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Arion Fasciatus
''Arion fasciatus'', also known by its common name the Orange-banded Arion, is a species of air-breathing, completely shell-less, land slug, a terrestrial pulmonate gastropod mollusk in the family Arionidae, the round-back slugs. The species was first described by Sven Nilsson in 1823. Distribution ''Arion fasciatus'' is originally from Northern Europe, but it has spread to other cool, wet climates, including the British Isles, Canada and the Northern United States. The species was presumably first brought across the Atlantic Ocean during the colonial era. These slugs are generally found in ecotonal habitats. Description ''Arion fasciatus'' is in many ways similar to most other stylommatophoran slugs. They are hermaphroditic. They have a head, mantle, and foot. There are two sets of retractable tentacles on their heads: the upper pair have light-sensing organs, and the lower two are used to smell. These slugs have a mantle that covers much of the top of the first third of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sven Nilsson (zoologist)
Sven Nilsson (8 March 1787 – 30 November 1883) was a Swedish zoologist and archaeologist. Life and work Nilsson was director of the Naturhistoriska Riksmuseet (Sweden's natural history museum) from 1828 to 1831, professor of Natural History at Lund University from 1832 to 1856, and rector of Lund University from 1845 to 1846.Chambers' Encyclopedia Volume 10 page 43 Nilsson was a prolific author, publishing large works on different groups of the fauna of Scandinavia. He worked as a field archaeologist and introduced ethnographic perspectives in archaeology. He was made a member of the Royal Swedish Academy of Sciences in 1821. Nilsson corresponded with William Yarrell, acting as the authority on Swedish avifauna for Yarrell's ''History of British Birds (1843)''. For example, Yarrell records Nilsson as saying "it infests every house", referring to the house sparrow. He was elected as a member of the American Philosophical Society in 1869. Legacy *A genus of turtles, '' N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mantle (mollusc)
The mantle (also known by the Latin word pallium meaning mantle, robe or cloak, adjective pallial) is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself. In many species of molluscs the epidermis of the mantle secretes calcium carbonate and conchiolin, and creates a shell. In sea slugs there is a progressive loss of the shell and the mantle becomes the dorsal surface of the animal. The words mantle and pallium both originally meant cloak or cape, see mantle (vesture). This anatomical structure in molluscs often resembles a cloak because in many groups the edges of the mantle, usually referred to as the ''mantle margin'', extend far beyond the main part of the body, forming flaps, double-layered structures which have been adapted for many different uses, including for example, the siphon. Mantle cavity The ''mantle cavity'' is a central fea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multivariate Statistics
Multivariate statistics is a subdivision of statistics encompassing the simultaneous observation and analysis of more than one outcome variable. Multivariate statistics concerns understanding the different aims and background of each of the different forms of multivariate analysis, and how they relate to each other. The practical application of multivariate statistics to a particular problem may involve several types of univariate and multivariate analyses in order to understand the relationships between variables and their relevance to the problem being studied. In addition, multivariate statistics is concerned with multivariate probability distributions, in terms of both :*how these can be used to represent the distributions of observed data; :*how they can be used as part of statistical inference, particularly where several different quantities are of interest to the same analysis. Certain types of problems involving multivariate data, for example simple linear regression an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arion Circumscriptus
''Arion circumscriptus'', common name brown-banded arion, is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Arionidae. It is commonest in woodland, occurring across most of Europe, except for more southern regions, and is also widespread in North America. It has been argued that ''A. circumscriptus'' is best considered a colour morph of ''Arion fasciatus''. Taxonomy The subgenus ''Carinarion'' Hesse, 1926 contains three species—'' Arion fasciatus'', ''Arion silvaticus'' and ''Arion circumscriptus''—distinguished on the basis of small differences in pigmentation and in proportions of their genital anatomy. Further study of these morphospecies (typological species) revealed that their body colour may be influenced by diet, and that the putative genital differences do not consistently agree with identifications based on pigmentation and allozymes. In much of their range these slugs predominantly self-fertilise, leading to distinct g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arion Silvaticus
''Arion silvaticus'' is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Arionidae. Description Note. In slugs it is often difficult to establish good criteria for identifying species using external features or internal features, as colouration can be quite variable, and the rather plastic anatomy makes diagnostic anatomical features difficult to establish. Up to 40 mm long. A roundback slug but with a keel consisting of pale, raised tubercles along the back. In colour the slug is grey to greyish brown becoming whitish down to the sides. There are broad and well marked dark lateral colour bands (white sides below the bands). The sole is whitish or cream. The mucus is transparent or slightly yellowish. Genitalia: atrium large, broad and flattened, epiphallus wider than vas deferens, oviduct wide, half diameter as atrium, spermatheca elongate and somewhat arrow-shaped. Distribution This species occurs in countries and islands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropods
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arthropod cuticle, cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an exoskeleton, external skeleton. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. Some species have wings. They are an extremely diverse group, with up to 10 million species. The haemocoel, an arthropod's internal cavity, through which its haemolymph – analogue of blood – circulates, accommodates its interior Organ (anatomy), organs; it has an open circulatory system. Like their exteriors, the internal or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthworms
An earthworm is a terrestrial invertebrate that belongs to the phylum Annelida. They exhibit a tube-within-a-tube body plan; they are externally segmented with corresponding internal segmentation; and they usually have setae on all segments. They occur worldwide where soil, water, and temperature allow. Earthworms are commonly found in soil, eating a wide variety of organic matter. This organic matter includes plant matter, living protozoa, rotifers, nematodes, bacteria, fungi, and other microorganisms. An earthworm's digestive system runs the length of its body. An earthworm respires (breathes) through its skin. It has a double transport system made of coelomic fluid that moves within the fluid-filled coelom and a simple, closed circulatory system. It has a central and peripheral nervous system. Its central nervous system consists of two ganglia above the mouth, one on either side, connected to a nerve running along its length to motor neurons and sensory cells in each se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorophyll
Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words , ("pale green") and , ("leaf"). Chlorophyll allow plants to absorb energy from light. Chlorophylls absorb light most strongly in the blue portion of the electromagnetic spectrum as well as the red portion. Conversely, it is a poor absorber of green and near-green portions of the spectrum. Hence chlorophyll-containing tissues appear green because green light, diffusively reflected by structures like cell walls, is less absorbed. Two types of chlorophyll exist in the photosystems of green plants: chlorophyll ''a'' and ''b''. History Chlorophyll was first isolated and named by Joseph Bienaimé Caventou and Pierre Joseph Pelletier in 1817. The presence of magnesium in chlorophyll was discovered in 1906, and was that element's first detection in living tissue. After initial work done by German chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detritus
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts communities of microorganisms that colonize and decompose (i.e. remineralize) it. In terrestrial ecosystems it is present as leaf litter and other organic matter that is intermixed with soil, which is denominated " soil organic matter". The detritus of aquatic ecosystems is organic material that is suspended in the water and accumulates in depositions on the floor of the body of water; when this floor is a seabed, such a deposition is denominated "marine snow". Theory The corpses of dead plants or animals, material derived from animal tissues (e.g. molted skin), and fecal matter gradually lose their form due to physical processes and the action of decomposers, including grazers, bacteria, and fungi. Decomposition, the process by which or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palatable
Palatability (or palatableness) is the hedonic reward (i.e., pleasure) provided by foods or fluids that are agreeable to the "palate", which often varies relative to the homeostatic satisfaction of nutritional, water, or energy needs. The palatability of a food or fluid, unlike its flavor or taste, varies with the state of an individual: it is lower after consumption and higher when deprived. It has increasingly been appreciated that this can create a hunger that is independent of homeostatic needs.Lowe MR, Butryn ML. (2007). Hedonic hunger: a new dimension of appetite? Physiol Behav. Jul 24;91(4):432-9. Brain mechanism The palatability of a substance is determined by opioid receptor-related processes in the nucleus accumbens and ventral pallidum.Wassum KM, Ostlund SB, Maidment NT, Balleine BW. (2009). Distinct opioid circuits determine the palatability and the desirability of rewarding events. Proc Natl Acad Sci U S A. 106:12512–12517 The opioid processes involve mu opi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Beetle
Ground beetles are a large, cosmopolitan distribution, cosmopolitan family (biology), family of beetles, the Carabidae, with more than 40,000 species worldwide, around 2,000 of which are found in North America and 2,700 in Europe. As of 2015, it is one of the 10 most species-rich animal families. They belong to the Adephaga. Members of the family are primarily carnivorous, but some members are phytophagous or omnivorous. Description and ecology Although their body shapes and coloring vary somewhat, most are shiny black or metallic and have ridged wing covers (elytra). The elytra are fused in some species, particularly the large Carabinae, rendering the beetles unable to fly. The species ''Mormolyce phyllodes'' is known as violin beetle due to their peculiarly shaped elytra. All carabids except the quite primitive flanged bombardier beetles (Paussinae) have a groove on their arthropod leg, fore leg tibiae bearing a comb of hairs used for cleaning their antenna (biology), antennae. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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