Edible crab
Encyclopedia
Cancer pagurus, commonly known as the edible crab or brown crab, is a species of crab
found in the North Sea
, North Atlantic Ocean
and perhaps in the Mediterranean Sea
. It is a robust crab of a reddish-brown colour, having an oval carapace
with a characteristic "pie crust" edge and black tips to the claws. A mature adult may have a carapace width of up to 25 cm (10 in) and weigh up to 3 kg (6.6 lb). C. pagurus is a nocturnal predator, targeting a range of molluscs and crustaceans. It is the subject of the largest crab fishery
in Western Europe
, centred around the coasts of the British Isles, with more than 60,000 tonnes caught annually.
of C. pagurus adults is a reddish-brown colour, while in young specimens it is purple-brown. It occasionally bears white patches, and is shaped along the front edge into nine rounded lobes, resembling a pie crust. Males typically have a carapace 60 millimetres (2.4 in) long, and females 98 mm (4 in) long, although they may reach up to 150 mm (6 in) long in exceptional cases. Carapace width is typically 150 mm (6 in), or exceptionally up to 250 mm (10 in). A fold of the carapace extends ventrally to constitute a branchial chamber where the gill
s lie.
The first pereiopod is modified into a strong cheliped (claw-bearing leg): the claw's fingers, the dactylus
and propodus, are black at the tips. The other pereiopods are covered with rows of short stiff seta
e; the dactylus of each is black towards the tip, and ends in a sharp point.
From the front, the antennae
and antennules are visible. Beside these there are the orbits in which the eyes are situated. The mouthparts comprise three pairs of maxillipeds, behind which there are a pair of maxillae, a pair of maxillules, and finally the mandibles.
In common with most crabs, the abdomen
is folded under the thorax and shows clear sexual dimorphism
: in males it is comparatively narrow, whereas in the female it is wider.
. Internal fertilisation
takes place before the hardening of the new carapace, with the aid of two abdominal appendages (gonopods). After mating, the female retreats to a pit on the sea floor to lay her eggs. Between 250,000 and 3,000,000 fertilised eggs are held under the female's abdomen for up to eight months until they hatch.
The first developmental stage after hatching is a plankton
ic larva (1 mm) called the zoea that develops into a postlarva (megalopa), and finally a juvenile. The first juvenile stage is characterised by a well-developed abdomen, which will, in time, become reduced in size and folded under the sternum. Juveniles settle to the sea floor in the intertidal zone
, where they stay until they reach a carapace
width of 60 millimetre and then migrate to deeper water. The growth rate in males slows from an increase in carapace width of 10 mm per year before it is eight years old, to 2 mm per year thereafter. Females grow at about half the rate of males, probably due to the energetic demands of egg laying. Sexual maturity
is reached at a carapace width of 12.7 cm (5 in) in females, and 11 cm (4.3 in) in males. Longevity
is typically 25–30 years, although exceptional individuals may live for up to 100 years.
as far as Norway
in the north and northern Africa
in the south, on mixed coarse grounds, mud and sand from the shallow sublittoral to depths of about 100 metres (328.1 ft). It is frequently found inhabiting cracks and holes in rocks but occasionally also in open areas. Smaller specimens may be found under rocks in the littoral zone. Unconfirmed reports suggest that C. pagurus may also occur in the Mediterranean Sea
and Black Sea
.
Adult C. pagurus are nocturnal, hiding buried in the substrate during the day, but foraging at night up to 50 metres (164 ft) from their hideouts. Their diet includes a variety of crustacean
s (including the crabs Carcinus maenas
and Pilumnus hirtellus
, the porcelain crab
s Porcellana platycheles
and Pisidia longicornis
, and the squat lobster
Galathea squamifera
) and molluscs
(including the gastropods
Nucella lapillus
and Littorina littorea
, and the bivalves
Ensis
, Mytilus edulis
, Cerastoderma edule, Ostrea edulis and Lutraria lutraria
). It may stalk or ambush motile prey, and may dig large pits to reach buried molluscs. The main predator of Cancer pagurus is the octopus
, which will even attack them inside the crab pots that fishermen use to trap them.
Compared to other commercially important crab species, relatively little is known about diseases of Cancer pagurus. Its parasites include virus
es, such as the white spot syndrome
virus, various bacteria
that cause dark lesion
s on the exoskeleton
, and Hematodinium
-like dinoflagellate
s that cause "pink crab disease". Other microscopic pathogen
s include fungi, microsporidia
ns, paramyxeans and ciliate
s. Cancer pagurus is also targeted by metazoan
parasites, including trematodes
and parasitic barnacle
s. A number of sessile
animals occasionally settle as epibiont
s on the exoskeleton of C. pagurus, including barnacles, sea anemone
s, serpulid
polychaete
s such as Janua pagenstecheri
, bryozoa
ns and saddle oysters
.
throughout its range, being the most commercially important crab species in Western Europe
. The crabs are caught using crab pots (similar to lobster pots
) which are placed offshore and baited. The catch of C. pagurus has increased steadily, rising from 26,000 tonnes in 1978 to 60,000 t in 2007, of which more than 70% was caught around the British Isles
. The fishery is widely dispersed around the British and Irish coasts, and C. pagurus is thought to be overfished
across much of this area. Most of the edible crabs caught by the British fleet are exported live for sale in France
and Spain
.
A number of legal restrictions apply to the catching of Cancer pagurus. It is illegal to catch "berried" crabs (females carrying eggs), but since ovigerous females remain in pits dug in the sediment and do not feed, fishing pressure does not affect the supply of larvae. Minimum landing size
s (MLS) for C. pagurus are set by both the European Union
technical regulations and by the UK government
. Different minimum sizes are employed in different geographical areas, to reflect differences in the crab's growth rate across its range. In particular, the "Cromer crab" fishery along the coasts of Suffolk
, Norfolk
and Lincolnshire
is subject to a MLS of 115 mm (4.5 in), rather than the 140 mm (5.5 in) MLS in most of the species' range. An intermediate value of 130 mm (5.1 in) is used in the rest of the North Sea between the 56th parallel north
and the Essex
–Kent
border, and in the Irish Sea
south of 55° N
. Around Devon
, Cornwall
and the Isles of Scilly
, there is a separate MLS for males (160 mm or 6.3 in) and females (140 mm or 5.5 in). The Norwegian catch is 8,500 tons annually, compared to 20,000 tons in the United Kingdom
, 13,000 tons in Ireland
, 8,500 tons in France
, and a total 45,000 tons globally.
or bouillabaisse
, pâté
s, mousse
s and hot soufflé
s.
, Cancer pagurus was first described by Carl Linnaeus in 1758, in the tenth edition
of his Systema Naturae
, which marks the starting point of zoological nomenclature. It was chosen to be the type species
of the genus Cancer
by Pierre André Latreille
in 1810. The specific epithet is a Latin
word, deriving from the Ancient Greek
(), which, alongside "" (), was used to refer to edible marine crabs; neither classical term can be confidently assigned to a particular species.
Although the genus Cancer formerly included most crabs, it has since been restricted to eight species. Within that set of closely related species, the closest relative of C. pagurus is the Jonah crab
, Cancer borealis, from the east coast of North America
.
Crab
True crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax...
found in the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
, North Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
and perhaps in the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
. It is a robust crab of a reddish-brown colour, having an oval carapace
Carapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
with a characteristic "pie crust" edge and black tips to the claws. A mature adult may have a carapace width of up to 25 cm (10 in) and weigh up to 3 kg (6.6 lb). C. pagurus is a nocturnal predator, targeting a range of molluscs and crustaceans. It is the subject of the largest crab fishery
Crab fisheries
Crab fisheries are fisheries which capture or farm crabs. True crabs make up 20% of all crustaceans caught and farmed worldwide, with about 1.4 million tonnes being consumed annually. The horse crab, Portunus trituberculatus accounts for one quarter of that total...
in Western Europe
Western Europe
Western Europe is a loose term for the collection of countries in the western most region of the European continents, though this definition is context-dependent and carries cultural and political connotations. One definition describes Western Europe as a geographic entity—the region lying in the...
, centred around the coasts of the British Isles, with more than 60,000 tonnes caught annually.
Description
The carapaceCarapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
of C. pagurus adults is a reddish-brown colour, while in young specimens it is purple-brown. It occasionally bears white patches, and is shaped along the front edge into nine rounded lobes, resembling a pie crust. Males typically have a carapace 60 millimetres (2.4 in) long, and females 98 mm (4 in) long, although they may reach up to 150 mm (6 in) long in exceptional cases. Carapace width is typically 150 mm (6 in), or exceptionally up to 250 mm (10 in). A fold of the carapace extends ventrally to constitute a branchial chamber where the gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
s lie.
The first pereiopod is modified into a strong cheliped (claw-bearing leg): the claw's fingers, the dactylus
Arthropod leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa , trochanter , femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus ,...
and propodus, are black at the tips. The other pereiopods are covered with rows of short stiff seta
Seta
Seta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....
e; the dactylus of each is black towards the tip, and ends in a sharp point.
From the front, the antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
and antennules are visible. Beside these there are the orbits in which the eyes are situated. The mouthparts comprise three pairs of maxillipeds, behind which there are a pair of maxillae, a pair of maxillules, and finally the mandibles.
In common with most crabs, the abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
is folded under the thorax and shows clear sexual dimorphism
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
: in males it is comparatively narrow, whereas in the female it is wider.
Life cycle
Reproduction occurs in winter; the male captures the female and holds her under himself until she moultsEcdysis
Ecdysis is the moulting of the cuticula in many invertebrates. This process of moulting is the defining feature of the clade Ecdysozoa, comprising the arthropods, nematodes, velvet worms, horsehair worms, rotifers, tardigrades and Cephalorhyncha...
. Internal fertilisation
Internal fertilization
In mammals, internal fertilization is done through copulation, which involves the insertion of the penis into the vagina. Some other higher vertebrate animals reproduce internally, but their fertilization is cloacal.The union of spermatozoa of the parent organism. At some point, the growing egg or...
takes place before the hardening of the new carapace, with the aid of two abdominal appendages (gonopods). After mating, the female retreats to a pit on the sea floor to lay her eggs. Between 250,000 and 3,000,000 fertilised eggs are held under the female's abdomen for up to eight months until they hatch.
The first developmental stage after hatching is a plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
ic larva (1 mm) called the zoea that develops into a postlarva (megalopa), and finally a juvenile. The first juvenile stage is characterised by a well-developed abdomen, which will, in time, become reduced in size and folded under the sternum. Juveniles settle to the sea floor in the intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
, where they stay until they reach a carapace
Carapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
width of 60 millimetre and then migrate to deeper water. The growth rate in males slows from an increase in carapace width of 10 mm per year before it is eight years old, to 2 mm per year thereafter. Females grow at about half the rate of males, probably due to the energetic demands of egg laying. Sexual maturity
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
is reached at a carapace width of 12.7 cm (5 in) in females, and 11 cm (4.3 in) in males. Longevity
Longevity
The word "longevity" is sometimes used as a synonym for "life expectancy" in demography or known as "long life", especially when it concerns someone or something lasting longer than expected ....
is typically 25–30 years, although exceptional individuals may live for up to 100 years.
Distribution and ecology
Cancer pagurus is abundant throughout the northeast AtlanticAtlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
as far as Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
in the north and northern Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
in the south, on mixed coarse grounds, mud and sand from the shallow sublittoral to depths of about 100 metres (328.1 ft). It is frequently found inhabiting cracks and holes in rocks but occasionally also in open areas. Smaller specimens may be found under rocks in the littoral zone. Unconfirmed reports suggest that C. pagurus may also occur in the Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
and Black Sea
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...
.
Adult C. pagurus are nocturnal, hiding buried in the substrate during the day, but foraging at night up to 50 metres (164 ft) from their hideouts. Their diet includes a variety of crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s (including the crabs Carcinus maenas
Carcinus maenas
Carcinus maenas is a common littoral crab, and an important invasive species, listed among the 100 "world's worst alien invasive species". It is native to the north-east Atlantic Ocean and Baltic Sea, but has colonised similar habitats in Australia, South Africa, South America and both Atlantic and...
and Pilumnus hirtellus
Pilumnus hirtellus
Pilumnus hirtellus, the bristly crab or hairy crab, is a species of European crab. It is less than long and covered in hair. It lives in shallow water and feeds on carrion.-Description:...
, the porcelain crab
Porcelain crab
Porcelain crabs are decapod crustaceans in the widespread family Porcellanidae, which superficially resemble true crabs. They are typically less than wide, and have flattened bodies as an adaptation for living in rock crevices...
s Porcellana platycheles
Porcellana platycheles
Porcellana platycheles, sometimes called the broad-clawed porcelain crab, is a species of porcelain crab. It may reach a size of , and is found in the Eastern North Atlantic Ocean and Mediterranean Sea, where it feeds on carrion and other organic debris....
and Pisidia longicornis
Pisidia longicornis
Pisidia longicornis, the long-clawed porcelain crab, is a species of porcelain crab that lives in the north-eastern Atlantic Ocean. It varies from reddish to white, and grows to a carapace width of . It was first named by Carl Linnaeus in 1767, although the etymology remains...
, and the squat lobster
Squat lobster
Squat lobsters are decapod crustaceans of the families Galatheidae, Chirostylidae and Kiwaidae, including the common genera Galathea and Munida. They are not lobsters at all, but are more closely related to porcelain crabs, hermit crabs and then, more distantly, true crabs...
Galathea squamifera
Galathea squamifera
Galathea squamifera, the black squat lobster, or Montagu's plated lobster, is a species of squat lobster that lives in the north-east Atlantic Ocean and Mediterranean Sea.-Description:...
) and molluscs
Mollusca
The Mollusca , common name molluscs or mollusksSpelled mollusks in the USA, see reasons given in Rosenberg's ; for the spelling mollusc see the reasons given by , is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. Mollusca is the largest...
(including the gastropods
Gastropoda
The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylum Mollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to quite large...
Nucella lapillus
Dog Whelk
The dog whelk, dogwhelk, or Atlantic dogwinkle, scientific name Nucella lapillus, is a species of predatory sea snail, a carnivorous marine gastropod mollusc in the family Muricidae, the rock snails....
and Littorina littorea
Common Periwinkle
The common periwinkle or winkle, scientific name Littorina littorea, is a species of small edible sea snail, a marine gastropod mollusk which has gills and an operculum, and is classified within the family Littorinidae, the periwinkles....
, and the bivalves
Bivalvia
Bivalvia is a taxonomic class of marine and freshwater molluscs. This class includes clams, oysters, mussels, scallops, and many other families of molluscs that have two hinged shells...
Ensis
Ensis
Ensis is a genus of medium-sized edible saltwater clams, littoral bivalve mollusks in the family Pharidae.In the United States, other common names for species in this genus are razor clams or jackknife clams. This is because the long, narrow, and parallel-sided shape of their shells is unusual in...
, Mytilus edulis
Blue mussel
The blue mussel, Mytilus edulis, is a medium-sized edible marine bivalve mollusc in the family Mytilidae. In spite of its specific name edulis, it is not the sole edible Mytilus species.-Distribution:...
, Cerastoderma edule, Ostrea edulis and Lutraria lutraria
Lutraria lutraria
Lutraria lutraria is a species of large marine bivalve mollusc in the family Mactridae. Its common names include the otter shell and the common otter shell...
). It may stalk or ambush motile prey, and may dig large pits to reach buried molluscs. The main predator of Cancer pagurus is the octopus
Octopus
The octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...
, which will even attack them inside the crab pots that fishermen use to trap them.
Compared to other commercially important crab species, relatively little is known about diseases of Cancer pagurus. Its parasites include virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
es, such as the white spot syndrome
White spot syndrome
White spot syndrome is a viral infection of penaeid shrimp. The disease is highly lethal and contagious, killing shrimps quickly. Outbreaks of this disease have wiped out within a few days the entire populations of many shrimp farms throughout the world.The disease is caused by a family of related...
virus, various bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
that cause dark lesion
Lesion
A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :...
s on the exoskeleton
Exoskeleton
An exoskeleton is the external skeleton that supports and protects an animal's body, in contrast to the internal skeleton of, for example, a human. In popular usage, some of the larger kinds of exoskeletons are known as "shells". Examples of exoskeleton animals include insects such as grasshoppers...
, and Hematodinium
Hematodinium
Hematodinium is a genus of dinoflagellates. Species in this genus, such as Hematodinium perezi, the type species, are internal parasites of the hemolymph of crustaceans such as the Atlantic blue crab and Norway lobster...
-like dinoflagellate
Dinoflagellate
The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on temperature, salinity, or depth...
s that cause "pink crab disease". Other microscopic pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s include fungi, microsporidia
Microsporidia
The microsporidia constitute a phylum of spore-forming unicellular parasites. They were once thought to be protists but are now known to be fungi. Loosely 1500 of the probably more than one million species are named now. Microsporidia are restricted to animal hosts, and all major groups of animals...
ns, paramyxeans and ciliate
Ciliate
The ciliates are a group of protozoans characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagella but typically shorter and present in much larger numbers with a different undulating pattern than flagella...
s. Cancer pagurus is also targeted by metazoan
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
parasites, including trematodes
Trematoda
Trematoda is a class within the phylum Platyhelminthes that contains two groups of parasitic flatworms, commonly referred to as "flukes".-Taxonomy and biodiversity:...
and parasitic barnacle
Barnacle
A barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
s. A number of sessile
Sessility (zoology)
In zoology, sessility is a characteristic of animals which are not able to move about. They are usually permanently attached to a solid substrate of some kind, such as a part of a plant or dead tree trunk, a rock, or the hull of a ship in the case of barnacles. Corals lay down their own...
animals occasionally settle as epibiont
Epibiont
An epibiont is an organism that lives on the surface of another living organism. An epibiont is usually considered harmless to the host; in this sense, the relationship between the two organisms can be considered neutralistic or commensalistic. Typical epibionts are barnacles, remoras, and algae,...
s on the exoskeleton of C. pagurus, including barnacles, sea anemone
Sea anemone
Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Zoantharia. Anthozoa often have large polyps that allow for digestion of larger...
s, serpulid
Serpulidae
Serpulidae is a family of sessile, tube-building annelid worms in the class Polychaeta. The members of this family differ from the sabellid tube worms in that they have a specialized operculum that blocks the entrance of their tubes when they withdraw into the tubes. In addition, serpulids secrete...
polychaete
Polychaete
The Polychaeta or polychaetes are a class of annelid worms, generally marine. Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. Indeed, polychaetes are sometimes referred to as bristle worms. More than 10,000...
s such as Janua pagenstecheri
Janua pagenstecheri
Janua pagenstecheri is a species of marine polychaete. It is widely distributed around the British Isles and across north-western Europe, and has been described as "probably the commonest spirorbid in the world"....
, bryozoa
Bryozoa
The Bryozoa, also known as Ectoprocta or commonly as moss animals, are a phylum of aquatic invertebrate animals. Typically about long, they are filter feeders that sieve food particles out of the water using a retractable lophophore, a "crown" of tentacles lined with cilia...
ns and saddle oysters
Anomia (genus)
Anomia is a genus of bivalves in the family Anomiidae, commonly known as jingle shells.-Species :* Anomia achaeus Gray* Anomia chinensis* Anomia ephippium Linnaeus, 1758* Anomia laqueata Reeve* Anomia nobilis...
.
Fishery
Cancer pagurus is heavily exploited commerciallyCrab fisheries
Crab fisheries are fisheries which capture or farm crabs. True crabs make up 20% of all crustaceans caught and farmed worldwide, with about 1.4 million tonnes being consumed annually. The horse crab, Portunus trituberculatus accounts for one quarter of that total...
throughout its range, being the most commercially important crab species in Western Europe
Western Europe
Western Europe is a loose term for the collection of countries in the western most region of the European continents, though this definition is context-dependent and carries cultural and political connotations. One definition describes Western Europe as a geographic entity—the region lying in the...
. The crabs are caught using crab pots (similar to lobster pots
Lobster trap
Not to be confused with Lobster-tailed potA lobster trap or lobster pot is a portable trap that traps lobsters or crayfish and is used in lobster fishing. A lobster trap can hold several lobsters. Lobster traps are constructed of wire and wood. An opening permits the lobster to enter a tunnel of...
) which are placed offshore and baited. The catch of C. pagurus has increased steadily, rising from 26,000 tonnes in 1978 to 60,000 t in 2007, of which more than 70% was caught around the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
. The fishery is widely dispersed around the British and Irish coasts, and C. pagurus is thought to be overfished
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
across much of this area. Most of the edible crabs caught by the British fleet are exported live for sale in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
and Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
.
A number of legal restrictions apply to the catching of Cancer pagurus. It is illegal to catch "berried" crabs (females carrying eggs), but since ovigerous females remain in pits dug in the sediment and do not feed, fishing pressure does not affect the supply of larvae. Minimum landing size
Minimum landing size
The minimum landing size is the smallest length at which it is legal to keep or sell a fish. What the MLS is depends on the species of fish. Sizes also vary around the world, as they are legal definitions which are defined by the local regulatory authority...
s (MLS) for C. pagurus are set by both the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
technical regulations and by the UK government
Government of the United Kingdom
Her Majesty's Government is the central government of the United Kingdom of Great Britain and Northern Ireland. The Government is led by the Prime Minister, who selects all the remaining Ministers...
. Different minimum sizes are employed in different geographical areas, to reflect differences in the crab's growth rate across its range. In particular, the "Cromer crab" fishery along the coasts of Suffolk
Suffolk
Suffolk is a non-metropolitan county of historic origin in East Anglia, England. It has borders with Norfolk to the north, Cambridgeshire to the west and Essex to the south. The North Sea lies to the east...
, Norfolk
Norfolk
Norfolk is a low-lying county in the East of England. It has borders with Lincolnshire to the west, Cambridgeshire to the west and southwest and Suffolk to the south. Its northern and eastern boundaries are the North Sea coast and to the north-west the county is bordered by The Wash. The county...
and Lincolnshire
Lincolnshire
Lincolnshire is a county in the east of England. It borders Norfolk to the south east, Cambridgeshire to the south, Rutland to the south west, Leicestershire and Nottinghamshire to the west, South Yorkshire to the north west, and the East Riding of Yorkshire to the north. It also borders...
is subject to a MLS of 115 mm (4.5 in), rather than the 140 mm (5.5 in) MLS in most of the species' range. An intermediate value of 130 mm (5.1 in) is used in the rest of the North Sea between the 56th parallel north
56th parallel north
The 56th parallel north is a circle of latitude that is 56 degrees north of the Earth's equatorial plane. It crosses Europe, Asia, the Pacific Ocean, North America, and the Atlantic Ocean....
and the Essex
Essex
Essex is a ceremonial and non-metropolitan county in the East region of England, and one of the home counties. It is located to the northeast of Greater London. It borders with Cambridgeshire and Suffolk to the north, Hertfordshire to the west, Kent to the South and London to the south west...
–Kent
Kent
Kent is a county in southeast England, and is one of the home counties. It borders East Sussex, Surrey and Greater London and has a defined boundary with Essex in the middle of the Thames Estuary. The ceremonial county boundaries of Kent include the shire county of Kent and the unitary borough of...
border, and in the Irish Sea
Irish Sea
The Irish Sea separates the islands of Ireland and Great Britain. It is connected to the Celtic Sea in the south by St George's Channel, and to the Atlantic Ocean in the north by the North Channel. Anglesey is the largest island within the Irish Sea, followed by the Isle of Man...
south of 55° N
55th parallel north
The 55th parallel north is a circle of latitude that is 55 degrees north of the Earth's equatorial plane. It crosses Europe, Asia, the Pacific Ocean, North America, and the Atlantic Ocean....
. Around Devon
Devon
Devon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with...
, Cornwall
Cornwall
Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...
and the Isles of Scilly
Isles of Scilly
The Isles of Scilly form an archipelago off the southwestern tip of the Cornish peninsula of Great Britain. The islands have had a unitary authority council since 1890, and are separate from the Cornwall unitary authority, but some services are combined with Cornwall and the islands are still part...
, there is a separate MLS for males (160 mm or 6.3 in) and females (140 mm or 5.5 in). The Norwegian catch is 8,500 tons annually, compared to 20,000 tons in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, 13,000 tons in Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
, 8,500 tons in France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, and a total 45,000 tons globally.
Cookery
Around one third of the weight of an adult edible crab is meat, of which one third is white meat from the claws, and two thirds is brown meat from the body. As food, male edible crabs are referred to as cocks and females as hens. Cocks have more sweet white meat; hens have more rich brown meat. Dishes include (crab meat arranged in the cleaned shell with other foodstuffs), soups such as bisqueBisque (food)
Bisque is a smooth, creamy, highly-seasoned soup of French origin, classically based on a strained broth of crustaceans. It can be made from lobster, crab, shrimp or crayfish...
or bouillabaisse
Bouillabaisse
Bouillabaisse is a seafood soup made with various kinds of cooked fish and shellfish and vegetables, flavored with a variety of herbs and spices such as garlic, orange peel, basil, bay leaf, fennel and saffron. Bouillabaisse is a traditional Provençal fish stew originating from the port city of...
, pâté
Pâté
Pâté is a mixture of ground meat and fat minced into a spreadable paste. Common additions include vegetables, herbs, spices, and either wine or cognac, armagnac or brandy...
s, mousse
Mousse
Mousse is derived from the French word mousse which means "lather" or "foam". A mousse is a prepared food that incorporates air bubbles to give it a light and airy texture...
s and hot soufflé
Soufflé
A soufflé is a light baked cake made with egg yolks and beaten egg whites combined with various other ingredients and served as a savoury main dish or sweetened as a dessert...
s.
Taxonomy and systematics
According to the rules of the International Code of Zoological NomenclatureInternational Code of Zoological Nomenclature
The International Code of Zoological Nomenclature is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals...
, Cancer pagurus was first described by Carl Linnaeus in 1758, in the tenth edition
10th edition of Systema Naturae
The 10th edition of Systema Naturae was a book written by Carl Linnaeus and published in two volumes in 1758 and 1759, which marks the starting point of zoological nomenclature...
of his Systema Naturae
Systema Naturae
The book was one of the major works of the Swedish botanist, zoologist and physician Carolus Linnaeus. The first edition was published in 1735...
, which marks the starting point of zoological nomenclature. It was chosen to be the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of the genus Cancer
Cancer (genus)
Cancer is a genus of marine crabs in the family Cancridae. It includes 8 extant species and 3 extinct species, including familiar crabs of the littoral zone, such as the European edible crab , the Jonah crab and the red rock crab...
by Pierre André Latreille
Pierre André Latreille
Pierre André Latreille was a French zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, and only regained his freedom after recognising a rare species he found in the prison, Necrobia ruficollis...
in 1810. The specific epithet is a Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
word, deriving from the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
(), which, alongside "" (), was used to refer to edible marine crabs; neither classical term can be confidently assigned to a particular species.
Although the genus Cancer formerly included most crabs, it has since been restricted to eight species. Within that set of closely related species, the closest relative of C. pagurus is the Jonah crab
Jonah crab
The Jonah crab, Cancer borealis, is a species of crab found on the Atlantic coast of North America. It is closely related to the Dungeness crab of the Pacific coast, and is known for its strong claws, although it is not a very aggressive species. It has been fished on a small scale since the 1970s,...
, Cancer borealis, from the east coast of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
.
External links
- Dressed crab, recipe from BBC FoodBBC FoodBBC Food was the name of the BBC's international commercial television channel focusing solely on food until it was replaced in the television markets it was broadcast by BBC Lifestyle. The channel was owned and operated by BBC Worldwide, the BBC's commercial arm.The channel launched in June 2002...