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Bythotrephes Longimanus
''Bythotrephes longimanus'' (also ''Bythotrephes cederstroemi''), or the spiny water flea, is a planktonic crustacean less than long. It is native to fresh waters of Northern Europe and Asia, but has been accidentally introduced and widely distributed in the Great Lakes area of North America since the 1980s.''Bythotrephes longimanus'' USGS NAS – Nonindigenous Aquatic Species ''Bythotrephes'' is typified by a long abdominal spine with several barbs which protect it from predators. Description and taxonomy ''Bythotrephes longimanus'' is a cladoceran crustacean (water flea) recognizable with its straight tail spine averaging about 70% of its length. Adult individuals have one to three pairs of barbs on the ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishhook Waterflea
A fish hook or fishhook, formerly also called an angle (from Old English ''angol'' and Proto-Germanic ''*angulaz''), is a hook used to fishing, catch fish either by piercing and embedding onto the inside of the fish jaw, fish mouth (angling) or, more rarely, by impaling and snagging the external fish body. Fish hooks are normally attached to a fishing line, line, which tethers the target fish to the angler for retrieval, and are typically dressed with some form of fishing bait, bait or fishing lure, lure that entices the fish to swallow the hook out of its own natural instinct to foraging, forage or predation, hunt. Fish hooks have been employed for millennia by fishermen to catch freshwater fish, freshwater and saltwater fish. There is an enormous variety of fish hooks in the world of fishing. Sizes, designs, shapes, and materials are all variable depending on the intended purpose of the hook. Fish hooks are manufactured for a range of purposes from general fishing to extremely l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invasive Species
An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native species that become harmful to their native environment after human alterations to its food web. Since the 20th century, invasive species have become serious economic, social, and environmental threats worldwide. Invasion of long-established ecosystems by organisms is a natural phenomenon, but human-facilitated introductions have greatly increased the rate, scale, and geographic range of invasion. For millennia, humans have served as both accidental and deliberate dispersal agents, beginning with their earliest migrations, accelerating in the Age of Discovery, and accelerating again with the spread of international trade. Notable invasive plant species include the kudzu vine, giant hogweed (''Heracleum mantegazzianum''), Japanese knotw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Crustaceans Of North America
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but 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. Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of vascular plants and most insects, amphibians, reptiles, mammals and birds need fresh water to survive. Fresh water is the water resource that is of the most and immediate use to humans. Fresh water is not always pot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladocera
The Diplostraca or Cladocera, commonly known as water fleas, is a superorder (biology), superorder of small, mostly freshwater crustaceans, most of which feed on microscopic chunks of organic matter, though some forms are predatory. Over 1000 species have been recognised so far, with many more undescribed species, undescribed. The oldest fossils of diplostracans date to the Jurassic, though their modern morphology suggests that they originated substantially earlier, during the Paleozoic. Some have also adapted to a life in the ocean, the only members of Branchiopoda to do so, though several anostracans live in hypersaline lakes. Most are long, with a down-turned head with a single median compound eye, and a carapace covering the apparently unsegmented Crustacean#Structure, thorax and abdomen. Most species show cyclical parthenogenesis, where asexual reproduction is occasionally supplemented by sexual reproduction, which produces resting eggs that allow the species to survive hars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States National Agricultural Library
The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Located in Beltsville, Maryland, it is one of five national libraries of the United States (along with the Library of Congress, the National Library of Medicine, the National Transportation Library, and the National Library of Education). It is also the coordinator for the Agriculture Network Information Center (AgNIC), a national network of state land-grant institutions and coordinator for the U.S. Department of Agriculture (USDA) field libraries. NAL was established on May 15, 1862, by the signing of the Organic Act by Abraham Lincoln. It served as a departmental library until 1962, when the Secretary of Agriculture officially designated it as the National Agricultural Library. The first librarian, appointed in 1867, was Aaron B. Grosh, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Geographic
''National Geographic'' (formerly ''The National Geographic Magazine'', sometimes branded as ''Nat Geo'') is an American monthly magazine published by National Geographic Partners. The magazine was founded in 1888 as a scholarly journal, nine months after the establishment of the society, but is now a popular magazine. In 1905, it began including pictures, a style for which it became well known. Its first color photos appeared in the 1910s. During the Cold War, the magazine committed itself to present a balanced view of the physical and human geography of countries beyond the Iron Curtain. Later, the magazine became outspoken on environmental issues. Until 2015, the magazine was completely owned and managed by the National Geographic Society. Since 2015, controlling interest has been held by National Geographic Partners. Topics of features generally concern geography, history, nature, science, and world culture. The magazine is well known for its distinctive appearance: a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Journal Of Fisheries And Aquatic Sciences
The ''Canadian Journal of Fisheries and Aquatic Sciences'' is a peer-reviewed academic journal which focuses on multidisciplinary field of aquatic sciences. It was founded in 1901 by the Biological Board of Canada, later known as the Fisheries Research Board of Canada. It is published monthly by Canadian Science Publishing. Publishing history *founded 1901, as ''Contributions to Canadian Biology and Fisheries'' *name changed to ''Journal of the Biological Board of Canada'' *name changed to ''Journal of the Fisheries Research Board of Canada'' *name changed to ''Canadian Journal of Fisheries and Aquatic Sciences'' Abstracting and indexing The journal is indexed in Science Citation Index Expanded, Scopus, Academic Search Premier Academic Search is a monthly indexing service. It was first published in 1997 by EBSCO Publishing in Ipswich, Massachusetts. Its academic focus is international universities, covering social science, education, psychology, and other subjects. P ..., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daphnia Retrocurva
''Daphnia'' is a genus of small planktonic crustaceans, in length. ''Daphnia'' are members of the Order (biology), order Anomopoda, and are one of the several small aquatic crustaceans commonly called water fleas because their Saltation (gait), saltatory swimming style resembles the movements of fleas. ''Daphnia'' spp. live in various aquatic environments ranging from acidic swamps to Fresh water, freshwater lakes and ponds. The two most commonly found species of ''Daphnia'' are ''Daphnia pulex, D. pulex'' (small and most common) and ''Daphnia magna, D. magna'' (large). They are often associated with a related genus in the order Cladocera: ''Moina'', which is in the Moinidae group instead of the Daphniidae, and is much smaller than ''D. pulex'' (roughly half the maximum length). Appearance and characteristics The body of a ''Daphnia'' species is usually long, and is divided into Segmentation (biology), segments, although this division is not visible. The hea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daphnia Pulicaria
''Daphnia pulicaria'' is a species of freshwater crustaceans found within the genus of ''Daphnia,'' which are often called "water fleas," and they are commonly used as model organisms for scientific research. Like other species of ''Daphnia'', they reproduce via cyclic parthenogenesis. ''D. pulicaria'' are filter-feeders with a diet primarily consisting of algae, including ''Ankistrodesmus falcatus,'' and they can be found in deep lakes located in temperate climates. Furthermore, ''D. pulicaria'' are ecologically important herbivorous zooplankton, which help control algal populations and are a source of food for some fish. ''D. pulicaria'' are closely related to ''Daphnia pulex ''Daphnia pulex'' is the most common species of water flea. It has a cosmopolitan distribution: the species is found throughout the Americas, Europe, and Australia. It is a model species, and was the first crustacean to have its genome sequenced. ...'', and numerous studies have investigated the nature an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Richness
Species richness is the number of different species represented in an community (ecology), ecological community, landscape or region. Species richness is simply a count of species, and it does not take into account the Abundance (ecology), abundances of the species or their Relative species abundance, relative abundance distributions. Species richness is sometimes considered synonymous with species diversity, but the formal metric species diversity takes into account both species richness and species evenness. Sampling considerations Depending on the purposes of quantifying species richness, the individuals can be Forest inventory#Simple random sampling, selected in different ways. They can be, for example, trees found in an forest inventory, inventory plot, birds observed from a monitoring point, or beetles collected in a pitfall trap. Once the set of individuals has been defined, its species richness can be exactly quantified, provided the species-level Taxonomy (biology), taxo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lakes Of Canada
A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from the ocean, although they may be connected with the ocean by rivers. Lakes, as with other bodies of water, are part of the water cycle, the processes by which water moves around the Earth. Most lakes are fresh water and account for almost all the world's surface freshwater, but some are salt lakes with salinities even higher than that of seawater. Lakes vary significantly in surface area and volume of water. Lakes are typically larger and deeper than ponds, which are also water-filled basins on land, although there are no official definitions or scientific criteria distinguishing the two. Lakes are also distinct from lagoons, which are generally shallow tidal pools dammed by sandbars or other material at coastal regions of oceans or large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
