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Marbled Duck
The marbled duck, or marbled teal (''Marmaronetta angustirostris'') is a medium-sized species of duck from southern Europe, northern Africa, and western and central Asia. The scientific name, ''Marmaronetta angustirostris'', comes from the Greek ''marmaros'', marbled and ''netta'', a duck, and Latin ''angustus'', narrow or small and ''-rostris'' billed. Distribution, habitat and breeding This duck formerly bred in large numbers in the Mediterranean region, but is now restricted to a few sites in southern Spain, southern Italy, northwest Africa and the broader Levant. Further east it survives in the Mesopotamian marshland in southern Iraq and in Iran (Shadegan Marshes - the world's most important site), as well as isolated pockets in Armenia, Azerbaijan, South European Russia, western India and western China. In general the species has nomadic tendencies. In some areas birds disperse from the breeding grounds, and have been encountered in the winter period in the Sahel zone, so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig Reichenbach
Heinrich Gottlieb Ludwig Reichenbach (8 January 1793 – 17 March 1879) was a German botanist and ornithologist. It was he who first requested Leopold Blaschka to make a set of glass marine invertebrate models for scientific education and museum showcasing, the successful commission giving rise to the creation of the Blaschkas' Glass sea creatures and, subsequently and indirectly, the more famous Glass Flowers. Early life Born in Leipzig and the son of Johann Friedrich Jakob Reichenbach (the author in 1818 of the first Greek-German dictionary) Reichenbach studied medicine and natural science at the University of Leipzig in 1810 and, eight years later in 1818, he the now Professor became an instructor before, in 1820, he was appointed the director of the Dresden natural history museum and a professor at the Surgical-Medical Academy in Dresden, where he remained for many years. Glass sea creatures Director of the natural history museum in Dresden, Professor Reichenbach was fac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkaline
In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a base (chemistry), basic, ionic compound, ionic salt (chemistry), salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The adjective alkaline, and less often, alkalescent, is commonly used in English language, English as a synonym for basic, especially for bases soluble in water. This broad use of the term is likely to have come about because alkalis were the first bases known to obey the acid-base reaction theories#Arrhenius theory, Arrhenius definition of a base, and they are still among the most common bases. Etymology The word "alkali" is derived from Arabic ''al qalīy'' (or ''alkali''), meaning ''the calcined ashes'' (see calcination), referring to the original source of alkaline substances. A water-extract of burned plant ashes, called potash and composed mostly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AEWA
The Agreement on the Conservation of African-Eurasian Migratory Waterbirds, or African-Eurasian Waterbird Agreement (AEWA) is an independent international treaty developed under the auspices of the United Nations Environment Programme's Convention on Migratory Species. It was founded to coordinate efforts to conserve bird species migrating between European and African nations, and its current scope stretches from the Arctic to South Africa, encompassing the Canadian archipelago and the Middle East as well as Europe and Africa. The agreement focuses on bird species that depend on wetlands for at least part of their lifecycle and cross international borders in their migration patterns. It currently covers 254 species. Parties Meetings The Parties meet every few years. So far there have been seven meetings: * 7–9 November 1999 in Cape Town, South Africa * 25–27 September 2002 in Bonn, Germany * 23–27 October 2005 in Dakar, Senegal * 15–19 September 2008 in Antananarivo, M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Destruction
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby reducing biodiversity and species abundance. Habitat destruction is the leading cause of biodiversity loss. Fragmentation and loss of habitat have become one of the most important topics of research in ecology as they are major threats to the survival of endangered species. Activities such as harvesting natural resources, industrial production and urbanization are human contributions to habitat destruction. Pressure from agriculture is the principal human cause. Some others include mining, logging, trawling, and urban sprawl. Habitat destruction is currently considered the primary cause of species extinction worldwide. Environmental factors can contribute to habitat destruction more indirectly. Geological processes, climate change, introdu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by currents in the ocean, or by currents in seas, lakes or rivers. Zooplankton can be contrasted with phytoplankton, which are the plant component of the plankton community ("phyto" comes from the Greek word for ''plant''). Zooplankton are heterotrophic (other-feeding), whereas phytoplankton are autotrophic (self-feeding). This means zooplankton cannot manufacture their own food but must eat other plants or animals instead — in particular they eat phytoplankton. Zooplankton are generally larger than phytoplankton, most are microscopic, but some (such as jellyfish) are macroscopic and can be seen with the naked eye. Many protozoans (single-celled protists that prey on other microscopic life) are zooplankton, including zooflagellates, fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filter Feed
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish (including some sharks). Some birds, such as flamingos and certain species of duck, are also filter feeders. Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers. They are also important in bioaccumulation and, as a result, as indicator organisms. Fish Most forage fish are filter feeders. For example, the Atlantic menhaden, a type of herring, lives on plankton caught in midwater. Adult menhaden can filter up to four gallons of water a minute and play an important role in clarifying ocean water. They are also a natural check to the deadly red tide. Extensive article on the role of menhaden in the ecosystem and possible res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pecten (biology)
A pecten (plural pectens or pectines) is a comb-like structure, widely found in the biological world. Although pectens in various animals look similar, they have a varied range of uses, from grooming and filtering to sensory adaptations. Etymology The adjective, pectinate, means supplied with a comb-like structure. This form, cognate to pecten with both derived from the Latin for comb, ''pectin'' (genitive ''pectinis''), is reflected in numerous scientific names in forms such as pectinata, pectinatus or pectinatum, or in specific epithets such as ''Murex pecten''. Some toothcombs are referred to as pectinations. Oral use In ducks, they exist on the sides of the bill and serve both as a strainer for food and a comb for preening. Whales have a similar oral comb-like structure called baleen. Retinal use The avian eye also contains a structure called a pecten oculi, which is a comb-like projection of the retina. It is thought to enhance nutrition for the cells of the ret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gizzard
The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ found in the digestive tract of some animals, including archosaurs (pterosaurs, crocodiles, alligators, dinosaurs, birds), earthworms, some gastropods, some fish, and some crustaceans. This specialized stomach constructed of thick muscular walls is used for grinding up food, often aided by particles of stone or grit. In certain insects and molluscs, the gizzard features chitinous plates or teeth. Etymology The word ''gizzard'' comes from the Middle English ''giser'', which derives from a similar word in Old French ''gésier'', which itself evolved from the Latin ''gigeria'', meaning giblets. Structure In birds Birds swallow food and store it in their crop if necessary. Then the food passes into their glandular stomach, also called the proventriculus, which is also sometimes referred to as the true stomach. This is the secretory part of the stomach. Then the food passes into the gizzard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamogeton
''Potamogeton'' is a genus of aquatic, mostly freshwater, plants of the family Potamogetonaceae. Most are known by the common name pondweed, although many unrelated plants may be called pondweed, such as Canadian pondweed (''Elodea canadensis''). The genus name means "river neighbor", originating from the Greek ''potamos'' (river) and ''geiton'' (neighbor). Morphology ''Potamogeton'' species range from large (stems of 6 m or more) to very small (less than 10 cm). Height is strongly influenced by environmental conditions, particularly water depth. All species are technically perennial, but some species disintegrate in autumn to a large number of asexually produced resting buds called turions, which serve both as a means of overwintering and dispersal. Turions may be borne on the rhizome, on the stem, or on stolons from the rhizome. Most species, however, persist by perennial creeping rhizomes. In some cases the turions are the only means to differentiate species. The leav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruppia
''Ruppia'', also known as the widgeonweeds, ditch grasses or widgeon grass, is the only extant genus in the family Ruppiaceae, with eight known species. These are aquatic plants widespread over much of the world. The genus name honours Heinrich Bernhard Rupp, a German botanist (1688-1719). They are widespread outside of frigid zones and the tropics. Description The leaf is simple and not rhizomatous. They can be annual (commonly) or perennial (rarely); stem growth is conspicuously sympodial, but sometimes is not. These species are adapted to be in brackish water (and salt marshes). The leaves are small or medium-sized. Their disposition can be alternate, opposite, or whorled (usually alternate except when subtending an inflorescence). Even, lamina keep entire and are setaceous or linear. The leaf just shows one vein without cross-venules. Stomata are not present. The mesophyll leaks calcium oxalate crystals. The minor leaf veins do not present phloem transfer cells and leaks ves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scirpus
''Scirpus'' is a genus of grass-like species in the sedge family Cyperaceae many with the common names club-rush, wood club-rush or bulrush (see also bulrush for other plant genera so-named). They mostly inhabit wetlands and damp locations. Taxonomy The taxonomy of the genus is complex, and under review by botanists. Recent studies by taxonomists of the Cyperaceae have resulted in the creation of several new genera, including the genera ''Schoenoplectus'' and ''Bolboschoenus''; others (including '' Blysmus'', ''Isolepis'', '' Nomochloa'', and ''Scirpoides'') have also been used. At one point this genus held almost 300 species, but many of the species once assigned to it have now been reassigned, and it now holds an estimated 120 species. Description ''Scirpus'' are rhizomatous perennial herbs, with 3-angled stems and flat grass-like leaves. The flowers are in clusters of small spikelets, often brown or greenish brown. Some species (e.g. ''S. lacustris'') can reach a height of 3 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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