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Enopla
Enopla is one of the classes of the worm phylum Nemertea, characterized by the presence of a peculiar armature of spines or plates in the proboscis. Evolution and systematics The record of nemerteans is extremely sparse, as would be expected from a soft-bodied animal. The Cambrian fossil, '' Amiskwia'', has been interpreted as a nemertean based on its resemblance to some pelagic ribbon worms; however, this interpretation is disputed by many paleontologists. The enoplan nemerteans have been regarded as highly derived based on a more complicated muscle arrangement in the body wall and a more complex nervous system. However, whether this is a plesiomorphic or apomorphic character is not clear, and recent molecular studies are inconclusive in this respect. Class Enopla used to be divided in two subclasses, Hoplonemertea and Bdellonemertea, but recent phylogenetic analyses based on nucleotide sequences show that Bdellonemertea should be included in Hoplonemertea. Hoplonemerte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nemertea
Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of about 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many have patterns of yellow, orange, red and green coloration. The foregut, stomach and intestine run a little below the midline of the body, the anus is at the tip of the tail, and the mouth is under the front. A little above the gut is the , a cavity which mostly runs above the midline and ends a little short of the rear of the body. All species have a proboscis which lies in the rhynchocoel when inactive but wikt:eversion, everts to emerge just above the mouth to capture the animal's prey with venom. A highly extensible muscle in the back of the rhynchocoel pulls the proboscis in when an attack ends. A few species with stubby bodies Filter feeders, filter feed and have suckers at the front and back ends, with which they attach to a Hos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anopla
Anopla (for changes in taxonomy, see reference from 2019) has long been used as name for a Class (biology), class of marine worms of the phylum Nemertea, characterized by the absence of stylet (anatomy), stylets on the proboscis, the mouth being below or behind the brain, and by having separate openings for the mouth and proboscis. The other long used class of Nemertea are the Enopla (for changes in taxonomy, see reference from 2019). Although Anopla is a paraphyletic grouping, it is used in almost all scientific classifications. Anopla is divided into two Order (biology), orders: Palaeonemertea and Heteronemertea.Norenburg, J.; Gibson, R.; Herrera Bachiller, A.; Strand, M. (2019). World Nemertea Database. Anopla. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=1293 on 2019-11-07 Palaeonemertea may be para- or Polyphyly, polyphyletic, consisting of 3-5 groupings and totalling about 100 species. These worms have seve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphiporus
''Amphiporus'' is a genus of marine ribbon worms belonging to the phylum Nemertea and class Enopla Enopla is one of the classes of the worm phylum Nemertea, characterized by the presence of a peculiar armature of spines or plates in the proboscis. Evolution and systematics The record of nemerteans is extremely sparse, as would be expected .... These worms are typically found in coastal habitats, often hiding under rocks or burrowed in sand and mud. Members of this genus are known for their elongated, soft, and unsegmented bodies, and they can range from a few centimeters to several inches in length. A distinctive feature of ''Amphiporus'' species is their eversible proboscis, which is armed with a sharp stylet used to capture and immobilize prey such as small crustaceans and worms. Many species display striking color patterns, often with bands or stripes, which can help in identification. One commonly studied species, '' Amphiporus lactifloreus'', is notable for its pale bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monostilifera
Monostilifera is a suborder of nemertean worms belonging to the class Hoplonemertea (formerly Enopla Enopla is one of the classes of the worm phylum Nemertea, characterized by the presence of a peculiar armature of spines or plates in the proboscis. Evolution and systematics The record of nemerteans is extremely sparse, as would be expected ...), a class of worms characterized by the presence of a peculiar armature of spines or plates in their proboscis. Families * Acteonemertidae * Amphiporidae * Carcinonemertidae * Cratenemertidae * Prosorhochmidae * Tetrastemmatidae Genus (unassigned family): '' Quasitetrastemma'' Chernyshev, 2004 References Hoplonemertea {{Nemertean-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enoplea
Enoplea (enopleans) is a Class (biology), class, which with the classes SecernenteaTree of Life Web Project (ToL) (2002)Nematoda Version of January 1, 2002. Retrieved November 2, 2008. and Chromadorea make up the phylum Nematode, Nematoda in current taxonomy (biology), taxonomy. The Enoplea are considered to be a more ancestral group than the Chromadorea, and researchers have referred to its members as the "ancestrally diverged nematodes", compared to the "more recently diverged nematodes" of Chromadorea. Description The Enoplea are distinguished from the Chromadorea by a number of characteristics. The enoplean esophagus is cylindrical or "bottle-shaped", compared to the bulbous chromadorean esophagus. Enopleans have pocket-like amphids, while chromadoreans have amphids shaped like slits, pores, coils, or spirals. An enoplean is smooth or marked with fine lines, while a chromadorean may have rings, projections, or setae. The enoplean excretory system is simple, sometimes made up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), nonmetal, and a potent oxidizing agent that readily forms oxides with most elements as well as with other chemical compound, compounds. Oxygen is abundance of elements in Earth's crust, the most abundant element in Earth's crust, making up almost half of the Earth's crust in the form of various oxides such as water, carbon dioxide, iron oxides and silicates.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. It is abundance of chemical elements, the third-most abundant element in the universe after hydrogen and helium. At standard temperature and pressure, two oxygen atoms will chemical bond, bind covalent bond, covalently to form dioxygen, a colorless and odorless diatomic gas with the chemical formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alga
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, such as cyanobacteria, '' Chlorella'', and diatoms, to multicellular macroalgae such as kelp or brown algae which may grow up to in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a division of green algae which includes, for example, ''Spirogyra'' and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton. Algae constitute a polyphyletic group because they do not include a common ancestor, and although eukaryotic algae with chlorophyll-bearing plastids seem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". Organisms living in this zone are called benthos and include microorganisms (e.g., bacteria and fungi) as well as larger invertebrates, such as crustaceans and polychaetes. Organisms here, known as bottom dwellers, generally live in close relationship with the substrate and many are permanently attached to the bottom. The benthic boundary layer, which includes the bottom layer of water and the uppermost layer of sediment directly influenced by the overlying water, is an integral part of the benthic zone, as it greatly influences the biological activity that takes place there. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, and bay mud. Description Oceans The benthic region of the ocean begins at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Littoral
The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely inundated), to coastal areas that are permanently submerged — known as the ''foreshore'' — and the terms are often used interchangeably. However, the geographical meaning of ''littoral zone'' extends well beyond the intertidal zone to include all neritic waters within the bounds of continental shelves. Etymology The word ''littoral'' may be used both as a noun and as an adjective. It derives from the Latin noun ''litus, litoris'', meaning "shore". (The doubled ''t'' is a late-medieval innovation, and the word is sometimes seen in the more classical-looking spelling ''litoral''.) Description The term has no single definition. What is regarded as the full extent of the littoral zone, and the way the littoral zone is divided into subre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic
The Antarctic (, ; commonly ) is the polar regions of Earth, polar region of Earth that surrounds the South Pole, lying within the Antarctic Circle. It is antipodes, diametrically opposite of the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau, and other list of Antarctic and Subantarctic islands, island territories located on the Antarctic Plate or south of the Antarctic Convergence. The Antarctic region includes the ice shelf, ice shelves, waters, and all the island territories in the Southern Ocean situated south of the Antarctic Convergence, a zone approximately wide and varying in latitude seasonally. The region covers some 20 percent of the Southern Hemisphere, of which 5.5 percent (14 million km2) is the surface area of the Antarctica continent itself. All of the land and ice shelf, ice shelves south of 60th parallel south, 60°S latitude are administered under the Antarctic Treaty System. Biogeograph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subtropical
The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical zone#Temperate zones, temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° to 40° north and south. The horse latitudes lie within this range. Subtropical climates are often characterized by hot summers and mild winters with infrequent frost. Most subtropical climates fall into two basic types: humid subtropical climate, humid subtropical (Köppen climate classification: Cfa/Cwa), where rainfall is often concentrated in the warmest months, for example list of regions of China, Southeast China and the Southeastern United States, and Mediterranean climate, dry summer or Mediterranean climate (Köppen climate classification: Csa/Csb), where seasonal rainfall is concentrated in the cooler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
