The class Aplacophora contains two subclasses: Neomeniomorpha (also called Solenogastres) and Chaetodermomorpha (also called Caudofoveata). (2021). Symbols represent something more than their literal meanings. Lawyers speak using particular jargon, as do soccer players. Straight digestive tract, a pair of coelomoducts serving as gonoducts. They are rather worm-like and average about an inch (2.5 cms.) Meaning ‘bearer of no shells’, the mantle of the Aplacophora does not produce a shell but is embedded with hard calcareous spicules (needle-like rods), possibly to deter predators. Noun 1. aplacophoran - deep-water wormlike mollusks lacking calcareous plates on the body but having fine slimy spicules on … Compare Polyplacophora. As their scientific name Aplacophora literally states, the members of this group actually are devoid of a shell and in that regard are unique among molluscs. 2. See more. The literal meaning is the most obvious or non-figurative sense of a word or words. Define aplacophoran. They have no shell, although small calcified spicules are embedded in the skin; these spicules are occasionally coated with an organic pellicle that is presumably secreted by microvilli. Purpose: Employing symbolism is a way for a writer to attach meaning to an object or action, some symbol within the piece, that goes beyond the face-value of the symbol itself. Literal definition is - according with the letter of the scriptures. Same as Solenogastres. Photo: Woods Hole Oceanographic Institute. Delivered to your inbox! It includes the families Neomeniidæ and Chætodermatidæ. Molecular and fossil evidence seemed to put Aplacophorans in the clade Aculifera, as a sister group to Polyplacophora. Aplacophorans are characterized by a narrow or completely reduced foot, a unique posterior dorsoterminal sensory organ, and a small mantle cavity restricted to the posterior-most part of the body. Classified under: Nouns denoting animals. Webster Dictionary (0.00 / 0 votes) Rate this definition: Aplacophora. Solenogasters are typically carnivores feeding on cnidarians or sometimes annelids or other taxa while caudofoveates are mostly detritovores or feed on foraminiferans. aplacophoran (plural aplacophorans) Any benthic mollusc of the class Aplacophora. You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary. During development, the mantle cavity of the larva curls up and closes, creating the worm-like form of the adult. Some workers are convinced that two classes are represented by these animals: class Caudofoveata and class Solenogastres. Aplacophora meaning A taxonomic class within the phylum Mollusca — vermiform marine mollusks lacking shells. Aplacophora: 1 n an order of Amphineura Synonyms: Solenogastres , order Aplacophora , order Solenogastres Type of: animal order the order of animals Aplacophora is a relatively small group of mollusks that are characterized by their lack of shells and worm-like appearance. Barnes et al. How to use a word that (literally) drives some pe... How well have you been paying attention this month? Vernacular - 1. [3] Caudofoveates lack a foot while solenogasters have a narrow foot which lacks intrinsic musculature. The mantle cavity is reduced into a simple cloaca, into which the anus and excretory organs empty, and is located at the posterior of the animal. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=411, "Evolution of calcareous hardparts in primitive molluscs", "The Aplacophoran Family Prochaetodermatidae in the North American Basin, Including, "Of tests, trochs, shells, and spicules: Development of the basal mollusk, "Evidence for a clade composed of molluscs with serially repeated structures: monoplacophorans are related to chitons", "Phylogenomics reveals deep molluscan relationships", "Deep molluscan phylogeny: synthesis of palaeontological and neontological data", "Aplacophora as Progenetic Aculiferans and the Coelomate Origin of Mollusks as the Sister Taxon of Sipuncula", "A molecular palaeobiological hypothesis for the origin of aplacophoran molluscs and their derivation from chiton-like ancestors", https://en.wikipedia.org/w/index.php?title=Aplacophora&oldid=1017536065, Creative Commons Attribution-ShareAlike License, This page was last edited on 13 April 2021, at 09:58. All known modern forms are shell-less: only some extinct primitive forms possessed valves. Learn a new word every day. It includes the families Neomeniidæ and Chætodermatidæ. Same as Solenogastres. having the body vermiform, foot absent or merely a groove, and the cuticle more or less covered with spicules. A large change in the shape or structure of an animal that happens as the animal grows. 2021. [6] Spines bear an organic matrix. having the body vermiform, foot absent or merely a groove, and the cuticle more or less covered with spicules. Noun 1. Aplacophora is a relatively small group of molluscs that are characterized by their lack of shells and worm-like appearance. Hard and soft anatomy in two genera of Dondersiidae (Mollusca, Aplacophora, Solenogastres) nov., a Pacific hydrothermal vent Aplacophora (Mollusca: Neomeniomorpha). The benthic beasts are members of the aplacophora class of mollusks—the naked mollusks. Learn to distinguish between sentence meaning and speaker meaning. This is a class of small, deep-water, exclusively benthic, marine molluscs found in all oceans of the world. long, a reduced foot, and mantle cavity. 'All Intensive Purposes' or 'All Intents and Purposes'? Synonyms: Aplacophora; order Aplacophora; order Solenogastres; Solenogastres Evidence is presented in support of the following phylogenetic hypotheses: (1) Sipuncula are the sister taxon of Mollusca; (2) the two aplacophoran taxa, Neomeniomorpha (= neomenioids) and Chaetodermomorpha (= chaetoderms), are monophyletic with a common neomenioid-like ancestor, and of the two taxa, Chaetodermomorpha are more derived; (3) Aplacophora and Polyplacophora are sister … Introduction to Aplacophora. Please tell us where you read or heard it (including the quote, if possible). [4] The cuticle of both subclasses is chitinous,[5] and has an irregular texture. Definition of Aplacophora. • APLACOPHORA (noun) Sense 1. Class Aplacophora (Glisten Worms) Etymology of Aplacophora: A = not or without, Plak = a plate or flat object, Phora = to bear (“Not having a shell”) Number of Species : Catalogue of Life : 2019 Annual Checklist = 28 families, 425 species; Molluscabase = 431 Until the mantle cavity and in some forms the radula was well recognized they were thought to be Echinoderms. Aplacophora Aplacophorans are the smallest class and are worm-like marine molluscs living mostly in deep water. Animal:The body shape is worm-like. [6] Sclerites can be shaped as simple spines, straight, curved, keeled, striated or hooked; or as cupped blades; more complex arrangements are common in copulatory spicules. Absence of shell. Dictionary entry overview: What does Aplacophora mean? The Aplacophora are a small group of molluscs, which have deviated from the normal molluscan form.There are approximately 100 known species living today. The classification fol­lowed here is after Ruppert and Barnes, 1994. 'Nip it in the butt' or 'Nip it in the bud'? Aplacophora: 1 n an order of Amphineura Synonyms: Solenogastres , order Aplacophora , order Solenogastres Type of: animal order the order of animals Start your free trial today and get unlimited access to America's largest dictionary, with: New Latin, from a- entry 2 + plac- + -phora. Aplacophora(Aplacophorans) Phylum MolluscaClass AplacophoraNumber of families 30Thumbnail description Vermiform (worm-shaped) marine mollusks lacking shells and living in the zone between the seashore and the edge of the continental shelf Source for information on Aplacophora (Aplacophorans): Grzimek's Animal Life Encyclopedia dictionary. cousins: Gastropods Terrestrial eliminating the gills and in length. They are presumed to be similar in appearance and nature to the basal mollusks from which the other classes of mollusks have evolved (although both fossil and molecular evidence is … Aplacophorans are cylindrical and worm-like in form, and most very small, being no longer than 5 centimetres (2 in); some species, however, can reach a length of 30 centimetres (12 in). It has been considered polyphyletic[12] but more recent molecular evidence supports it as a monophyletic clade. Aplacophora synonyms, Aplacophora pronunciation, Aplacophora translation, English dictionary definition of Aplacophora. Mollusca, including shellfish, squid, octopus, whelks, Nautilus, cuttlefish, nudibranchs, scallops, sea snails, Aplacophora, Caudofoveata, Monoplacophora, Polyplacophora, and Scaphopoda; Myzostomida, a taxonomic group of small marine worms which are parasitic on crinoids or "sea lilies"; Nemertinea, also known as "ribbon worms" or "proboscis worms"; [6] They probably start life as amorphous calcium carbonate, which the organic matrix coaxes into an aragonitic habit as the spines mature. This is a class of small, deep-water, exclusively benthic, marine molluscs found in all oceans of the world. The head is rudimentary, and has no eyes or tentacles. 3. Common name:Solengaster. B. Aplacophoran characters no shell (mantle), foot, nephridia. These are worm-like molluscs that lack hard-parts. Caudofoveates generally burrow into the substrate while solenogasters are usually epibenthic. a division of Amphineura in which the body is naked or covered with slender spines or setae, but is without shelly plates. For many years biologists classified the aplacophorans with the sea cucumbers (Phylum Echinodermata) but in 1875 they correctly identified them as a class of the Phylum Mollusca. [2], Aplacophorans are worm-like animals, with little resemblance to most other molluscs. Aplacophora. [1]. The Class Aplacophora (a = without, placo = tablet, phoros = bearing) describes a small group of worm-like marine animals that have no shell. Literal meaning: Without plates. : an order of Amphineura comprising wormlike mollusks in which the body is without calcareous plates but the mantle bears numerous calcified spicules over its entire surface. Ironic definition, using words to convey a meaning that is the opposite of its literal meaning; containing or exemplifying irony: an ironic novel; an ironic remark. Foot absent or reduced to a ventral ridge. The aplacophorans are traditionally considered ancestral to the other mollusc classes. The Taxonomy of the Aplacophora (Chaetodermomorpha or Caudofoveata & Neomeniomorpha or Solenogastres), Sclerite-Bearing Deep-Sea Mollusks. [6] Sclerites generally form within the cuticle, protruding through when they are fully grown. [8][9] In several species of solenogaster, sclerites change morphology during growth; young specimens might bear flat, solid, scale-like sclerites, to be replaced with longer hollow spine-like sclerites in adults. Aplacophora. However, the relationship between the two aplacophoran groups and to the other molluscan classes and to each other is as yet unclear. They have worm like bodies and usually less than 5 cm. [13][14][15][16][17] The discovery of Kulindroplax in 2012, a fossil aplacophoran with a polyplacophoran-like armour, strongly supports this hypothesis, and shows that aplacophorans evolved from progenitors that bore valves.[18]. All known modern forms are shell-less: only some extinct primitive forms possessed valves. Aplacophora as progenetic aculiferans and the coelomate origin of mollusks as the sister taxon of Sipuncula. The foot, if present, is small and narrow. • APLACOPHORA (noun) The noun APLACOPHORA has 1 sense:. Aplacophora /æpləˈkɒfərə/ is a presumably paraphyletic taxon. aplacophora: A suborder of Amphineura. [13][14], The affinities of Aplacophorans have long been uncertain. … in length. Denotation - The literal, explicit meaning of a word, without its connotations. … There are only about 320 species of these exclusively marine molluscs. Language or dialect of a particular country. Jargon – The diction used by a group which practices a similar profession or activity. imagen Representación literal o mental de algo real o imaginado, o una combinación de ambas, cuya finalidad es que el lector las pueda reconstruir a través de su imaginación. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is … Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free! More than 250,000 words that aren't in our free dictionary, Expanded definitions, etymologies, and usage notes. MolluscaBase. [7] Sclerites can be hollow or solid; the void within the sclerites of some species fills during growth. The foot is either much reduced or completely absent. Aplacophora are a small group of molluscs, which have deviated from the normal molluscan form. All known modern forms are shell-less: only some extinct primitive forms possessed valves. Among the shell-less molluscs ("Aplacophora") there are about 340 of the most primordial molluscs to be found on earth. Compare Polyplacophora. Possibly representive of the primitive molluscan condition or a secondary reduction from more advanced, shelled ancestors. [4], This class was once classified as sea cucumbers in the echinoderms. (1999) has split Aplacophora into two classes Chaetodermorpha and Neomeniomorpha. Meaning: An order of Amphineura. There are only about 320 species of these exclusively marine mollusks. It is thought that the Polyplacophora (meaning carriers of many plates) and the Aplacophora (meaning without plates) are the oldest living forms of molluscs. Systematic Resume of Phylum Mollusca: Class Aplacophora: 1. There are approximately 320 described species in Aplacophora. Test your visual vocabulary with our 10-question challenge! The group comprises the two clades Solenogastres and Caudofoveata, which between them contain 28 families and about 320 species. Both taxa are most common in water regions deeper than 20 metres (66 ft) where some species may reach densities up to four or five specimens per square metre (three or four per square yard). On the other hand, some workers are convinced that the Aplacophora and the Polyplacophora together comprise the class Amphineura. Gr. class Aplacophora. Meaning “bearer of no shells”, the mantle does not produce a shell but is embedded with hard calcareous spicules (needle-like rods), possibly to deter predators. What made you want to look up Aplacophora? Preface to Class of Aplacophora. Anomia is a deficit of expressive language. Falcidens australocaudatus sp. Accessed 2 May. Example: Consider the phrase “a new dawn.” It literally refers to the beginning of a new day. La imagen se percibe por los sentidos: imagen visual, auditiva, táctil, etc. The group comprises the two clades Solenogastres (Neomeniomorpha) and Caudofoveata (Chaetodermomorpha), which between them contain 28 families and about 320 species. Instead of a shell, their mantle secretes tiny calcareous spicules which give them a beautiful shine. aplacophora: A suborder of Amphineura. In 1987, they were officially recognized as molluscs and given their own class. Por ejemplo, en “Prendimiento de Antoñito el In mollusk: Annotated classification Class AplacophoraWorm-shaped and without shells; marine, mostly in deep water. There are approximately 100 known species living today. 2. The group comprises the two clades Solenogastres (Neomeniomorpha) and Caudofoveata (Chaetodermomorpha), which between them contain 28 families and about 320 species. Abstract : The Aplacophora are a spicule-covered, vermiform class of Mollusca important in understanding molluscan evolution and the biogeography and ecology of the deep sea. How to use literal in a sentence. A taxonomic clade within the phylum Mollusca Wormlike marine mollusks lacking shells A taxonomic class within the phylum Mollusca. Post the Definition of Aplacophora to Facebook, Share the Definition of Aplacophora on Twitter, An Analysis of 'Delve' vs. 'Dig' vs. 'Dive'. Shell:There is no shell, however spiculesmay be embedded in the cuticle. Aplacophora +‎ -n. Noun . Etymology: [NL., fr. [10], The relationship with other molluscs, however, is apparent from some features of the digestive system; aplacophorans possess both a radula and a style. “Aplacophora.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Aplacophora. There is a good chance that Aplacophora is a paraphyletic group. MolluscaBase eds. Aplacophorans are found throughout the oceans over the world. The foot is either much reduced or completely absent. [11] Solenogasters are hermaphroditic, but caudofoveates have two sexes, and reproduce by external fertilization. Instead of a shell, their mantle secretes tiny calcareous spicules which give them a beautiful shine. Anomic aphasia (also known as dysnomia, nominal aphasia, and amnesic aphasia) is a mild, fluent type of aphasia where individuals have word retrieval failures and cannot express the words they want to say (particularly nouns and verbs). 'a priv. + a flat cake + fe`rein to bear.] Aplacophora are worm-like marine molluscs that mostly live in deep water. 1. an order of Amphineura Familiarity information: APLACOPHORA used as a noun is very rare. A variety of radular forms and functions exist. Most neomenioids creep by means of They are rather worm-like and average about an inch (2.5 cms.) Worm like mollusc, body covered by cuticle. With the exception of a ventralgroove, the mantlecovers the entire body. Aplacophora /æpləˈkɒfərə/ is a presumably paraphyletic taxon. Biblical literalism or biblicism is a term used differently by different authors concerning biblical interpretation.It can equate to the dictionary definition of literalism: "adherence to the exact letter or the literal sense", where literal means "in accordance with, involving, or being the primary or strict meaning of the word or words; not figurative or metaphorical". Aplacophora is a monophyletic group of small, deep-water, exclusively benthic, marine molluscs found in all oceans of the world. It consists of two clades: the Solenogastres and the Caudofoveata. They first became known to scientists from dredgings made in the waters around Scandinavia in 1844. nov. is described from the southeastern Brazilian coast, based on characters of external anatomy, including size, shape, and ornamentation of the sclerites, and on the structure of the radula. Most live in deep water, Can you correctly identify these flowers? aplacophoran synonyms, aplacophoran pronunciation, aplacophoran translation, English dictionary definition of aplacophoran. Definition of the class A. Molluscan characters coelomate Bilateria with little or no metamerism, a soft body, a pharynx with a radula, gills, a heart, an open circulatory system.