|
Theodoxus Bolivari
''Theodoxus'' is a genus of nerites, small water snails with an operculum, some of which live in freshwater, and some in both freshwater and brackish water, aquatic gastropod mollusks in the family Neritidae, the nerites.Bouchet, P. (2014). Theodoxus Montfort, 1810. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=153531 on 2014-11-17. Distribution The distribution of the genus ''Theodoxus'' includes Europe and northern Africa and also extends east to southern Iran. No other species within Neritidae have sympatrical distribution with ''Theodoxus''. The distribution of the genus ''Theodoxus'' is an exception within Neritidae, because Neritidae live primarily in the southern hemisphere. Species within ''Theodoxus'' are the only Neritidae snails, that live in temperate climate. Bunje & Lindberg (2007) presented the first phylogenetic hypothesis of the clade ''Theodoxus''.Bunje P. M. & Lindberg D. R. (2007). "Line ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodoxus Fluviatilis
''Theodoxus fluviatilis'', common name the river nerite, is a species of small freshwater and brackish water snail with a gill and an operculum, an aquatic gastropod mollusk in the family Neritidae, the nerites.Neubauer, Thomas A. (2014). ''Theodoxus'' (''Theodoxus'') ''fluviatilis'' (Linnaeus, 1758). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=821986 on 2014-11-18 This widely distributed neritid snail species occurs from Europe to Central Asia. It has a thick shell with a calcified operculum. The coloration pattern on the shell is very variable. ''Theodoxus fluviatilis'' lives in freshwater and in brackish water, in rivers and lakes on stones. It feeds mainly by grazing on biofilms and diatoms. Some of the populations of this species are spreading, and these can reach densities up to thousands of snails per square meter. Females lay egg capsules, each of which contains a large number of eggs, but only one snai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodoxus Fluviatilis Radula
''Theodoxus'' is a genus of nerites, small water snails with an operculum, some of which live in freshwater, and some in both freshwater and brackish water, aquatic gastropod mollusks in the family Neritidae, the nerites.Bouchet, P. (2014). Theodoxus Montfort, 1810. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=153531 on 2014-11-17. Distribution The distribution of the genus ''Theodoxus'' includes Europe and northern Africa and also extends east to southern Iran. No other species within Neritidae have sympatrical distribution with ''Theodoxus''. The distribution of the genus ''Theodoxus'' is an exception within Neritidae, because Neritidae live primarily in the southern hemisphere. Species within ''Theodoxus'' are the only Neritidae snails, that live in temperate climate. Bunje & Lindberg (2007) presented the first phylogenetic hypothesis of the clade ''Theodoxus''.Bunje P. M. & Lindberg D. R. (2007). "Lineage div ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodoxus Acuticarinatus
''Theodoxus'' is a genus of nerites, small water snails with an operculum, some of which live in freshwater, and some in both freshwater and brackish water, aquatic gastropod mollusks in the family Neritidae, the nerites.Bouchet, P. (2014). Theodoxus Montfort, 1810. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=153531 on 2014-11-17. Distribution The distribution of the genus ''Theodoxus'' includes Europe and northern Africa and also extends east to southern Iran. No other species within Neritidae have sympatrical distribution with ''Theodoxus''. The distribution of the genus ''Theodoxus'' is an exception within Neritidae, because Neritidae live primarily in the southern hemisphere. Species within ''Theodoxus'' are the only Neritidae snails, that live in temperate climate. Bunje & Lindberg (2007) presented the first phylogenetic hypothesis of the clade ''Theodoxus''.Bunje P. M. & Lindberg D. R. (2007). "Lineage div ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theodoxus Petasatus
''Theodoxus'' is a genus of nerites, small water snails with an operculum, some of which live in freshwater, and some in both freshwater and brackish water, aquatic gastropod mollusks in the family Neritidae, the nerites.Bouchet, P. (2014). Theodoxus Montfort, 1810. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=153531 on 2014-11-17. Distribution The distribution of the genus ''Theodoxus'' includes Europe and northern Africa and also extends east to southern Iran. No other species within Neritidae have sympatrical distribution with ''Theodoxus''. The distribution of the genus ''Theodoxus'' is an exception within Neritidae, because Neritidae live primarily in the southern hemisphere. Species within ''Theodoxus'' are the only Neritidae snails, that live in temperate climate. Bunje & Lindberg (2007) presented the first phylogenetic hypothesis of the clade ''Theodoxus''.Bunje P. M. & Lindberg D. R. (2007). "Lineage div ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN Red List
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit. The aim of the IUCN Red List is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to reduce species extinction. According to IUCN the formally stated goals of the Red List are to provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulase
Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccharides: : Endohydrolysis of (1→4)-β-D-glucosidic linkages in cellulose, lichenin and cereal β-D-glucan The name is also used for any naturally occurring mixture or complex of various such enzymes, that act serially or synergistically to decompose cellulosic material. Cellulases break down the cellulose molecule into monosaccharides ("simple sugars") such as β-glucose, or shorter polysaccharides and oligosaccharides. Cellulose breakdown is of considerable economic importance, because it makes a major constituent of plants available for consumption and use in chemical reactions. The specific reaction involved is the hydrolysis of the 1,4-β-D-glycosidic linkages in cellulose, hemicellulose, lichenin, and cereal β-D-glucans. Because cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substrate (biology)
In biology, a substrate is the surface on which an organism (such as a plant, fungus, or animal) lives. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock (its substrate) can be itself a substrate for an animal that lives on top of the algae. Inert substrates are used as growing support materials in the hydroponic cultivation of plants. In biology substrates are often activated by the nanoscopic process of substrate presentation. In agriculture and horticulture * Cellulose substrate * Expanded clay aggregate (LECA) * Rock wool * Potting soil * Soil In animal biotechnology Requirements for animal cell and tissue culture Requirements for animal cell and tissue culture are the same as described for plant cell, tissue and organ culture (In Vitro Culture Techniques: The Biotechnological Principles). Desirable requirements are (i) air conditioning of a room, (ii) hot room with temperature recorder, (iii) microscope r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Conchology
The ''Journal of Conchology'' is a peer-reviewed scientific journal published by The Conchological Society of Great Britain and Ireland, covering research in conchology and malacology. It claims to be the world's oldest continuing publication on the subject. The journal publishes original research and short communications on molluscs, with emphasis on conservation, biogeography and taxonomy. The contents include descriptions of new species from anywhere in the world, and reports concerning the ecology Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ..., distribution, and status of molluscs, both living and fossil. References External links * {{Official website, http://www.conchsoc.org/journal Digital archiveof volumes 2–16 (1879–1922) in BHL Malacology journals English ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radula
The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs 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 molluscs, and is found in every class of mollusc 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 molluscs. Other predatory marine snails ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (gastropod)
The operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periostracum
The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods and bivalves, but it is also found in cephalopods such as ''Allonautilus scrobiculatus''. The periostracum is an integral part of the shell, and it forms as the shell forms, along with the other shell layers. The periostracum is used to protect the organism from corrosion. The periostracum is visible as the outer layer of the shell of many molluscan species from terrestrial, freshwater, and marine habitats, and may be seen in land snails, river mussels, and other kinds of freshwater bivalves, as well as in many kinds of marine shelled molluscs. The word ''periostracum'' means "around the shell", meaning that the periostracum is wrapped around what is usually the more calcareous part of the shell. Technically, the calcareous part of the shel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in numerous gastropods, but it is also found in shelled cephalopods including ''Nautilus'', ''Spirula'' and the large extinct subclass of cephalopods known as the ammonites. A spiral shell can be visualized as consisting of a long conical tube, the growth of which is coiled into an overall helical or planispiral shape, for reasons of both strength and compactness. The number of whorls which exist in an adult shell of a particular species depends on mathematical factors in the geometric growth, as described in D'Arcy Wentworth Thompson's classic 1917 book ''On Growth and Form'', and by David Raup. The main factor is how rapidly the conical tube expands (or flares-out) over time. When the rate of expansion is low, such that each subsequent whorl is not that much wider than the previous one, then the adult shell has numerous whorls. When the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_torquata_002.jpg "Click for more on -> Operculum (gastropod)")
