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Hydrobiid Snail
Hydrobiidae, commonly known as mud snails, is a large cosmopolitan family of very small freshwater and brackish water snails with an operculum; they are in the order Littorinimorpha. Distribution Hydrobiidae are found in much of the world, inhabiting all continents except Antarctica. In Australia alone there are over 260 species in the family. Description These are very small or minute snails, with a shell height of less than 8 mm. The dextrally-coiled shells are smooth (except for growth lines conforming to the shape of the outer lip) and are usually rather nondescript. The shell offers very few robust characteristics to the systematist who is attempting to classify the species within this family. This difficulty is compounded by a high degree of intraspecific variation. Descriptions often have to be based on the characteristics of the operculum, radula and penis. The shell of species within this family varies from planispiral to needle-shaped. The shell may hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peringia Ulvae
''Peringia ulvae'' (or ''Hydrobia ulvae''), common name the Laver spire shell or mudsnail, is a European species of very small aquatic snail with gills and an operculum, a gastropod mollusk in the family Hydrobiidae.Gofas, S. (2010). ''Hydrobia ulvae'' (Pennant, 1777). In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2010) World Marine Mollusca database. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=140126 on 2010-11-27. This is arguably a marine snail, but it is often also listed as a non-marine species because it tolerates brackish water and lives in salt marshes and similar habitats. ''Peringia ulvae'' is the type species of the genus ''Peringia''. Distribution This species occurs on the coasts of the Baltic Sea, the White Sea the Eastern Atlantic and the western Mediterranean Sea, (the Mediterranean records may be in error) including: * Great Britain * Ireland * The Netherlands The type locality is "on the shore ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoconch
A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called "nucleus". The protoconch may sometimes consist of several whorls, but when this is the case, the whorls show no growth lines. The whorls of the adult shell, which are formed after the protoconch, are known as the teleoconch. The teleoconch starts forming when the larval gastropod becomes a juvenile, and the protoconch may dissolve. Quite often there is a visible line of demarcation where the protoconch ends and the teleoconch begins, and there may be a noticeable change in sculpture, or a sudden appearance of sculpture at that point. In some gastropod groups (such as the Architectonicidae), the teleoconch whorls spiral in the opposite direction to the protoconch. In those cases, the shell is called heterostrophic. In species which ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franz Hermann Troschel
Franz Hermann Troschel (10 October 1810 – 6 November 1882) was a German zoologist born in Spandau. He studied mathematics and natural history at the University of Berlin, where he was awarded his doctorate in 1834.Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. xiii + 296 pp. . ("Troschel", p. 268). From 1840 to 1849 he was an assistant to Martin Lichtenstein at the Natural History Museum of Berlin. In 1849 he became a professor of zoology and natural history at the University of Bonn. In 1851 he became a member of the Academy of Sciences Leopoldina. ''Deutschen Akademie der Naturforscher Leopoldina''. Troschel is remembered for the identification and classification of species in the fields of [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estuary
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water, and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world. Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are typically classified according to their geomorphological features or to water-circulation patterns. They can have many different names, such as bays, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Mollusc
Freshwater molluscs are those members of the Phylum Mollusca which live in freshwater habitats, both lotic (flowing water) such as rivers, streams, canals, springs, and cave streams (stygobite species) and lentic A lake ecosystem or lacustrine ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (non-living) physical and chemical interactions. Lake ecosystems are a prime example of lentic ecosystems (''lentic'' re ... (still water) such as lakes, ponds (including temporary or vernal ponds), and ditches. This article is about freshwater Mollusca in general; for information on one particular family of freshwater molluscs, please follow the appropriate links in the lists below. The two major classes of molluscs have representatives in freshwater: the gastropods (snails) and the pelecypoda, bivalves (freshwater mussels and clams.) It appears that the other classes within the Phylum Mollusca -the cephalopods, scaphopods, polyplacophorans, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Truncatelloidea
Truncatelloidea is a superfamily of snails, gastropod mollusks in the clade Caenogastropoda.Bouchet, P. (2013). ''Truncatelloidea''. Retrieved through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=722756 on 2013-06-11 The families are marine, brackish, freshwater and terrestrial. Families * Amnicolidae Tryon, 1863 * Anabathridae Keen, 1971 * Assimineidae H. Adams & A. Adams, 1856 * Bithyniidae Gray, 1857 * Bythinellidae Locard, 1893 * Caecidae Gray, 1850 * Calopiidae Ponder, 1999 * Clenchiellidae D. W. Taylor, 1966 * Cochliopidae Tryon, 1866 * Elachisinidae Ponder, 1985 * Emmericiidae Brusina, 1870 * Epigridae Ponder, 1985 * Falsicingulidae Slavoshevskaya, 1975 * Helicostoidae Pruvot-Fol, 1937 * Hydrobiidae Stimpson, 1865 * Hydrococcidae Thiele, 1928 * Iravadiidae Thiele, 1928 * Lithoglyphidae Tryon, 1866 * Lithoglyphulidae Radoman, 1973 * Moitessieriidae Bourguignat, 1863 * Pomatiopsidae Stimpson, 1865 * Spirostyliferinidae Layt ... [...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] |
Diatom
A diatom (Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising several genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of the Earth's biomass: they generate about 20 to 50 percent of the oxygen produced on the planet each year, take in over 6.7 billion metric tons of silicon each year from the waters in which they live, and constitute nearly half of the organic material found in the oceans. The shells of dead diatoms can reach as much as a half-mile (800 m) deep on the ocean floor, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up of a system of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as ''Chlorella,'' ''Prototheca'' and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to in length. Most are aquatic and autotrophic (they generate food internally) and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the ''Charophyta'', a division of green algae which includes, for example, ''Spirogyra'' and stoneworts. No definition of algae is generally accepted. One definition is that algae "have chlorophyll ''a'' as their primary photosynthetic pigment and lack a sterile covering of cells around thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Carboniferous
Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early Branch, a stream in Missouri * Early County, Georgia Other uses * Early (Scritti Politti album), ''Early'' (Scritti Politti album), 2005 * Early (A Certain Ratio album), ''Early'' (A Certain Ratio album), 2002 * Early (name) * Early effect, an effect in transistor physics * Early Records, a record label * the early part of the morning See also * Earley (other) {{disambiguation, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Veliger
A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells. Description The veliger is the characteristic larva of the gastropod, bivalve and scaphopod taxonomic classes. It is produced following either the embryonic or trochophore larval stage of development. In bivalves the veliger is sometimes referred to as a D-stage (early in its development) or pediveliger (late in its development) larva. This stage in the life history of these groups is a free-living planktonic organism; this mode of life potentially enhances dispersal to new regions far removed from the adult mollusks that produced the larvae. The general structure of the veliger includes a shell that surrounds the visceral organs of the larva (e.g., digestive tract, much of the nervous system, excretory organs) and a ciliated velum that extends beyond the shell as a single or multi-lobed structure used for swimming and particula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
