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Pachydrobiella
''Pachydrobiella brevis'' is a species of freshwater snail, an aquatic gastropod mollusk in the family Pomatiopsidae. ''Pachydrobiella brevis'' is the only species in the genus ''Pachydrobiella''. Distribution The distribution of ''Pachydrobiella brevis'' includes Khong Island in the Mekong River, southern Laos. The type locality is Khong Island. This species is probably endemic to the Khong Island region. Description The shape of the shell is ovate-conic. The shell is thick and smooth. The smooth shell is unique in the tribe Jullieniini. The outer lip is thick with growth lines. The width of the shell is 2.5 mm. The height of the shell is 2.2–3.6 mm. Thiele (1928) and Brandt (1970) made a drawing showing smooth teeth in the radula, but Davis (1979) showed multiserrate teeth in the radula. Ecology ''Pachydrobiella brevis'' lives primarily in freshwater habitats that lack a current or have only a slight current. However this species sometimes or rarel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachydrobiella Brevis Shell 2
''Pachydrobiella brevis'' is a species of freshwater snail, an aquatic gastropod mollusk in the family Pomatiopsidae. ''Pachydrobiella brevis'' is the only species in the genus ''Pachydrobiella''. Distribution The distribution of ''Pachydrobiella brevis'' includes Khong Island in the Mekong River, southern Laos. The type locality is Khong Island. This species is probably endemic to the Khong Island region. Description The shape of the shell is ovate-conic. The shell is thick and smooth. The smooth shell is unique in the tribe Jullieniini. The outer lip is thick with growth lines. The width of the shell is 2.5 mm. The height of the shell is 2.2–3.6 mm. Thiele (1928) and Brandt (1970) made a drawing showing smooth teeth in the radula, but Davis (1979) showed multiserrate teeth in the radula. Ecology ''Pachydrobiella brevis'' lives primarily in freshwater habitats that lack a current or have only a slight current. However this species sometimes or rarel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pomatiopsidae
Pomatiopsidae is a family of small, mainly freshwater snails, (some also occur in other habitats) that have gills and an operculum, aquatic gastropod mollusks in the superfamily Truncatelloidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). Pomatiopsidae are well known as intermediate hosts of Asian schistosomes. Distribution Species in the family Pomatiopsidae occur worldwide. The generic diversity of Pomatiopsinae is particularly high in the Japanese Archipelago, where four of the eight genera, including two endemics, are recorded. The subfamily Triculinae radiated as aquatic snails in freshwater habitats in Southeast Asia. Description The American malacologist William Stimpson first defined this taxon as Pomatiopsinae in 1865. Stimpson W. (1865). "Researches upon the Hydrobiinae and allied forms chiefly made upon materials in the museum of the Smithsonian Institution". '' Smithsonian Miscellaneous Collections'' 7'(201) 1-59page 4 Stimpson's d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triculinae
Pomatiopsidae is a family of small, mainly freshwater snails, (some also occur in other habitats) that have gills and an operculum, aquatic gastropod mollusks in the superfamily Truncatelloidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005). Pomatiopsidae are well known as intermediate hosts of Asian schistosomes. Distribution Species in the family Pomatiopsidae occur worldwide. The generic diversity of Pomatiopsinae is particularly high in the Japanese Archipelago, where four of the eight genera, including two endemics, are recorded. The subfamily Triculinae radiated as aquatic snails in freshwater habitats in Southeast Asia. Description The American malacologist William Stimpson first defined this taxon as Pomatiopsinae in 1865. Stimpson W. (1865). "Researches upon the Hydrobiinae and allied forms chiefly made upon materials in the museum of the Smithsonian Institution". '' Smithsonian Miscellaneous Collections'' 7'(201) 1-59page 4 Stimpson's d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Animal
An aquatic animal is any animal, whether invertebrate or vertebrate, that lives in water for most or all of its lifetime. Many insects such as mosquitoes, mayflies, dragonflies and caddisflies have aquatic larvae, with winged adults. Aquatic animals may breathe air or extract oxygen from water through specialised organs called gills, or directly through the skin. Natural environments and the animals that live in them can be categorized as aquatic (water) or terrestrial (land). This designation is polyphyletic. Description The term aquatic can be applied to animals that live in either fresh water or salt water. However, the adjective marine is most commonly used for animals that live in saltwater, i.e. in oceans, seas, etc. Aquatic animals (especially freshwater animals) are often of special concern to conservationists because of the fragility of their environments. Aquatic animals are subject to pressure from overfishing, destructive fishing, marine pollution, hunting, and cli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitewater
Whitewater forms in a rapid context, in particular, when a river's gradient changes enough to generate so much turbulence that air is trapped within the water. This forms an unstable current that froths, making the water appear opaque and white. The term "whitewater" also has a broader meaning, applying to any river or creek that has a significant number of rapids. The term is also used as an adjective describing boating on such rivers, such as whitewater canoeing or whitewater kayaking. Fast rivers Four factors, separately or in combination, can create rapids: gradient, constriction, obstruction, and flow rate. Gradient, constriction, and obstruction are streambed topography factors and are relatively consistent. Flow rate is dependent upon both seasonal variation in precipitation and snowmelt and upon release rates of upstream dams. Streambed topography Streambed topography is the primary factor in creating rapids, and is generally consistent over time. Increased f ... [...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] |
Gastropod Shell
The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less (slugs) but may have a remnant within the mantle, or in some cases the shell is reduced such that the body cannot be retracted within it (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the Aperture (mollusc), aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. Shell layers The gastropod shell has three major layers secreted by the Mantle (mollusc), mantle. The calcareous central layer, tracum, is typically made of calcium carbonate precipitated into an organic matrix known as c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Locality (biology)
In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen. A taxon is a scientifically named grouping of organisms with other like organisms, a set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Type specimen According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the scientific name of every taxon is almost a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laos
Laos (, ''Lāo'' )), officially the Lao People's Democratic Republic ( Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ, French: République démocratique populaire lao), is a socialist state and the only landlocked country in Southeast Asia. At the heart of the Indochinese Peninsula, Laos is bordered by Myanmar and China to the northwest, Vietnam to the east, Cambodia to the southeast, and Thailand to the west and southwest. Its capital and largest city is Vientiane. Present-day Laos traces its historic and cultural identity to Lan Xang, which existed from the 14th century to the 18th century as one of the largest kingdoms in Southeast Asia. Because of its central geographical location in Southeast Asia, the kingdom became a hub for overland trade and became wealthy economically and culturally. After a period of internal conflict, Lan Xang broke into three separate kingdoms: Luang Phrabang, Vientiane and Champasak. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mekong River
The Mekong or Mekong River is a trans-boundary river in East Asia and Southeast Asia. It is the world's twelfth longest river and the third longest in Asia. Its estimated length is , and it drains an area of , discharging of water annually. From the Tibetan Plateau the river runs through China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. The extreme seasonal variations in flow and the presence of rapids and waterfalls in the Mekong make navigation difficult. Even so, the river is a major trade route between western China and Southeast Asia. Names The Mekong was originally called ''Mae Nam Khong'' from a contracted form of Tai shortened to ''Mae Khong''. In Thai and Lao, ''Mae Nam'' ("Mother of Water ) is used for large rivers and ''Khong'' is the proper name referred to as "River Khong". However, ''Khong'' is an archaic word meaning "river", loaned from Austroasiatic languages, such as Vietnamese ''sông'' (from *''krong'') and Mon ''kruŋ'' "river", which led to Chin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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