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Plectus Parvus
''Plectus parvus'' is a species of nematode ( roundworm) found in freshwater and terrestrial environments. It has been sampled in Europe and New Zealand. Along with the similar nematode ''Panagrolaimus detritophagus'', in 2018 it was the first species of multicellular eukaryote to be thawed into a living state after prolonged cryopreservation. Female worms of this species were found in Pleistocene permafrost in the Kolyma River lowland (one of the sites was near the Alazeya River). They were mobile and ate, after being frozen for 30–40 thousand years. Taxonomy ''Plectus parvus'' was described by the English zoologist Henry Charlton Bastian in 1865. The names ''Plectus potamogeti'' (Schneider, 1937) and ''Rhabdolaimus baltonicus'' (Daaday, 1894) are considered synonyms. Sources differ on its higher level taxonomy. The World Register of Marine Species places it in order Plectida, while the Integrated Taxonomic Information System places it in the order Araeolaimida. Anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, 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 Symmetry in biology#Bilate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alazeya River
The Alazeya ( rus, Алазея, r=; sah, Алаһыай, translit=Alahıay) is a river in the northeastern part of Yakutia, Russia which flows into the Arctic between the basins of the larger Indigirka to the west and the Kolyma to the east. Mount Kisilyakh-Tas is a notable kigilyakh site on the right bank of the Alazeya River at . Geography The river is long. The area of its basin is . The Alazeya is formed at the confluence of the Nelkan and Kadylchan rivers in the slopes of the Alazeya Plateau. It crosses roughly northwards through the tundra meandering among the flat, marshy areas of the Kolyma Lowland, part of the greater East Siberian Lowland. Finally the Alazeya drains into the Kolyma Bay of the East Siberian Sea, close to Logashkino. The river freezes in late September through early October and stays icebound until late May through early June. There are more than 24,000 lakes in its basin. Google Earth [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Legacy Pollution
Legacy pollution or legacy pollutants are persistent materials in the environment that were created through a polluting industry or process that have polluting effects after the process has finished. Frequently these include persistent organic pollutants, heavy metals or other chemicals residual in the environment long after the industrial or extraction processes that produced them. Often these are chemicals produced by industry and polluted before there was widespread awareness of the toxic effects of the pollutants, and subsequently regulated or banned. Notable legacy pollutants include mercury, PCBs, Dioxins and other chemicals that are widespread health and environmental effects. Sites for legacy pollutants include mining sites, industrial parks, waterways contaminated by industry, and other dump sites. These chemicals often have outsized impact in countries jurisdictions with little or no environmental monitoring or regulation—because the chemical were often produced in new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megafauna
In terrestrial zoology, the megafauna (from Greek μέγας ''megas'' "large" and New Latin ''fauna'' "animal life") comprises the large or giant animals of an area, habitat, or geological period, extinct and/or extant. The most common thresholds used are weight over see page 17 (i.e., having a mass comparable to or larger than a human) or over a tonne, (i.e., having a mass comparable to or larger than an ox). The first of these include many species not popularly thought of as overly large, and being the only few large animals left in a given range/area, such as white-tailed deer, Thomson's gazelle, and red kangaroo. In practice, the most common usage encountered in academic and popular writing describes land mammals roughly larger than a human that are not (solely) domesticated. The term is especially associated with the Pleistocene megafauna – the land animals often larger than their extant counterparts that are considered archetypical of the last ice age, such as mammoth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Podzol
In soil science, podzols are the typical soils of coniferous or boreal forests and also the typical soils of eucalypt forests and heathlands in southern Australia. In Western Europe, podzols develop on heathland, which is often a construct of human interference through grazing and burning. In some British moorlands with podzolic soils, cambisols are preserved under Bronze Age barrows (Dimbleby, 1962). Term Podzol means "under-ash" and is derived from the Russian под (pod) + зола́ (zola); the full form is "подзо́листая по́чва" (podzolistaya pochva, "under-ashed soil"). The term was first given in middle of 1875 by Vasily Dokuchaev. It refers to the common experience of Russian peasants of plowing up an apparent under-layer of ash (leached or E horizon) during first plowing of a virgin soil of this type. Characteristics Podzols can occur on almost any parent material but generally derive from either quartz-rich sands and sandstone or sedimentary debri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bursilla Monhysteria
''Mesorhabditis'' is a genus of nematodes. Species in the genus ''Mesorhabditis'' exhibit an unusual form of 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 developmen ..., in which sperm-producing males copulate with females, but the sperm do not fuse with the ovum. Contact with the sperm is essential for the ovum to begin dividing, but because there is no fusion of the cells, the male contributes no genetic material to the offspring, which are essentially clones of the female. References * Problems in New Zealand mushroom production associated with bacterial feeding nematodes (Mesorhabditis sp.). FR Sanderson, JW Marshall, GE Ovenden, HM Stengs - … , 1981/edited by NG Nair, AD …, 1981 * Systematik, Phylogenie und Okologie der holzbewohnenden Nematoden Gruppe Rhabdit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthos
Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.Benthos from the Census of Antarctic Marine Life website This community lives in or near marine or freshwater sedimentary environments, from s along the , out to the , and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spicule (nematode Anatomy)
In nematodes, spicules, also known as copulatory spicules, are needle-like mating structures found only in males. Male nematodes may have one or two spicules which serve to open the vulva of females and facilitate the transmission of sperm, although sperm is not transferred directly by or through the spicules.Chitwood, B. G. & Chitwood, M. B. (1950). Introduction to Nematology (Vol. 1). Baltimore: Monumental Printing Co. (Function of spicule: pages 123-124) The gubernaculum The paired gubernacula (from Ancient Greek κυβερνάω = pilot, steer) also called the caudal genital ligament, are embryonic structures which begin as undifferentiated mesenchyme attaching to the caudal end of the gonads (testes in male ... is another organ of the nematode male copulatory system which guides the spicules during copulation. References Nematode anatomy Animal male reproductive system {{nematode-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alae (nematode Anatomy)
The alae is a protruding ridge that forms longitudinally on many nematodes. In the ''Caenorhabditis elegans'' nematode they are present in the L1, dauer (an alternative long living larvae stage where the nematode is dormant) and adult stages. The alae are most pronounced during the dauer larval stage and not present in the L2, and L3 ''C. elegans'' stages. The term ‘alae’ is the plural of ala (wing), describing either one of the pair of ridges that forms on a nematode or an individual crease found on an individual ridge. The term ‘ala’ is rarely used in describing the alae and scientific journals use the term ‘alae’ both singularly and in the plural. Structure The alae is formed by the hypodermal seam cells where a fibrous ribbon of a zona pellucida (ZP) domain protein is produced. In ''C. elegans'' many of these proteins are termed CUT-1. The CUT refers to cuticulins which are the various proteins that are not solubilised by both reducing agents and detergents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Taxonomic Information System
The Integrated Taxonomic Information System (ITIS) is an American partnership of federal agencies designed to provide consistent and reliable information on the taxonomy of biological species. ITIS was originally formed in 1996 as an interagency group within the US federal government, involving several US federal agencies, and has now become an international body, with Canadian and Mexican government agencies participating. The database draws from a large community of taxonomic experts. Primary content staff are housed at the Smithsonian National Museum of Natural History and IT services are provided by a US Geological Survey facility in Denver. The primary focus of ITIS is North American species, but many biological groups exist worldwide and ITIS collaborates with other agencies to increase its global coverage. Reference database ITIS provides an automated reference database of scientific and common names for species. As of May 2016, it contains over 839,000 scientific names, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Register Of Marine Species
The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialists on each group of organism. These taxonomists control the quality of the information, which is gathered from the primary scientific literature as well as from some external regional and taxon-specific databases. WoRMS maintains valid names of all marine organisms, but also provides information on synonyms and invalid names. It is an ongoing task to maintain the registry, since new species are constantly being discovered and described by scientists; in addition, the nomenclature and taxonomy of existing species is often corrected or changed as new research is constantly being published. Subsets of WoRMS content are made available, and can have separate badging and their own home/launch pages, as "subregisters", such as the ''World List of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
