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Veined Rapa Whelk
''Rapana venosa'', common name the veined rapa whelk or Asian rapa whelk, is a species of large predatory sea snail, a marine gastropod mollusc or whelk, in the family Muricidae, the rock shells. This large sea snail has become an invasive species in many different localities around the world. Shell description The shell of ''Rapana venosa'' is globose (rounded) and heavy, possessing a very short spire, a large body whorl, a strong columella and a deep umbilicus. The aperture is large and roughly ovate. Ornamentation is present externally as axial ribs, smooth spiral ribs ending in blunt knobs at both the shoulder and body whorl, and internally as small elongated teeth disposed along the outer lip margin. The external color varies from gray to reddish-brown, with dark brown dashes on the spiral ribs. Some specimens may have distinctive black/dark blue vein-like coloration patterns throughout the inner portions of the shell, usually originating from each individual too ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (gastropod)
The operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Body Whorl
The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the body whorl, or last whorl, is the most recently formed and largest whorl (or revolution) of a spiral or helical shell, terminating in the aperture. It is called the "body whorl" because most of the body of the soft parts of the animal fits into this whorl. The proportional size of the body whorl in gastropod shells differs greatly according to the actual shell morphology. For shells in which the rate of whorl expansion of each revolution around the axis is very high, the aperture and the body whorl are large, and the shell tends to be low spired. The shell of the abalone is a good example of this kind of shell. The opposite tendency can sometimes create a high spire with very little whorl increase per revolution. In these instances, e.g. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crimea
Crimea, crh, Къырым, Qırım, grc, Κιμμερία / Ταυρική, translit=Kimmería / Taurikḗ ( ) is a peninsula in Ukraine, on the northern coast of the Black Sea, that has been occupied by Russia since 2014. It has a population of 2.4 million. The peninsula is almost entirely surrounded by the Black Sea and the smaller Sea of Azov. The Isthmus of Perekop connects the peninsula to Kherson Oblast in mainland Ukraine. To the east, the Crimean Bridge, constructed in 2018, spans the Strait of Kerch, linking the peninsula with Krasnodar Krai in Russia. The Arabat Spit, located to the northeast, is a narrow strip of land that separates the Sivash lagoons from the Sea of Azov. Across the Black Sea to the west lies Romania and to the south is Turkey. Crimea (called the Tauric Peninsula until the early modern period) has historically been at the boundary between the classical world and the steppe. Greeks colonized its southern fringe and were absorbed by the Ro ... [...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] |
Far East
The ''Far East'' was a European term to refer to the geographical regions that includes East and Southeast Asia as well as the Russian Far East to a lesser extent. South Asia is sometimes also included for economic and cultural reasons. The term first came into use in European geopolitical discourse in the 15th century, particularly the British, denoting the Far East as the "farthest" of the three "Easts", beyond the Near East and the Middle East. Likewise, during the Qing dynasty of the 19th and early 20th centuries, the term "Far West (Taixi), Tàixī ()" – i.e., anything further west than the Arab world – was used to refer to the Western countries. Since the mid-20th century, the term has mostly gone out of use for the region in international mass media outlets due to its eurocentric connotations.Reischauer, Edwin and John K Fairbank, ''East Asia: The Great Tradition,'' 1960. The Russian Far East is often excluded due to cultural and ethnic differences, and is often cons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Data Book Of The Russian Federation
''Red Data Book of the Russian Federation'' (''RDBRF''), also known as ''Red Book'' (russian: Красная книга) or ''Russian Red Data Book'', is a state document established for documenting rare and endangered species of animals, plants and fungi, as well as some local subspecies (such as the Ladoga seal) that exist within the territory of the Russian Federation and its continental shelf and marine economic zone. The book has been adopted by Russia to enact a common agreement on rare and endangered species protection. Conservation The book provides a central information source in organizing studies and monitoring programs on rare and endangered species and their habitats. History The first Russian ''Red Data Book'' was based upon research conducted between 1961 and 1964 by a number of Soviet biologists. It represented the Soviet part of the IUCN Red List (hence the name). At that time it was just the Soviet Union's first organized list of endangered species, not a leg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bohai Sea
The Bohai Sea () is a marginal sea approximately in area on the east coast of Mainland China. It is the northwestern and innermost extension of the Yellow Sea, to which it connects to the east via the Bohai Strait. It has a mean depth of approximately , with a maximum depth of about located in the northern part of the Bohai Strait. The Bohai Sea is enclosed by three provinces and one direct-administered municipality from three different regions of China — Liaoning Province (of Northeast China), Hebei Province and Tianjin Municipality (of North China), and Shandong Province (of East China). The whole of the Bohai Sea is considered a part of both the internal waters of the People's Republic of China and the center of the Bohai Economic Rim. Its proximity to the Chinese capital of Beijing and the municipality of Tianjin makes it one of the busiest seaways in the world. History During the Pleistocene, the Bohai Sea experienced numerous glacioeustatic transgressions and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East China Sea
The East China Sea is an arm of the Western Pacific Ocean, located directly offshore from East China. It covers an area of roughly . The sea’s northern extension between mainland China and the Korean Peninsula is the Yellow Sea, separated by an imaginary line between the eastern tip of Qidong at the Yangtze River estuary and the southwestern tip of South Korea's Jeju Island. The East China Sea is bounded in the east and southeast by the middle portion of the first island chain off the eastern Eurasian continental mainland, including the Japanese island of Kyushu and the Ryukyu Islands, and in the south by the island of Taiwan. It connects with the Sea of Japan in the northeast through the Korea Strait, the South China Sea in the southwest via the Taiwan Strait, and the Philippine Sea in the southeast via gaps between the various Ryukyu Islands (e.g. Tokara Strait and Miyako Strait). Most of the East China Sea is shallow, with almost three-fourths of it being less than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yellow Sea
The Yellow Sea is a marginal sea of the Western Pacific Ocean located between mainland China and the Korean Peninsula, and can be considered the northwestern part of the East China Sea. It is one of four seas named after common colour terms (the others being the Black Sea, the Red Sea and the White Sea), and its name is descriptive of the golden-yellow colour of the silt-laden water discharged from major rivers. The innermost bay of northwestern Yellow Sea is called the Bohai Sea (previously Pechihli Bay or Chihli Bay), into which flow some of the most important rivers of northern China, such as the Yellow River (through Shandong province and its capital Jinan), the Hai River (through Beijing and Tianjin) and the Liao River (through Liaoning province). The northeastern extension of the Yellow Sea is called the Korea Bay, into which flow the Yalu River, the Chongchon River and the Taedong River. Since 1 November 2018, the Yellow Sea has also served as the location of "peace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Of Japan
The Sea of Japan is the marginal sea between the Japanese archipelago, Sakhalin, the Korean Peninsula, and the mainland of the Russian Far East. The Japanese archipelago separates the sea from the Pacific Ocean. Like the Mediterranean Sea, it has almost no tides due to its nearly complete enclosure from the Pacific Ocean. This isolation also affects faunal diversity and salinity, both of which are lower than in the open ocean. The sea has no large islands, bays or capes. Its water balance is mostly determined by the inflow and outflow through the straits connecting it to the neighboring seas and the Pacific Ocean. Few rivers discharge into the sea and their total contribution to the water exchange is within 1%. The seawater has an elevated concentration of dissolved oxygen that results in high biological productivity. Therefore, fishing is the dominant economic activity in the region. The intensity of shipments across the sea has been moderate owing to political issues, but it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columella (mollusc)
The columella (meaning "little column") or (in older texts) pillar is a central anatomical feature of a coiled snail shell, a gastropod shell. The columella is often only clearly visible as a structure when the shell is broken, sliced in half vertically, or viewed as an X-ray image. The columella runs from the apex of the shell to the midpoint of the undersurface of the shell, or the tip of the siphonal canal in those shells which have a siphonal canal. If a snail shell is visualized as a cone of shelly material which is wrapped around a central axis, then the columella more or less coincides spatially with the central axis of the shell. In the case of shells that have an umbilicus, the columella is a hollow structure. The columella of some groups of gastropod shells can have a number of plications or folds (the columellar fold, plaits or plicae), which are usually visible when looking to the inner lip into the aperture of the shell. These folds can be wide or narrow, prominent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sculpture (mollusc)
Sculpture is a feature of many of the shells of mollusks. It is three-dimensional ornamentation on the outer surface of the shell, as distinct from either the basic shape of the shell itself or the pattern of colouration, if any. Sculpture is a feature found in the shells of gastropods, bivalves, and scaphopods. The word "sculpture" is also applied to surface features of the aptychus of ammonites, and to the outer surface of some calcareous opercula of marine gastropods such as some species in the family Trochidae. Sculpture can be concave or convex, incised into the surface or raised from it. Sometimes the sculpture has microscopic detailing. The term "sculpture" refers only to the calcareous outer layer of shell, and does not include the proteinaceous periostracum, which is in some cases textured even when the underlying shell surface is smooth. In many taxa, there is no sculpture on the shell surface at all, apart from the presence of fine growth lines. The sculpture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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