Bryozoa
"Bryozoa", from Ernst Haeckel's Kunstformen der Natur, 1904
Scientific classification
Kingdom: Animalia Superphylum: Lophotrochozoa Phylum: Bryozoa
Classes
Stenolaemata Gymnolaemata Phylactolaemata Image File history File links Download high-resolution version (2323x3289, 1497 KB) Summary The 23rd plate from Ernst Haeckels Kunstformen der Natur (1904), depicting oranisms classified as Bryozoa. ... Ernst Haeckel. ... Wikimedia Commons has media related to: Kunstformen der Natur Kunstformen der Natur (Artforms of Nature) is a book of lithographic prints by German biologist Ernst Haeckel. ... Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... “Animalia” redirects here. ... Phyla Trochozoa Mollusca Annelida Sipuncula Nemertea Lophophorata Brachiopoda Phoronida Bryozoa Entoprocta The Lophotrochozoa are one of two or three major groups of protostome animals. ... Stenolaemata is a class under phylum Ectoprocta. ... Orders Ctenostomida Cheilostomida Cheilostomatida Ctenostomatida Gymnolaemata is a class under phylum Ectoprocta which was renamed from Bryozoa. ...

Bryozoans are tiny colonial animals that generally build stony skeletons of calcium carbonate, superficially similar to coral. They are also known as moss animals (which is the literal Greek translation) or sea mats. They generally prefer warm, tropical waters but are known to occur worldwide. There are about 5,000 living species, with several times that number of fossil forms known. This article or section does not cite any references or sources. ... Calcium carbonate is a chemical compound, with chemical formula CaCO3. ... Extant Subclasses and Orders Alcyonaria    Alcyonacea    Helioporacea Zoantharia    Antipatharia    Corallimorpharia    Scleractinia    Zoanthidea [1][2]  See Anthozoa for details For other uses, see Coral (disambiguation). ... In biology, a species is one of the basic units of biodiversity. ...

Ecology

Most species of Bryozoan live in marine environments, though there are about 50 species which inhabit freshwater. In their aquatic habitats, bryozoans may be found on all types of hard substrates: sand grains, rocks, shells, wood, blades of kelp, pipes and ships may be heavily encrusted with bryozoans. Some bryozoan colonies, however, do not grow on solid substrates, but form colonies on sediment. While some species have been found at depths of 8,200 m, most bryozoans inhabit much shallower water. Most bryozoans are sessile and immobile, but a few colonies are able to creep about, and a few species of non-colonial bryozoans live and move about in the spaces between sand grains. One remarkable species makes its living while floating in the Southern Ocean. Several bryozoan species can be found in the Midwestern United States, especially in Ohio, Indiana, and Kentucky which used to be a part of a large ocean. Patterns in the sand Sand is a granular material made up of fine rock particles. ... Trunks A tree trunk as found at the Veluwe, The Netherlands Wood is a solid material derived from woody plants, notably trees but also shrubs. ... Insert non-formatted text hereLink title Families Alariaceae Chordaceae Laminariaceae Lessoniaceae Phyllariaceae Pseudochordaceae For other uses, see Kelp (disambiguation). ... This article or section cites very few or no references or sources. ... The or meter (see spelling differences) is a measure of length. ... This article does not cite its references or sources. ... Official language(s) None Capital Columbus Largest city Columbus Largest metro area Cleveland Area  Ranked 34th  - Total 44,825 sq mi (116,096 km²)  - Width 220 miles (355 km)  - Length 220 miles (355 km)  - % water 8. ... Official language(s) English Capital Indianapolis Largest city Indianapolis Area  Ranked 38th  - Total 36,418 sq mi (94,321 km²)  - Width 140 miles (225 km)  - Length 270 miles (435 km)  - % water 1. ... Official language(s) English[1] Capital Frankfort Largest city Louisville Area  Ranked 37th  - Total 40,444 sq mi (104,749 km²)  - Width 140 miles (225 km)  - Length 379 miles (610 km)  - % water 1. ...

Bryozoans are also colony-forming animals. Many millions of individuals can form one colony. The colonies range from millimeters to meters in size, but the individuals that make up the colonies are tiny, usually less than a millimeter long. In each colony, different individuals assume different functions. Some individuals gather up the food for the colony (autozooids), others depend on them (heterozooids). Some individuals are devoted to strengthening the colony (kenozooids), and still others to cleaning the colony (vibracula). There is only a single known solitary species, Monobryozoon ambulans, which does not form colonies.

Anatomy

Costazia costazi, a coralline bryozoan

Bryozoan skeletons grow in a variety of shapes and patterns: mound-shaped, lacy fans, branching twigs, and even corkscrew-shaped. Their skeletons have numerous tiny openings, each of which is the home of a minute animal called a zooid. They also have a coelomate body with a looped alimentary canal or gut, opening at the mouth and terminating at the anus. They feed with a specialized, ciliated structure called a lophophore, which is a crown of tentacles surrounding the mouth. Their diet consists of small microorganisms, including diatoms and other unicellular algae. In turn, bryozoans are preyed on by grazing organisms such as sea urchins and fish. Bryozoans do not have any defined respiratory, or circulatory systems due to their small size. However, they do have a hydrostatic skeletal system and a simple nervous system. Image File history File links Download high-resolution version (1273x853, 113 KB) Costazia costazi, a bryozoan. ... Image File history File links Download high-resolution version (1273x853, 113 KB) Costazia costazi, a bryozoan. ... Coralline is a kind of hard, encrusting algae that is commonly found on coral reefs. ... This article or section does not cite any references or sources. ... By the broadest definition, a body cavity is any fluid filled space in a multicellular organism. ... It has been suggested that this article or section be merged with mouth (human). ... Female Human Anatomy Male Human Anatomy This article is about the bodily orifice. ... cross-section of two cilia, showing 9+2 structure A cilium (plural cilia) is a fine projection from a eukaryotic cell that constantly beats in one direction. ... Freshwater bryozoan with lophophore extended The lophophore is a characteristic feeding organ possessed by three major groups of animals: the Brachiopoda, Bryozoa, and Phoronida. ... Tentacles can refer to the elongated flexible organs that are present in some animals, especially invertebrates, and sometimes to the hairs of the leaves of some insectivorous plants. ... Orders Centrales Pennales Diatoms (Greek: (dia) = through + (temnein) = to cut, i. ... A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ... Subclasses Euechinoidea Superorder Atelostomata Order Cassiduloida Order Spatangoida (heart urchins) Superorder Diadematacea Order Diadematoida Order Echinothurioida Order Pedinoida Superorder Echinacea Order Arbacioida Order Echinoida Order Phymosomatoida Order Salenioida Order Temnopleuroida Superorder Gnathostomata Order Clypeasteroida (sand dollars) Order Holectypoida Perischoechinoidea Order Cidaroida (pencil urchins) Sea urchins are small spiny sea creatures... A giant grouper at the Georgia Aquarium Fish are aquatic vertebrates that are typically cold-blooded; covered with scales, and equipped with two sets of paired fins and several unpaired fins. ...

The tentacles of the bryozoans are ciliated, and the beating of the cilia creates a powerful current of water which drives water together with entrained food particles (mainly phytoplankton) towards the mouth. The gut is U-shaped, and consists of a pharynx which passes into the esophagus, followed by the stomach, which has three parts: the cardia, the caecum, and the pylorus. The pylorus leads to an intestine and a short rectum terminating at the anus, which opens outside the lophophore. In some groups, notably some ctenostomes, a specialized gizzard may be formed from the proximal part of the cardia. Gut and lophophore are the principal components of the polypide. Cyclical degeneration and regeneration of the polypide is characteristic of marine bryozoans. After the final polypide degeneration, the skeletal aperture of the feeding zooid may become sealed by the secretion of a terminal diaphragm. In many bryozoans only the zooids within a few generations of the growing edge are in an actively feeding state; older, more proximal zooids (e.g. in the interiors of bushy colonies) are usually dormant. cross-section of two cilia, showing 9+2 structure A cilium (plural cilia) is a fine projection from a eukaryotic cell that constantly beats in one direction. ... The pharynx (plural: pharynges) is the part of the neck and throat situated immediately posterior to the mouth and nasal cavity, and cranial, or superior, to the esophagus, larynx, and trachea. ... The esophagus (also spelled oesophagus/Å“sophagus, Greek ), or gullet is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. ... In anatomy, the stomach is a bean-shaped hollow muscular organ of the gastrointestinal tract involved in the second phase of digestion, following mastication. ... The cardia is the anatomical term for the junction orifice of the stomach and the esophagus. ... In anatomy of the digestive system, the cecum or caecum is a pouch connected to the large intestine between the ileum and the colon. ... From Greek pylorus; pyl- = gate, -orus = guard. ... The rectum (from the Latin rectum intestinum, meaning straight intestine) is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. ... Freshwater bryozoan with lophophore extended The lophophore is a characteristic feeding organ possessed by three major groups of animals: the Brachiopoda, Bryozoa, and Phoronida. ... The gizzard is an adapted stomach that is found in birds, earthworms, and other animals. ... Look up diaphragm in Wiktionary, the free dictionary. ...

Freshwater bryozoan

Because of their small size, bryozoans have no need of a blood system. Gaseous exchange occurs across the entire surface of the body, but particularly through the tentacles of the lophophore. Image File history File linksMetadata Download high-resolution version (1280x960, 122 KB) Freshwater bryozoan from a lake in NC, USA. File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Bryozoa Lophophore Metadata This file contains additional information, probably added... Image File history File linksMetadata Download high-resolution version (1280x960, 122 KB) Freshwater bryozoan from a lake in NC, USA. File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Bryozoa Lophophore Metadata This file contains additional information, probably added... Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ...

Bryozoans can reproduce both sexually and asexually. All Bryozoans, as far as is known, are hermaphroditic (meaning they are both male and female). Asexual reproduction occurs by budding off new zooids as the colony grows, and is the main way by which a colony expands in size. If a piece of a bryozoan colony breaks off, the piece can continue to grow and will form a new colony. A colony formed this way is composed entirely of clones (genetically identical individuals) of the first animal, which is called the ancestrula. In zoology, a hermaphrodite is a species that contains both male and female sexual organs at some point during their lives. ... It has been suggested that Parthenogenesis be merged into this article or section. ... For other uses, see clone. ...

One species of bryozoan, Bugula neritina, is of current interest as a source of cytotoxic chemicals, bryostatins, under clinical investigation as anti-cancer agents. Cytotoxicity is the quality of being poisonous to cells. ... Bryostatins are a group of macrocyclic lactones first discovered in the late 1960s in a species of bryozoan, Bugula neritina. ...

Fossils

Fossilized Bryozoa, Ordovician limestone, Batavia, Ohio

Fossil bryozoans are found in rocks beginning in the early Ordovician. They were often major components of Ordovician seabed communities and, like modern-day bryozoans, played an important role in sediment stabilization and binding, as well as providing sources of food for other benthic organisms. During the Mississippian (354 to 323 million years ago) bryozoans were so common that their broken skeletons form entire limestone beds. Bryozoan fossil record comprises more than 1,000 described species. It is plausible that the Bryozoa existed in the Cambrian but were soft-bodied or not preserved for some other reason; perhaps they evolved from a phoronid-like ancestor at about this time. Bryozoa, Ordovician limestone, Batavia, Ohio Image copyleft: Image taken by me, released under GFDL Pollinator 14:46, Aug 24, 2004 (UTC) ( ) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Bryozoa, Ordovician limestone, Batavia, Ohio Image copyleft: Image taken by me, released under GFDL Pollinator 14:46, Aug 24, 2004 (UTC) ( ) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... FOSSIL is a standard for allowing serial communication for telecommunications programs under DOS. FOSSIL is an acronym for Fido Opus Seadog Standard Interface Layer. ... The Ordovician period is the second of the six (seven in North America) periods of the Paleozoic era. ... This article or section cites very few or no references or sources. ... In marine geology and biology, benthos are the organisms and habitats of the sea floor; in freshwater biology they are the organisms and habitats of the bottoms of lakes, rivers, and creeks. ... This article is about the geologic period; for the North American culture, see Mississippian culture. ... This article does not cite any references or sources. ... The Cambrian is a major division of the geologic timescale that begins about 542 ± 1. ... Genera Phoronis Phoronopsis Phoronids (Phoronida), commonly known as horseshoe worms, are a relatively small animal phylum: twenty species are known, in two genera, Phoronis and Phoronopsis. ...

Bryozoans are important members of sclerobiont (organisms which dwell on hard substrates such as shells and rocks) communities in the fossil record and in the Recent. For a review of sclerobiont evolution, history and ecology, see Taylor & Wilson (2003).

Most fossil bryozoans have mineralized skeletons. The skeletons of individual zooids vary from tubular to box-shaped and contain a terminal aperture from which the lophophore is protruded to feed. No pores are present in the great majority of Ordovician bryozoans, but skeletal evidence shows that epithelia were continuous from one zooid to the next. Freshwater bryozoan with lophophore extended The lophophore is a characteristic feeding organ possessed by three major groups of animals: the Brachiopoda, Bryozoa, and Phoronida. ... In zootomy, epithelium is a tissue composed of a layer of cells. ...

With regard to the bryozoan groups lacking mineralized skeletons, the statoblasts of freshwater phylactolaemates have been recorded as far back as the Permian, and the ctenostome fossils date only from the Triassic. The Permian is a geologic period that extends from about 299. ... The Triassic is a geologic period that extends from about 251 ± 0. ...

One of the most important events during bryozoan evolution was the acquisition of a calcareous skeleton and the related change in the mechanism of tentacle protrusion. The rigidity of the outer body walls allowed a greater degree of zooid contiguity and the evolution of massive, multiserial colony forms.

Classification

The Bryozoans were formerly considered to contain two subgroups: the Ectoprocta and the Entoprocta, based on the similar bodyplans and mode of life of these two groups. (Some researchers also included the Cycliophora, which are thought to be closely related to the Entoprocta.) However, the Ectoprocta are coelomate (possessing a body cavity) and their embryos undergo radial cleavage, while the Entoprocta are acoelemate and undergo spiral cleavage. Molecular studies are ambiguous about the exact position of the Entoprocta, but do not support a close relationship with the Ectoprocta. For these reasons, the Entoprocta are now considered a phylum of their own.^[1] The removal of the 150 species of Entoprocta leaves Bryozoa synonymous with Ectoprocta; some authors have adopted the latter name for the group, but the majority continue to use the former. Classes Phylactolaemata Stenolaemata Gymnolaemata The Ectoprocta are a phylum of lophophorate animals. ... Orders Barentsiidae (Urnatellidae) Loxokalypodidae Loxosomatidae Pedicellinidae Entoprocta (Gr. ... Binomial name Symbion pandora Funch & Kristensen, 1995 Symbion is a genus of peculiar animals, with a single species, . It was discovered in 1995 by Reinhardt Kristensen and Peter Funch on the mouthparts of the Norwegian lobster Nephrops norvegicus. ... By the broadest definition, a body cavity is any fluid filled space in a multicellular organism. ... Radial cleavage is a cleavage pattern characteristic of vertebrates and echinoderms, in which the spindle axes are parallel or at right angles to the polar axis of the oocyte. ... This article needs cleanup. ...

References

• Taylor, P.D. and Wilson, M.A., 2003. Palaeoecology and evolution of marine hard substrate communities. Earth-Science Reviews 62: 1-103. [1]

1. ^ James W. Valentine (2004). On the origins of phyla. University of Chicago Press. 

See also

• International Bryozoology Association

The International Bryozoology Association (IBA) is a professional association with international membership specialising on research of the Phylum Bryozoa. ...

External links

• Index to Bryozoa Bryozoa Home Page, was at RMIT; now bryozoa.net
• Other Bryozoan WWW Resources
• International Bryozoology Association official website
• Bryozoan Introduction
• The Phylum Ectoprocta (Bryozoa)
• Phylum Bryozoa at Wikispecies
• Bryozoans in the Connecticut River