|
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 rarely also ... [...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 Stimpso ... [...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 dia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Biology, biological Kingdom (biology), kingdom Animalia (). With few exceptions, animals heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, have myocytes and are motility, able to move, can reproduce sexually, and grow from a hollow sphere of Cell (biology), cells, the blastula, during embryonic development. Animals form a clade, meaning that they arose from a single common ancestor. Over 1.5 million extant taxon, living animal species have been species description, described, of which around 1.05 million are insects, over 85,000 are molluscs, and around 65,000 are vertebrates. It has been estimated there are as many as 7.77 million animal species on Earth. Animal body lengths range from to . They have complex ecologies and biological interaction, interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Animal
An aquatic animal is any animal, whether vertebrate or invertebrate, that lives in a body of water for all or most of its lifetime. Aquatic animals generally conduct gas exchange in water by extracting dissolved oxygen via specialised respiratory system, respiratory organ (biology), organs called gills, cutaneous respiration, through the skin or enteral respiration, across enteral mucosae, although some are evolution, evolved from terrestrial ancestors that re-adaptation, adapted to aquatic environments (e.g. marine reptiles and marine mammals), in which case they actually use lungs to breathing, breathe air and are essentially apnea, holding their breath when living in water. Some species of gastropod mollusc, such as the Elysia chlorotica, eastern emerald sea slug, are even capable of kleptoplastic photosynthesis via endosymbiosis with ingested yellow-green algae. Almost all aquatic animals reproduce in water, either oviparously or viviparously, and many species routinely fish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitewater
Whitewater forms in the context of rapids, in particular, when a river's Stream gradient, gradient changes enough to generate so much turbulence that air is trapped within the water. This forms an unstable current that foam, 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 consist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radula
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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod Shell
The gastropod shell is part of the body of many gastropods, including snails, 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, ostracum, is typically made of calcium carbonate (CaCO3) precipitated into an organic matrix ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found only 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 also be referred to as an ''endemism'' or, in scientific literature, as an ''endemite''. Similarly, many species found in the Western ghats of India are examples of endemism. Endemism is an important concept in conservation biology for measuring biodiversity in a particular place and evaluating the risk of extinction for species. Endemism is also of interest in evolutionary biology, because it provides clues about how changes in the environment cause species to undergo range shifts (potentially expanding their range into a larger area or b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Locality (biology)
In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. 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 (mathematics), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laos
Laos, officially the Lao People's Democratic Republic (LPDR), is the only landlocked country in Southeast Asia. It is bordered by Myanmar and China to the northwest, Vietnam to the east, Cambodia to the southeast, and Thailand to the west and southwest. The country has a population of approximately eight million. Its Capital city, capital and most populous city is Vientiane. The country is characterized by mountainous terrain, Buddhist temples, including the UNESCO's World Heritage Site of Luang Prabang, and French colonial architecture. The country traces its historic and cultural identity to Lan Xang, a kingdom which existed from the 13th to 18th centuries. Through its location, the kingdom was a hub for overland trade. In 1707, Lan Xang split into three kingdoms: Kingdom of Luang Phrabang, Luang Prabang, Kingdom of Vientiane, Vientiane, and Kingdom of Champasak, Champasak. In 1893, these kingdoms were unified under French protection as part of French Indochina. Laos was und ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mekong River
The Mekong or Mekong River ( , ) is a transboundary river in East Asia and Southeast Asia. It is the world's List of rivers by length, twelfth-longest river and List of longest rivers of Asia, the third-longest in Asia with an estimated length of and a drainage area of , discharging of water annually. From its headwaters in the Tibetan Plateau, the river runs through Southwest China (where it is officially called the Lancang River), Myanmar, Laos, Thailand, Cambodia, and southern Vietnam. The extreme seasonal variations in flow and the presence of Rapids, rapids and waterfalls in the Mekong make navigation difficult, though the river remains a major trade route between Tibet and Southeast Asia. The construction of hydroelectric dams along the Mekong in the 2000s through the 2020s has caused serious problems for the river's ecosystem, including the exacerbation of drought. Names The Mekong was originally called ''Mae Nam Khong'' from a contracted form of Kra-Dai language, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
