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Radula Laxiramea
The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus. The radula is unique to the mollusks, and is found in every class of mollusk except the bivalves, which instead use cilia, waving filaments that bring minute organisms to the mouth. Within the gastropods, the radula is used in feeding by both herbivorous and carnivorous snails and slugs. The arrangement of teeth ( denticles) on the radular ribbon varies considerably from one group to another. In most of the more ancient lineages of gastropods, the radula is used to graze, by scraping diatoms and other microscopic algae off rock surfaces and other substrates. Predatory marine snails such as the Naticidae use the radula plus an acidic secretion to bore through the shell of other mollusks. Other predatory marine snails, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusca
Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The number of additional fossil species is estimated between 60,000 and 100,000, and the proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine biology, marine phylum, comprising about 23% of all the named marine organisms. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat, as numerous groups are freshwater mollusc, freshwater and even terrestrial molluscs, terrestrial species. The phylum is typically divided into 7 or 8 taxonomy (biology), taxonomic class (biology), classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurobiology, neurologi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonate
Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includes many land and freshwater families, and several marine families. The taxon Pulmonata as traditionally defined was found to be polyphyletic in a molecular study per Jörger ''et al.'', dating from 2010. Pulmonata are known from the Carboniferous period to the present. Pulmonates have a single atrium and kidney, and a concentrated symmetrical nervous system. The mantle cavity is on the right side of the body, and lacks gills, instead being converted into a vascularised lung. Most species have a shell, but no operculum, although the group does also include several shell-less slugs. Pulmonates are hermaphroditic, and some groups possess love darts. Linnean taxonomy The taxonomy of this group according to the taxonomy of the Gastrop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Slug
Sea slug is a common name for some Marine biology, marine invertebrates with varying levels of resemblance to terrestrial Slug, slugs. Most creatures known as sea slugs are gastropods, i.e. they are Sea snail, sea snails (marine gastropod mollusks) that, over evolutionary time, have either entirely lost their shells or have seemingly lost their shells due to having a significantly reduced or internal shell. The name "sea slug" is often applied to Nudibranch, nudibranchs and a paraphyletic set of other marine gastropods without apparent Gastropod shell, shells. Sea slugs have an enormous variation in body shape, color, and size. Most are partially translucent. The often bright colors of Coral reef, reef-dwelling species imply that these animals are under constant threat of predators. Still, the color can warn other animals of the sea slug's toxic stinging cells (nematocysts) or offensive taste. Like all Gastropod, gastropods, they have small, razor-sharp teeth called Radula, rad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacoglossa
Sacoglossa are a superorder of small sea slugs and sea snails, marine gastropod mollusks that belong to the clade Heterobranchia known as sacoglossans. There are 284 valid species recognized within this superorder. Sacoglossans live by ingesting the cellular contents of algae, hence they are sometimes called "sap-sucking sea slugs". Some sacoglossans simply digest the fluid which they suck from the algae, but in some other species, the slugs sequester and use within their own tissues living chloroplasts from the algae they eat, a very unusual phenomenon known as kleptoplasty, for the "stolen" plastids. This earns them the title of the "solar-powered sea slugs", and makes them unique among metazoan organisms, for otherwise kleptoplasty is known only among other euthyneurans and single-celled protists. The Sacoglossa are divided into two clades - the shelled families (Oxynoacea) and the shell-less families (Plakobranchacea). The four families of shelled species are Cylindrobul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Snail Radula Tracks
Land, also known as dry land, ground, or earth, is the solid terrestrial surface of Earth not submerged by the ocean or another body of water. It makes up 29.2% of Earth's surface and includes all continents and islands. Earth's land surface is almost entirely covered by regolith, a layer of rock, soil, and minerals that forms the outer part of the crust. Land plays an important role in Earth's climate system, being involved in the carbon cycle, nitrogen cycle, and water cycle. One-third of land is covered in trees, another third is used for agriculture, and one-tenth is covered in permanent snow and glaciers. The remainder consists of desert, savannah, and prairie. Land terrain varies greatly, consisting of mountains, deserts, plains, plateaus, glaciers, and other landforms. In physical geology, the land is divided into two major categories: Mountain ranges and relatively flat interiors called cratons. Both form over millions of years through plate tectonics. Streams – ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scaphopod
Scaphopoda (plural scaphopods , from Ancient Greek σκᾰ́φης ''skáphē'' "boat" and πούς ''poús'' "foot"), whose members are also known as tusk shells or tooth shells, are a class (biology), class of shelled Marine life, marine invertebrates belonging to the phylum Mollusca with worldwide distribution and are the only class of exclusively infaunal marine molluscs. Shells of species within this class range in length (with ''Fissidentalium metivieri'' as the longest). Members of the order Dentaliida tend to be larger than those of the order Gadilida. These molluscs live in soft substrate (biology), substrates offshore (usually not intertidally). Because of this subtidal habitat and the small size of most species, many beachcombing, beachcombers are unfamiliar with them; their shells are not as common or as easily visible in the beach drift as the shells of sea snails and clams. Molecular data suggest that the scaphopods are a sister group to the cephalopods, althoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radula Docoglosse
The radula (; : radulae or radulas) is an anatomical structure used by Mollusca, mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus. The radula is unique to the mollusks, and is found in every class of mollusk except the Bivalvia, bivalves, which instead use cilia, waving filaments that bring minute organisms to the mouth. Within the gastropods, the radula is used in feeding by both herbivore, herbivorous and carnivore, carnivorous snails and slugs. The arrangement of teeth (Denticle (tooth feature), denticles) on the radular ribbon varies considerably from one group to another. In most of the more ancient lineages of gastropods, the radula is used to graze, by scraping diatoms and other microscopic algae off rock surfaces and other substrates. Predatory marine snails such as the Naticidae use the radula plus an acidic secretion to bore throug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ghost Slug Teeth
In folklore, a ghost is the soul or Spirit (supernatural entity), spirit of a dead Human, person or non-human animal that is believed by some people to be able to appear to the living. In ghostlore, descriptions of ghosts vary widely, from an invisible presence to translucent or barely visible wispy shapes to realistic, lifelike forms. The deliberate attempt to contact the spirit of a deceased person is known as necromancy, or in Kardecist spiritism, spiritism as a ''séance''. Other terms associated with it are apparition, haunt, haint, phantom, poltergeist, Shade (mythology), shade, specter, spirit, spook, wraith, demon, and ghoul. The belief in the existence of an afterlife, as well as manifestations of the spirits of the dead, is widespread, dating back to animism or ancestor worship in pre-literate cultures. Certain religious practices—funeral rites, exorcisms, and some practices of Spiritualism (beliefs), spiritualism and ritual magic—are specifically designed to re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyaline Shield
The hyaline shield is a part of the radula in many kinds of molluscs. It serves as an attachment point for the muscles that retract the radula, and is thus located on the upper surface of the radula, arching backwards into the mouth. This retraction fires any food particles backwards into the mouth. The hyaline shield is constructed from chitin. The features is present in most radula-bearing molluscan groups, including the cephalopods and the chiton Chitons () are marine molluscs of varying size in the class Polyplacophora ( ), formerly known as Amphineura. About 940 extant and 430 fossil species are recognized. They are also sometimes known as sea cradles or coat-of-mail shells or suck ...s. References Mollusc anatomy {{mollusc-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bilateral Symmetry
Symmetry in biology refers to the symmetry observed in organisms, including plants, animals, fungi, and bacteria. External symmetry can be easily seen by just looking at an organism. For example, the face of a human being has a plane of symmetry down its centre, or a pine cone displays a clear symmetrical spiral pattern. Internal features can also show symmetry, for example the tubes in the human body (responsible for transporting gases, nutrients, and waste products) which are cylindrical and have several planes of symmetry. Biological symmetry can be thought of as a balanced distribution of duplicate body parts or shapes within the body of an organism. Importantly, unlike in mathematics, symmetry in biology is always approximate. For example, plant leaves – while considered symmetrical – rarely match up exactly when folded in half. Symmetry is one class of patterns in nature whereby there is near-repetition of the pattern element, either by Reflection (geometry), reflect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Von Middendorff
Alexander Theodor von Middendorff (; 18 August 1815 – 24 January 1894) was a Russian zoologist and explorer of Baltic German and Estonian extraction. He was known for his expedition in 1843–45 to the extreme north and east of Siberia, describing the effects of permafrost on the spread of animals and plants. Early life Middendorff's mother, Sophia Johanson (1782–1868), the daughter of an Estonian farmer, had been sent to Saint Petersburg for education by her parents. There, she met with the future director of the St. Petersburg Pedagogical Institute, Theodor Johann von Middendorff (1776–1856), whose father was a Baltic German pastor in Karuse, Estonia. As the two young people came from different social ranks and were unable to marry each other, their daughter Anette (b. 1809) and son Alexander were born out of wedlock. Alexander was born on 18 August 1815 in St. Petersburg, but could not be baptized until six months later in the Estonian Lutheran Congregation of St. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
