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Acanthaster Brevispinus
''Acanthaster brevispinus'', the short-spined crown-of-thorns starfish, is one of the two members of the starfish genus ''Acanthaster'', along with the much better-known '' A. planci'', the common crown-of-thorns starfish. Physical description The body form of ''A. brevispinus'' is fundamentally the same as that of a typical starfish or seastar. Like ''A. planci'', however, its distinctive traits include being disc-shaped, multiple-armed with multiple madreporites, flexible, prehensile, and densely spined, and having a large ratio of stomach surface to body mass. Its prehensile ability arises from the two rows of numerous tube feet that extend to the tip of each arm. In being multiple-armed, it has lost the five-fold symmetry (pentamerism) typical of starfish, although it begins with this symmetry in its life cycle. ''Acanthaster brevispinus'' is readily distinguished from ''A. planci'' in that it has: * dense blunt spines over the upper (aboral) surface of its disc * short pedic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthaster
''Acanthaster'' is a bitypic genus of large and venomous starfish placed in its own family, Acanthasteridae. Its two members are known as crown-of-thorns starfish. Acanthaster are native to coral reefs in Indo-Pacific region. The species in this genus are a contributor to coral reef degradation because they prey on a large amount of live coral at high density. Species These species are listed in the World Register of Marine Species: *'' Acanthaster brevispinus'' Fisher, 1917 *''Acanthaster planci'' (Linnaeus, 1758) Some sources add ''Acanthaster ellisi'', (Gray, 1840) but it is now considered as a subspecies of ''A. planci'' in the eastern Pacific. Recent molecular work has suggested that ''Acanthaster planci'' is a species complex of up to 4 different species that have yet to be separately described (Vogler et al., 2008). Haszprunar, Vogler & Wörheide (2017) suggest to split "''A. planci''" in : * ''Acanthaster planci'' (Linnaeus, 1758) -- Northern Indian Ocean, always ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Barrier Reef
The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, Australia, separated from the coast by a channel 100 miles wide in places and over 200 feet deep. The Great Barrier Reef can be seen from outer space and is the world's biggest single structure made by living organisms. This reef structure is composed of and built by billions of tiny organisms, known as coral polyps. It supports a wide diversity of life and was selected as a World Heritage Site in 1981. CNN labelled it one of the seven natural wonders of the world in 1997. Australian World Heritage places included it in its list in 2007. The Queensland National Trust named it a state icon of Queensland in 2006. A large part of the reef is protected by the Great Barrier Reef Marine Park, which helps to limit the impact of human use, such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and its subdisciplines are traditionally done in labware such as test tubes, flasks, Petri dishes, and microtiter plates. Studies conducted using components of an organism that have been isolated from their usual biological surroundings permit a more detailed or more convenient analysis than can be done with whole organisms; however, results obtained from ''in vitro'' experiments may not fully or accurately predict the effects on a whole organism. In contrast to ''in vitro'' experiments, ''in vivo'' studies are those conducted in living organisms, including humans, and whole plants. Definition ''In vitro'' ( la, in glass; often not italicized in English usage) studies are conducted using components of an organism that have been isolated fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oocytes
An oocyte (, ), oöcyte, or ovocyte is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in a female fetus in the ovary during female gametogenesis. The female germ cells produce a primordial germ cell (PGC), which then undergoes mitosis, forming oogonia. During oogenesis, the oogonia become primary oocytes. An oocyte is a form of genetic material that can be collected for cryoconservation. Formation The formation of an oocyte is called oocytogenesis, which is a part of oogenesis. Oogenesis results in the formation of both primary oocytes during fetal period, and of secondary oocytes after it as part of ovulation. Characteristics Cytoplasm Oocytes are rich in cytoplasm, which contains yolk granules to nourish the cell early in development. Nucleus During the primary oocyte stage of oogenesis, the nucleus is called a germinal vesicle. The only normal human type of secondary oocyte has the 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthaster Brevispinus Hybrid
''Acanthaster'' is a bitypic genus of large and venomous starfish placed in its own family, Acanthasteridae. Its two members are known as crown-of-thorns starfish. Acanthaster are native to coral reefs in Indo-Pacific region. The species in this genus are a contributor to coral reef degradation because they prey on a large amount of live coral at high density. Species These species are listed in the World Register of Marine Species: *''Acanthaster brevispinus'' Fisher, 1917 *''Acanthaster planci'' ( Linnaeus, 1758) Some sources add ''Acanthaster ellisi'', (Gray, 1840) but it is now considered as a subspecies of ''A. planci'' in the eastern Pacific. Recent molecular work has suggested that ''Acanthaster planci'' is a species complex of up to 4 different species that have yet to be separately described (Vogler et al., 2008). Haszprunar, Vogler & Wörheide (2017) suggest to split "''A. planci''" in : * ''Acanthaster planci'' (Linnaeus, 1758) -- Northern Indian Ocean, always pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthaster Planci Hybrid
''Acanthaster'' is a bitypic genus of large and venomous starfish placed in its own family, Acanthasteridae. Its two members are known as crown-of-thorns starfish. Acanthaster are native to coral reefs in Indo-Pacific region. The species in this genus are a contributor to coral reef degradation because they prey on a large amount of live coral at high density. Species These species are listed in the World Register of Marine Species: *''Acanthaster brevispinus'' Fisher, 1917 *''Acanthaster planci'' ( Linnaeus, 1758) Some sources add ''Acanthaster ellisi'', (Gray, 1840) but it is now considered as a subspecies of ''A. planci'' in the eastern Pacific. Recent molecular work has suggested that ''Acanthaster planci'' is a species complex of up to 4 different species that have yet to be separately described (Vogler et al., 2008). Haszprunar, Vogler & Wörheide (2017) suggest to split "''A. planci''" in : * ''Acanthaster planci'' (Linnaeus, 1758) -- Northern Indian Ocean, always pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scallops
Scallop () is a common name that encompasses various species of marine bivalve mollusks in the taxonomic family Pectinidae, the scallops. However, the common name "scallop" is also sometimes applied to species in other closely related families within the superfamily Pectinoidea, which also includes the thorny oysters. Scallops are a cosmopolitan family of bivalves found in all of the world's oceans, although never in fresh water. They are one of the very few groups of bivalves to be primarily "free-living", with many species capable of rapidly swimming short distances and even migrating some distance across the ocean floor. A small minority of scallop species live cemented to rocky substrates as adults, while others attach themselves to stationary or rooted objects such as seagrass at some point in their lives by means of a filament they secrete called a byssal thread. The majority of species, however, live recumbent on sandy substrates, and when they sense the presence of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Townsville
Townsville is a city on the north-eastern coast of Queensland, Australia. With a population of 180,820 as of June 2018, it is the largest settlement in North Queensland; it is unofficially considered its capital. Estimated resident population, 30 June 2018. Townsville hosts a significant number of governmental, community and major business administrative offices for the northern half of the state. Part of the larger local government area of the City of Townsville, it is in the dry tropics region of Queensland, adjacent to the central section of the Great Barrier Reef. The city is also a major industrial centre, home to one of the world's largest zinc refineries, a nickel refinery and many other similar activities. As of December 2020, $30M operations to expand the Port of Townsville are underway, which involve channel widening and installation of a 70-tonne Liebherr Super Post Panamax Ship-to-Shore crane, to allow much larger cargo and passenger ships to utilise the port. It is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympatric
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation. Such speciation may be a product of reproductive isolation – which prevents hybrid offspring from being viable or able to reproduce, thereby reducing gene flow – that results in genetic divergence. Sympatric speciation may, but need not, arise through secondary contact, which refers to speciation or divergence in allopatry followed by range expansions leading to an area of sympatry. Sympatric species or taxa in secondary contact may or may not interbreed. Types of populations Four main types of population pairs exist in nature. Sympatric populations (or species) contrast with parapatric populations, which contact one another in adjacent but not shared ranges and do no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthaster Planci
The crown-of-thorns starfish (frequently abbreviated to COTS), ''Acanthaster planci'', is a large starfish that preys upon hard, or stony, coral polyps (Scleractinia). The crown-of-thorns starfish receives its name from venomous thorn-like spines that cover its upper surface, resembling the biblical crown of thorns. It is one of the largest starfish in the world. ''A. planci'' has a very wide Indo-Pacific distribution. It is perhaps most common around Australia, but can occur at tropical and subtropical latitudes from the Red Sea and the East African coast across the Indian Ocean, and across the Pacific Ocean to the west coast of Central America. It occurs where coral reefs or hard coral communities occur in the region. Description The body form of the crown-of-thorns starfish is fundamentally the same as that of a typical starfish, with a central disk and radiating arms. Its special traits, however, include being disc-shaped, multiple-armed, flexible, prehensile, and heavily sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Kenrick Fisher
Walter Kenrick Fisher (February 1, 1878 – November 2, 1953) was an American zoologist, evolutionary biologist, illustrator and painter. He taught in Stanford University before eventually becoming Emeritus Professor in Zoology until his retirement in 1943. Fisher was the son of ornithologist Albert Kenrick Fisher. Early life Walter K. Fisher was born on February 1, 1878 in Ossining, New York. His father was Albert Kenrick Fisher and his mother was Alwilda Fisher (''née'' Merritt). As a boy, Fisher explored the countryside around his home in the Hudson Valley, and when he was older conducted similar explorations around Washington, D. C. following his family's move to the capital. During these ventures he collected birds and plants, and he drew sketches of the skulls he collected and of the landscapes. He was a talented artist and was initially tempted to follow his artistic side, and he continued to paint and draw throughout his life, but he decided that he wanted to follow a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acanthaster Brevispinus Holotype
''Acanthaster'' is a bitypic genus of large and venomous starfish placed in its own family, Acanthasteridae. Its two members are known as crown-of-thorns starfish. Acanthaster are native to coral reefs in Indo-Pacific region. The species in this genus are a contributor to coral reef degradation because they prey on a large amount of live coral at high density. Species These species are listed in the World Register of Marine Species: *''Acanthaster brevispinus'' Fisher, 1917 *''Acanthaster planci'' ( Linnaeus, 1758) Some sources add ''Acanthaster ellisi'', (Gray, 1840) but it is now considered as a subspecies of ''A. planci'' in the eastern Pacific. Recent molecular work has suggested that ''Acanthaster planci'' is a species complex of up to 4 different species that have yet to be separately described (Vogler et al., 2008). Haszprunar, Vogler & Wörheide (2017) suggest to split "''A. planci''" in : * ''Acanthaster planci'' (Linnaeus, 1758) -- Northern Indian Ocean, always pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
