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Sipunculids
The Sipuncula or Sipunculida (common names sipunculid worms or peanut worms) is a class containing about 162 species of marine annelid worms, that have secondarily lost their segmentation. Sipuncula was once considered a phylum of unsegmented worms, 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 crevices or in other concealed locations. Most sipunculans are deposit feeder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Terms Of Location
Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. 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 axes. The meaning of terms that are used can change depending on whether a vertebrate is a biped or a quadruped, due to the difference in the neuraxis, or if an invertebrate is a non-bilaterian. A non-bilaterian has no anterior or posterior surface for example but can still have a descriptor used such as proximal or distal in relation to a body part that is nearest to, or furthest from its middle. International organisations have determined vocabularies that are often used as standards for subdisciplines of anatomy. For example, '' Termi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annelid
The annelids (), also known as the segmented worms, are animals that comprise the phylum Annelida (; ). The phylum contains 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-grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetics
In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data and observed heritable traits of DNA sequences, protein amino acid sequences, and morphology. The results are a phylogenetic tree—a diagram depicting the hypothetical relationships among the organisms, reflecting their inferred evolutionary history. The tips of a phylogenetic tree represent the observed entities, which can be living taxa or fossils. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the taxa represented on the tree. An unrooted tree diagram (a network) makes no assumption about directionality of character state transformation, and does not show the origin or "root" of the taxa in question. In addition to their use for inferring phylogenetic pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sipunculus Nudus
''Sipunculus nudus'' is a cosmopolitan species of unsegmented marine worm of the class 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. File:Sipunculus nudus P5033280.jpg, ''Sipunculus nudus'' in Pula, Croatia. File:Sipunculus nudus DSC_0565.jpg, ''Sipunculus nudus'' (front end) in Pula, Croatia. File: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming organisms. He is known as the "father of modern Taxonomy (biology), taxonomy". Many of his writings were in Latin; his name is rendered in Latin as and, after his 1761 ennoblement, as . Linnaeus was the son of a curate and was born in Råshult, in the countryside of Småland, southern Sweden. He received most of his higher education at Uppsala University and began giving lectures in botany there in 1730. He lived abroad between 1735 and 1738, where he studied and also published the first edition of his ' in the Netherlands. He then returned to Sweden where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on several journeys through Sweden to find and classify plants and animals. In the 1750s and 1760s, he co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pipe (fluid Conveyance)
Pipe(s), PIPE(S) or piping may refer to: Objects * Pipe (fluid conveyance), a hollow cylinder following certain dimension rules ** Piping, the use of pipes in industry * Smoking pipe ** Tobacco pipe * Half-pipe and quarter pipe, semi-circular ramps for performing skateboarding/snowboarding tricks * Piping (sewing), tubular ornamental fabric sewn around the edge of a garment * ''For the musical instruments'', see #Music, below Music * Pipe (instrument), a traditional perforated wind instrument * Bagpipe, a class of musical instrument, aerophones using enclosed reeds ** Pipes and drums or pipe bands, composed of musicians who play the Scottish and Irish bagpipes * Organ pipe, one of the tuned resonators that produces the main sound of a pipe organ * Pan pipes, see Pan flute, an ancient musical instrument based on the principle of the stopped pipe * Piped music, or elevator music, a type of background music * "Pipe", by Christie Front Drive from ''Christie Front Drive (EP), Christ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tube (fluid Conveyance)
A tube, or tubing, is a long hollow cylinder used for moving fluids (liquids or gases) or to protect electrical or optical cables and wires. The terms "Pipe (fluid conveyance), pipe" and "tube" are almost interchangeable, although minor distinctions exist — generally, a tube has tighter engineering requirements than a pipe. Both pipe and tube imply a level of rigidity and permanence, whereas a Hose (tubing), hose is usually portable and flexible. A tube and pipe may be specified by standard pipe size designations, ''e.g.'', nominal pipe size, or by nominal (value), nominal outside or inside diameter and/or wall thickness. The actual dimensions of pipe are usually not the nominal dimensions: A 1-inch pipe will not actually measure 1 inch in either outside or inside diameter, whereas many types of tubing are specified by actual inside diameter, outside diameter, or wall thickness. Manufacture There are three classes of manufactured tubing: seamless, as-welded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greek Language
Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek Dark Ages, Dark Ages (), the Archaic Greece, Archaic or Homeric Greek, Homeric period (), and the Classical Greece, Classical period (). Ancient Greek was the language of Homer and of fifth-century Athens, fifth-century Athenian historians, playwrights, and Ancient Greek philosophy, philosophers. It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Homeric Greek, Epic and Classical periods of the language, which are the best-attested periods and considered most typical of Ancient Greek. From the Hellenistic period (), Ancient Greek was followed by Koine Greek, which is regar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diminutive (linguistics)
A diminutive is a word obtained by modifying a root word to convey a slighter degree of its root meaning, either to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment, and sometimes to belittle something or someone. A (abbreviated ) is a word-formation device used to express such meanings. A is a diminutive form with two diminutive suffixes rather than one. Purpose Diminutives are often employed as nicknames and pet names when speaking to small children and when expressing extreme tenderness and intimacy to an adult. The opposite of the diminutive form is the augmentative. In some contexts, diminutives are also employed in a pejorative sense to denote that someone or something is weak or childish. For example, one of the last Western Roman emperors was Romulus Augustus, but his name was diminutivized to "Romulus Augustulus" to express his powerlessness. Formation In many languages, diminutives are word forms that are formed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latin Language
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area around Rome, Italy. Through the expansion of the Roman Republic, it became the dominant language in the Italian Peninsula and subsequently throughout the Roman Empire. It has greatly influenced many languages, Latin influence in English, including English, having contributed List of Latin words with English derivatives, many words to the English lexicon, particularly after the Christianity in Anglo-Saxon England, Christianization of the Anglo-Saxons and the Norman Conquest. Latin Root (linguistics), roots appear frequently in the technical vocabulary used by fields such as theology, List of Latin and Greek words commonly used in systematic names, the sciences, List of medical roots, suffixes and prefixes, medicine, and List of Latin legal terms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sipunculus
''Sipunculus'' is a genus of worms belonging to the family Sipunculidae. Taxonomy is a variant spelling of the Latin ("little tube"), a diminutive of from Greek (''síphōn'', "tube, pipe"). was used for fossilized worm-shaped organisms like by the Welsh naturalist Edward Lhuyd in 1699. In the next century, the Swedish naturalist Carl Linnaeus used the scientific name for a species of worms in his 1766 . In 1814, the French zoologist Constantine Samuel Rafinesque used the feminine form to distinguish the family including ; this was later elevated to the class, the family being renamed and the species reorganized into different genera. Distribution The genus has cosmopolitan distribution. Species Species included in Sipunculus are: *'' Sipunculus angasoides'' *'' Sipunculus clavatus'' *'' Sipunculus corallicolus'' *'' Sipunculus echinorhynchus'' *'' Sipunculus gulfus'' *'' Sipunculus indicus'' *'' Sipunculus lomonossovi'' *'' Sipunculus longipapillosus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
