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Opisthoteuthis Borealis
''Opisthoteuthis borealis'' is a lesser-known species of octopus found near Greenland and Iceland, especially in the Davis Strait. The species was described from 9 specimens, and is one of the most recent Opisthoteuthis species described. Not much is known about it besides its anatomy and habitat. Description ''Opisthoteuthis borealis'' belongs to the order Cirrata, a subdivision of octopuses which have fleshy fins to assist in swimming, internal shells supporting their bodies, and two threadlike structures called cirri for each sucker. Many cirrate octopuses live in deep water. Octopuses in the species ''Opisthoteuthis borealis'' have mantles up to long. They are medium-sized when compared to closely related species. They have long arms and large eyes. Males of ''O. borealis'' have some enlarged suckers; their purpose is unknown. Females don't have enlarged suckers. This specific kind of sex difference, or sexual dimorphism, is also seen in Opisthoteuthis albatrossi and Opist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Davis Strait
Davis Strait is a northern arm of the Atlantic Ocean that lies north of the Labrador Sea. It lies between mid-western Greenland and Baffin Island in Nunavut, Canada. To the north is Baffin Bay. The strait was named for the English explorer John Davis (1550–1605), who explored the area while seeking a Northwest Passage. By the 1650s it was used for whale hunting. Extent The International Hydrographic Organization defines the limits of the Davis Strait as follows: ''On the North.'' The Southern limit of Baffin Bay 70° North between Greenland and Baffin Island">Baffin Land]. ''On the East.'' The Southwest coast of Greenland. ''On the South.'' The parallel of 60th parallel north, 60° North between Greenland and Labrador. ''On the West.'' The Eastern limit of the Northwestern Passages South of 70° North he East coast of Baffin Island to East Bluff, its Southeastern extremityand of Hudson Strait line from East Bluff, the Southeast extreme of Baffin Island (), to Point ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthoteuthis
''Opisthoteuthis'' is a genus of cirrate octopuses, sometimes known as flapjack octopuses, which are found in all the world's oceans. Behavior Like other cirrates, octopuses in Opisthoteuthis are generally small, and many dwell in the deep sea. They have cirri on their arms, internal shells to support their bodies, and muscular fins for steering. Like octopuses of Grimpoteuthis ''Grimpoteuthis'' is a genus of pelagic umbrella octopuses known as the dumbo octopuses. The name "dumbo" originates from their resemblance to the title character of Disney's 1941 film ''Dumbo'', having a prominent ear-like fin which extends from ..., opisthoteuthids have been seen resting or crawling on the seafloor. Species The following 24 species have been placed in ''Opisthoteuthis'': Notes References External links * * {{Taxonbar, from=Q3816282 Octopuses Cephalopod genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirrata
Cirrina or Cirrata is a suborder and one of the two main divisions of octopuses. Cirrate octopuses have a Cirrate shell, small, internal shell and Cephalopod fin, two fins on their head, while their sister suborder Incirrina has neither. The fins of cirrate octopods are associated with a unique cartilage-like shell in a shell sac. In cross-section, the fins have distinct proximal and distal regions, both of which are covered by a thin surface sheath of muscle. The suborder is named for small, cilia-like strands (cirri) on the arms of the octopus, a pair for each sucker. These are thought to play some role in feeding, perhaps by creating currents of water that help bring food closer to the beak. Cirrate octopuses are noteworthy for lacking ink sacs. Phylogeny A molecular phylogeny based on mitochondrial and nuclear DNA marker sequences by Sanchez et al., 2018, shows that the Cirrina is paraphyletic, i.e. it is not a single clade. Instead, a clade containing Opisthoteuthidae and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirrate Shell
Cirrate octopuses possess a well-developed internal shell that supports their muscular swimming fins. This is in contrast to the more familiar, finless, incirrate octopuses, in which the shell remnant is either present as a pair of stylets or absent altogether. The cirrate shell is quite unlike that of any other living cephalopod group and has its own dedicated set of descriptive terms. It is usually roughly arch- or saddle-shaped and is rather soft, being similar in consistency to cartilage. Each of the eight extant cirrate genera is characterised by a distinct shell morphology: * Cirroteuthidae **'' Cirroteuthis'' — saddle-shaped, with large wings **'' Cirrothauma'' — butterfly-shaped * Opisthoteuthidae **'' Cirroctopus'' — V-shaped, lateral wings tapering to fine points **'' Cryptoteuthis'' — U-shaped, each lateral wing ending in broad lobe with pointed projection **''Grimpoteuthis'' — U-shaped, lateral wings ending bluntly **'' Luteuthis'' — W-shaped **'' Opi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cirrus (biology)
In biology, a cirrus , plural ''cirri'', , (from the Latin ''cirrus'' meaning a ''curl-like tuft or fringe'') is a long, thin structure in an animal similar to a tentacle but generally lacking the tentacle's strength, flexibility, thickness, and sensitivity. In the sheep liver fluke, for example, the ''cirrus'' is the worm's muscular penis and when not in use is retained within a ''cirrus sac'' or ''pouch'' near the animal's head. The same structure exists in the various ''Taenia'' species of tapeworm. In the clam worms, however, the cirrus is the tentacular process or growth on each of the feet (''parpodia''), either the ''dorsal cirrus'' or the ''ventral cirrus'', and has nothing to do with reproduction. Among the bristleworms, a cirrus is a tentacular growth near the head or notopodium containing sense organs and may be either dorsal, ventral, or lamellar. Among the ribbonworms, the ''caudal cirrus'' is a small thread-like growth at the posterior end of the worm. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, or behavioural or cognitive traits. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is ''monomorphism'', which is when both biological sexes are phenotypically indistinguishable from each other. Overview Ornamentation and coloration Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated dim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthoteuthis Albatrossi
''Opisthoteuthis albatrossi'' (common name in ja, オオクラゲダコ) is a cirrate octopus originally found off Kinkasan in Japan. This species was described from only four specimens. It is similar to '' Opisthoteuthis californiana;'' the two may be the same species. It is also similar to '' Opisthoteuthis japonica.'' ''O. albatrossi'' lives in the North Pacific, from Japanese waters to the Sea of Okhotsk. It exists at recorded depths of below the surface. Description ''Opisthoteuthis albatrossi'' is a small octopus; its total length is . Each arm has more than 80 suckers, and males have some very enlarged suckers, typical to opisthoteuthids. Like other cirrate octopuses, it has a thick, fleshy web connecting its arms; a small internal shell to support its body; and cirri Giovanni Battista Cirri (1 October 1724 – 11 June 1808) was an Italian cellist and composer in the 18th century. Biography Cirri was born in Forlì in the Emilia-Romagna Region of Italy. He had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthoteuthis Californiana
''Opisthoteuthis californiana'', also known as the flapjack octopus or adorabilis, is a species of umbrella octopus. Description The flapjack octopus usually appear pinkish. They have fins above their eyes, similar to those found on some species of squid. Their maximum size is mantle length. They have eight jointed legs which are affixed together in an umbrella shape. They have a gelatinous body, which spreads into a parachute shape when maneuvering through dimly lit water. They swim by moving their fins, pulsing their webbed arms, pushing water through their funnel for jet propulsion, or all three at once. Distribution ''Opisthoteuthis californiana'' has a distribution in the northern and northeastern Pacific, ranging in the west from off central Honshū (Japan) and the Sea of Okhotsk, its northernmost range is the Bering Sea, and its eastern range is along the western coast of North America as far south as Eureka Bar, California (the type locality, at 350 m depth). The dept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthoteuthis Grimaldii
''Opisthoteuthis grimaldii'' is an octopus found near the Azores. ''O. grimaldii'' lives in the Northeast Atlantic Ocean from deep. This species lives far deeper than other Opisthoteuthis members in the Atlantic. The type specimen, upon which the species' description was based, was captured near Faial Island. The octopus has been found as far south as Namibian waters and as far north as British waters. In the early 1900s, many octopuses living all over the Atlantic and Indian oceans were classed as ''Opisthoteuthis grimaldii'', but later scientists decided that only those specimens found in the Eastern Atlantic Ocean actually belonged to the species. This octopus occupies in the bathyal zone, a deep area of the ocean where no sunlight reaches. Like many other cirrate octopuses, it lives on or just above the seafloor. ''Opisthoteuthis grimaldii'' is anatomically very similar to ''Opisthoteuthis borealis'', but the two species have differently structured digestive systems. It h ... [...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] |
Benthic Zone
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 ancient Greek, βένθος (bénthos), 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 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 shore line (intertida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molluscs Described In 2005
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 gastropods ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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