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Psychroteuthis Glacialis Paralarva2
''Psychroteuthis glacialis'', the glacial squid, is the only known species in the monotypic genus ''Psychroteuthis'', in the family Psychroteuthidae. While only one species has been confirmed, two undescribed species also probably exist. The species occurs in coastal waters near Antarctica and South America. It grows to a mantle length of . Ecology ''P. glacialis'' is known to feed on many crustaceans, fish, lanternfish, Antarctic krill, and Antarctic silverfish, and has been known to practice cannibalism. Animals known to routinely feed on glacial squid include the Antarctic petrel, light-mantled albatross, Ross seal, southern elephant seal, Weddell seal, Patagonian toothfish, wandering albatross, grey-headed albatross The grey-headed albatross (''Thalassarche chrysostoma'') also known as the gray-headed mollymawk, is a large seabird from the albatross family. It has a circumpolar distribution, nesting on isolated islands in the Southern Ocean and feeding at h ..., the A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paralarva
Paralarvae (singular: ''paralarva'') are young cephalopods in the planktonic stages between hatchling and subadult. This stage differs from the larval stage of animals that undergo true metamorphosis. Paralarvae have been observed only in members of the orders Octopoda and Teuthida. The term was first introduced by Richard E. Young and Robert F. Harman in 1988. Paralarvae usually spend an uncertain amount of time in the plankton and then typically descend to an adult habitat in the mesopelagic or bathypelagic zone. Their population abundance is dependent on the variation of mortality rates during the planktonic period. See also *Larva *Crustacean larvae Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The ... References Further reading *Bigelow, Keith A. "Age and growth in par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic Petrel
The Antarctic petrel (''Thalassoica antarctica'') is a boldly marked dark brown and white petrel, found in Antarctica, most commonly in the Ross and Weddell Seas. They eat Antarctic krill, fish, and small squid. They feed while swimming but can dive from both the surface and the air. Taxonomy and systematics Captain James Cook saw the Antarctic petrel on his second voyage to the south Pacific. In 1777 both Cook and the naturalist Georg Forster mentioned the petrel in their separate accounts of the voyage. Forster wrote: On the 17th, in the forenoon, we crossed the antarctic circle, and advanced into the southern frigid zone, which had hitherto remained impenetrable to all navigators. Some days before this period we had seen a new species of petrel, of a brown colour, with a white belly and rump, and a large white spot on the wings, which we now named the antarctic petrel, as we saw great flights of twenty on thirty of them hereabouts, of which we shot many that unfortunately neve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molluscs Described In 1920
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 (s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squid
True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting these criteria. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius (cephalopod), gladius or pen, made of chitin. Squid diverged from other cephalopods during the Jurassic and occupy a similar role to teleost fish as open water predators of similar size and behaviour. They play an important role in the open water food web. The two long tentacles are used to grab prey and the eight arms to hold and control it. The beak then cuts the food into suitable size chunks for swallowing. Squid are rapid swimmers, moving by Aquatic locomotion#Jet propulsion, jet propulsion, and largely locate their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subtropics
The subtropical zones or subtropics are geographical and climate zones to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 35° 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 (Koppen climate Cfa), where rainfall is often concentrated in the warmest months, for example Southeast China and the Southeastern United States, and dry summer or Mediterranean climate (Koppen climate Csa/Csb), where seasonal rainfall is concentrated in the cooler months, such as the Mediterranean Basin or Southern California. Subtropical climates can also occur at high elevations within the tropics, such as in the southern end of the Mexican Plateau and in Da Lat of the Vietnamese Central Highlands. The six climate cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelagic Zone
The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the surface of the sea and the bottom. Conditions in the water column change with depth: pressure increases; temperature and light decrease; salinity, oxygen, micronutrients (such as iron, magnesium and calcium) all change. Marine life is affected by bathymetry (underwater topography) such as the seafloor, shoreline, or a submarine seamount, as well as by proximity to the boundary between the ocean and the atmosphere at the ocean surface, which brings light for photosynthesis, predation from above, and wind stirring up waves and setting currents in motion. The pelagic zone refers to the open, free waters away from the shore, where marine life can swim freely in any direction unhindered by topographical constraints. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emperor Penguin
The emperor penguin (''Aptenodytes forsteri'') is the tallest and heaviest of all living penguin species and is endemic to Antarctica. The male and female are similar in plumage and size, reaching in length and weighing from . Feathers of the head and back are black and sharply delineated from the white belly, pale-yellow breast and bright-yellow ear patches. Like all penguins, it is flightless, with a streamlined body, and wings stiffened and flattened into flippers for a marine habitat. Its diet consists primarily of fish, but also includes crustaceans, such as krill, and cephalopods, such as squid. While hunting, the species can remain submerged around 20 minutes, diving to a depth of . It has several adaptations to facilitate this, including an unusually structured haemoglobin to allow it to function at low oxygen levels, solid bones to reduce barotrauma, and the ability to reduce its metabolism and shut down non-essential organ functions. The only penguin species t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adélie Penguin
The Adélie penguin (''Pygoscelis adeliae'') is a species of penguin common along the entire coast of the Antarctic continent, which is the only place where it is found. It is the most widespread penguin species, and, along with the emperor penguin, is the most southerly distributed of all penguins. It is named after Adélie Land, in turn named for Adèle Dumont d'Urville, who was married to French explorer Jules Dumont d'Urville, who first discovered this penguin in 1840. Adélie penguins obtain their food by both predation and foraging, with a diet of mainly krill and fish. Taxonomy and systematics The first Adélie penguin specimens were collected by crew members of French explorer Jules Dumont d'Urville on his expedition to Antarctica in the late 1830s and early 1840s. Jacques Bernard Hombron and Honoré Jacquinot, two French surgeons who doubled as naturalists on the journey, described the bird for science in 1841, giving it the scientific name ''Catarrhactes adelià ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grey-headed Albatross
The grey-headed albatross (''Thalassarche chrysostoma'') also known as the gray-headed mollymawk, is a large seabird from the albatross family. It has a circumpolar distribution, nesting on isolated islands in the Southern Ocean and feeding at high latitudes, further south than any of the other mollymawks. Its name derives from its ashy-gray head, throat and upper neck. Taxonomy Mollymawks are a type of albatross that belong to the family Diomedeidae from the order Procellariiformes, along with shearwaters, fulmars, storm petrels, and diving petrels. They share certain identifying features. First, they have nasal passages that attach to the upper bill called naricorns, although the nostrils of an albatross are on the sides of the bill. The bills of Procellariiformes are also unique in that they are split into between seven and nine horny plates. Finally, they produce a stomach oil made up of wax esters and triglycerides that is stored in the proventriculus. This is used against pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wandering Albatross
The wandering albatross, snowy albatross, white-winged albatross or goonie (''Diomedea exulans'') is a large seabird from the family Diomedeidae, which has a circumpolar range in the Southern Ocean. It was the last species of albatross to be described, and was long considered the same species as the Tristan albatross and the Antipodean albatross. A few authors still consider them all subspecies of the same species. The SACC has a proposal on the table to split this species, and BirdLife International has already split it. Together with the Amsterdam albatross, it forms the wandering albatross species complex. The wandering albatross is one of the two largest members of the genus ''Diomedea'' (the great albatrosses), being similar in size to the southern royal albatross. It is one of the largest, best known, and most studied species of bird in the world. It has the greatest known wingspan of any living bird, and is also one of the most far-ranging birds. Some individual wandering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patagonian Toothfish
The Patagonian toothfish (''Dissostichus eleginoides'') is a species of notothen found in cold waters () between depths of in the southern Atlantic, Pacific, and Indian Oceans and Southern Ocean on seamounts and continental shelves around most Subantarctic islands. A close relative, the Antarctic toothfish (), is found farther south around the edges of the Antarctic shelf, and a Marine Stewardship Council-certified fishery is active in the Ross Sea. Both species are sometimes marketed as Chilean sea bass. The average weight of a commercially caught Patagonian toothfish is , depending on the fishery, with large adults occasionally exceeding . They are thought to live up to 50 years and to reach a length up to . Several commercial fisheries exist for Patagonian toothfish, which are detailed below. Taxonomy The Patagonian toothfish was first formally described in 1898 by the Swedish zoologist Fredrik Adam Smitt with the type locality given as Puerto Toro at 55°24'S, 68°17'W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weddell Seal
The Weddell seal (''Leptonychotes weddellii'') is a relatively large and abundant true seal with a circumpolar distribution surrounding Antarctica. The Weddell seal was discovered and named in the 1820s during expeditions led by British sealing captain James Weddell to the area of the Southern Ocean now known as the Weddell Sea. The life history of this species is well documented since it occupies fast ice environments close to the Antarctic continent and often adjacent to Antarctic bases. This is the only species in the genus ''Leptonychotes''. Description Weddell seals measure about 2.5–3.5 m (8 ft 2 in–11 ft 6 in) long and weigh 400–600 kg (880–1,320 lb). They are amongst the largest seals, with a rather bulky body and short fore flippers relative to their body length. Males weigh less than females, usually about 500 kg (1,100 lb) or less. Male and female Weddell seals are generally about the same length, though females can be slightly l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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