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Eledone Massyae
''Eledone massyae'', the combed octopus, is a small benthic octopus found off the Atlantic coasts of southern South America, particularly Argentina and southern Brazil. Description The body is rounded and slightly flattened dorso-ventrally. The head is narrower than the mantle and separated by a slight constriction. The opening in the mantle is very large and the arms are the same length. The suckers are small, separated from one another and deeply anchored in the arm. The third arm possesses a hypocotyl in the male individuals. Also in males, other arms have suckers that decrease in number until the tip of the arm. After the last sucker are two ranges of papillae that diverge on the sides. On female individuals, the arms are not modified. Females have a variable size ranging from 24 to 91 mm and males vary between 22 to 80 mm. ''Eledone massyae'' feeds mostly on macro crustaceans such as crabs from the Portunidae family as well as polychaetes and mullusks. Distribution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilbert L
Gilbert may refer to: People and fictional characters * Gilbert (given name), including a list of people and fictional characters *Gilbert (surname), including a list of people Places Australia * Gilbert River (Queensland) * Gilbert River (South Australia) Kiribati * Gilbert Islands, a chain of atolls and islands in the Pacific Ocean United States * Gilbert, Arizona, a town * Gilbert, Arkansas, a town * Gilbert, Florida, the airport of Winterhaven * Gilbert, Iowa, a city * Gilbert, Louisiana, a village * Gilbert, Michigan, and unincorporated community * Gilbert, Minnesota, a city * Gilbert, Nevada, ghost town * Gilbert, Ohio, an unincorporated community * Gilbert, Pennsylvania, an unincorporated community * Gilbert, South Carolina, a town * Gilbert, West Virginia, a town * Gilbert, Wisconsin, an unincorporated community * Mount Gilbert (other), various mountains * Gilbert River (Oregon) Outer space * Gilbert (lunar crater) * Gilbert (Martian crater) Arts a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusca
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gastropod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eledone Gaucha
''Eledone gaucha'' is a species of octopus from the southern Atlantic Ocean. It is a predator of fish, crabs, lobsters and molluscs. This octopus is a member of the genus ''Eledone'' and belongs to the family Eledonidae. It was distinguished from a similar species, ''Eledone massyae''. ''Eledone gaucha'' is smaller in size than '' E. massyae'' and has a smaller mantle and head. Description ''Eledone gaucha'' possesses a firm, thin, ovoid and elongated mantle. It is separated from the head by a small constriction. The body is smooth and papillae can be found on the dorsal mantle and on the head. The head is narrower than the mantle and the eyes are protruding. The syphon is long, W-shaped and free from its front half. The arms are long and thin. The dorsal arms are notably longer than the other arms and the arms from the males are longer than those of the females.The suckers are small, well separated and deeply anchored in the arms. On the arms of females, suckers are regrouped ... [...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] |
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe and Asia from the "New World" of the Americas in the European perception of the World. The Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Europe and Africa to the east, and North and South America to the west. As one component of the interconnected World Ocean, it is connected in the north to the Arctic Ocean, to the Pacific Ocean in the southwest, the Indian Ocean in the southeast, and the Southern Ocean in the south (other definitions describe the Atlantic as extending southward to Antarctica). The Atlantic Ocean is divided in two parts, by the Equatorial Counter Current, with the North(ern) Atlantic Ocean and the South(ern) Atlantic Ocean split at about 8°N. Scientific explorations of the A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continental Shelf
A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island is known as an ''insular shelf''. The continental margin, between the continental shelf and the abyssal plain, comprises a steep continental slope, surrounded by the flatter continental rise, in which sediment from the continent above cascades down the slope and accumulates as a pile of sediment at the base of the slope. Extending as far as 500 km (310 mi) from the slope, it consists of thick sediments deposited by turbidity currents from the shelf and slope. The continental rise's gradient is intermediate between the gradients of the slope and the shelf. Under the United Nations Convention on the Law of the Sea, the name continental shelf was given a legal definition as the stretch of the seabed adjacent to the shores of a par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valdes Peninsula
The Valdes Peninsula (Spanish: ''Península Valdés'') is a peninsula into the Atlantic Ocean in the Biedma Department of north-east Chubut Province, Argentina. Around in size (not taking into account the isthmus of Carlos Ameghino which connects the peninsula to the mainland), it is an important nature reserve which was listed as a World Heritage Site by UNESCO in 1999. Geography The nearest large town is Puerto Madryn. The only town on the peninsula is the small settlement of Puerto Pirámides. There are also a number of ''estancias'', where sheep are raised. Most of the peninsula is barren land with some salt lakes. The largest of these lakes is at an elevation of about 40 m below sea level (see extremes on Earth), until recently thought to be the lowest elevation in Argentina and South America (the lowest point actually being Laguna del Carbón, Argentina). Fauna The coastline is inhabited by marine mammals, like sea lions, elephant seals and fur seals. The peninsu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rio De Janeiro (state)
Rio de Janeiro () is one of the 27 federative units of Brazil. It has the second largest economy of Brazil, with the largest being that of the state of São Paulo. The state, which has 8.2% of the Brazilian population, is responsible for 9.2% of the Brazilian GDP. The state of Rio de Janeiro is located within the Brazilian geopolitical region classified as the Southeast (assigned by IBGE). Rio de Janeiro shares borders with all the other states in the same Southeast macroregion: Minas Gerais ( N and NW), Espírito Santo ( NE) and São Paulo ( SW). It is bounded on the east and south by the South Atlantic Ocean. Rio de Janeiro has an area of . Its capital is the city of Rio de Janeiro, which was the capital of the Portuguese Colony of Brazil from 1763 to 1815, of the following United Kingdom of Portugal, Brazil and the Algarves from 1815 to 1822, and of later independent Brazil as a kingdom and republic from 1822 to 1960. The state's 22 largest cities are Rio de Janeiro, São G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polychaete
Polychaeta () is a paraphyletic class (biology), class of generally marine invertebrate, marine annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. More than 10,000 species are described in this class. Common representatives include the lugworm (''Arenicola marina'') and the Alitta virens, sandworm or Alitta succinea, clam worm ''Alitta''. Polychaetes as a class are robust and widespread, with species that live in the coldest ocean temperatures of the abyssal plain, to forms which tolerate the extremely high temperatures near hydrothermal vents. Polychaetes occur throughout the Earth's oceans at all depths, from forms that live as plankton near the surface, to a 2- to 3-cm specimen (still unclassified) observed by the robot ocean probe Nereus (underwater vehicle), ''Nereus'' at the bottom of the Challenger Deep, the deepes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octopus
An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like other cephalopods, an octopus is bilaterally symmetric with two eyes and a beaked mouth at the center point of the eight limbs. The soft body can radically alter its shape, enabling octopuses to squeeze through small gaps. They trail their eight appendages behind them as they swim. The siphon is used both for respiration and for locomotion, by expelling a jet of water. Octopuses have a complex nervous system and excellent sight, and are among the most intelligent and behaviourally diverse of all invertebrates. Octopuses inhabit various regions of the ocean, including coral reefs, pelagic waters, and the seabed; some live in the intertidal zone and others at abyssal depths. Most species grow quickly, mature ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portunidae
Portunidae is a family of crabs which contains the swimming crabs. Description Portunid crabs are characterised by the flattening of the fifth pair of legs into broad paddles, which are used for swimming. This ability, together with their strong, sharp claws, allows many species to be fast and aggressive predators. Examples Its members include many well-known shoreline crabs, such as the European shore crab (''Carcinus maenas''), blue crab (''Callinectes sapidus''), and velvet crab ('' Necora puber''). Two genera in the family are contrastingly named ''Scylla'' and ''Charybdis''; the former contains the economically important species black crab (''Scylla serrata'') and ''Scylla paramamosain''. Taxonomy The circumscription of the family varies, with some authors treating "Carcinidae", "Catoptridae" and "Macropipidae" as separate families, and others considering them subfamilies of a wider Portunidae. Swimming crabs reach their greatest species diversity in the Pacific and Indian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the world's oceans, in freshwater, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers. They first appeared during the Jurassic Period. Description Crabs are generally covered with a thick exoskeleton, composed primarily of highly mineralized chitin, and armed with a pair of chelae (claws). Crabs vary in size from the pea crab, a few millimeters wide, to the Japanese spider crab, with a leg span up to . Several other groups of crustaceans with similar appearances – such as king crabs and porcelain crabs – are not true crabs, but have evolved features similar to true crabs through a process known as carcinisation. Environment Crabs are found in all of the world's oceans, as well as in fresh w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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