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Pontoscolex Corethrurus
''Pontoscolex corethrurus'' is an earthworm in the genus ''Pontoscolex''. It has a circumtropical distribution, although it originates in the Neotropics, probably in the Guiana Plateau. Description The worms are unpigmented and have around 200 segments. Adults measure in length. Reproduction It reproduces both parthenogenetically and (rarely) sexually, and under experimental conditions can complete its life cycle in about one year. Ecology and habitat The worm thrives in difficult environments with poor food nutrition. It is key to emergence of agriculture in the Amazon Basin, where soil is extremely poor. It may have facilitated the formation of ''terra preta''. On the other hand, the worm's adaptability has allowed it to spread to many disturbed tropical areas, especially urban sites and industrially-farmed areas. It is now considered an invasive species in many parts of the world. An endogeic worm creating globular casts, it is considered responsible for soil compact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pontoscolex
''Pontoscolex'' is a genus of earthworms in the family Glossoscolecidae, or alternatively, in the family Rhinodrilidae. General characteristics The type species ''Pontoscolex corethrurus'' has a circumtropical distribution, although it originates in the Neotropics, probably in the Guiana Shield, Guiana Plateau. It reproduces Parthenogenesis, parthenogenetically, and under experimental conditions can complete its life cycle in about one year. Adults measure in length. Diagnostic characteristics There are eight setae per segment, arranged in regular rows, at least in the anterior part of the animal, whereas in the posterior part the arrangement varies (regular, more or less irregular, or in quincunx). No pigment is usually present. Male pores and tubercula pubertatis are in the Clitellum, clitellar region. The gizzard is in the segment VI. Three pairs of calciferous glands of tubular-dichotomous (panicled) structure are in the segments VII–IX. Earthworm#Form and function, Dorsa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumtropical
A pantropical ("all tropics") distribution is one which covers tropical regions of both hemispheres. Examples of species include caecilians, modern sirenians and the plant genera ''Acacia'' and ''Bacopa''. ''Neotropical'' is a zoogeographic term that covers a large part of the Americas, roughly from Mexico and the Caribbean southwards (including cold regions in southernmost South America). ''Palaeotropical'' refers to geographical occurrence. For a distribution to be palaeotropical a taxon must occur in tropical regions in the Old World. According to Takhtajan (1978), the following families have a pantropical distribution: Annonaceae, Hernandiaceae, Lauraceae, Piperaceae, Urticaceae, Dilleniaceae, Tetrameristaceae, Passifloraceae, Bombacaceae, Euphorbiaceae, Rhizophoraceae, Myrtaceae, Anacardiaceae, Sapindaceae, Malpighiaceae, Proteaceae, Bignoniaceae, Orchidaceae and Arecaceae.Takhtajan, A. (1986). ''Floristic Regions of the World''. (translated by T.J. Crovello & A. Cronquis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neotropics
The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropics, tropical Ecoregion#Terrestrial, terrestrial ecoregions of the Americas and the entire South American temperate climate, temperate zone. Definition In biogeography, the Neotropic or Neotropical realm is one of the eight terrestrial realms. This realm includes South America, Central America, the Caribbean islands, and southern North America. In Mexico, the Yucatán Peninsula and southern lowlands, and most of the east and west coastlines, including the southern tip of the Baja California Peninsula are Neotropical. In the United States southern Florida and coastal Central Florida are considered Neotropical. The realm also includes temperate southern South America. In contrast, the Neotropical Phytochorion, Floristic Kingdom excludes southernmost South America, which instead is placed in the Antarctic Floristic Kingdom, Antarctic kingdom. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guiana Shield
The Guiana Shield (french: Plateau des Guyanes, Bouclier guyanais; nl, Hoogland van Guyana, Guianaschild; pt, Planalto das Guianas, Escudo das Guianas; es, Escudo guayanés) is one of the three cratons of the South American Plate. It is a 1.7 billion-year-old Precambrian geological formation in northeast South America that forms a portion of the northern coast. The higher elevations on the shield are called the Guiana Highlands, which is where the table-like mountains called tepuis are found. The Guiana Highlands are also the source of some of the world's most well-known waterfalls such as Angel Falls, Kaieteur Falls and Cuquenan Falls. The Guiana Shield underlies Guyana (previously British Guiana), Suriname (previously Dutch Guiana) and French Guiana (or Guyane), much of southern Venezuela, as well as parts of Colombia and Brazil. The rocks of the Guiana Shield consist of metasediments and metavolcanics ( greenstones) overlain by sub-horizontal layers of sandstones, quartz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parthenogenesis
Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development of embryos occur in a gamete (egg or sperm) without combining with another gamete (e.g., egg and sperm fusing). In animals, parthenogenesis means development of an embryo from an unfertilized Gametophyte, egg cell. In plants, parthenogenesis is a component process of apomixis. In algae, parthenogenesis can mean the development of an embryo from either an individual sperm or an individual egg. Parthenogenesis occurs naturally in some plants, algae, invertebrate animal species (including nematodes, some tardigrades, water fleas, some scorpions, aphids, some mites, some bees, some Phasmatodea and parasitic wasps) and a few vertebrates (such as some fish, amphibians, reptiles and birds). This type of reproduction has been induced artificially ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazon Basin
The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname, and Venezuela. Most of the basin is covered by the Amazon rainforest, also known as Amazonia. With a area of dense tropical forest, this is the largest rainforest in the world. Geography The Amazon River begins in the Andes Mountains at the west of the basin with its main tributary the Marañón River and Apurimac River in Peru. The highest point in the watershed of the Amazon is the second biggest peak of Yerupajá at . With a length of about before it drains into the Atlantic Ocean, it is one of the two longest rivers in the world. A team of scientists has claimed that the Amazon is longer than the Nile, but debate about its exact length continues. The Amazon system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terra Preta
''Terra preta'' (, locally , literally "black soil" in Portuguese) is a type of very dark, fertile anthropogenic soil ( anthrosol) found in the Amazon Basin. It is also known as "Amazonian dark earth" or "Indian black earth". In Portuguese its full name is or ("black soil of the Indian", "Indians' black earth"). ''Terra mulata'' ("mulatto earth") is lighter or brownish in color. ''Terra preta'' owes its characteristic black color to its weathered charcoal content, and was made by adding a mixture of charcoal, bones, broken pottery, compost and manure to the low fertility Amazonian soil. A product of indigenous soil management and slash-and-char agriculture, the charcoal is stable and remains in the soil for thousands of years, binding and retaining minerals and nutrients. ''Terra preta'' is characterized by the presence of low-temperature charcoal residues in high concentrations; of high quantities of tiny pottery shards; of organic matter such as plant residues, animal feces, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invasive Species
An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, 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 webfor example the purple sea urchin (''Strongylocentrotus purpuratus'') which has decimated kelp forests along the northern California coast due to overharvesting of its natural predator, the California sea otter (''Enhydra lutris''). Since the 20th century, invasive species have become a serious economic, social, and environmental threat. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecosystem Engineer
An ecosystem engineer is any species that creates, significantly modifies, maintains or destroys a habitat. These organisms can have a large impact on species richness and landscape-level heterogeneity of an area. As a result, ecosystem engineers are important for maintaining the health and stability of the environment they are living in. Since all organisms impact the environment they live in one way or another, it has been proposed that the term "ecosystem engineers" be used only for keystone species whose behavior very strongly affects other organisms. aemig PD (2012). Ecosystem Engineers: wildlife that create, modify and maintain habitats. ECOLOGY.INFO #12/ref> Types Jones et al. identified two different types of ecosystem engineers: Allogenic engineers Allogenic engineers modify the biophysical environment by mechanically changing living or nonliving materials from one form to another. Beavers are the original model for ecosystem engineers; in the process of clearcutting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthworms As Invasive Species
Earthworms are invasive species throughout the world. Of a total of about 6,000 species of earthworm, about 120 species are widely distributed around the globe. These are the peregrine or cosmopolitan earthworms. Some of these are invasive species in many regions. Australia Australia has 650 known species of native earthworm that survive in both rich and in nutrient-poor conditions where they may be sensitive to changes in the environment. The total native species numbers are predicted to exceed 1,000.Blakemore, Rob''Diversity of exotic earthworms in Australia - a status report.''Transactions of the Royal Zoological Society of New South Wales, 1999 "Approximately 350 native species in about 30 genera are currently described for Australia, but an estimate of total number is about three times as large (Blakemore 1997a)." Introduced species are commonly found in agricultural environments along with persistent natives. 66 exotic species are known by 1999, most of which have been intr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clitellata
The Clitellata are a class of annelid worms, characterized by having a clitellum - the 'collar' that forms a reproductive cocoon during part of their life cycles. The clitellates comprise around 8,000 species. Unlike the class of Polychaeta, they do not have parapodia and their heads are less developed. Characteristics Clitellate annelids are segmented worms characterised by the clitellum or girdle which is located near the head end of mature individuals. The mouth is on the ventral surface and is overhung by the prostomium (proboscis). The brain is not located in the head but in one of the body segments. The clitellum is formed by a modification of several segments, and either includes the female gonopores or is located just behind them. During copulation, this glandular tissue secretes mucus that keeps the paired individuals together while they exchange sperm. Afterwards it secretes material that forms a cocoon that encircles the animal's body and encloses the eggs and sperm. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animals Described In 1856
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinoderms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.JPG "Click for more on -> Guiana Shield")
