Keratosa | |
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Chelonaplysilla violacea off Réunion | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Porifera |
Class: | Demospongiae |
Subclass: | Keratosa Grant, 1861 [1] |
Orders | |
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Keratosa, the keratose sponges or horny sponges, is a subclass of demosponges. [2]
Keratosa sponges are nonspicular demosponges with organic spongin fibers forming flexible skeletons. [3] [4]
Recently discovered in the Andaman and Nicobar Islands, these sponges contribute to reef structures in tropical regions. [5]
Archaeocyatha is a taxon of extinct, sessile, reef-building marine sponges that lived in warm tropical and subtropical waters during the Cambrian Period. It is believed that the centre of the Archaeocyatha origin is now located in East Siberia, where they are first known from the beginning of the Tommotian Age of the Cambrian, 525 million years ago (mya). In other regions of the world, they appeared much later, during the Atdabanian, and quickly diversified into over a hundred families.
Sponges or sea sponges are members of the metazoan phylum Porifera, a basal animal clade and a sister taxon of the diploblasts. They are sessile filter feeders that are bound to the seabed, and are one of the most ancient members of macrobenthos, with many historical species being important reef-building organisms.
Parazoa are a taxon with sub-kingdom category that is located at the base of the phylogenetic tree of the animal kingdom in opposition to the sub-kingdom Eumetazoa; they group together the most primitive forms, characterized by not having proper tissues or that, in any case, these tissues are only partially differentiated. They generally group a single phylum, Porifera, which lack muscles, nerves and internal organs, which in many cases resembles a cell colony rather than a multicellular organism itself. All other animals are eumetazoans, which do have differentiated tissues.
Demosponges (Demospongiae) are the most diverse class in the phylum Porifera. They include greater than 90% of all species of sponges with nearly 8,800 species worldwide. They are sponges with a soft body that covers a hard, often massive skeleton made of calcium carbonate, either aragonite or calcite. They are predominantly leuconoid in structure. Their "skeletons" are made of spicules consisting of fibers of the protein spongin, the mineral silica, or both. Where spicules of silica are present, they have a different shape from those in the otherwise similar glass sponges. Some species, in particular from the Antarctic, obtain the silica for spicule building from the ingestion of siliceous diatoms.
Dendroceratida is an order of sponges of the class Demospongiae. They are typically found in shallow coastal and tidal areas of most coasts around the world. They are generally characterized by concentric layers of fibers containing spongin, and by large flagellated chambers that open directly into the exhalant canals. Along with the Dictyoceratida, it is one of the two orders of demosponges that make up the keratose or "horny" sponges, in which a mineral skeleton is minimal or absent and a skeleton of organic spongin-containing fibers is present instead.
The Chancelloriids are an extinct family of superficially sponge-like animals common in sediments from the Early Cambrian to the early Late Cambrian. Many of these fossils consists only of spines and other fragments, and it is not certain that they belong to the same type of organism. Other specimens appear to be more complete and to represent sessile, radially symmetrical hollow bag-like organisms with a soft skin armored with star-shaped calcareous sclerites from which radiate sharp spines.
Amphimedon queenslandica is a sponge native to the Great Barrier Reef. Its genome has been sequenced. It has been the subject of various studies on the evolution of metazoan development.
Spicules are structural elements found in most sponges. The meshing of many spicules serves as the sponge's skeleton and thus it provides structural support and potentially defense against predators.
Suberites is a genus of sea sponges in the family Suberitidae. Sponges, known scientifically as Porifera, are the oldest metazoans and are used to elucidate the basics of multicellular evolution. These living fossils are ideal for studying the principal features of metazoans, such as extracellular matrix interactions, signal-receptor systems, nervous or sensory systems, and primitive immune systems. Thus, sponges are useful tools with which to study early animal evolution. They appeared approximately 580 million years ago, in the Ediacaran.
Spongilla lacustris is a species of freshwater sponge from the family Spongillidae. It inhabits freshwater rivers and lakes, often growing under logs or rocks. Lacustris is a Latin word meaning "related to or associated with lakes". The species ranges from North America to Europe and Asia. It is the most common freshwater sponge in central Europe. It is the most widespread sponge in Northern Britain, and is one of the most common species of sponges in lakes and canals. Spongilla lacustris have the ability to reproduce both sexually and asexually. They become dormant during winter. The growth form ranges from encrusting, to digitate, to branched, depending upon the quality of the habitat.
Spongia officinalis, better known as a variety of bath sponge, is a commercially used sea sponge. Individuals grow in large lobes with small openings and are formed by a mesh of primary and secondary fibers. It is light grey to black in color. It is found throughout the Mediterranean Sea up to 100 meters deep on rocky or sandy surfaces.
Poecilosclerida is an order of the demosponge class. It is the most speciose demosponge order with over 2200 species. It contains about 25 recognised families. They are characterised by having chelae microscleres, that is, the minute spicules scattered through the tissues, usually in the 10-60 μm range, have a shovel-like structure on the end.
Cliona patera, commonly called Neptune's cup sponge, is a species of demosponge in the family Clionaidae.
Callyspongia truncata is a species of marine sea sponge. Like all marine sponges, C. truncata is a member of phylum Porifera and is defined by its filter-feeding lifestyle and flagellated choanocytes, or collar cells, that allow for water movement and feeding. It is a species of demosponge and a member of Demospongiae, the largest class of sponges as well as the family Callyspongiidae. C. truncata is most well known for being the organism from which the polyketide Callystatin A was identified. Callystatin A is a polyketide natural product from the leptomycin family of antibiotics. It was first isolated in 1997 from this organism, which was collected from the Goto Islands in the Nagasaki Prefecture of Japan by the Kobayashi group. Recent studies have revealed numerous other bioactive compounds that have been found in this species.
Dictyoceratida is an order of sponges in the subclass Ceractinomorpha containing five families. Along with the Dendroceratida, it is one of the two orders of demosponges that make up the keratose or "horny" sponges, in which a mineral skeleton is minimal or absent and a skeleton of organic fibers containing spongin, a collagen-like material, is present instead.
Dysidea arenaria is a species of marine sponge (poriferan) found in the Pacific Ocean. It is a member of the order Dictyoceratida, one of two sponge orders that make up the keratose or "horny" sponges in which a mineral skeleton is absent and a skeleton of organic fibers is present instead.
Geodia barretti is a massive deep-sea sponge species found in the boreal waters of the North Atlantic Ocean, and is fairly common on the coasts of Norway and Sweden. It is a dominant species in boreal sponge grounds. Supported by morphology and molecular data, this species is classified in the family Geodiidae.
Verongimorpha is the name of a subclass of sea sponges within the phylum Porifera. It was first authenticated and described by Erpenbeck et al. in 2012.
Silicateins are enzymes which catalyse the formation of biosilica from monomeric silicon compounds extracted from the natural environment. Environmental silicates are absorbed by specific biota, including diatoms, radiolaria, silicoflagellates, and siliceous sponges; silicateins have so far only been found in sponges. Silicateins are homologous to the cysteine protease cathepsin.
Gert Wörheide is a German marine biologist who works mainly on marine invertebrates. He earned his doctorate in geobiology from Georg-August-Universität, following this with a post-doctorate at Queensland Museum (1998-2002), where he worked with John Hooper on sponges, a collaboration which continues.