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Baikal Yellowfin
The Baikal yellowfin (''Cottocomephorus grewingkii''), also known as the yellow-finned sculpin or yellow-wing sculpin, is a species of freshwater ray-finned fish belonging to the family Cottidae, the typical sculpins. This species is endemic to Lake Baikal and its tributaries in Siberia, Russia. It is most common in the southern part of the lake and lives from near the shore to a depth of . Appearance It can reach up to in total length, but most are . They have relatively large pectoral fins, which are yellow in males. During the breeding season, the male's head becomes black when encountering other males. Behavior The Baikal yellowfin feeds on copepods (notably '' Epischura baikalensis''), amphipods, insect larvae and fish larvae. There are three separate breeding periods: March, May and August. There are some differences in the breeding behavior and site depending on when the fish breeds. Breeding occurs at a depth of in a crevice under a rock, which measures from to . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benedykt Dybowski
Benedykt Tadeusz Dybowski (12 May 183331 January 1930) was a Polish naturalist and physician. Life Benedykt Dybowski was born in Adamaryni, within the Minsk Governorate of the Russian Empire to Polish nobility. He was the brother of naturalist Władysław Dybowski and the cousin of the French explorer Jean Dybowski. He studied at Minsk High School, and later medicine at Tartu (earlier Dorpat) University in present-day Estonia. He later studied at Wroclaw University and went on expeditions to seek and study oceanic fishes and crustaceans. He became a professor of zoology at the Warsaw main school. In 1864 he was arrested and condemned to death for taking part in the Polish January Uprising. His sentence was later reduced to 12 years in Siberia. He started studying the natural history of Siberia and in 1866 a governor Muraviov dismissed Dybowski from hard labour (''katorga''), renewed his civil rights and proposed him to work as a doctor in hospital. He later settled in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commercial Fishing
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions. Large-scale commercial fishing is also known as industrial fishing. The major fishing industries are not only owned by major corporations but by small families as well. In order to adapt to declining fish populations and increased demand, many commercial fishing operations have reduced the sustainability of their harvest by fishing further down the food chain. This raises concern for fishery managers and researchers, who highlight how further they say that for those reasons, the sustainability of the marine ecosystems could be in danger of collapsing. Commercial fishermen harvest a wide variety of animals. However, a very small number of species support the majority of the world ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Fish Of Asia
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non- salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/ sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranean rivers and lakes. Fresh water is the water resource that is of the most and immediate use to humans. Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of higher plants and most insects, amphibians, reptiles, mammals and birds need fresh water to survive. Fresh water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Of Lake Baikal
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 fis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cottocomephorus
''Cottocomephorus'' is a genus of freshwater ray-finned fishes belonging to the Family (biology), family Cottidae, the typical sculpins. This genus is endemism, endemic to Lake Baikal and its surrounding tributaries in Russia. They have relatively large pectoral fins and reach up to in total length. They are an important food for the Baikal seal, during the winter second only to the golomyankas. Taxonomy ''Cottocomephorus'' was first proposed as a monospecific genus in 1900 by the French ichthyologist Jacques Pellegrin when he Species description, described ''Cottocomephorus megalops'' as a new species. The genus was classified in the family Cottocomephoridae; however, the 5th edition of ''Fishes of the World'' classifies the genus within the subfamily Cottinae of the family Cottidae, studies having found that the genera formerly included in the Cottocomephoridae were a clade arising from the genus ''Cottus (fish), Cottus''. Species There are currently three recognized species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algal Bloom
An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ''algae'' encompasses many types of aquatic photosynthetic organisms, both macroscopic multicellular organisms like seaweed and microscopic unicellular organisms like cyanobacteria. ''Algal bloom'' commonly refers to the rapid growth of microscopic unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest. Algal blooms are the result of a nutrient, like nitrogen or phosphorus from various sources (for example fertilizer runoff or other forms of nutrient pollution), entering the aquatic system and causing excessive growth of algae. An algal bloom affects the whole ecosystem. Consequences range from the benign feeding of higher trophic levels to more harmful effects like blocking sunlight from reaching other organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulothrix
''Ulothrix'' is a genus of green algae in the family Ulotrichaceae. ''Ulothrix'' is a genus of non-branching filamentous green algae, generally found in fresh and marine water. Its cells are normally as broad as they are long, and they thrive in the low temperatures of spring and winter. They become attached to surfaces by a modified holdfast cell. Reproduction is normally vegetative. They are Eukaryotic and multicellular because the cells have specific functions as the lowermost cell serves as holdfast and it doesn't have chloroplast, and the apical cell is dome-shaped. The genus includes: * ''Ulothrix aequalis'' KützingGuiry, M.D., John, D.M., Rindi, F and McCarthy, T.K. (ed.) 2007. ''New Survey of Clare Island Volume: The Freshwater and Terrestrial Algae''. Royal Irish Academy. . * ''Ulothrix moniliformis'' Kützing * ''Ulothrix flacca'' (Dillwyn) Thuret in Le JolisBurrows, E.M. 1991. ''Seaweeds of the British Isles Volume 2: Chlorophyta''. Natural History Museum, London . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spirogyra
''Spirogyra'' (common names include water silk, mermaid's tresses, and blanket weed) is a genus of filamentous charophyte green algae of the order Zygnematales, named for the helical or spiral arrangement of the chloroplasts that is characteristic of the genus. ''Spirogyra'' species, of which there are more than 400, are commonly found in freshwater habitats. ''Spirogyra'' measures approximately 10 to 100 μm in width and may grow to several centimetres in length. It is often observed as green slimy patches on the ground near ponds and other water bodies having stagnant water. General characteristics ''Spirogyra'' is very common in relatively clear eutrophic water, developing slimy filamentous green masses. In spring ''Spirogyra'' grows under water, but when there is enough sunlight and warmth they produce large amounts of oxygen, adhering as bubbles between the tangled filaments. The filamentous masses come to the surface and become visible as slimy green mats. ''Spirogyr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algal
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 their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siltation
Siltation, is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or permanent) of fine sediments on bottoms where they are undesirable. Siltation is most often caused by soil erosion or sediment spill. It is sometimes referred to by the ambiguous term "sediment pollution", which can also refer to a chemical contamination of sediments accumulated on the bottom, or to pollutants bound to sediment particles. Although "siltation" is not perfectly stringent, since it also includes particle sizes other than silt, it is preferred for its lack of ambiguity. Causes The origin of the increased sediment transport into an area may be erosion on land or activities in the water. In rural areas, the erosion source is typically soil degradation by intensive or inadequate agricultural practices, leading to soil eros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irkutsk Hydroelectric Power Station
The Irkutsk Hydroelectric Power Station (Irkutsk HPS) is a rock-fill dam on the Angara River with an adjacent hydroelectric power station. It is located adjacent to Irkutsk, Irkutsk Oblast in Russia and is the first dam on the Angara cascades. Construction on the dam began in 1950, its reservoir began filling in 1956 and its first turbines were also commissioned in 1956. It was the first large hydroelectric power station constructed in Eastern Siberia and its completion was hailed by the Soviets as an engineering success. History Background Complex studies to develop the Angara River began in 1930 as part of a large effort for economic development along the river. In 1935, the research stage of the study was complete and recommended a hydroelectric power plant at the top of the Angara for industrial consumption. In 1936, the State Plan of the USSR reviewed the results and determined that six hydroelectric power stations in a cascade should be built on the river, the Irkutsk bein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omul
The omul, ''Coregonus migratorius'', also known as Baikal omul (russian: байкальский омуль), is a whitefish species of the salmon family endemic to Lake Baikal in Siberia, Russia. It is considered a delicacy and is the object of one of the largest commercial fisheries on Lake Baikal. In 2004, it was listed in Russia as an endangered species. Taxonomy The omul has traditionally been regarded as a subspecies of the Arctic cisco ''Coregonus autumnalis''. However, recent genetic studies have shown it actually belongs to the circumpolar '' Coregonus lavaretus- clupeaformis'' complex of lake whitefishes, which also has other members in Lake Baikal, and it is now considered its own species within ''Coregonus''. The four or five traditionally accepted subpopulations of omul within Lake Baikal are: North Baikal (северобайкальский), Selenga (селенгинский), Chivyrkui (чивыркуйский) and Posolsk (посольский). These vary in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
