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Astracanthidae
''Astracantha'' is a genus of planktonic phaeodaria and the only member of the family Astracanthidae. They are an unusual family of marine life, marine protists, but can be found across all oceans, from tropical to Arctic Ocean, Arctic and Antarctic Ocean, Antarctic waters. Morphology This genus is characterized by a skeleton or theca comprised by 30 to 40 hollow spines radiating from the central focal point. Midway along each spine there are numerous short, irregularly spaced, outwardly curved branches that bear terminal thorns proximally (i.e. closer to the cell), but become terminally (i.e. further from the cell) smooth-pointed and slightly thicker. The length of their radial tubes is around 1.8 millimeters. Distribution The Astracanthidae are a very unusual family of phaeodarians. ''Astracantha paradoxa'' was reported in 1908 by Valentin Haecker in five warm water stations in the Atlantic Ocean, Atlantic and Inddian Ocean, Indian oceans. In 1986 it was reported for th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astracantha Heteracanthoides
''Astracantha'' is a genus of planktonic phaeodaria and the only member of the family Astracanthidae. They are an unusual family of marine protists, but can be found across all oceans, from tropical to Arctic and Antarctic waters. Morphology This genus is characterized by a skeleton or theca comprised by 30 to 40 hollow spines radiating from the central focal point. Midway along each spine there are numerous short, irregularly spaced, outwardly curved branches that bear terminal thorns proximally (i.e. closer to the cell), but become terminally (i.e. further from the cell) smooth-pointed and slightly thicker. The length of their radial tubes is around 1.8 millimeters. Distribution The Astracanthidae are a very unusual family of phaeodarians. '' Astracantha paradoxa'' was reported in 1908 by Valentin Haecker in five warm water stations in the Atlantic and Indian oceans. In 1986 it was reported for the first time from the Antarctic and South Pacific oceans. ''Astracantha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phaeodaria
Phaeodarea or Phaeodaria is a group of amoeboid cercozoan organisms. They are traditionally considered radiolarians, but in molecular trees do not appear to be close relatives of the other groups, and are instead placed among the Cercozoa. They are distinguished by the structure of their central capsule and by the presence of a phaeodium, an aggregate of waste particles within the cell. The term "Radiozoa" has been used to refer to radiolaria when Phaeodarea is explicitly excluded. Phaeodarea produce hollow skeletons composed of amorphous silica and organic material, which rarely fossilize. The endoplasm is divided by a cape with three openings, of which one gives rise to feeding pseudopods, and the others let through bundles of microtubules that support the axopods. Unlike true radiolarians, there are no cross-bridges between them. They also lack symbiotic algae, generally living below the photic zone, and do not produce any Celestine (mineral), strontium sulfate. Character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Life
Marine life, sea life or ocean life is the collective ecological communities that encompass all aquatic animals, aquatic plant, plants, algae, marine fungi, fungi, marine protists, protists, single-celled marine microorganisms, microorganisms and associated marine virus, viruses living in the saline water of marine habitats, either the sea water of marginal seas and oceans, or the brackish water of coastal wetlands, lagoons, estuary, estuaries and inland seas. , more than 242,000 marine species have been documented, and perhaps two million marine species are yet to be documented. An average of 2,332 new species per year are being described. Marine life is studied scientifically in both marine biology and in biological oceanography. By volume, oceans provide about 90% of the living space on Earth, and served as the cradle of life and vital biotic sanctuaries throughout Earth's geological history. The earliest known life forms evolved as anaerobe, anaerobic prokaryotes (archaea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protist
A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic grouping of all descendants of the last eukaryotic common ancestor excluding land plants, animals, and fungi. Protists were historically regarded as a separate taxonomic kingdom known as Protista or Protoctista. With the advent of phylogenetic analysis and electron microscopy studies, the use of Protista as a formal taxon was gradually abandoned. In modern classifications, protists are spread across several eukaryotic clades called supergroups, such as Archaeplastida ( photoautotrophs that includes land plants), SAR, Obazoa (which includes fungi and animals), Amoebozoa and " Excavata". Protists represent an extremely large genetic and ecological diversity in all environments, including extreme habitats. Their diversity, larger than for all other eukaryotes, has only been discovered in rece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Ocean
The Arctic Ocean is the smallest and shallowest of the world's five oceanic divisions. It spans an area of approximately and is the coldest of the world's oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, although some oceanographers call it the Arctic Mediterranean Sea. It has also been described as an estuary of the Atlantic Ocean. It is also seen as the northernmost part of the all-encompassing world ocean. The Arctic Ocean includes the North Pole region in the middle of the Northern Hemisphere and extends south to about 60°N. The Arctic Ocean is surrounded by Eurasia and North America, and the borders follow topographic features: the Bering Strait on the Pacific side and the Greenland Scotland Ridge on the Atlantic side. It is mostly covered by sea ice throughout the year and almost completely in winter. The Arctic Ocean's surface temperature and salinity vary seasonally as the ice cover melts and freezes; its salinity is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic Ocean
The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the world ocean, generally taken to be south of 60th parallel south, 60° S latitude and encircling Antarctica. With a size of , it is the second-smallest of the five principal oceanic divisions, smaller than the Pacific Ocean, Pacific, Atlantic Ocean, Atlantic and Indian Ocean, Indian oceans, and larger than the Arctic Ocean. The maximum depth of the Southern Ocean, using the definition that it lies south of 60th parallel, was surveyed by the Five Deeps Expedition in early February 2019. The expedition's multibeam sonar team identified the deepest point at 60° 28' 46"S, 025° 32' 32"W, with a depth of . The expedition leader and chief submersible pilot Victor Vescovo, has proposed naming this deepest point the "Factorian Deep", based on the name of the crewed submersible ''DSV Limiting Factor'', in which he successfully visited the bottom for the first time on February 3, 2019 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planktonic
Plankton are the diverse collection of organisms that drift in water (or air) but are unable to actively propel themselves against currents (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish, and baleen whales. Marine plankton include bacteria, archaea, algae, protozoa, microscopic fungi, and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in lakes and rivers. Mostly, plankton just drift where currents take them, though some, like jellyfish, swim slowly but not fast enough to generally overcome the influence of currents. Although plankton are usually thought of as inhabiting water, there are also airborne versions that live part of their lives drifting in the atmosphere. These '' aeroplankton'' include plant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
