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''Homarus gammarus'', known as the European lobster or common lobster, is a species of clawed lobster from the eastern Atlantic Ocean,
Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...
and parts of the
Black Sea The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...
. It is closely related to the
American lobster The American lobster (''Homarus americanus'') is a species of lobster found on the Atlantic Ocean, Atlantic coast of North America, chiefly from Labrador to New Jersey. It is also known as Atlantic lobster, Canadian lobster, true lobster, norther ...
, ''H. americanus''. It may grow to a length of and a mass of , and bears a conspicuous pair of
claw A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or Arthro ...
s. In life, the lobsters are blue, only becoming "lobster red" on cooking.
Mating In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. '' Copulation'' is the union of the sex organs of two sexually repr ...
occurs in the summer, producing eggs which are carried by the females for up to a year before hatching into
plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...
ic
larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...
. ''Homarus gammarus'' is a highly esteemed food, and is widely
caught Caught is a method of dismissing a batsman in cricket. A batsman is out caught if the batsman hits the ball, from a legitimate delivery, with the bat, and the ball is caught by the bowler or a fielder before it hits the ground. If the catch ...
using lobster pots, mostly around the
British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...
.


Description

''Homarus gammarus'' is a large
crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...
, with a body length up to and weighing up to , although the lobsters caught in lobster pots are usually long and weigh . Like other crustaceans, lobsters have a hard
exoskeleton An exoskeleton () . is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the internal organs, in contrast to an internal endoskeleton (e.g. human skeleton, that ...
which they must shed in order to grow, in a process called
ecdysis Ecdysis is the moulting of the cuticle in many invertebrates of the clade Ecdysozoa. Since the cuticle of these animals typically forms a largely inelastic exoskeleton, it is shed during growth and a new, larger covering is formed. The remnant ...
(molting). This may occur several times a year for young lobsters, but decreases to once every 1–2 years for larger animals. The first pair of
pereiopod The anatomy of a decapod consists of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment – often called a somite – may possess one pair of appendages, although in various groups these m ...
s is armed with a large, asymmetrical pair of
feet The foot (: feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is an organ at the terminal part of the leg made up of ...
. The larger one is the "crusher", and has rounded nodules used for crushing prey; the other is the "cutter", which has sharp inner edges, and is used for holding or tearing the prey. Usually, the left claw is the crusher, and the right is the cutter. The
exoskeleton An exoskeleton () . is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the internal organs, in contrast to an internal endoskeleton (e.g. human skeleton, that ...
is generally blue above, with spots that coalesce, and yellow below. The red colour associated with lobsters only appears after cooking. This occurs because, in life, the red
pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub ...
astaxanthin Astaxanthin is a keto- carotenoid within a group of chemical compounds known as carotenoids or terpenes. Astaxanthin is a metabolite of zeaxanthin and canthaxanthin, containing both hydroxyl and ketone functional groups. It is a lipid-solu ...
is bound to a
protein complex A protein complex or multiprotein complex is a group of two or more associated polypeptide chains. Protein complexes are distinct from multidomain enzymes, in which multiple active site, catalytic domains are found in a single polypeptide chain. ...
, but the complex is broken up by the heat of cooking, releasing the red pigment. The closest relative of ''H. gammarus'' is the
American lobster The American lobster (''Homarus americanus'') is a species of lobster found on the Atlantic Ocean, Atlantic coast of North America, chiefly from Labrador to New Jersey. It is also known as Atlantic lobster, Canadian lobster, true lobster, norther ...
, ''Homarus americanus''. The two species are very similar, and can be crossed artificially, although hybrids are unlikely to occur in the wild since their ranges do not overlap. The two species can be distinguished by a number of characteristics: *The
rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit ** podium * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ...
of ''H. americanus'' bears one or more spines on the underside, which are lacking in ''H. gammarus''. *The spines on the claws of ''H. americanus'' are red or red-tipped, while those of ''H. gammarus'' are white or white-tipped. *The underside of the claw of ''H. americanus'' is orange or red, while that of ''H. gammarus'' is creamy white or very pale red.


Life cycle

Female ''H. gammarus'' reach
sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans, it is related to both puberty and adulthood. ''Puberty'' is the biological process of sexual maturation, while ''adulthood'', the condition of being socially recognized ...
when they have grown to a carapace length of , whereas males mature at a slightly smaller size.
Mating In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. '' Copulation'' is the union of the sex organs of two sexually repr ...
typically occurs in summer between a recently moulted female, whose shell is therefore soft, and a hard-shelled male. The female carries the eggs attached to her
pleopod The anatomy of a decapod consists of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment – often called a somite – may possess one pair of appendages, although in various groups these m ...
s for up to 12 months, depending on the temperature. Females carrying eggs are said to be "berried" and can be found throughout the year. The eggs hatch at night, and the
larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...
swim to the water surface where they drift with the
ocean current An ocean current is a continuous, directed movement of seawater generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, sh ...
s, preying on
zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...
. This stage involves three moults and lasts for 15–35 days. After the third moult, the juvenile takes on a form closer to the adult, and adopts a benthic lifestyle. The juveniles are rarely seen in the wild, and are poorly known, although they are known to be capable of digging extensive
burrow file:Chipmunk-burrow (exits).jpg, An eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of Animal lo ...
s. It is estimated that only 1 larva in every 20,000 survives to the benthic phase. When they reach a carapace length of , the juveniles leave their burrows and start their adult lives.


Distribution

''Homarus gammarus'' is found across the north-eastern Atlantic Ocean from northern Norway to the
Azores The Azores ( , , ; , ), officially the Autonomous Region of the Azores (), is one of the two autonomous regions of Portugal (along with Madeira). It is an archipelago composed of nine volcanic islands in the Macaronesia region of the North Atl ...
and
Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...
, not including the
Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...
. It is also present in most of the
Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...
, only missing from the section east of
Crete Crete ( ; , Modern Greek, Modern: , Ancient Greek, Ancient: ) is the largest and most populous of the Greek islands, the List of islands by area, 88th largest island in the world and the List of islands in the Mediterranean#By area, fifth la ...
, and along only the south-west coast of the
Black Sea The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...
. The northernmost populations are found in the Norwegian
fjord In physical geography, a fjord (also spelled fiord in New Zealand English; ) is a long, narrow sea inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Antarctica, the Arctic, and surrounding landmasses of the n ...
s
Tysfjorden or (also: Storrusten, Erling. 1998. ''Hurtigruten: The World's Most Beautiful Sea Voyage''. Narvik: Ofotens og Vesteraalens Dampskibsselskab, p. 69.) is a fjord in Nordland county, Norway. The fjord is the border between Narvik Municipality and ...
and Nordfolda, inside the
Arctic Circle The Arctic Circle is one of the two polar circles, and the northernmost of the five major circle of latitude, circles of latitude as shown on maps of Earth at about 66° 34' N. Its southern counterpart is the Antarctic Circle. The Arctic Circl ...
. The species can be divided into four genetically distinct populations, one widespread population, and three which have diverged due to small
effective population size The effective population size (''N'e'') is the size of an idealised population that would experience the same rate of genetic drift as the real population. Idealised populations are those following simple one- locus models that comply with ass ...
s, possibly due to
adaptation In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the p ...
to the local environment. The first of these is the population of lobsters from northern Norway, which have been referred to as the "midnight-sun lobster". The populations in the Mediterranean Sea are distinct from those in the Atlantic Ocean. The last distinct population is found in part of the Netherlands: samples from the
Oosterschelde The Eastern Scheldt () is a former estuary in the province of Zeeland, Netherlands, between Schouwen-Duiveland and Tholen on the north and Noord-Beveland and Zuid-Beveland on the south. It also features the largest Oosterschelde National Pa ...
were distinct from those collected in the
North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...
or
English Channel The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...
. Attempts have been made to introduce ''H. gammarus'' to New Zealand, alongside other European species such as the edible crab, '' Cancer pagurus''. Between 1904 and 1914, one million lobster
larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...
were released from hatcheries in
Dunedin Dunedin ( ; ) is the second-most populous city in the South Island of New Zealand (after Christchurch), and the principal city of the Otago region. Its name comes from ("fort of Edin"), the Scottish Gaelic name for Edinburgh, the capital of S ...
, but the species did not become established there.


Ecology

Adult ''H. gammarus'' live on the
continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an islan ...
at depths of , although not normally deeper than . They prefer hard substrates, such as rocks or hard mud, and live in holes or crevices, emerging at night to feed. The diet of ''H. gammarus'' mostly consists of other benthic
invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...
s. These include
crab Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek language, Greek), which typically have a very short projecting tail-like abdomen#Arthropoda, abdomen, usually hidden entirely under the Thorax (arthropo ...
s,
molluscs Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...
,
sea urchin Sea urchins or urchins () are echinoderms in the class (biology), class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal zone to deep seas of . They typically have a globular body cove ...
s,
starfish Starfish or sea stars are Star polygon, star-shaped echinoderms belonging to the class (biology), class Asteroidea (). Common usage frequently finds these names being also applied to brittle star, ophiuroids, which are correctly referred to ...
and polychaete worms. The three clawed lobster species ''Homarus gammarus'', '' H. americanus'' and '' Nephrops norvegicus'' are hosts to the three known species of the animal phylum Cycliophora; the species on ''H. gammarus'' has not been described. ''Homarus gammarus'' is susceptible to the disease gaffkaemia, caused by the
bacterium Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the ...
'' Aerococcus viridans''. Although it is frequently found in
American lobster The American lobster (''Homarus americanus'') is a species of lobster found on the Atlantic Ocean, Atlantic coast of North America, chiefly from Labrador to New Jersey. It is also known as Atlantic lobster, Canadian lobster, true lobster, norther ...
s, the disease has only been seen in captive ''H. gammarus'', where prior occupation of the tanks by ''H. americanus'' could not be ruled out.


Human consumption

''Homarus gammarus'' is traditionally "highly esteemed" as a foodstuff and was mentioned in " The Crabfish" a seventeenth century English
folk song Folk music is a music genre that includes #Traditional folk music, traditional folk music and the Contemporary folk music, contemporary genre that evolved from the former during the 20th-century folk revival. Some types of folk music may be ca ...
. It may fetch very high prices and may be sold fresh, frozen, canned or powdered. Both the claws and the abdomen of ''H. gammarus'' contain "excellent" white meat, and most of the contents of the
cephalothorax The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cepha ...
are edible. The exceptions are the gastric mill and the "sand vein" ( gut). The price of ''H. gammarus'' is up to three times higher than that of ''H. americanus'', and the European species is considered to be more flavorful. Lobsters are mostly fished using lobster pots, although lines baited with
octopus An octopus (: octopuses or octopodes) is a soft-bodied, eight-limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like oth ...
or
cuttlefish Cuttlefish, or cuttles, are Marine (ocean), marine Mollusca, molluscs of the order (biology), suborder Sepiina. They belong to the class (biology), class Cephalopoda which also includes squid, octopuses, and nautiluses. Cuttlefish have a unique ...
sometimes succeed in tempting them out, to allow them to be caught in a net or by hand. In 2008, 4,386 t of ''H. gammarus'' were caught across Europe and North Africa, of which 3,462 t (79%) was caught in the
British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...
(including the
Channel Islands The Channel Islands are an archipelago in the English Channel, off the French coast of Normandy. They are divided into two Crown Dependencies: the Jersey, Bailiwick of Jersey, which is the largest of the islands; and the Bailiwick of Guernsey, ...
). The
minimum landing size The minimum landing size (MLS) is the smallest fish measurement at which it is legal to keep or sell a fish. The MLS depends on the species of fish. Sizes also vary around the world, as they are legal definitions which are defined by the local regu ...
for ''H. gammarus'' is a carapace length of . To protect known breeding females, lobsters caught carrying eggs are to be notched on a uropod, the inner tail flap of female lobsters of reproductive size (usually above the minimum landing size 87mm carapace length). Following this, it is illegal for the female to be kept or sold, and is commonly referred to as a "v-notch". This notch remains for three molts of the lobster exoskeleton, providing harvest protection and continued breeding availability for 3–5 years.
Aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. Nelu ...
systems for ''H. gammarus'' are under development, and production rates are still very low.


Taxonomic history

''Homarus gammarus'' was first given a
binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, altho ...
by
Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
in the tenth edition of his ''
Systema Naturae ' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the syste ...
'', published in 1758. That name was ''Cancer gammarus'', since Linnaeus' concept of the genus ''
Cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...
'' at that time included all large crustaceans. ''H. gammarus'' is the
type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...
of the genus '' Homarus'' Weber, 1795, as determined by Direction 51 of the
International Commission on Zoological Nomenclature The International Commission on Zoological Nomenclature (ICZN) is an organization dedicated to "achieving stability and sense in the scientific naming of animals". Founded in 1895, it currently comprises 26 commissioners from 20 countries. Orga ...
. Prior to that direction, confusion arose because the species had been referred to by several different names, including ''Astacus marinus'' Fabricius, 1775 and ''Homarus vulgaris'' H. Milne-Edwards, 1837, and also because Friedrich Weber's description of the genus had been overlooked until rediscovered by Mary J. Rathbun, rendering any prior assignments of type species (for ''Homarus'' H. Milne-Edwards, 1837) invalid for ''Homarus'' Weber, 1795. The
type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...
of ''Homarus gammarus'' was a
lectotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to anchor or centralizes ...
selected by
Lipke Holthuis Lipke Bijdeley Holthuis (21 April 1921 – 7 March 2008) was a Dutch carcinologist, considered one of the "undisputed greats" of carcinology, and "the greatest carcinologist of our time". Holthuis was born in Probolinggo, East Java and obtained ...
in 1974. It came from , near
Marstrand Marstrand () is a seaside locality situated in Kungälv Municipality, Västra Götaland County, Sweden. It had 1,320 inhabitants in 2010. The town got its name from its location on the island of Marstrand. Despite its small population, for histo ...
, Sweden ( northwest of
Gothenburg Gothenburg ( ; ) is the List of urban areas in Sweden by population, second-largest city in Sweden, after the capital Stockholm, and the fifth-largest in the Nordic countries. Situated by the Kattegat on the west coast of Sweden, it is the gub ...
), but both it and the paralectotypes have since been lost. The
common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...
for ''H. gammarus'' preferred by the
Food and Agriculture Organization The Food and Agriculture Organization of the United Nations; . (FAO) is a specialized agency of the United Nations that leads international efforts to defeat hunger and improve nutrition and food security. Its Latin motto, , translates ...
is "European lobster", but the species is also widely known as the "common lobster".


References


Further reading

*


External links

* * {{Authority control Crustaceans described in 1758 Commercial crustaceans Crustaceans of the Atlantic Ocean Edible crustaceans Taxa named by Carl Linnaeus True lobsters