Temporal range: Valanginian–Recent
( Homarus gammarus )
|Family:|| Nephropidae |
Lobsters are a family (Nephropidae, sometimes also Homeridae) of large marine crustaceans.
Lobsters have long bodies with muscular tails, and live in crevices or burrows on the sea floor. Three of their five pairs of legs have claws, including the first pair, which are usually much larger than the others. Highly prized as seafood, lobsters are economically important, and are often one of the most profitable commodities in coastal areas they populate.Commercially important species include two species of Homarus (which looks more like the stereotypical lobster) from the northern Atlantic Ocean, and scampi (which looks more like a shrimp, or a "mini lobster") – the Northern Hemisphere genus Nephrops and the Southern Hemisphere genus Metanephrops . Although several other groups of crustaceans have the word "lobster" in their names, the unqualified term "lobster" generally refers to the clawed lobsters of the family Nephropidae. Clawed lobsters are not closely related to spiny lobsters or slipper lobsters, which have no claws (chelae), or to squat lobsters. The closest living relatives of clawed lobsters are the reef lobsters and the three families of freshwater crayfish.
Lobsters are invertebrates with a hard protective exoskeleton.Like most arthropods, lobsters must moult to grow, which leaves them vulnerable. During the moulting process, several species change color. Lobsters have eight walking legs; the front three pairs bear claws, the first of which are larger than the others. The front pincers are also biologically considered legs, so they belong in the order Decapods ("ten-footed"). Although lobsters are largely bilaterally symmetrical like most other arthropods, some genera possess unequal, specialized claws.
Lobster anatomy includes two main body parts: the cephalothorax and the abdomen. The cephalothorax fuses the head and the thorax, both of which are covered by a chitinous carapace. The lobster's head bears antennae, antennules, mandibles, the first and second maxillae. The head also bears the (usually stalked) compound eyes. Because lobsters live in murky environments at the bottom of the ocean, they mostly use their antennae as sensors. The lobster eye has a reflective structure above a convex retina. In contrast, most complex eyes use refractive ray concentrators (lenses) and a concave retina.The lobster's thorax is composed of maxillipeds, appendages that function primarily as mouthparts, and pereiopods, appendages that serve for walking and for gathering food. The abdomen includes pleopods (also known as swimmerets), used for swimming as well as the tail fan, composed of uropods and the telson.
Lobsters, like snails and spiders, have blue blood due to the presence of hemocyanin, which contains copper.In contrast, vertebrates and many other animals have red blood from iron-rich hemoglobin. Lobsters possess a green hepatopancreas, called the tomalley by chefs, which functions as the animal's liver and pancreas.
Lobsters of the family Nephropidae are similar in overall form to a number of other related groups. They differ from freshwater crayfish in lacking the joint between the last two segments of the thorax,and they differ from the reef lobsters of the family Enoplometopidae in having full claws on the first three pairs of legs, rather than just one. The distinctions from fossil families such as the Chilenophoberidae are based on the pattern of grooves on the carapace.
Typically, lobsters are dark colored, either bluish green or greenish brown as to blend in with the ocean floor, but they can be found in a multitude of colors.Lobsters with atypical coloring are extremely rare, accounting for only a few of the millions caught every year, and due to their rarity, they usually aren't eaten, instead released back into the wild or donated to aquariums. Often, in cases of atypical coloring, there is a genetic factor, such as albinism or hermaphroditism. Notably, the New England Aquarium has a collection of such lobsters, called the Lobster Rainbow, on public display. Special coloring doesn't appear to have an effect on the lobster's taste once cooked; with the exception of albinos, all lobsters possess astaxanthin, which is responsible for the bright red color lobsters turn after being cooked.
|albino||1 in 100,000,000||Also called white; translucent; ghost; crystal.|
|"cotton candy"||1 in 100,000,000||Also called pastel. Possibly a sub-type of albino.|
|blue||1 in 1,000,000 to 1 in 2,000,000||Caused by a genetic defect.||Lord Stanley (2019, Massachusetts) (2019, St. Louis)|
|calico||1 in 30,000,000||Eve (2019, Maryland)|
|orange||1 in 30,000,000|
|split-colored||1 in 50,000,000||Almost all split-coloreds are hermaphroditic.|
|"Halloween"||1 in 50,000,000 to 1 in 100,000,000||Sub-type of split-colored, specifically orange and black.||Pinchy (2012, Massachusetts)|
|red||1 in 10,000,000 to 1 in 30,000,000|
|yellow||1 in 30,000,000|
Lobsters live up to an estimated 45 to 50 years in the wild, although determining age is difficult.In 2012, a report was published describing how growth bands in calcified regions of the eyestalk or gastric mill in shrimps, crabs and lobsters could be used to measure growth and mortality in decapod crustaceans. Without such a technique, a lobster's age is estimated by size and other variables; this new knowledge "could help scientists better understand the population and assist regulators of the lucrative industry".
Research suggests that lobsters may not slow down, weaken or lose fertility with age, and that older lobsters may be more fertile than younger lobsters. This longevity may be due to telomerase, an enzyme that repairs long repetitive sections of DNA sequences at the ends of chromosomes, referred to as telomeres. Telomerase is expressed by most vertebrates during embryonic stages, but is generally absent from adult stages of life.However, unlike most vertebrates, lobsters express telomerase as adults through most tissue, which has been suggested to be related to their longevity. Telomerase is especially present in 'Green Spotted' lobsters - whose markings are thought to be produced by the enzyme interacting with their shell pigmentation Lobster longevity is limited by their size. Moulting requires metabolic energy and the larger the lobster, the more energy is needed; 10 to 15% of lobsters die of exhaustion during moulting, while in older lobsters, moulting ceases and the exoskeleton degrades or collapses entirely leading to death.
Lobsters, like many other decapod crustaceans, grow throughout life and are able to add new muscle cells at each moult. 20.15 kilograms (44.4 lb).Lobster longevity allows them to reach impressive sizes. According to Guinness World Records , the largest lobster ever caught was in Nova Scotia, Canada, weighing
Lobsters live in all oceans, 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.
Lobsters are omnivores and typically eat live prey such as fish, mollusks, other crustaceans, worms, and some plant life. They scavenge if necessary, and are known to resort to cannibalism in captivity. However, when lobster skin is found in lobster stomachs, this is not necessarily evidence of cannibalism – lobsters eat their shed skin after moulting.While cannibalism was thought to be nonexistent among wild lobster populations, it was observed in 2012 by researchers studying wild lobsters in Maine. These first known instances of lobster cannibalism in the wild are theorized to be attributed to a local population explosion among lobsters caused by the disappearance of many of the Maine lobsters' natural predators.
In general, lobsters are 25–50 cm (10–20 in) long, and move by slowly walking on the sea floor. However, when they flee, they swim backward quickly by curling and uncurling their abdomens. A speed of 5 m/s (11 mph) has been recorded. This is known as the caridoid escape reaction.
Symbiotic animals of the genus Symbion , the only member of the phylum Cycliophora, live exclusively on lobster gills and mouthparts.Different species of Symbion have been found on the three commercially important lobsters of the North Atlantic Ocean – Nephrops norvegicus , Homarus gammarus , and Homarus americanus .
The examples and perspective in this section may not represent a worldwide view of the subject. (August 2017) (Learn how and when to remove this template message)
Lobster recipes include lobster Newberg and lobster Thermidor. Lobster is used in soup, bisque, lobster rolls, and cappon magro . Lobster meat may be dipped in clarified butter, resulting in a heightened flavor. Cooks boil or steam live lobsters. When a lobster is cooked, its shell's color changes from blue to orange because the heat from cooking breaks down a protein called crustacyanin, which suppresses the orange hue of the chemical astaxanthin, which is also found in the shell.
According to the United States Food and Drug Administration (FDA), the mean level of mercury in American lobster between 2005 and 2007 was 0.107 ppm.
In North America, the American lobster did not achieve popularity until the mid-19th century, when New Yorkers and Bostonians developed a taste for it, and commercial lobster fisheries only flourished after the development of the lobster smack,a custom-made boat with open holding wells on the deck to keep the lobsters alive during transport.
Prior to this time, lobster was considered a poverty food or as a food for indentured servants or lower members of society in Maine, Massachusetts, and the Canadian Maritimes. Some servants specified in employment agreements that they would not eat lobster more than twice per week,however there is limited evidence for this. Lobster was also commonly served in prisons, much to the displeasure of inmates. American lobster was initially deemed worthy only of being used as fertilizer or fish bait, and until well into the 20th century, it was not viewed as more than a low-priced canned staple food.
As a crustacean, lobster remains a taboo food in the dietary laws of Judaism and certain streams of Islam. (See also: Kashrut, Halal, and List of halal and kosher fish)[ citation needed ]
Caught lobsters are graded as new-shell, hard-shell, or old-shell, and because lobsters which have recently shed their shells are the most delicate, an inverse relationship exists between the price of American lobster and its flavor. New-shell lobsters have paper-thin shells and a worse meat-to-shell ratio, but the meat is very sweet. However, the lobsters are so delicate, even transport to Boston almost kills them, making the market for new-shell lobsters strictly local to the fishing towns where they are offloaded. Hard-shell lobsters with firm shells, but with less sweet meat, can survive shipping to Boston, New York, and even Los Angeles, so they command a higher price than new-shell lobsters. Meanwhile, old-shell lobsters, which have not shed since the previous season and have a coarser flavor, can be air-shipped anywhere in the world and arrive alive, making them the most expensive. One seafood guide notes that an $8 lobster dinner at a restaurant overlooking fishing piers in Maine is consistently delicious, while "the eighty-dollar lobster in a three-star Paris restaurant is apt to be as much about presentation as flavor".
Several methods are used for killing lobsters. The most common way of killing lobsters is by placing them live in boiling water, sometimes after having been placed in a freezer for a period of time. Another method is to split the lobster or sever the body in half lengthwise. Lobsters may also be killed or immobilized immediately before boiling by a stab into the brain (pithing), in the belief that this will stop suffering. However, a lobster's brain operates from not one but several ganglia and disabling only the frontal ganglion does not usually result in death.The boiling method is illegal in some places, such as in Reggio Emilia, Italy, where offenders face fines up to €495. Lobsters can be killed by electrocution prior to cooking, with one device, the CrustaStun, applying a 110-volt, 2 to 5 amp electrical charge to the animal. The Swiss government banned boiling lobster live without stunning them first; Since March 2018, lobsters in Switzerland need to be knocked out, or killed instantly, before they are prepared. They also get other protections while in transit.
The killing methods most likely to cause pain and distress are:
Lobsters are caught using baited one-way traps with a color-coded marker buoy to mark cages. Lobster is fished in water between 2 and 900 metres (1 and 500 fathoms), although some lobsters live at 3,700 metres (2,000 fathoms). Cages are of plastic-coated galvanized steel or wood. A lobster fisher may tend as many as 2,000 traps. Around year 2000, owing to overfishing and high demand, lobster aquaculture expanded. However, as of 2008, no lobster aquaculture operation had achieved commercial success, mainly because of lobsters' tendency towards cannibalism and the slow growth of the species.
The fossil record of clawed lobsters extends back at least to the Valanginian age of the Cretaceous (140 million years ago).This list contains all extant species in the family Nephropidae:
The American lobster is a species of lobster found on the Atlantic coast of North America, chiefly from Labrador to New Jersey. It is also known as Atlantic lobster, Canadian lobster, true lobster, northern lobster, Canadian Reds, or Maine lobster. It can reach a body length of 64 cm (25 in), and a mass of over 20 kilograms (44 lb), making it not only the heaviest crustacean in the world, but also the heaviest of all living arthropod species. Its closest relative is the European lobster Homarus gammarus, which can be distinguished by its coloration and the lack of spines on the underside of the rostrum. American lobsters are usually bluish green to brown with red spines, but several color variations have been observed.
Homarus is a genus of lobsters, which include the common and commercially significant species Homarus americanus and Homarus gammarus. The Cape lobster, which was formerly in this genus as H. capensis, was moved in 1995 to the new genus Homarinus.
Homarus gammarus, known as the European lobster or common lobster, is a species of clawed lobster from the eastern Atlantic Ocean, Mediterranean Sea and parts of the Black Sea. It is closely related to the American lobster, H. americanus. It may grow to a length of 60 cm (24 in) and a mass of 6 kilograms (13 lb), and bears a conspicuous pair of claws. In life the lobsters are blue, only becoming "lobster red" on cooking. Mating occurs in the summer, producing eggs which are carried by the females for up to a year before hatching into planktonic larvae. Homarus gammarus is a highly esteemed food, and is widely caught using lobster pots, mostly around the British Isles.
Lobsters are widely fished around the world for their meat. They are often hard to catch in large numbers, but their large size can make them a profitable catch. Although the majority of the targeted species are tropical, the majority of the global catch is in temperate waters.
Nephrops norvegicus, known variously as the Norway lobster, Dublin Bay prawn, langoustine or scampi, is a slim, orange-pink lobster which grows up to 25 cm (10 in) long, and is "the most important commercial crustacean in Europe". It is now the only extant species in the genus Nephrops, after several other species were moved to the closely related genus Metanephrops. It lives in the north-eastern Atlantic Ocean, and parts of the Mediterranean Sea, but is absent from the Baltic Sea and Black Sea. Adults emerge from their burrows at night to feed on worms and fish.
Nephrops is a genus of lobsters comprising a single extant species, Nephrops norvegicus, and several fossil species. It was erected by William Elford Leach in 1814, to accommodate N. norvegicus alone, which had previously been placed in genera such as Cancer, Astacus or Homarus. Nephrops means "kidney eye" and refers to the shape of the animal's compound eye.
The Astacidea are a group of decapod crustaceans including lobsters, crayfish, and their close relatives.
The Cape lobster, Homarinus capensis, is a species of small lobster that lives off the coast of South Africa, from Dassen Island to Haga Haga. Only a few dozen specimens are known, mostly regurgitated by reef-dwelling fish. It lives in rocky reefs, and is thought to lay large eggs that have a short larval phase, or that hatch directly as a juvenile. The species grows to a total length of 10 cm (3.9 in), and resembles a small European or American lobster; it was previously included in the same genus, Homarus, although it is not very closely related to those species, and is now considered to form a separate, monotypic genus – Homarinus. Its closest relatives are the genera Thymops and Thymopides.
Metanephrops challengeri is a species of slim, pink lobster that lives around the coast of New Zealand. It is typically 13–18 cm (5–7 in) long and weighs around 100 g (3.5 oz). The carapace and abdomen are smooth, and adults are white with pink and brown markings and a conspicuous pair of long, slim claws. M. challengeri lives in burrows at depths of 140–640 m (460–2,100 ft) in a variety of sediments. Although individuals can live for up to 15 years, the species shows low fecundity, where small numbers of larvae hatch at an advanced stage.
The family Thaumastochelidae contains five known species of deep-sea lobsters, three in the genus Thaumastocheles, and two in the genus Thaumastochelopsis. The fifth species was discovered in the ten–year Census of Marine Life. These creatures are distinguished from other clawed lobsters by their blindness, and by their single elongated, spiny chela.
Metanephrops is a genus of lobsters, commonly known as scampi. Important species for fishery include Metanephrops australiensis and Metanephrops challengeri. It differs from other lobsters such as Homarus and Nephrops norvegicus in that its two main claws are of equal size, rather than being differentiated into a crusher and a pincher. There are 18 extant species recognised in the genus:
Metanephrops boschmai, known as the Bight lobster, Bight scampi or Boschma's scampi, is a species of lobster endemic to Western Australia.
Sagmariasus verreauxi is a species of spiny lobster that lives around northern New Zealand, the Kermadec Islands the Chatham Islands and Australia from Queensland to Tasmania. It is probably the longest decapod crustacean in the world, alongside the American lobster Homarus americanus, growing to lengths of up to 60 centimetres (24 in).
Scyllarides latus, the Mediterranean slipper lobster, is a species of slipper lobster found in the Mediterranean Sea and in the eastern Atlantic Ocean. It is edible and highly regarded as food, but is now rare over much of its range due to overfishing. Adults may grow to 1 foot (30 cm) long, are camouflaged, and have no claws. They are nocturnal, emerging from caves and other shelters during the night to feed on molluscs. As well as being eaten by humans, S. latus is also preyed upon by a variety of bony fish. Its closest relative is S. herklotsii, which occurs off the Atlantic coast of West Africa; other species of Scyllarides occur in the western Atlantic Ocean and the Indo-Pacific. The larvae and young animals are largely unknown.
Nephropsis atlantica, sometimes called the scarlet lobsterette or scarlet clawed lobster, is a species of lobster from the Atlantic Ocean.
Dinochelus ausubeli is a small deep sea lobster discovered in 2007 in the Philippines during the Census of Marine Life and described in 2010 in the new genus Dinochelus. Its two claws are very different in size, are elongated, and bear many long teeth on the inner surface.
Thymopides is a genus of deep-water lobsters, comprising the two species Thymopides grobovi and Thymopides laurentae.
Nephropides caribaeus is a species of lobster, the only species in the genus Nephropides. It is found in western parts of the Caribbean Sea, from Belize to Colombia. It grows to a total length of around 170 mm (6.7 in), and is covered in conspicuous tubercles.
Nephropsis is a genus of lobsters containing 15 extant species:
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