks stinging nematocystswhich are found only on the tentacles and outer surface.

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. Several approaches for expressing their interrelationships were proposed and heavily contested since the late 19th century, but in more recent klasifjkasi a consensus seems to be emerging.

In some species, the reproductive polyps, known as gonozooids or “gonotheca” in thecate hydrozoans bud off asexually produced medusae. The klasfiikasi system is unusually advanced for cnidarians. 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.

In any case, according to this classification, the hydrozoans kkasifikasi be subdivided as follows, with taxon names emended to end in “-ae”: This page was last edited on 16 Decemberat These tiny, new medusae which are either male or female mature and spawn, cndiaria gametes freely into the sea in most cases.


Cubozoa box jellyfish Hydrozoa hydrozoans Scyphozoa true jellyfish Staurozoa stalked jellyfish Polypodiozoa Polypodium. Uses authors parameter Webarchive template wayback cidaria. It is klasifkiasi placed in the Hydrozoa, though its relationships are currently unresolved—a somewhat controversial 18S rRNA sequence analysis found it to be closer to the also parasitic Myxozoan.

Numerous sense organs are closely associated with the nerve rings. In addition to these two basic types of polyps, a few colonial species have other specialized forms. Articles with ‘species’ microformats Commons category link from Wikidata CS1 maint: The colonies of the colonial species can be large, and in some cases the specialized individual animals cannot survive outside the colony.

An introduction to Hydrozoa. The medusae of hydrozoans are smaller than those of typical jellyfish, ranging from 0. From Wikipedia, the free encyclopedia. Especially the presumed phylogenetic distinctness of the Siphonophora is a major flaw that was corrected only recently. In other projects Wikimedia Commons Wikispecies.

In addition, there exists a cnidarian parasitePolypodium hydriformewhich lives inside its cniidaria cells. Stinging cells are found on the tentacles and around the mouth. Where the hydrocaulus runs along the substrate, it form a horizontal root-like stolon that anchors the colony to the bottom.

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 klasifikais and feed in the plankton for months, spawning daily for many days before their supply of food or other cnicaria conditions deteriorate and cause their demise.

The colonies are generally small, no more than a few centimeters across, but some in Siphonophorae can reach sizes of several meters. 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 cniearia related to the other “hydroids.

Historically, the hydrozoans were divided into a number of ordersaccording to their mode of growth and reproduction.

In some, defensive polyps are found, armed with large numbers of stinging cells. The genus Sarsia has even been reported to possess organised ganglia. These have a more or less cylindrical body with a terminal mouth on a raised protuberance called the hypostomesurrounded by a number of tentacles.


Most hydromedusae have shorter lifespans than the larger scyphozoan jellyfish.

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The arrangement and type klasifiikasi these reproductive polyps varies considerably between different groups. Retrieved from ” https: Two nerve rings lie close to the margin of the bell, and send fibres into the muscles and tentacles. ITIS uses the same system, but unlike here, does not use the oldest available names for many groups. Partially digested food may then be passed into the hydrocaulus for distribution around the colony and completion of the digestion process.

The body consists of a dome-like umbrella ringed by tentacles.

Though they are often found in seemingly authoritative Internet sources and databases, they do not agree with the available data. Hydroid colonies are usually dioeciouswhich means they have separate sexes—all the polyps in each colony are either male or female, but not usually both sexes in the same colony. By using this site, you agree to the Terms of Use and Privacy Policy. Hydrozoan systematics are highly complex. Most hydrozoan medusae have just four tentacles, although a number of exceptions exist.

Hydrozoans are related to jellyfish and corals and belong to the phylum Cnidaria.

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Some of the more widespread classification systems for the Hydrozoa are listed below. Although most hydrozoans have a medusoid stage, this is not always free-living, and in many species, exists solely cnidxria a sexually reproducing bud on the surface of the hydroid colony.

They may have a tree-like or fan-like appearance, depending on species. In any given colony, the majority of polyps are specialized for feeding. The hollow cavity in the middle of the polyp extends into the associated hydrocaulus, so that all the individuals of the colony are intimately connected.

Striated muscle fibres also line the rim of the bell, allowing the animal to move along by alternately contracting and relaxing its body. A tube-like structure hangs down from the centre of the umbrella, and includes the mouth at its tip.