Oopsacas minuta | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Porifera |
Class: | Hexactinellida |
Order: | Lyssacinosida |
Family: | Leucopsacidae |
Genus: | Oopsacas |
Species: | O. minuta |
Binomial name | |
Oopsacas minuta Topsent, 1927 | |
Oopsacas minuta is a glass sponge that is a member of the Hexactinellida. Oopsacas minuta is found in submarine caves in the Mediterranean. It is reproductive year-round. This species is a part of a class that are usually bathyal and abyssal. [1] Meaning they grow at a depth over 200 meters. At this depth the temperature is low and constant, so silica metabolism is optimized. However, this species has been observed in shallow water. [1] O. minuta have only been observed by exploring caves that trap cold water. The shape of the sponge is elongated, cylindrical and a little flared. It is between a few millimeters and 3.5 centimeters. O. minuta are white are held up with a siliceous skeleton. The spicules of the skeleton intersect in an intricate network. [2] These spindles partially block the top of the sponge. There are no obvious oscules. The sponge is anchored or suspended from the cave by silica fibers. This class of sponge is different from the three other classes of Porifera. It differs in tissue organization, ecology, development and physiology. O. minuta belongs to the order Lyssacinosida. Lyssacinosida are characterized by the parenchymal spicules mostly being unconnected; this is unlike other sponges in the subclass where the spicules form a connected skeleton. [3] The genome of O. minuta are one of the smallest of all the animal genomes that have been sequenced so far. [4] Its genome contains 24 noncoding genes and 14 protein-encoding genes. [5] The spindles of O. minuta have three axes and six points. This species does not have pinacocytes, which are the cells that form the outer layer in other sponges. [6] Instead of true choanocytes it has frill structures that bud from the syncytium.
The Oopsacas minuta is a filter feeder. It sucks in water and eats microphage. The internal flagellum beat and create a stream of water filled with bacteria and food particles; it is retained in frills that come from a syncytium. [7] This multinucleated syncytium is the major tissue component of Hexactinellid sponges. [8] Glass sponge reefs are known for having the highest grazing rate of any benthic suspension feeding community. [9]
Oopsacas minuta is a viviparous species, meaning they produce living young instead of eggs. The mother sponge will release a small ciliated larva. This larva leads a short pelagic life in the open water inside the cave. It then settles on the bedrock of the cave. Embryonic development of the O. minuta goes through the classic cell divisions, some of the cells fuse and the syncytium is formed secondary. Something that is unique in the Porifera phylum is that the first stages of cleavage are spiral, and gastrulation happens by primary delamination. [10] O. minuta reproduce year-round and produces the only known live larvae. [11] Asexual reproduction has not been observed from this species.
Glass sponges (Hexactinellids) have different body plans than other members of the Metazoan because the adult tissue is made up of a single giant multinucleated syncytium. This multinucleated syncytium creates the inner and outer layers of the sponge and is connected to uninucleate cellular regions by cytoplasmic bridges. [7] In O. minuta differentiation of the tissues happens early in embryogenesis. All cells and syncytia are linked together by cytoplasmic bridges. [7]
A study done using three-dimensional models showed the larval tissue reorganization at metamorphosis of the larva. The larvae land on their anterior swimming pole or on one side. During the first stage of metamorphosis the multiciliate cells form a belt around the larva and then are discarded. Throughout metamorphosis the larval flagellated chambers are maintained. These larval flagellated chambers become the kernels of the first pumping chambers of the juvenile sponge. [12] Once the larvae of the O. minuta settle syncytial tissues containing yolk inclusions enlarge the larval chambers. Lipid inclusions that are located at the basal attachment site, become smaller. The post-metamorphic flagellated chambers are formed from flagellated chambers. [12]
Sponges, the members of the phylum Porifera, are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells.
Hexactinellid sponges are sponges with a skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges. They are usually classified along with other sponges in the phylum Porifera, but some researchers consider them sufficiently distinct to deserve their own phylum, Symplasma. Some experts believe glass sponges are the longest-lived animals on earth; these scientists tentatively estimate a maximum age of up to 15,000 years.
The calcareoussponges are members of the animal phylum Porifera, the cellular sponges. They are characterized by spicules made of calcium carbonate, in the form of high-magnesium calcite or aragonite. While the spicules in most species are triradiate, some species may possess two- or four-pointed spicules. Unlike other sponges, calcareans lack microscleres, tiny spicules which reinforce the flesh. In addition, their spicules develop from the outside-in, mineralizing within a hollow organic sheath.
The Venus' flower basket is a glass sponge in the phylum Porifera. It is a marine sponge found in the deep waters of the Pacific ocean, usually at depths below 500 meters. Like other sponges, they feed by filtering sea water to capture plankton and marine snow. Similar to other glass sponges, they build their skeletons out of silica, which forms a unique lattice structure of spicules. The sponges are usually between 10 cm and 30 cm tall, and their bodies act as refuge for their mutualist shrimp partners. This body structure is of great interest in materials science as the optical and mechanical properties are in some ways superior to man-made materials. Little is known regarding their reproduction habits, however fluid dynamics of their body structure likely influence reproduction and it is hypothesized that they may be hermaphroditic.
A syncytium or symplasm is a multinucleate cell which can result from multiple cell fusions of uninuclear cells, in contrast to a coenocyte, which can result from multiple nuclear divisions without accompanying cytokinesis. The muscle cell that makes up animal skeletal muscle is a classic example of a syncytium cell. The term may also refer to cells interconnected by specialized membranes with gap junctions, as seen in the heart muscle cells and certain smooth muscle cells, which are synchronized electrically in an action potential.
In evolutionary biology, the term cellularization (cellularisation) has been used in theories to explain the evolution of cells, for instance in the pre-cell theory, dealing with the evolution of the first cells on this planet, and in the syncytial theory attempting to explain the origin of Metazoa from unicellular organisms.
Hexasterophora are a subclass of glass sponges in the class Hexactinellida. Most living hexasterophorans can be divided into three orders: Lyssacinosida, Lychniscosida, and Sceptrulophora. Like other glass sponges, hexasterophorans have skeletons composed of overlapping six-rayed spicules. In addition, they can be characterized by the presence of hexasters, a type of microsclere with six rays unfurling into multi-branched structures.
Multinucleate cells are eukaryotic cells that have more than one nucleus per cell, i.e., multiple nuclei share one common cytoplasm. Mitosis in multinucleate cells can occur either in a coordinated, synchronous manner where all nuclei divide simultaneously or asynchronously where individual nuclei divide independently in time and space. Certain organisms may have a multinuclear stage of their life cycle. For example, slime molds have a vegetative, multinucleate life stage called a plasmodium.
Sponge reefs are reefs produced by sea sponges. All modern sponge reefs are formed by hexactinellid sponges, which have a skeleton made of silica, and are often referred to as glass sponges. Such reefs are now very rare, and found only in waters off the coast of British Columbia, Washington and southern Alaska. Recently sponge reefs were identified within the strait of Georgia and Howe sound close to Vancouver. Although common in the late Jurassic period, reef-building sponges were believed to have gone extinct during or shortly after the Cretaceous period, until the existing reefs were discovered in Queen Charlotte sound in 1987–1988 – hence these sometimes being dubbed living fossils.
Lyssacinosida is an order of glass sponges (Hexactinellida) belonging to the subclass Hexasterophora. These sponges can be recognized by their parenchymal spicules usually being unconnected, unlike in other sponges in the subclass where the spicules form a more or less tightly connected skeleton. Lyssacine sponges have existed since the Upper Ordovician, and three families are still alive today. The Venus' flower basket is one of the most well-known and culturally significant of the glass sponges.
The cloud sponge(Aphrocallistes vastus) is a species of sea sponge in the class Hexactinellida. It is a deep-water reef-forming animal. The species was first described by F.E. Schulze in 1886.
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.
Reticulosa is an extinct order of sea sponges in the class Hexactinellida and the subclass Amphidiscophora. Reticulosans were diverse in shape and size, similar to their modern relatives, the amphidiscosidans. Some were smooth and attached to a surface at a flat point, others were polyhedral or ornamented with nodes, many were covered in bristles, and a few were even suspended above the seabed by a rope-like anchor of braided glass spicules.
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.
Amphidiscosida is an order of hexactinellids. The Amphidiscosida are commonly regarded as the only living sponges in the subclass Amphidiscophora.
Sceptrulophora is an order of hexactinellid sponges. They are characterized by sceptrules, a type of microsclere with a single straight rod terminating at a bundle of spines or knobs. An anchor- or nail-shaped sceptrule is called a clavule. A fork-shaped sceptrule, ending at a few large tines, is called a scopule. A broom-shaped sceptrule, ending at many small bristles, is called a sarule.
Claviscopulia is a genus of glass sponge in the family Farreidae.
Bolosoma is a genus of pedunculated siliceous sponges belonging to the family Euplectellidae. This genus lives in deep-sea environments and provides a habitat for a plethora of other benthic species, giving Bolosoma an incredibly important ecological role in the ecosystems it is a part of.
Sally Leys is a Canadian spongiologist. She is a professor of biology at the University of Alberta where she and her colleagues study sponges in all their aspects including ecology, physiology, their adaptations to a fluid environment and the evolution of sensory systems using sponges as their model organism. A current project is Evaluating ecosystem function, vulnerability, resilience, and ability to recover from multiple stressors.
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