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Sipuncula
The Sipuncula or Sipunculida (common names sipunculid worms or peanut worms) is a class containing about 162 species of unsegmented marine annelid worms. The name ''Sipuncula'' is from the genus name ''Sipunculus'', and comes from the Latin ''siphunculus'' meaning a "small tube". Sipuncula was once considered a phylum, but was demoted to a class of Annelida, based on recent molecular work. Sipunculans vary in size but most species are under in length. The body is divided into an unsegmented, bulbous trunk and a narrower, anterior section, called the "introvert", which can be retracted into the trunk. The mouth is at the tip of the introvert and is surrounded in most groups by a ring of short tentacles. With no hard parts, the body is flexible and mobile. Although found in a range of habitats throughout the world's oceans, the majority of species live in shallow water habitats, burrowing under the surface of sandy and muddy substrates. Others live under stones, in rock crevic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annelid
The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments. The Annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistic research since 1997 has radically changed this scheme, viewing leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-groups of polychae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sipunculus Nudus
''Sipunculus nudus'' is a cosmopolitan species of unsegmented marine worm of the phylum Sipuncula, also known as peanut worms. Description As in all peanut worms, the body of ''S. nudus'' consists of a sac-like portion called the trunk and an eversible proboscis called the introvert. The mouth is located at the anterior end of the introvert and is surrounded by a group of tentacles. The body of the adult worm is around in length but can reach up to in some cases, of which about to correspond to the introvert. The epidermis contains a series of longitudinal coelomic canals that are connected to the main coelomic cavity by pores. Below the epidermis there are circular muscles surrounding the body which, as the coelomic canals, are marked on the surface, making the animal's surface be marked by rectangular ridges. Distribution ''Sipunculus nudus'' is commonly found on subtidal zones of sandy shores to seabeds deep in temperate or tropical waters worldwide. The worm hides in sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annelid
The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecologies – some in marine environments as distinct as tidal zones and hydrothermal vents, others in fresh water, and yet others in moist terrestrial environments. The Annelids are bilaterally symmetrical, triploblastic, coelomate, invertebrate organisms. They also have parapodia for locomotion. Most textbooks still use the traditional division into polychaetes (almost all marine), oligochaetes (which include earthworms) and leech-like species. Cladistic research since 1997 has radically changed this scheme, viewing leeches as a sub-group of oligochaetes and oligochaetes as a sub-group of polychaetes. In addition, the Pogonophora, Echiura and Sipuncula, previously regarded as separate phyla, are now regarded as sub-groups of polychae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspidosiphonidae
''Aspidosiphonidae'' is a family of peanut worms. It is the only family in the monotypic order Aspidosiphonida, which is in the class Phascolosomatidea.Gibbs, P.E. (1977): British sipunculans. Academic Press. London. 35p. Ditadi, A.S.F. & Migotto, A.E. (1982): O Filo Sipuncula. Concelho Nacional de Desemvolvimento Cientifico e Tecnologico CNPq Brasilia. 43p.Cutler, Edward B. & Gibbs, Peter E. (1985): A Phylogenetic analysis of higher taxa in the Phylum Sipuncula. Systematic Zoology 34(2):162-173.Cutler, Edward B. & Cutler, Norma J (1989): A revision of the genus Aspidosiphon (Sipuncula: Aspidosiphonidaea). Proceedings of Biological Society of Washington 102(4):826-86Bistor/ref>Cutler, Edward B. (1994): The Sipuncula: their systematic, biology and evolution. 406pGoogle Books/ref> Description The family Aspidosiphonidae is characterized by an oval disk with short tentacles, arranged in a crescent-shape made of an enclosed nuchal organ. It has a canal of sacs in the coelom, lying i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sipunculidea
Golfingiida, also known as the Golfingiiformes, is an order of peanut worms.Gibbs, P.E. (1977): ''British sipunculans''. Academic Press. London. 35p. Ditadi, A.S.F. & Migotto, A.E. (1982): ''O Filo Sipuncula''. Concelho Nacional de Desemvolvimento Cientifico e Tecnologico CNPq Brasilia. 43p.Cutler, Edward B. (1994): ''The Sipuncula: their systematic, biology and evolution''. Cornell University Press. 406p The tentacles form a circle around the mouth, while those of the sister taxon, Phascolosomatidea, are only found above the mouth. Most species burrow in the substrate but some live in the empty shells of gastropods. It is an order of the class Sipuncula (previously considered a phylum), and contains the following families: * Golfingiidae * Phascolionidae *Sipunculidae Sipunculidae is a family of peanut worms. Species ''Phascolopsis'' * '' Phascolopsis gouldii'' (De Pourtalés, 1851) ''Siphonomecus'' * '' Siphonomecus multicinctus'' Fisher 1947 ''Siphonosoma'' * '' Siph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Themistidae
''Themiste'' is a genus of peanut worms. It is the only genus in the family Themistidae. Members of this family are filter feeders, and have their feeding tentacles arranged in an elaborate crown-like structure. This is in contrast to other sipunculans which are deposit feeders. Species The genus contains the following species: * '' Themiste alutacea'' ( Grube & Ørsted, 1858) * ''Themiste blanda'' (Selenka and de Man, 1883) * '' Themiste cymodoceae'' (Edmonds, 1956) * ''Themiste dehamata'' (Kesteven, 1903) * ''Themiste dyscrita'' (Fisher, 1952) * ''Themiste hennahi'' (Gray, 1828) * ''Themiste lageniformis'' (Baird, 1868) * ''Themiste minor'' (Ikeda, 1904) * ''Themiste pyroides'' (Chamberlain, 1920) * ''Themiste variospinosa In Greek mythology, Themiste () or Themis was a Trojan princess and daughter of King Ilus II of Troad and possibly, Eurydice or Leucippe. She was the (half) sister of Laomedon, Tithonius and Telecleia. Themiste was married off by Ilus to her ...'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golfingiidae
Golfingiidae is a family of peanut worms. Species ''Golfingia'' * '' Golfingia anderssoni'' (Théel, 1911) * '' Golfingia birsteini'' Murina 1973 * '' Golfingia capensis'' (Teuscher, 1874) * '' Golfingia elongata'' (Keferstein, 1862) * '' Golfingia iniqua'' (Sluiter, 1912) * '' Golfingia margaritacea'' (Sars, 1851) * '' Golfingia mirabilis'' Murina 1969 * '' Golfingia muricaudata'' (Southern, 1913) * '' Golfingia pectinatoides'' Cutler and Cutler, 1979 * '' Golfingia vulgaris'' (de Blainville, 1827) ''Nephasoma'' * '' Nephasoma abyssorum'' (Koren and Danielssen, 1875) * '' Nephasoma bulbosum'' (Southern, 1913) * '' Nephasoma capilleforme'' (Murina, 1973) * '' Nephasoma confusum'' (Sluiter, 1902) * '' Nephasoma constricticervix'' (Cutler, 1969) * '' Nephasoma constrictum'' (Southern, 1913) * '' Nephasoma cutleri'' (Murina, 1975) * '' Nephasoma diaphanes'' (Gerould, 1913) * '' Nephasoma eremita'' (Sars, 1851) * '' Nephasoma filiforme'' (Sluiter, 1902) * '' Nephasoma flagriferum'' ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golfingiida
Golfingiida, also known as the Golfingiiformes, is an order of peanut worms.Gibbs, P.E. (1977): ''British sipunculans''. Academic Press. London. 35p. Ditadi, A.S.F. & Migotto, A.E. (1982): ''O Filo Sipuncula''. Concelho Nacional de Desemvolvimento Cientifico e Tecnologico CNPq Brasilia. 43p.Cutler, Edward B. (1994): ''The Sipuncula: their systematic, biology and evolution''. Cornell University Press. 406p The tentacles form a circle around the mouth, while those of the sister taxon, Phascolosomatidea, are only found above the mouth. Most species burrow in the substrate but some live in the empty shells of gastropods. It is an order of the class Sipuncula (previously considered a phylum), and contains the following families: * Golfingiidae * Phascolionidae *Sipunculidae Rafinesque, 1814 * Themistidae ''Themiste'' is a genus of peanut worms. It is the only genus in the family Themistidae. Members of this family are filter feeders, and have their feeding tentacles arranged i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nemertea
Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many have patterns of yellow, orange, red and green coloration. The foregut, stomach and intestine run a little below the midline of the body, the anus is at the tip of the tail, and the mouth is under the front. A little above the gut is the rhynchocoel, a cavity which mostly runs above the midline and ends a little short of the rear of the body. All species have a proboscis which lies in the rhynchocoel when inactive but everts to emerge just above the mouth to capture the animal's prey with venom. A highly extensible muscle in the back of the rhynchocoel pulls the proboscis in when an attack ends. A few species with stubby bodies filter feed and have suckers at the front and back ends, with which they attach to a host. The brain is a rin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusca
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Terms Of Location
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes. The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle ("proximal") or further from the middle ("distal"). International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphogenesis
Morphogenesis (from the Greek ''morphê'' shape and ''genesis'' creation, literally "the generation of form") is the biological process that causes a cell, tissue or organism to develop its shape. It is one of three fundamental aspects of developmental biology along with the control of tissue growth and patterning of cellular differentiation. The process controls the organized spatial distribution of cells during the embryonic development of an organism. Morphogenesis can take place also in a mature organism, such as in the normal maintenance of tissue by stem cells or in regeneration of tissues after damage. Cancer is an example of highly abnormal and pathological tissue morphogenesis. Morphogenesis also describes the development of unicellular life forms that do not have an embryonic stage in their life cycle. Morphogenesis is essential for the evolution of new forms. Morphogenesis is a mechanical process involving forces that generate mechanical stress, strain, and mov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
