Calcareous sponge
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{{Taxobox | color = pink | name = Calcareous sponges | image = Haeckel Calcispongiae.jpg | image_caption = "Calcispongiae" from Ernst Haeckel's Artforms of Nature, 1904 | regnum = Animalia | phylum = Porifera | classis = Calcarea | classis_authority = Bowerbank, 1864 | subdivision_ranks = Orders | subdivision =
- Subclass Calcinea
- Subclass Calcaronea
}}
The Calcareous sponges belong to the Class Calcarea and are characterized by spicules made out of calcium carbonate (calcite). If one were to look at a poriferan spicule under the microscope, it might resemble the mercedes-benz emblem. Indeed, this is how the spicules in the calcaerous sponges look. However, instead of the common three-pointed star shape, calcareous spicules can be four-pointed.
All sponges in this class are strictly marine dwellers. All three body plans are represented within class Calcarea : asconoid, syconoid, and leuconoid. Typically, the Calcarea are very small, measuring about 3-4 inches in height. Of the 15,000 or so species of Porfiera that exist, only 150 of those are Calcareans.
Calcareous sponge is a class of the Phylum Porifera. The species of Calcarea varies from radially symmetrical vase-shaped body types to colonies made up of a reticulum of thin tubes or irregular massive forms. Calcareous sponges are generally characterized by their endoskeleton made up of spicules, and they are sedentary filter feeders, lacking any real tissues. Calcareous sponges are most commonly found in shallow tropical waters. Generally, Calcarea are small sponges. The different shapes of calcareous sponges are relatively simple, either purse, vase, pear or cylinder-shaped. The skeleton has either a mesh or honeycomb structure. Unlike most other sponges, calcareous sponges lack hollow canals, which makes the sponge stronger.
Recent molecular analysis suggests that the class Calcarea ought to be delegated as a phylum, in particular the first to have diverged in the kingdom Animalia; the other sponges belong to the phylum Silicarea.cs:Vápenatí de:Kalkschwämme fr:Calcarea it:Calcispongiae pl:Gąbki wapienne pt:Calcarea sk:Vápnice