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Volga Undermouth
The Volga undermouth or Volga nase (''Chondrostoma variabile'') is a species of cyprinid freshwater fish. This one lives in the Emba, Ural and Volga drainages of the Caspian Sea basin, and the Don River drainage of the Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Rom ... basin. It is a riverine fish but is also found in reservoirs. The distribution is in lowland areas and foothills, and the fish prefer river stretches with strong currents, including rapids. Larvae and juveniles have a superior mouth, but at 3–4 months they change to adult feeding mode (undermouth) and start grazing the bottom, eating benthic diatoms and detritus from hard substrate. Breeding females deposit sticky eggs on gravel bottom in shallow parts of rivers with moderate to strong current. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasilii Evgrafovich Yakovlev
Vasily Evgrafovich Yakovlev (russian: Василий Евграфович Яковлев; also transliterated Vasiliy Ewgrafowitsch Jakovlev or Vasiliy Yevgrafovich Yakovlev; 9 February 1839 – 15 August 1908) was a Russian zoologist who studied fishes, molluscs and insects. He is not to be confused with Alexander Ivanovich Yakovlev, another entomologist. His name was spelled Wassily Ewgrafowitsch Jakowlew in French, in which he sometimes wrote. Yakovlev lived in Saint Petersburg, but travelled extensively collecting insects in the Crimea, Volga region and Turkestan until he finally travelled and settled in Griffin, GA. Although primarily interested in Coleoptera Yakovlev also worked on Hemiptera and Lepidoptera. From around 1867 Yakovlev conducted zoological observations in the vicinity of Astrakhan. Yakovlev described Caspian roach (''Rutilus caspicus'') and Volga undermouth (''Chondrostoma variabile''). Publications Partial list *Description de quelques Longicornes pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyprinid
Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest vertebrate animal family in general with about 3,000 species, of which only 1,270 remain extant, divided into about 370 genera. Cyprinids range from about 12 mm in size to the giant barb (''Catlocarpio siamensis''). By genus and species count, the family makes up more than two-thirds of the ostariophysian order Cypriniformes. The family name is derived from the Greek word ( 'carp'). Biology and ecology Cyprinids are stomachless fish with toothless jaws. Even so, food can be effectively chewed by the gill rakers of the specialized last gill bow. These pharyngeal teeth allow the fish to make chewing motions against a chewing plate formed by a bony process of the skull. The pharyngeal teeth are unique to each species and are used by scient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emba River
The Emba ( kk, Ембі ''Embı'' or ''Jem'', russian: Эмба) in west Kazakhstan rises in the Mugodzhar Hills and flows into the Caspian Sea. It is long, and has a drainage basin of . It flows through the north of the Ust-Urt plateau, and reaches the Caspian by a series of shallow s, which were navigable in the 18th century. The lower course traverses an area of salt domes and the petroleum-rich Emba fields. It is sometimes regarded as a definition for the natural < ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ural River
The Ural (russian: Урал, ), known before 1775 as Yaik (russian: Яик, ba, Яйыҡ, translit=Yayıq, ; kk, Жайық, translit=Jaiyq, ), is a river flowing through Russia and Kazakhstan in the continental border between Europe and Asia. It originates in the southern Ural Mountains and discharges into the Caspian Sea. At , it is the third-longest river in Europe after the Volga and the Danube, and the 18th-longest river in Asia. The Ural is conventionally considered part of the boundary between the continents of Europe and Asia. The Ural arises near Mount Kruglaya in the Ural Mountains, flows south parallel and west of the north-flowing Tobol, through Magnitogorsk, and around the southern end of the Urals, through Orsk where it turns west for about , to Orenburg, where the river Sakmara joins. From Orenburg it continues west, passing into Kazakhstan, then turning south again at Oral, and meandering through a broad flat plain until it reaches the Caspian a few miles be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volga River
The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the List of rivers of Europe#Rivers of Europe by length, longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Caspian Sea. The Volga has a length of , and a catchment area of «Река Волга» , Russian State Water Registry which is more than twice the size of Ukraine. It is also Europe's largest river in terms of average discharge (hydrology), discharge at delta – between and – and of drainage basin. It is widely regarded as the Rivers in Russia, national river of Russia. The hypothetical old Russian state, the Rus' Khaganate, arose along the Volga . Historically, the river served as an important meeting place of various Eurasian civilizations. The river flows in Russia through forests, Fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caspian Sea
The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia, south of the fertile plains of Southern Russia in Eastern Europe, and north of the mountainous Iranian Plateau of Western Asia. It covers a surface area of (excluding the highly saline lagoon of Garabogazköl to its east) and a volume of . It has a salinity of approximately 1.2% (12 g/L), about a third of the salinity of average seawater. It is bounded by Kazakhstan to the northeast, Russia to the northwest, Azerbaijan to the southwest, Iran to the south, and Turkmenistan to the southeast. The sea stretches nearly from north to south, with an average width of . Its gross coverage is and the surface is about below sea level. Its main freshwater inflow, Europe's longest river, the Volga, enters at the shallow north end. Two deep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Don River (Russia)
The Don ( rus, Дон, p=don) is the fifth-longest river in Europe. Flowing from Central Russia to the Sea of Azov in Southern Russia, it is one of Russia's largest rivers and played an important role for traders from the Byzantine Empire. Its basin is between the Dnieper basin to the west, the lower Volga basin immediately to the east, and the Oka basin (tributary of the Volga) to the north. Native to much of the basin were Slavic nomads. The Don rises in the town of Novomoskovsk southeast of Tula (in turn south of Moscow), and flows 1,870 kilometres to the Sea of Azov. The river's upper half ribbles (meanders subtly) south; however, its lower half consists of a great eastern curve, including Voronezh, making its final stretch, an estuary, run west south-west. The main city on the river is Rostov-on-Don. Its main tributary is the Seversky Donets, centred on the mid-eastern end of Ukraine, thus the other country in the overall basin. To the east of a series of thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Sea
The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Romania, Russia, Turkey, and Ukraine. The Black Sea is supplied by major rivers, principally the Danube, Dnieper, and Don. Consequently, while six countries have a coastline on the sea, its drainage basin includes parts of 24 countries in Europe. The Black Sea covers (not including the Sea of Azov), has a maximum depth of , and a volume of . Most of its coasts ascend rapidly. These rises are the Pontic Mountains to the south, bar the southwest-facing peninsulas, the Caucasus Mountains to the east, and the Crimean Mountains to the mid-north. In the west, the coast is generally small floodplains below foothills such as the Strandzha; Cape Emine, a dwindling of the east end of the Balkan Mountains; and the Dobruja Plateau considerably farth ... [...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] |
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] |
Chondrostoma
''Chondrostoma'' (from the Ancient Greek roots (''khondros'') 'lump' + (''stoma'') 'mouth' = 'lump-mouth') is a genus of ray-finned fish in the family Cyprinidae. They are commonly known as nases, although this term is also used locally to denote particular species, most frequently the common nase (''C. nasus''). The common name refers to the protruding upper jaw of these fishes; it is derived from the German term ''Nase'' 'nose'. Several species have a very restricted range. Some of these endemics are very rare nowadays, and at least one species is globally extinct. Systematics In 2007 it was determined that the presumed monophyletic group consisted of six at least partly independent lineages of Leuciscinae, meaning that the rasping feeding apparatus evolved more than once. It was proposed to split the genus in six in consequence: ''Achondrostoma'', ''Chondrostoma'', ''Iberochondrostoma'', ''Pseudochondrostoma'', '' Protochondrostoma'' and ''Parachondrostoma''. But at leas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Described In 1870
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Most f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
