Home About us Products Services Contact us Bookmark
:: wikimiki.org ::
Lobster

Lobster



- Neophoberinae
  - Acanthacaris
- Thymopinae
  - Nephropsis
  - Nephropides
  - Thymops
  - Thymopsis
- Nephropinae
  - Homarus
  - Nephrops
  - Homarinus
  - Metanephrops
  - Eunephrops
  - Thymopides Clawed lobsters comprise a family (Nephropidae, sometimes also Homaridae) of large marine crustaceans. They are important as an animal, a business and a food.

Biology

Clawed lobsters should not be confused with spiny lobsters, which have no claws (chelae), and are not closely related. The closest relatives of clawed lobsters are the reef lobster Enoplometopus and the three families of freshwater crayfish. Smaller varieties are sometimes called "lobsterettes". Lobsters are invertebrates, and have a tough exoskeleton, which protects them. Like all arthropods, lobsters must molt in order to grow, leaving them vulnerable during this time. Lobsters are considered a food delicacy around the world. In Europe, they are extremely expensive; in some parts of North America, much less so. Lobsters live on rocky, sandy, or muddy bottoms from the shoreline to beyond the edge of the continental shelf. They generally live singly in crevices or in burrows under rocks. Although many studies suggested that lobsters are primarily scavengers, feeding on mollusks and decaying animal matter, recent studies have shown that they primarily feed on live fish, dig for clams, sea urchins, and feed on algae and eel-grass. They occasionally eat other lobsters, too. An average adult lobster is about 230 mm (9 inches) long and weighs 700 to 900 g (1.5 to 2 pounds). Lobsters grow throughout their lives, though, and are long-lived. They can thus reach impressive sizes. According to the Guinness World Records, the largest lobster was caught in Nova Scotia, Canada and weighed 20.14 kg (44.4 lb). The environmental conditions of the lobsters can vary from ocean to ocean, but the lobster's temperature environment does not fluctuate much since their home is a large mass of water, the ocean. Like all arthropods, lobsters are largely bilaterally symmetrical; clawed lobsters often possess unequal, specialized claws, like the stone crab. The anatomy of the lobster includes the cephalothorax which is the head fused with the thorax, both of which are covered by the carapace, and the abdomen. The lobster's head consists of antennae, antennules, mandibles, the first and second maxillae, and the first, second, and third maxillipeds. Because a lobster lives in a murky environment at the bottom of the ocean, its vision is poor and it mostly uses its antennae as sensors. The abdomen of the lobster includes swimmerets and its tail is composed of uropods and the telson.

The lobster industry

telson Most lobster comes from the north-eastern coast of North America with the Canadian Maritimes and the U.S. state of Maine being the largest producers. They are caught using lobster traps. These devices made of shrimp mesh and wire (wooden traps, now obsolete, were traditionally used) are baited and lowered to the sea floor. They allow a lobster to enter, but make it impossible for the larger specimens to turn around and exit. This allows the creatures to be captured alive. The traps have a buoy, sometimes referred to as a "pot", floating on the surface and lobster fishermen check their traps daily. Studies have shown that the inefficient trap system—which permits small, juvenile lobsters to easily escape—has inadvertently prevented the lobster population from being overfished.

As food

Prior to the 20th century, lobster wasn't popular as food. In the Maritimes, eating lobster was considered a mark of poverty. In some parts of the Maritime provinces of Canada, lobster was used as a fertilizer for farmers' fields. Outside of the rural outports lobster was sold canned, losing much of its flavour which can be disregarded if the lobster is dipped in butter. The reputation of lobster changed with the development of the modern transportation industry that allowed live lobsters to be shipped from the outports to large urban centres. Fresh lobster quickly became a luxury food and a tourist attraction for the Maritimes and Maine and an export to Europe and Japan where it is especially expensive. Lobster is most commonly cooked by placing a live whole lobster in a pot of boiling water. Some consider this method cruel, and more humane ways of killing them include inserting a knife into the back of their head and slicing downward, and freezing them for 15 minutes before boiling [http://www.cooking-lobster.com/cooking-lobster/lobster-killing.html]. The apparent cruelty of boiling lobsters alive was challenged in a Norwegian study released in February of 2005, which determined that lobsters cannot feel pain due to their diminished central nervous system capacity. [http://www.guardian.co.uk/animalrights/story/0,11917,1408050,00.html] When cooking a lobster experienced cooks drop the lobster in upside down, head first. The tail may flap for several seconds, so placing the lobster in the pot upside down prevents the cook from being splashed with boiling water. Lobster is best eaten fresh, and they are normally purchased live. Lobsters are usually shipped and sold with their claws banded to prevent them from injuring each other or the purchaser. Restaurants that serve lobster keep a tank of the live creatures, often allowing patrons to pick their own. The shell of the lobster makes eating them a slow process for the unskilled or timid, who may require a number of implements, including nutcrackers, a small fork, and a plastic bib. It is possible to shell a lobster by hand if one is careful to avoid the sharp points. The tail can be snapped open by first squeezing its sides inward, and then grabbing the edges of the shell, placing the thumbs on the dorsal side and pulling the sides apart. The claws usually open by hyper-extending the lobster's "thumb" and then pulling it out. Sometimes the claws can then by cracked by simply squeezing them. Otherwise, an ordinary fork is usually sufficient to snap open the side of the claw. This style of lobster-eating is best done outdoors or dockside where flying bits of lobster will not annoy anyone. In a fine restaurant it is possible to cover the shell parts with a napkin before snapping them apart. This also helps prevent injury to the hands from sharp points of the shell. Often a knowledgeable waiter will provide this service. The majority of the meat is in the tail and the two front claws, but smaller quantities can be found in the legs and torso. Lobsters are often eaten plain, or with butter, lemon juice or white vinegar. Lobster can also be cut up and used in a wide array of dishes. One popular way of serving lobster was to combine it with steak in what became known by the 1960s as surf and turf. It can also be served boiled as lobster soup. In Canada, Shediac, New Brunswick promotes itself as the "Lobster Capital of the World". :"Lobster Newberg. Also "lobster a la Newburg"...The dish was made famous at Delmonico's Restaurant in New York in 1876 when the recipe was brought to chef Charles Ranhofer by a West Indies sea captain named Ben Wenberg. It was an immediate hit, especially for after-theater suppers, and owner Charles Delmonico honored the captain by naming the dish "lobster a la Wenberg." But later Wenberg and Delmonico had a falling-out, and the restauranteur took the dish off the menu, restoring it only by popular demand by renaming it "lobster a la Newberg," reversing the first three letters of the captain's name. Chef Ranhofer also called it "lobster a la Delmonico," but the appelation "Newberg" (by 1897 it was better known under the spelling "Newburg") stuck, and the dish became a standard in hotel dining rooms in the United States. It is still quite popular and is found in French cookbooks, where it is sometimes referred to as "Homard saute a la creme."...The first printed recipe appeared in 1895.”—Encyclopedia of American Food and Drink, John F. Mariani. New York: Lebhar-Friedman, 1999. Pages 187–8. In the Indian subcontinent, especially in West Bengal and Bangladesh, a delicacy of lobsters is called "Golda Chingrir Malai Curry" and is cooked with coconut milk and spices.

Symbion

In December 1995, the parasitic Symbion pandora, the only member of its phylum, was discovered attached to the feeding appendages of a Norway lobster. Since then, at least two other species pf Symbion have been discovered, on the American lobster (Homarus americanus) and the European lobster (Homarus gammarus).

Types of lobster

Lobster species include:
- Atlantic deep-sea lobster (Acanthacaris caeca)
- Prickly deep-sea lobster (Acanthacaris tenuimana)
- Red lobster (Eunephrops bairdii)
- Sculptured lobster (Eunephrops cadenasi)
- Banded lobster (Eunephrops manningi)
- Cape lobster (Homarinus capensis)
- American lobster (Homarus americanus)
- European lobster (Homarus gammarus)
- Andaman lobster (Metanephrops andamanicus)
- Arafura lobster (Metanephrops arafurensis)
- Armored lobster (Metanephrops armatus)
- Northwest lobster (Metanephrops australensis)
- Caribbean lobsterette (Metanephrops binghami)
- New Zealand lobster (Metanephrops challengeri)
- Formosa lobster (Metanephrops formosanus)
- Japanese lobster (Metanephrops japonicus)
- African lobster (Metanephrops mozambicus)
- Neptune lobster (Metanephrops neptunus)
- Urugavian lobster (Metanephrops rubellus)
- Sculpted lobster (Metanephrops sagamiensis)
- Siboga lobster (Metanephrops sibogae)
- China lobster (Metanephrops sinensis)
- Red-banded lobster (Metanephrops thomsoni)
- Velvet lobster (Metanephrops velutinus)
- Bight lobster (Metanephrops boschmai)
- Mitten lobsterette (Nephropides caribaeus)
- Norway lobster (Nephrops norvegicus)
- Spinetail lobsterette (Nephropsis acanthura)
- Florida lobsterette (Nephropsis aculeata)
- Prickly lobsterette (Nephropsis agassizii)
- Scarlet lobsterette (Nephropsis atlantica)
- Ridge-back lobsterette (Nephropsis carpenteri)
- Gladiator lobsterette (Nephropsis ensirostris)
- Saya de Malha lobsterette (Nephropsis malhaensis)
- Ruby lobsterette (Nephropsis neglecta)
- Pacific lobsterette (Nephropsis occidentalis)
- Rosy (or two-toned) lobsterette (Nephropsis rosea)
- Indian Ocean lobsterette (Nephropsis stewarti)
- Red and white lobsterette (Nephropsis suhmi)
- Grooved lobsterette (Nephropsis sulcata)
- Bellator lobster (Thymopides grobovi)
- Patagonian lobsterette (Thymops birsteini)
- Nilenta lobsterette (Thymopsis nilenta)

See also


- Spiny lobster
- Tomalley (the soft green liver of the lobster)
- Bubba the lobster

External links


- [http://www.factmonster.com/ipka/A0854908.html Lobster FAQ]
- [http://homepage.mac.com/mooncusser/PhotoAlbum.html Photos and Video of Cape Cod Lobstering by Mooncusser Films] Category:True lobsters Category:Seafood ja:イセエビ

Homarus


- H. americanus - American lobster
- H. gammarus - European lobster Homarus is a genus of lobsters, which include the common and commercially significant species Homarus americanus (American lobster) and the European lobster (Homarus gammarus). The Cape lobster, which was formerly in this genus as H. capensis, was moved in 1995 to the new genus Homarinus Category:True lobsters

Norway lobster

The Norway lobster, Nephrops norvegicus (also called Dublin Bay Prawn or Langoustine), is a slim orange-pink lobster found in the north-eastern Atlantic Ocean and the Mediterranean Sea. The tail is muscular, and is frequently eaten, often under the name "scampi". Norway lobsters are solitary predators, feeding mostly on molluscs and other crustaceans. In December 1995, the commensal Symbion pandora was discovered attached to the mouthparts of a Norway lobster, and was found to be the first member of a new phylum, the Cycliophora.

External links


- [http://www.fao.org/figis/servlet/species?fid=2647 Nephrops norvegicus] on the Fisheries Global Information System (FIGIS). Category:True lobsters Category:Seafood

Spiny lobster


- Jasus
- Linuparus
- Palinurellus
- Palinurus
- Panulirus Spiny lobsters, also known as rock lobsters are a family (Palinuridae) of about 45 species of achelate crustaceans, in the Decapoda Reptantia. Spiny lobsters are also called crayfish, sea crayfish, or crawfish (compare crayfish). Although they superficially resemble true lobsters in terms of overall shape, and having a hard carapace and exoskeleton, the two groups are quite unrelated. Spiny lobsters can be easily distinguished from true lobsters by their very long, thick, spiny antennae, and by their complete lack of claws (chelae); true lobsters have much smaller antennae and claws on the first three pairs of legs, with the first being particularly enlarged. Like true lobsters, however, spiny lobsters are edible and are an economically significant food source; they are the biggest food export of the Bahamas http://www.internationalreports.net/theamericas/bahamas/2003/thespiny.html 1. The furry lobsters (e.g. Palinurellus) are sometimes separated into a family of their own, the Synaxidae, but are usually considered members of the Palinuridae. The slipper lobsters (Scyllaridae) are their next closest relatives, and these two or three families make up the Achelata. Genera of spiny lobsters include Palinurus and a number of anagrams thereof: Panulirus, Linuparus, etc. (Palinurus was also a helmsman in Virgil's Æneid.) Æneid Spiny lobsters are found in almost all warm seas, including the Caribbean and the Mediterranean, but are particularly common around Australasia, where they are referred to commonly as crayfish (Jasus novaehollandiae and Jasus edwardsii) and South Africa (Jasus lalandii). Spiny lobsters tend to live in crevices of rocks and coral reefs, only occasionally venturing out at night to seek snails, clams, crabs, sea urchins or carrion to eat. Sometimes, they migrate en masse, in long files of lobsters across the sea floor. Potential predators may be deterred from eating spiny lobsters by a loud screech made by the antennae of the spiny lobsters rubbing against a smooth part of the exoskeleton http://news.nationalgeographic.com/news/2004/07/0728_040728_spinylobsters.html 2. Category:Crustaceans ja:伊勢海老

Crayfish

:For the crustaceans commonly known as "sea crayfish", see spiny lobster.

Astacoidea
  Astacidae
  Cambaridae
Parastacoidea
  Parastacidae Crayfish, sometimes called crawfish, lobsters, crawdads, mudbugs, carmels, yabbies, or spoondogs, are freshwater crustaceans resembling small lobsters, to which they are closely related. They are found in bodies of fresh water that do not freeze to the bottom, which are not polluted, and which have shelter against predators. Some crayfish have been found living as much as 3 m (10 feet) underground.

The name crayfish

The name "crayfish" has nothing to do with fish; it is derived from the Old French word escrevisse (Modern French écrevisse), and has been modified by folk etymology to crayfish. The largely American variant "crawfish" is similarly derived.

Geographical distribution

American There are three families of crayfish, two in the northern hemisphere and one in the southern hemisphere. The southern-hemisphere (Gondwana-distributed) family Parastacidae lives in South America, Madagascar and Australasia. Many Australian crayfish are of the genus Cherax; and include the marron (Cherax tenuimanus), red-claw crayfish (Cherax quadricarinatus), yabby (Cherax destructor) and western yabby (Cherax preissii). The world's largest crayfish, Astacopsis gouldi, is found in the rivers of northern Tasmania. It can achieve a mass in excess of 3 kilograms. kilograms The family Astacidae contains the native European crayfish, as well as those in western North America, such as Pacifastacus. The third family, Cambaridae, the most species-rich family, contains crayfish in east Asia and eastern North America, such as Cambarus, Orconectes, Procambarus and zarigani (Cambaroides japonicus), a crayfish indigenous to Japanese rivers and ponds. In New Zealand the name crayfish or cray, refers to a spiny lobster, and crayfish are called freshwater crays or koura, the Maori name for the animal.

Crayfish as a dish

Maori Crayfish are eaten in Europe and China, but they are perhaps most popular in Louisiana, where the standard culinary term is crawfish. They are usually boiled in a huge pot with heavy seasoning (cayenne pepper, paprika, etc.) and other items such as potatoes, sausage, corn, onions and garlic bulbs. garlic They are also served in various American dishes in restaurants around the United States. They may be fried or blackened. There are also specific preparations for crawfish in cajun and creole food, the best-known of which are crawfish étouffée, crawfish po' boy, crawfish pie, and crawfish beignets. Crayfish is a popular dish in Sweden and Finland, and is by tradition primarily consumed during the fishing season in August. The boil is typically flavored with salt, sugar, and the flowers of the dill plant. The catch of domestic fresh water crayfish, and even of an implanted American species is very limited and to satisfy demand the majority of what is consumed has to be imported. Sales depended on imports from Turkey for several decades, but after a decline in supply, China and the United States are today the biggest sources of import. On the western coast of Sweden, many tend to prefer the larger salt water crayfish, which is caught in the North Sea. (See Swedish cuisine.) The mexican crayfish is named locally as Acocil and was a very important nutition source of the ancient mexican Aztec culture, now this kind of crayfish is consumed (mainly boiled) and prepared with typically mexican sauces or condiments in central and south Mexico.

Crayfish as pets

Crayfish are sometimes kept as pets in fresh water aquariums. They will eat fish flakes, rice, blood worms, and chopped carrots. They are aggressive and will attempt to eat other fish, and climb out of the tank. In the night, some fish become less energetic and settle to the bottom. The crayfish might see it as a danger and hurt or kill it with its claws. In nations where imported alien crayfish are a danger to rivers, such as England, catching and keeping crayfish as pets is one of the main means of the spread of destructive species - since they are often flung back into a different river. Crayfish are also used as fishing bait and as live food for larger species of aquarium fish, oscars, for example.

Moulting in Crayfish

Crayfish also need to moult as they grow because their hard exoskeletons do not allow much room for expansion. Baby crayfish can moult on a daily basis but as they grow older, the regularity of moults decreases to a period of weeks or even months. The early signs of moulting include lack of appetite and a slow down in activity. During this period the crayfish ingests calcium into an internal organ, rather than to the exoskeleton. When the crayfish is ready to moult, it will move onto its back and begin fanning its pincers, legs and swimmerettes (under the tail) in order to get as much oxygen as possible. The carapace will begin to crack behind the head; the new appendages then pierce the old shell; and then after about five minutes, a sudden, violent movement will detach the old shell from the crayfish. The freshly moulted crayfish will invariably be larger as part of the growing process, but is vulnerable on several fronts. Firstly, the shell is very soft and vulnerable to predators, including other crayfish and fish. The crayfish needs to eat the old shell to replace the lost calcium and stengthen the weakened carapace.

External links


- [http://www.canadiancrayfish.ca/phpbb2/index.php Crayfish Forum]
- [http://www.canadiancrayfish.ca/phpbb2/viewtopic.php?t=1136 Crayfish Moult] Very rare Crayfish moulting video
- [http://www.realcajunrecipes.com/search/searchresults.asp?andor=and&searchtype=keywords&Keyword=crawfish&titleOnly=yes Crawfish recipes at RealCajunRecipes.com]
- [http://www.aquaticcommunity.com/universal-id32.html Crayfish in aquariums]
- [http://somethin-tropical.epaulv.com Crayfish News]
- [http://crayfish.epaulv.com Crayfish Pictures]

References


- Gilbertson, Lance; Zoology Lab Manual; McGraw Hill Companies, New York; ISBN 0-07-237716-X (fourth edition, 1999) Category:Swedish cuisine Category:Crayfish Category:Seafood ja:ザリガニ下目

Exoskeleton

An exoskeleton, in contrast to an endoskeleton, is an external anatomical feature that supports and protects an animal's body. Many invertebrate animals such as insects, crustaceans and shellfish have exoskeletons. Lobsters, for example, have tough outer shell systems which provide rigidity and shape to their bodies. Humans have long used armour as an artificial exoskeleton for protection, especially in combat. Exoskeletal items are also used for medical and industrial purposes. Human exoskeletons are a feature of science fiction writing. Orthoses are a form of exoskeleton.

Natural exoskeletons

Types of exoskeletons

Orthoses]
- Bone and cartilage
  - Armored fish
- Chitin
  - Arthropods
    - Crustaceans
    - Insects
- Calcium compounds
  - Corals
  - Mollusks
- Silicate
  - Diatoms
  - Radiolaria

Moulting

An exoskeleton may interfere with an animal's growth. To overcome this, arthropods go through a process called moulting in which they shed their exoskeleton and replace it with a new, larger one. Excellent as a principle of defence, exoskeletons may nevertheless cause problems where entities carry an excessive weight to surface-area ratio; or whenever organism growth requires an enlarged exoskeleton.

Artificial human exoskeletons

Exoskeletons in history

Medieval armour (in the case of mounted knights) is not load-bearing, but furnishes the appearance of an artificial human exoskeleton.

Exoskeletons in medicine

An orthosis (plural orthoses) is a device which attaches to a limb, or the torso, to support the function or correct the shape of that limb or the spine. Orthotics is the field dealing with orthoses, their use, and their manufacture. An orthotist is a person who designs and fits orthoses. A limb prosthesis (plural prostheses) is a device that substitutes for a missing part of a limb. If the prosthesis is a hollow shell and self-carrying, it is exoskeletal. If internal tubes are used in the device and the cover (cosmesis) to create the outside shape is made of a soft, non-carrying material, it is endoskeletal. Prosthetics is the field that deals with prostheses, their use, and their manufacture. A prosthetist is a person who designs and fits prostheses.

Exoskeletons in modern and near-future technology

prosthetist In the early 2000s a number of companies and research centres developed the first practical models of human exoskeletons. One of the main uses is enabling a soldier to carry heavy weights (50–100 kg) while running or climbing stairs. Most models use a hydraulic system controlled by an on-board computer. They can be powered by an internal combustion engine, batteries or, potentially, fuel cells. Another area of application is medical care, nursing in particular. Faced with the impending shortage of medical professionals and the increasing number of people in elderly care, several teams of Japanese engineers have developed exoskeletons designed to help nurses lift and carry patients. Commercially-available exoskeletons are expected by the end of 2005 [http://www.newscientist.com/article.ns?id=mg18624945.800]. In the future exoskeletons are expected to become widely used by the military and police in the form of nanotechnological combat clothes. Civilian uses will no doubt be found later. However they will have to compete for adoption with another approach — surgically and genetically enhancing the human body itself by use of artificial bones and muscles.

Human exoskeletons in science fiction

Science fiction authors utilize the idea of personal self-powered exoskeletons, usually referred to as powered armor. They are often robotic in nature. Examples include:
- The novel The War of the Worlds featured Martians using tripodal powered armors to attack the humans.
- The novel Starship Troopers details the tactics involved with powered armor.
- The armour worn by Gray Fox in Metal Gear Solid and Solidus Snake and Raiden (Metal Gear) in Metal Gear Solid 2: Sons of Liberty
- The loaders used to enable dockyard workers to move heavy weights in Aliens (1986)
- The Hardman gear Raimi wears in the 1994 movie Death Machine
- The Armored Personnel Units seen in Matrix Revolutions (2003).
- Standard issue battle armor in Joe Haldeman's book The Forever War is an exoskeleton using logarithmic force amplification.
- In the American action cartoon series Centurions, the Centurions used uniform like powered exoframes that has hard points, which enable them to be with merged multiple weapon systems.
- Exoskeletal vehicles named "E-frames" were one of the central aspects of the American animated television series Exosquad.
- In comic books, the superheroes Iron Man and War Machine, the supervillain Doctor Doom and countless others wear suits of powered armor which have the equivalent exoskeleton function.
- In the American action comedy TV series The Greatest American Hero, a regular American school teacher was given a suit by aliens, that enable him to have super powers like Superman, which includes the ability to fly and being resistant to bullet attacks.
- Not all SF exoskeletons are mechanical, as modification of biological systems can produce similar strength, such as the Pak Protector in Larry Niven's Known Space universe, Jim Shooter's X-O Manowar comic book, and the Guyver Japanese animation series.
- In Japanese manga Gantz, the characters wear wet suit like exoskeleton, which gives them enormous strength and provides protection.
- Biological suits known as skins are mentioned in Peter Hamilton's Fallen Dragon.
- In the Battletech universe, genetically engineered Clan soldiers are bred for strength and other qualities to wear Elemental powered armor. Elemental armor also provides advanced medical technologies to keep the wearer alive in case of severe injury or trauma during combat.
- Exoskeletons have surfaced in many video games, usually because thicker types of armor must require some mechanical power source. Some examples would be certain marines from Unreal II: The Awakening, MAX Units from Planetside and the Terminators from Warhammer 40000: Dawn of War.
- Many Japanese animation featuring mechanical objects also have humans controlling gigantic exo-skeletons, such as Escaflowne or Ghost in the Shell: Stand Alone Complex. Although many of these are not exactly exoskeletons because of their inhumane forms, the main principle is identical.
- In Digimon Tamers, the Tamers merged with their Digimon partners, enabling the bodies of their Digimon partners to evolved into the ultimate form, after the merged, the Tamers along with their Digimon partners use the ultimate form bodies like some sort of powered armors. While in Digimon Frontier, the Chosen Children merged with their Digimon Spirits, enabling them to use the bodies of the Digimon Spirit as some sort of powered armor.
- The character Master Chief from the Halo video game series wears an exoskeleton.
- Exoskeletal suits named "EMACS" (Energized Monster Armed Containment Suit) or simply power suits are a standard weapon in the animated cartoon series Monster Force.
- The main protagonists of the anime Bubblegum Crisis wear exosuits in combat.
- Gordon Freeman's Hazard Suit from Half-Life and Half-Life 2 is an exoskeleton originally designed for extra dimensional survival and exploration.
- Samus from the Metroid series wears an exoskeleton, the Power Suit, designed by the Chozo.

External links

Biology


- [http://www.microscopy-uk.net/mag/artfeb05/cbdiatoms.html Geometry and Pattern in Nature 3: The holes in radiolarian and diatom tests]

Modern technology


- [http://bleex.me.berkeley.edu/bleex.htm Video, images and articles about the Bleex exoskeleton project]
- [http://www.berkeley.edu/news/media/releases/2004/03/03_exo.shtml Berkeley Bleex press release]
- [http://www.wired.com/wired/archive/13.01/ironmen.html?tw=wn_tophead_4 Wired article about the power-suit weighlifting championship]
- [http://www.ananova.com/news/story/sm_1252537.html Mecha in AK]
- [http://www.springwalker.com/ SpringWalker Walking Aid]
- [http://pages.zoom.co.uk/bionicboots/index.html Bionic Boots]
- [http://www.newscientist.com/article.ns?id=dn1072 Japanese nurse assisting skeleton]
- [http://sanlab.kz.tsukuba.ac.jp/HAL/indexE.html HAL project]
- [http://www.spectrum.ieee.org/oct05/1901 The Rise of the Body Bots], IEEE Spectrum
- [http://brl.ee.washington.edu/Research_Active/Exoskeleton/Exoskeleton_Index.html University of Washington Exo Arm Project] Category:Animal anatomy Category:Arthropods Category:Robotics

Molt

:For the town in France, see Moult, Calvados. In birds, moulting or molting is the routine shedding off old feathers. Also, the shedding of old skin in reptiles. In arthropods, such as insects, arachnids and crustaceans, molting describes the shedding of the exoskeleton, typically to allow for further growth. See ecdysis.

Molting in Arachnids

The exoskeleton of an arachnid is hard. This does not allow for growth. To overcome this problem, spiders will shed their old exoskeletons, allowing a new and larger one to replace it. The new larger exoskeleton fits underneath the old one, because it is still elastic. A layer of fluid separates the new and old skeletons. As the old skeleton is shed, the new one will expand to its full size, before hardening out on contact with air. The arachnid will have to flex its new exoskeleton, or it will become inflexible and less mobile until its next molt. Other reasons for molting are damaged tissue and missing limbs. Over a series of molts, a missing limb can be regenerated, the stump being a little larger with each mould until it is of normal size again. After molting, the exoskeleton is still delicate and the arachnid is vulnerable to predators or even its own prey. The Process of Molting with Spiders - especially Tarantulas Before molting, some spiders will not eat for weeks, while others will eat up to the moment of molting. Likewise, after a molt, some spiders will not eat for days or even weeks.
- The molting commences, when a split appears on the side of a carapace part of the Cephalothorax (head and upper body)
- The split continues horizontally along the Opisthosoma (abdomen) and opens like a box
- The spider pushes its body out of the old skin, after which it withdraws its legs from it
- The spider will rest for a period of time, varying from minutes for spiderlings, to more than a day for a large mature Tarantula

Moulting in Insects

Insects need to molt as they grow because their hard exoskeletons do not allow much room for expansion. Each stage in the development of an insect between moults is called an instar, or stadium. instar

Moulting in birds

Moulting in birds is a comparatively slow process, as a bird never sheds all its feathers at once; it must keep enough of its feathers to regulate its body temperature and repel moisture. Some species of wild bird become flightless during an annual "wing moult" and must seek protected habitat with a reliable food supply during that time. A moulting bird should never have any bald spots. If a pet bird has any bald spots, the bird should be taken to an avian veterinarian to search for possible causes for the baldness, which may include giardia, mites, or feather-plucking. The process of moulting # The bird begins to shed some old feathers # Pin feathers grow in to replace the old feathers # As the pin feathers become full feathers, other feathers are shed This is a cyclical process that happens in many phases. In general, a moult begins at a bird's head, progresses down the body to its wings and torso, and finishes with the tail feathers.

Moulting in Reptiles

The most familiar example of moulting in reptiles is when snakes "shed their skin".

Moulting in Crayfish

Crayfish also need to molt as they grow because their hard exoskeletons do not allow much room for expansion. Baby crayfish can moult on a daily basis but as they grow older, the regularity of moults decreases to a period of weeks or even months. The early signs of moulting include lack of appetite and a slow down in activity. During this period the crayfish ingests calcium into an internal organ, rather than to the exoskeleton. When the crayfish is ready to moult, it will move onto its back and begin fanning its pincers, legs and swimmerettes (under the tail) in order to get as much oxygen as possible. The carapace will begin to crack behind the head, the new appendages then pierce the old shell and after about five minutes a sudden, violent movement will detach the old shell from the crayfish. The freshly moulted crayfish will invariable be larger as part of the growing process, but is vulnerable on several fronts. Firstly, the shell is very soft and vulnerable to predators, including other crayfish and fish. The crayfish needs to eat the old shell to replace the lost calcium and stengthen the weakned carapace.

External links


- [http://www.canadiancrayfish.ca/phpbb2/viewtopic.php?t=1136 Crayfish Moult] Very rare Crayfish moulting video
- PLOS primer: [http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0030349 How the Ecdysozoan Changed Its Coat] Category:Developmental biology

Europe

:This article is about the continent. For other meanings, see Europe (disambiguation). Europe is geologically and geographically a peninsula or subcontinent, forming the westernmost part of Eurasia. It is conventionally considered a continent, which, in this case, is more of a cultural distinction than a geographic one. It is bounded to the north by the Arctic Ocean, to the west by the Atlantic Ocean and to the south by the Mediterranean and Black Seas and the Caucasus. Europe's boundary to the east is vague, but has traditionally been given as the Ural Mountains and Caspian Sea to the southeast: the Urals are considered by most to be a geographical and tectonic landmark separating Asia from Europe. :See also Continent, Bicontinental country, and Table of European territories and regions. Table of European territories and regions Table of European territories and regions Europe is the world's second-smallest continent in terms of area, covering around 10,790,000 km² (4,170,000 sq mi) or 2.1% of the Earth's surface, and is only larger than Australia. In terms of population, it is the third-largest continent (Asia and Africa are larger) with a population of more than 700,000,000, or about 11% of the world's population.

Etymology

Africa.]] In Greek mythology, Europa was a Phoenician princess who was abducted by Zeus in bull form and taken to the island of Crete, where she gave birth to Minos. For Homer, Europé (Greek: Ευρωπη; see also List of traditional Greek place names) was a mythological queen of Crete, not a geographical designation. Later Europa stood for mainland Greece, and by 500 BC its meaning had been extended to lands to the north. The Greek term Europe has been derived from Greek words meaning broad (eurys) and face (ops) -- broad having been an epitheton of Earth herself in the reconstructed Proto-Indo-European religion; see Prithvi (Plataia). A minority, however, suggest this Greek popular etymology is really based on a Semitic word such as the Akkadian erebu meaning "sunset" (see also Erebus). From the Middle Eastern vantagepoint, the sun does set over Europe, the lands to the west. Likewise, Asia is sometimes thought to have derived from the Akkadian word asu, meaning "sunrise", and is the land to the east from a Mesopotamian perspective.

History

Europe has a long history of cultural and economic achievement, starting as far back as the Palaeolithic, although this is true for the rest of the Old World as well. The recent discovery at Monte Poggiolo, Italy, of thousands of hand-shaped stones, tentatively carbon-dated to 800,000 years ago, may prove to be of particular importance. The origins of Western democratic and individualistic culture are often attributed to Ancient Greece, though numerous other distinct influences, in particular Christianity, can also be credited with the spread of concepts like egalitarianism and universality of law. The Roman Empire divided the continent along the Rhine and Danube for several centuries. Following the decline of the Roman Empire, Europe entered a long period of changes arising from what is known as the Age of Migrations. That period has been known as the "Dark Ages" to Renaissance thinkers. During this time, isolated monastic communities in Ireland and elsewhere carefully safeguarded and compiled written knowledge accumulated previously. The Renaissance and the New Monarchs marked the start of a period of discovery, exploration, and increase in scientific knowledge. In the 15th century Portugal opened the age of discoveries, soon followed by Spain. They were later joined by France, the Netherlands and the United Kingdom in building large colonial empires with vast holdings in Africa, the Americas, and Asia. After the age of discovery, the ideas of democracy took hold in Europe. Struggles for independence arose, most notably in France during the period known as the French Revolution. This led to vast upheaval in Europe as these revolutionary ideas propagated across the continent. The rise of democracy led to increased tensions within Europe on top of the tensions already existing due to competition within the New World. The most famous of these conflicts was when Napoleon Bonaparte rose to power and set out on a conquest, forming a new French empire that soon collapsed. After these conquests Europe stabilised, but the old foundations were already beginning to crumble. The Industrial Revolution started in the United Kingdom in the late 18th century, leading to a move away from agriculture, much greater general prosperity and a corresponding increase in population. Many of the states in Europe took their present form in the aftermath of World War I. From the end of World War II through the end of the Cold War, Europe was divided into two major political and economic blocks: Communist nations in Eastern Europe and capitalist countries in Western Europe. Around 1990, with the fall of the Berlin Wall, the Eastern bloc disintegrated.

Geography and extent

Eastern bloc Geographically Europe is a part of the larger landmass known as Eurasia. The continent begins at the Ural Mountains in Russia, which define Europe's eastern boundary with Asia. The southeast boundary with Asia isn't universally defined. Most commonly the Ural or, alternatively, the Emba river can serve as possible boundaries. The boundary continues with the Caspian Sea, and then the Araxes river in the Caucasus, and on to the Black Sea; the Bosporus, the Sea of Marmara, and the Dardanelles conclude the Asian boundary. The Mediterranean Sea to the south separates Europe from Africa. The western boundary is the Atlantic Ocean, but Iceland, much farther away than the nearest points of Africa and Asia, is also often included in Europe. There is ongoing debate on where the geographical centre of Europe is. At times "Europe" is defined with greater regard to political, economic, and other cultural considerations. This has led to there being several different Europes that are not always identical in size, including or excluding countries according to the definition of Europe used. Almost all European countries are members of the Council of Europe, the exceptions being Belarus, and the Holy See (Vatican City). The idea of the European continent is not held across all cultures. Some non-European geographical texts refer to the continent of Eurasia, or to the European peninsula, given that Europe is not surrounded by sea. In the past concepts such as Christendom were deemed more important. In another usage, Europe is increasingly being used as a short-form for the European Union (EU) and its members, currently consisting of 25 member states. A number of other European countries are negotiating for membership, and several more are expected to begin negotiations in the future (see Enlargement of the European Union).

Physical features

In terms of shape, Europe is a collection of connected peninsulas. The two largest of these are "mainland" Europe and Scandinavia to the north, divided from each other by the Baltic Sea. Three smaller peninsulas (Iberia, Italy and the Balkans) emerge from the southern margin of the mainland into the Mediterranean Sea, which separates Europe from Africa. Eastward, mainland Europe widens much like the mouth of a funnel, until the boundary with Asia is reached at the Ural Mountains. Land relief in Europe shows great variation within relatively small areas. The southern regions, however, are more mountainous, while moving north the terrain descends from the high Alps, Pyrenees and Carpathians, through hilly uplands, into broad, low northern plains, which are vast in the east. This extended lowland is known as the Great European Plain, and at its heart lies the North German Plain. An arc of uplands also exists along the northwestern seaboard, beginning in the western British Isles and continuing along the mountainous, fjord-cut spine of Norway. This description is simplified. Sub-regions such as Iberia and Italy contain their own complex features, as does mainland Europe itself, where the relief contains many plateaus, river valleys and basins that complicate the general trend. Iceland and the British Isles are special cases. The former is a land unto itself in the northern ocean which is counted as part of Europe, while the latter are upland areas that were once joined to the mainland until rising sea levels cut them off. Due to the few generalisations that can be made about the relief of Europe, it is less than surprising that its many separate regions provided homes for many separate nations throughout history.

Biodiversity

Having lived side-by-side with agricultural peoples for millennia, Europe's animals and plants have been profoundly affected by the presence and activities of man. With the exception of Scandinavia and northern Russia, few areas of untouched wilderness are today to be found in Europe, except for different natural parks. The main natural vegetation cover in Europe is forest. The conditions for growth are very favourable. In the north, the Gulf Stream and North Atlantic Drift warm the continent. Southern Europe could be described as having a warm, but mild climate. There are frequent summer droughts in this region. Mountain ridges also affect the conditions. Some of these (Alps, Pyrenees) are oriented east-west and allow the wind to carry large masses of water from the ocean in the interior. Others are oriented south-north (Scandinavian Mountains, Dinarides, Carpathians, Apennines) and because the rain falls primarily on the side of mountains that is oriented towards sea, forests grow well on this side, while on the other side, the conditions are much less favourable. Few corners of mainland Europe have not been grazed by livestock at some point in time, and the cutting down of the pre-agricultural forest habitat caused disruption to the original plant and animal ecosystems. Eighty to ninety per cent of Europe was once covered by forest. It stretched from the Mediterranean Sea to the Arctic Ocean. Though over half of Europe's original forests disappeared through the centuries of colonisation, Europe still has over one quarter of the world's forests - spruce forests of Scandinavia, vast pine forests in Russia, chestnut rainforests of the Caucasus and the cork oak forests in the Mediterranean. During recent times, deforestation has been stopped and many trees were planted. However, in many cases conifers have been preferred over original deciduous trees, because these grow quicker. The plantations and monocultures now cover vast areas of land and this offers very poor habitats for European forest dwelling species. The amount of original forests in Western Europe is just two to three per cent (in the European part of Russia five to ten per cent). The country with the smallest forest-covered area is Ireland (eight per cent), while the most forested country is Finland (72 per cent). In "mainland" Europe, deciduous forest prevails. The most important species are beech, birch and oak. In the north, where taiga grows, a very common tree species is the birch tree. In the Mediterranean, many olive trees have been planted, which are very well adapted to its arid climate. Another common species in Southern Europe is the cypress. Coniferous forests prevail at higher altitudes up to the forest boundary and as one moves north within Russia and Scandinavia, giving way to tundra as the Arctic is approached. The semi-arid Mediterranean region hosts much scrub forest. A narrow east-west tongue of Eurasian grassland—the steppe—extends eastwards from Ukraine and southern Russia and ends in Hungary and traverses into taiga to the north. Glaciation during the most recent ice age and the presence of man affected the distribution of European fauna. As for the animals, in many parts of Europe most large animals and top predator species have been hunted to extinction. The woolly mammoth and aurochs were extinct before the end of the Neolithic period. Today wolves (carnivores) and bears (omnivores) are endangered. Once they were found in most parts of Europe. However, deforestation caused these animals to withdraw further and further. By the Middle Ages the bears' habitats were limited to more or less inaccessible mountains with sufficient forest cover. Today, the brown bear lives primarily in the Balkan peninsula, in the North and in Russia; a small number also persist in other countries across Europe (Austria, Pyrenees etc.), but in these areas brown bear populations are fragmented and marginalised because of the destruction of their habitat. In the far North of Europe, polar bears can also be found. The wolf, the second largest predator in Europe after the brown bear, can be found primarily in Eastern Europe and in the Balkans. Other important European carnivores are Eurasian lynx, European wild cat, foxes (especially the red fox), jackal and different species of martens, hedgehogs, different species of snakes (vipers, grass snake...), different birds (owls, hawks and other birds of prey) Important European herbivores are snails, amphibians, fish, different birds, and mammals, like rodents, deers and roe deers, boars, and living in the mountains, marmots, steinbocks, chamoises among others. Sea creatures are also an important part of European flora and fauna. The sea flora is mainly phytoplankton. Important animals that live in European seas are zooplankton, molluscs, echinoderms, different crayfish, squids and octopuses, fish, dolphins, and whales. Some animals live in caves, for example proteus and bats.

Demographics

Almost all of Europe was possibly settled before or during the last ice age ca. 10,000 years ago. Neanderthal man and modern man coexisted during at least some of this time. Roman road building helped with the interbreeding of the native Europeans' genetics. In contemporary times Europe has one of the lowest inbreeding rates in the world because of an extensive transport network paired with open borders. Europe passed well over 600 million people before the turn of the 20th century, but now is entering a period of population decline, for a variety of social factors.

Territories and divisions

Political divisions

Independent states

interbreeding on this map.]] :See also: Table of European territories and regions The following independent states have territory in Europe: 2 Azerbaijan and Georgia lie partly in Europe according to the usual definition which consider the crest of the Caucasus as the boundary with Asia.
3 Kazakhstan's European territory consists of a portion west of the Ural and Emba Rivers.
4 The name of this state is a matter of international dispute. See Republic of Macedonia for details.
5 Those territories of Russia lying west of the Ural Mountains are considered as part of Europe.
6 State union of Republic of Serbia and the Republic of Montenegro.
7 European Turkey comprises territory to the west and north of the Bosporus and the Dardanelles straits.
2, 3, 5, 7 See Countries in both Europe and Asia for details.

Dependent territories

The European territories listed below are recognised as being culturally and geographically defined. Most have a degree of autonomy. In the list below, each territory is followed by its legal status.
- Faroe Islands (autonomous region of Denmark)
- Gibraltar (UK overseas territory)
- Guernsey (British crown dependency)
- Jersey (British crown dependency)
- Man, Isle of (British crown dependency)
- Svalbard (autonomous region of Norway) Note that this is not a list of all dependencies of all European countries. Dependencies located on other continents are not listed.

Unilaterally seceded territories

Following are breakaway regions of independent states. These regions have declared and de facto achieved independence, but this is not recognised de jure by their home state or by the other independent states.
- Abkhazia (from Georgia)
- Nagorno-Karabakh (disputed by Armenia and Azerbaijan)
- South Ossetia (from Georgia)
- Transnistria (from Moldova)

Territories under United Nations administration


- Kosovo and Metohia (province of Serbia)

Table of European territories and regions

Notes:
1 Continental regions as per UN categorisations/map. Depending on definitions, various territories cited below (notes 2-6, 8, 9) may be in one or both of Europe and Asia.
2 Armenia is sometimes considered a transcontinental country in Eastern Europe and Western Asia (as per UN categorisations/map).
3 Azerbaijan is often considered a transcontinental country in Western Asia (UN region) and Eastern Europe; population and area figures are for European portion only.
4Cyprus is often considered a transcontinental country in Western Asia (UN region) and Southern Europe; population and area figures are for de jure Greek-administered portion only.
5Georgia is often considered a transcontinental country in Western Asia (UN region) and Eastern Europe; population and area figures are for European portion only.
6Kazakhstan is sometimes considered a transcontinental country in Central Asia (UN region) and Eastern Europe.
7Netherlands population for July 2004; Amsterdam is the de facto capital, while The Hague is the country's administrative seat.
8Russia is generally considered a transcontinental country in Eastern Europe (UN region) and Asia; population and area figures are for European portion only.
9Turkey is generally considered a transcontinental country in Western Asia (UN region) and Southern Europe; population and area figures are for European portion only, including all of Istanbul.

Linguistic and cultural regions

The sub-division in several linguistic and cultural regions is much less subjective than the geographical sub-division, since they correspond to people's cultural connections. There are three main groups:

Germanic Europe

Germanic Europe, where Germanic languages are spoken. This area corresponds more or less to north-western Europe and some parts of central Europe. The main religion of the region is Protestantism, even if there are also some countries with Catholic majority (particularly Austria). This region consists of: United Kingdom, Ireland, Iceland, Germany, Austria, Netherlands, Denmark, Sweden, Norway, Luxembourg, Liechtenstein, the Faroe Islands, German-speaking Switzerland, the Flemish part of Belgium, the Swedish-speaking municipalities of Finland, and the South Tyrol part of Italy.

Latin Europe

Latin Europe, where the Romance languages are spoken. This area corresponds more or less to south-western Europe, with the exception of Romania and Moldova which are situated in Eastern Europe. The major religion is Catholicism, except in Romania and Moldova. This area consists of: Italy, Spain, Portugal, France, Romania, Moldova, French-speaking Belgium and French speaking Switzerland, and Italian and Romansh speaking Switzerland as well.

Slavic Europe

Slavic Europe, where Slavic languages are spoken. This area corresponds, more or less, to Central and Eastern Europe. The main religions are Orthodox Christianity and Catholicism, with large Muslim populations in some parts formerly ruled by the Ottoman Empire. This area consists of: Belarus, Bosnia and Herzegovina, Bulgaria, Croatia, the Czech Republic, the Republic of Macedonia, Poland, Russia, Serbia and Montenegro, Slovakia, Slovenia and Ukraine.

Others

Outside of these three main groups we can find:
- The Celtic nations: Scotland, Wales, Northern Ireland, Cornwall (within the United Kingdom); the Isle of Man (a British Crown dependency); the Republic of Ireland; Brittany (within France). These are all nations where a Celtic language is spoken, or was spoken into modern times, and there is a degree of shared culture (see Pan Celticism). Also considered Celtic nations, by some, are both Galicia (Spain) and Asturias, (within Spain), whose own Celtic language died out several hundred years ago.
- Greece, the only country of "Hellenic Europe".In Hellenic Europe we can consider also the Greek Cypriot community It is sometimes associated with the Latin countries, due to the geographical and cultural ties to the Mediterranean Sea, and sometimes to the Slavic-Orthodox part of Europe due to the importance or Orthodoxy in Greece.
- Armenia has a language that constitutes a separate branch of Indo-European family of languages. The Armenian language is spoken in Armenia and other European countries with Armenian communities (such as France, Greece, Belgium, Russia, Germany etc.).
- Ibero-Caucasian, a group that includes ethnic groups throughout the Caucasus region (both North and South). Ibero-Caucasian languages are not linked to the Indo-European languages. This group includes Georgians, Abkhaz, Chechens, Balkars, and a number of other smaller ethnic groups that reside in the Caucasus.
- Turkey, having an Altaic language not of Indo-European origin, and mainly a Muslim country, unlike the main regions' different versions of Christianity.
- Hungary, having a language related to Finnish and Estonian. Due to its location Hungary is normally grouped with Central or Eastern European countries.
- Finland and Estonia, whose languages are related to Hungarian. Despite this connection (not a close one), Finland and Estonia are normally associated with northern European countries (of an even farther connection).

See also


- Eurasia
- Culture of Europe
- Economy of Europe
- Geography of Europe
- History of Europe
- Politics of Europe
- Transport in Europe
- Eurozone
- European Union
- Euroregion
- Europium

Lists and tables


- General
  - Table of European territories and regions
- Demographics
  - Area and population of European countries
  - European Union Statistics
  - The most populous metropolitan areas in Europe
  - The most populous urban areas of the European Union
- Economy
  - Economy of the European Union
  - Financial and social rankings of European countries
  - GDP of European Countries
- Political
  - Alternative names of European cities
  - Date of independence of European countries
  - International Organisations in Europe (table of membership)
- Other
  - List of Europe-related topics

External links


-
- [http://www.democracyineurope.com Democracy in Europe]
- [http://www.holidayhomeseuro.com European holiday homes]
- [http://phoenicia.org/europa.html Europa, the Phoenician Princess] - overwhelmed Zeus with love
- [http://www.europestartpage.com EUROPEstartpage.com, travel and city guide to Europe]
- [http://www.limitlesseurope.com LimitlessEurope.com : information guide to Europe]
- [http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=13266 Europe at Night] at NASA Earth Observatory
- [http://www.geog.tamu.edu/~prout/GVmidtermTwo.html Regions of Europe]
- [http://p086.ezboard.com/balbanau Evropa / Europa / Europe]
- [http://www.eufpc.org EUFPC European Foreign Policy Council]
- [http://www.itmaps.com/?modul=map Map of Europe]
- [http://www.freeworldmaps.net/europe/index.html Physical Map of Europe]
- [http://www.parks.it/europa/Eindex.html Parks in Europe] - National parks, nature parks, reserves and other protected areas. Category:Continents als:Europa roa-rup:Evropa zh-min-nan:Europa ko:유럽 ms:Eropah ja:ヨーロッパ simple:Europe th:ทวีปยุโรป

North America

North America is a continent in the northern hemisphere bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the south by the Caribbean Sea, and on the west by the North Pacific Ocean. It covers an area of 24,497,994 km² (9,458,728 sq mi), or about 4.8% of the Earth's surface. As of July 2002, its population was estimated at more than 514,600,000. It is the third largest continent in area, after Asia and Africa, and is fourth in population after Asia, Africa, and Europe. Both North and South America are named after Amerigo Vespucci, who was the first European to suggest that the Americas were not the East Indies, but a previously undiscovered (by Europeans) New World. North America occupies the northern portion of the landmass generally referred to as the New World, the Western Hemisphere, the Americas, or simply America. North America's only land connection is to South America at the narrow Isthmus of Panama. (For geopolitical reasons, all of Panama – including the segment east of the Panama Canal in the isthmus – is often considered a part of North America alone.) According to some authorities, North America begins not at the Isthmus of Panama but at the Isthmus of Tehuantepec, with the intervening region called Central America and resting on the Caribbean Plate. Most, however, tend to see Central America as a region of North America, considering it too small to be a continent on its own. Greenland, although a part of North America geographically, is not considered to be part of the continent politically.

Physical features

Greenland, plutonic, metamorphic rock types of North America. ]] Plate tectonics recognizes the vast majority of North America as being the surface of the North American Plate. Parts of California and western Mexico are known for being the edge of the Pacific Plate, with the two plates meeting along the San Andreas fault. The continent can be divided into four great regions (each of which contains many sub-regions): the Great Plains stretching from the Gulf of Mexico to the Canadian Arctic; the geologically young, mountainous west, including the Rocky Mountains, the Great Basin, California and Alaska; the raised but relatively flat plateau of the Canadian Shield in the northeast; and the varied eastern region, which includes the Appalachian Mountains, the coastal plain along the Atlantic seaboard, and the Florida peninsula. Mexico, with its long plateaus and cordilleras, falls largely in the western region, although the eastern coastal plain does extend south along the Gulf. The western mountains are split in the middle, into the main range of the Rockies and the coast ranges in California, Oregon, Washington, and British Columbia with the Great Basin – a lower area containing smaller ranges and low-lying deserts – in between. The highest peak is Denali in Alaska. Since 1931, Rugby, North Dakota, has officially been recognized as being at the geographic center of North America. The location is marked by a 4.5 metre (15 foot) field stone obelisk. Image:North america terrain 2003 map.jpg|North America bedrock and terrain. Image:North america basement rocks.png|North American cratons and basement rocks. Image:North America Tectonic Elements.jpg|Tectonic elements of North America Image:North america craton nps.gif|North American craton.

Territories and regions

craton On the main continent landmass, there are three large and relatively populous countries:
- Canada - many large islands off the shore of North America belong to Canada, including Vancouver Island and the Queen Charlotte Islands on the west, Prince Edward Island, Newfoundland and Cape Breton Island on the east, and the Canadian Arctic islands (including Ellesmere Island, Baffin Island, and Victoria Island) in the north
- Mexico - the Revillagigedo archipelago and numerous smaller islands off its coast belong to Mexico
- The United States - the 48 contiguous states and Alaska are part of North America, while the state of Hawaii in the Pacific Ocean is not; the Aleutian Islands south of Alaska also belong to the U.S. At the southern end of the continent, in a relatively small area known as Central America, are the countries of:
- Belize
- Costa Rica
- El Salvador
- Guatemala
- Honduras
- Nicaragua
- Panama 1 At the southeastern end of the continent lies a chain of islands territories called the Antilles, the Caribbean or the West Indies, which include the countries:
- Antigua and Barbuda
- Bahamas
- Barbados
- Cuba
- Dominica
- Dominican Republic
- Grenada
- Haiti
- Jamaica
- Saint Kitts and Nevis
- Saint Lucia
- Saint Vincent and the Grenadines
- Trinidad and Tobago 1 And the dependencies:
- Anguilla (British overseas territory)
- Aruba 2 (part of the Kingdom of the Netherlands)
- Cayman Islands (British overseas territory)
- Guadeloupe (French région d'outre-mer)
- Martinique (French région d'outre-mer)
- Montserrat (British overseas territory)
- Navassa Island (U.S. territory)
- Netherlands Antilles 1 (part of the Kingdom of the Netherlands)
- Puerto Rico (U.S. commonwealth)
- Turks and Caicos Islands (British overseas territory)
- British Virgin Islands (British overseas territory)
- U.S. Virgin Islands (territory of the USA) Lying in the Atlantic Ocean but considered part of the continent are the dependencies:
- Bermuda, a British overseas territory found about 1,072 km (670 mi.) southeast of New York City
- Greenland, the largest island in the world and a self-governing dependency of Denmark, which is located in the far north of the continent to the east of Nunavut.
- Saint Pierre and Miquelon, a French collectivité d'outre-mer off the south coast of Newfoundland, is the last of France's once vast possessions in America north of the Caribbean. 1 These states and dependencies have territory both in North and South America.
2 These dependencies lie in South America, but are considered North American because of cultural and historical reasons.
See here for details.

Usage

The United States, Canada, and the other English-speaking nations of the Americas (Belize, Guyana, and the Anglophone Caribbean) are sometimes grouped under the term Anglo-America, while the remaining nations of North and South America are grouped under the term Latin America. Alternatively, Northern America is used to refer to Canada and the U.S. together (plus Greenland and Bermuda), while Central America is mainland North America south of the United States. The West Indies generally include all islands in the Caribbean Sea. In this respect, Latin America generally includes Central America and South America and, sometimes, the West Indies. The term Middle America is sometimes used to refer to Mexico, Central America, and the Caribbean collectively. The term "North America" may mean different things to different people. The term in common usage is often taken to mean "the United States and Canada, only" by some people of the United States and Canada, excluding Mexico and the countries of Central America, unless the context makes it clear that they are to be included (such as with specific reference to Mexico, when talking about NAFTA). For example, guides to wild flora and fauna published by the National Audubon Society for "North America" frequently include only species found in Canada and the U.S. This may be attributed to the fact that culturally and economically, the U.S. and Canada are more alike to each other than they are to the rest of North America. Mexicans, however, are acutely aware that Mexico is a part of North America and object to this usage. Central Americans, however, are generally content to be called Central Americans – largely because of their shared history, which includes several attempts at supranational integration in the region and in which Mexico, their much larger northern neighbor, was never involved.

Political divisions and regions

Notes:
1 Continental regions as per UN categorisations/map.
2 Depending on definitions, Aruba, Netherlands Antilles, Panama, and Trinidad and Tobago have territory in one or both of North and South America.
3 Due to ongoing activity of the Soufriere Hills volcano beginning 1995, much of Plymouth, Montserrat's de jure capital, was destroyed and government offices relocated to Brades.

See also


- Discoverer of the Americas
- Economy of North America
- European colonization of the Americas
- History of North America
- Birds of North America

External links


- http://www.america-norte.com/america-norte-mapa.htm Category:Continents Category:North America zh-min-nan:Pak Bí-chiu ko:북아메리카 ja:北アメリカ simple:North America th:ทวีปอเมริกาเหนือ

Continental shelf

The continental shelf is the extended perimeter of each continent, which is covered during interglacial periods such as the current epoch by relatively shallow seas (known as shelf seas) and gulfs. The shelf usually ends at a gradual slope (called the shelf break). The sea bottom below the break is the continental slope. The slope merges into the deep ocean floor, the abyssal plain. The width of the continental shelf varies significantly. It is common for an area to have virtually no shelf at all, especially where the forward edge of an advancing oceanic plate dives beneath continental crust in an offshore subduction zone such as off the coasts of Chile or the west coast of Sumatra. The largest shelf—the Siberian shelf in the Arctic Ocean—stretches to 1500 kilometers in width. The South China Sea lies over another extensive area of continental shelf, the Sunda shelf, which joins Borneo, Sumatra, and Java to the Asian mainland. Other familiar bodies of water that overlie continental shelves are the North Sea and the Persian Gulf. The average width of continental shelves is about 80 kilometers. The depth of the shelf also varies. It may be as shallow as 30 m or as deep as 600 m. Along the continental shelves sediment is carried from erosion of the land. Combined with the sunlight available in shallow waters, the continental shelves teem with life compared to the biotic desert of the oceans' abyssal plain. If anoxic conditions in the sedimentary deposits prevail, the shelves may in geologic time become sources of fossil fuels. The relatively accessible continental shelf is by far the best understood part of the ocean floor. Most commercial exploitation, such as oil and gas extraction, from the sea takes place on the continental shelf. Sovereign rights over their continental shelves were claimed by the marine nations that signed the Convention on the Continental Shelf drawn up by the UN's International Law Commission in 1958,[http://www.un.org/law/ilc/texts/contsh.htm] partly superseded by the 1982 United Nations Convention on the Law of the Sea.

External links


- [http://www.onr.navy.mil/focus/ocean/regions/oceanfloor2.htm Office of Naval Research: Ocean Regions]Continental Margin & Rise Category:Physical oceanography Category:Aquatic biomes ja:大陸棚

Scavengers

Scavenger

Mollusk

:For the 1997 album by Ween, see The Mollusk.
Caudofoveata
Aplacophora
Polyplacophora - Chitons
Monoplacophora
Bivalvia - Bivalves
Scaphopoda - Tusk shells
Gastropoda - Snails and Slugs
Cephalopoda - Squids, Octopuses, etc.
The molluscs or mollusks are the large and diverse phylum Mollusca, which includes a variety of familiar creatures well-known for their decorative shells or as seafood. These range from tiny snails, clams, and abalone to the octopus and squid (which are considered the most intelligent invertebrates). The giant squid, which until recently had not been observed alive in its adult form is the largest invertebrate although it is likely that the Colossal Squid<