|
Salmo Ezenami
''Salmo ezenami'' is a critically endangered freshwater salmonid fish, endemic to Lake Kezenoi-Am (Lake Eizenam) in Northern Caucasus. The only native occurrence, in Lake Kezenoi-Am in Chechnya at the border of Dagestan, is in a cold alpine lake (area 2.4 km2, maximum depth 74 m, 1870 m altitude). In addition, the species has been introduced to another lake in Dagestan, Lake Mochokh, probably successfully.Freyhof, J. & Kottelat, M. 2008''Salmo ezenami''.In: IUCN Red List of Threatened Species. Version 2010.1. Downloaded on 5 April 2010. ''Salmo ezenami'' used to be the only fish species in Lake Kezenoi-Am. However, two other species, the European chub and Caspian gudgeon have been introduced, and present a threat by eating the fry of ''Salmo''. ''Salmo ezenami'' spawns in the lake, close to underwater springs. Adult fish also probably migrate to tributaries. There are separate small-sized (adults 160–260 mm) and large-sized forms (380–1130 mm). Young pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lev Berg
Lev Semyonovich Berg, also known as Leo S. Berg (russian: Лев Семёнович Берг; 14 March 1876 – 24 December 1950) was a leading Russian geographer, biologist and ichthyologist who served as President of the Soviet Geographical Society between 1940 and 1950. He is known for his own evolutionary theory, nomogenesis (a form of orthogenesis incorporating mutationism) as opposed to the theories of Darwin and Lamarck. Life Lev Berg was born in Bessarabia in a Jewish family, the son of Simon Gregoryevich Berg, a notary, and Klara Lvovna Bernstein-Kogan. He graduated from the Second Kishinev Gymnasium in 1894. Like some of his relatives, Berg converted to Christianity in order to pursue his studies at Moscow State University. At Moscow University, Berg studied hydrobiology and geography. He later studied ichthyology and in 1928 was awarded he was also a member of the Russian Academy of Sciences. Lev Berg graduated from the Moscow State University in 1898. Between 190 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caspian Gudgeon
The Caspian gudgeon (''Gobio holurus'') is a freshwater fish species in the family Cyprinidae. It is a small fish, less than 10 cm, which is distributed in the drainages of the Western Caspian Sea basin ( Kuma, Terek and Sulak Sulak may refer to: ;Places *Sulak, Khuzestan, a village in Khuzestan Province, Iran * Sulak, Kohgiluyeh and Boyer-Ahmad, a village in Kohgiluyeh and Boyer-Ahmad Province, Iran * Sulak, Russia, several inhabited localities in Russia *Sulak, Silvan ... river drainages) in Russia and adjacent countries. It is widespread and not threatened, but there is no information about its biology. References holurus Fish described in 1976 {{Gobioninae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxa Named By Lev Berg
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's system in '' Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first made widely available in 1805 in the i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmo
''Salmo'' is a genus of ray-finned fish from the family Salmonidae. The single ''Salmo'' species naturally found in the Atlantic North America is the Atlantic salmon, whereas the salmon and trout of the Pacific basin belong to another genus, ''Oncorhynchus''. The natural distribution of ''Salmo'' also extends to North Africa and to West Asia around the Black Sea basin. The generic name ''Salmo'' derives from the Latin ''salmō'' (salmon). The number of distinct species and subspecies in ''Salmo'' is a debated issue. Atlantic salmon and brown trout are widespread species, while most of the other taxa are narrowly distributed forms endemic to single watersheds. Species The species currently listed in this genus are: * ''Salmo abanticus'' Tortonese, 1954 (Lake Abant trout) * ''Salmo aestivalis'' Fortunatov, 1926 (Lake Sevan summer trout) * ''Salmo akairos'' Delling & Doadrio, 2005 (Lake Ifni trout) * ''Salmo aphelios'' Kottelat, 1997 (summer trout) * ''Salmo balcanicus'' ( S. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chironomid
The Chironomidae (informally known as chironomids, nonbiting midges, or lake flies) comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many species superficially resemble mosquitoes, but they lack the wing scales and elongated mouthparts of the Culicidae. The name Chironomidae stems from the Ancient Greek word ''kheironómos'', "a pantomimist". Common names and biodiversity This is a large taxon of insects; some estimates of the species numbers suggest well over 10,000 world-wide. Males are easily recognized by their plumose antennae. Adults are known by a variety of vague and inconsistent common names, largely by confusion with other insects. For example, chironomids are known as "lake flies" in parts of Canada and Lake Winnebago, Wisconsin, but "bay flies" in the areas near the bay of Green Bay, Wisconsin. They are called "sand flies", "muckleheads", "muffleheads", "Canadian so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gammarid
Gammaridae is a family of amphipods. In North America they are included among the folk taxonomic category of " scuds", and otherwise gammarids is usually used as a common name. They have a wide distribution, centered on Eurasia, and are euryhaline as a lineage, inhabiting fresh to marine waters. Systematics The Gammaridae were for a long time used as a "wastebin taxon", which included numerous genera of gammaridean amphipods that since then have been removed to their own families, such as the Anisogammaridae, Melitidae, Niphargidae. The following genera are currently listed in the family: *'' Akerogammarus'' Derzhavin & Pjatakova, 1967 *'' Albanogammarus'' Ruffo, 1995 *'' Amathillina'' G. O. Sars, 1894 *'' Axelboeckia'' Stebbing, 1899 *''Baku'' Karaman & Barnard, 1979 *'' Cephalogammarus'' Karaman & Barnard, 1979 *'' Chaetogammarus'' Martynov, 1924 *'' Comatogammarus'' Stock, 1981 *'' Condiciogammarus'' G. Karaman, 1984 *'' Dershavinella'' Birstein, 1938 *''Dikerogammarus'' S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tributaries
A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean. The Irtysh is a chief tributary of the Ob river and is also the longest tributary river in the world with a length of . The Madeira River is the largest tributary river by volume in the world with an average discharge of . A confluence, where two or more bodies of water meet, usually refers to the joining of tributaries. The opposite to a tributary is a distributary, a river or stream that branches off from and flows away from the main stream. PhysicalGeography.net, Michael Pidwirny & Scott ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fry (biology)
Fish go through various life stages between fertilization and adulthood. The life of a fish start as spawned eggs which hatch into immotile larvae. These larval hatchlings are not yet capable of feeding themselves and carry a yolk sac which provides stored nutrition. Before the yolk sac completely disappears, the young fish must mature enough to be able to forage independently. When they have developed to the point where they are capable of feeding by themselves, the fish are called fry. When, in addition, they have developed scales and working fins, the transition to a juvenile fish is complete and it is called a fingerling, so called as they are typically about the size of human fingers. The juvenile stage lasts until the fish is fully grown, sexually mature and interacting with other adult fish. Growth stages Ichthyoplankton ''(planktonic or drifting fish)'' are the eggs and larvae of fish. They are usually found in the sunlit zone of the water column, less than 200 met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Chub
''Squalius cephalus'' is a European species of freshwater fish in the carp family Cyprinidae. It frequents both slow and moderate rivers, as well as canals and still waters of various kinds. This species is referred to as the common chub, European chub, or simply chub. Description It is a stocky fish with a large rounded head. Its body is long and cylindrical in shape and is covered in large greenish-brown scales which are edged with narrow bands of black across the back, paling to golden on the flanks and even paler on the belly. The tail is dark brown or black, the dorsal fin is a greyish-green in colour and all the other fins are orange-red. The dorsal fin has 3 spines and 7-9 soft rays while the anal fin has 3 spines and 7-10 rays. The vertebrae count is 42-48. It can grow to 60 cm standard length but most fish are around 30 cm. Distribution The chub is distributed throughout most of northern Eurasia, it can be found in the rivers flowing into the North, Baltic, n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Mochokh
A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger oceans, they do form part of the Earth's water cycle. Lakes are distinct from lagoons, which are generally coastal parts of the ocean. Lakes are typically larger and deeper than ponds, which also lie on land, though there are no official or scientific definitions. Lakes can be contrasted with rivers or streams, which usually flow in a channel on land. Most lakes are fed and drained by rivers and streams. Natural lakes are generally found in mountainous areas, rift zones, and areas with ongoing glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers, where a river channel has widened into a basin. Some parts of the world have many lakes formed by the chaotic drainage patterns left over from the last ice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
