Cancer (genus)

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Cancer
Temporal range: Miocene–Recent
Boi.crab2.jpg
Edible crab, Cancer pagurus
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Suborder: Pleocyemata
Infraorder: Brachyura
Family: Cancridae
Genus: Cancer
Linnaeus, 1758
Type species
Cancer pagurus
Linnaeus, 1758
Synonyms   [1]

PlatycarcinusH. Milne-Edwards, 1834

Cancer is a genus of marine crabs in the family Cancridae. It includes eight extant species and three extinct species, including familiar crabs of the littoral zone, such as the European edible crab ( Cancer pagurus ), the Jonah crab (Cancer borealis) and the red rock crab ( Cancer productus ). It is thought to have evolved from related genera in the Pacific Ocean in the Miocene.

Contents

Description

The species placed in the genus Cancer are united by the presence of a single posterolateral spine (on the edge of the carapace, towards the rear), anterolateral spines with deep fissures (on the carapace edge, towards the front), and a short extension of the carapace forward between the eyes. [2] Their claws are typically short, with grainy or smooth, rather than spiny, keels. [2] The carapace is typically oval, being 58%–66% as long as wide, and the eyes separated by 22%–29% of the carapace width. [2]

Species

The genus Cancer, as currently circumscribed, contains eight extant species: [1] [3]

ImageNameCommon nameDistribution
Cancer bellianus Johnston 1861 stuffed museum La Rochelle.jpg Cancer bellianus Johnson, 1861toothed rock crabnorth-eastern Atlantic Ocean.
Jonah crab (11823580556).jpg Cancer borealis Stimpson, 1859Jonah crabeast coast of North America from Newfoundland to Florida.[
Rock crab on tunicate colony.jpg Cancer irroratus Say, 1817Atlantic rock crabfrom Iceland to South Carolina
Cancer johngarthi Carvacho, 1989eastern Pacific Ocean from Mexico to Panama
Arthropods crab.jpg Cancer pagurus Linnaeus, 1758edible crab or brown crabthe North Sea, North Atlantic Ocean, and perhaps the Mediterranean Sea.
Cancer plebejus - Finnish Museum of Natural History - DSC04680 1.jpg Cancer plebejus Poeppig, 1836Chilean crabSoutheast Pacific and Southwest Atlantic: Chile and Peru.
Cancer porteri Rathbun, 1930bocoGulf of Panama to Valparaiso, Chile; Pacific South America.
Cancer productus.jpg Cancer productus J. W. Randall, 1840red rock crabKodiak Island, Alaska to Isla San Martine, Baja California

Three fossil species are also included: [2]

As their generic delimitation was based on characters of the dorsal carapace, Schweitzer and Feldmann (2000) were unable to confirm the placement of Cancer tomowoi in the genus, since it is known only from parts of the sternum and the legs. [2] Other species until recently included in the genus Cancer have since been transferred to other genera, such as Glebocarcinus , Metacarcinus and Romaleon . [1]

Taxonomic history

When zoological nomenclature was first standardised by Carl Linnaeus in the 1758 10th edition of Systema Naturae , the genus Cancer included almost all crustaceans, including all the crabs. [3] [4] Linnaeus' cumbersome genus was soon divided into more meaningful units, and Cancer had been restricted to one group of true crabs by the time of Pierre André Latreille's 1802 work Histoire naturelle, générale et particulière des Crustacés et des Insectes ("Natural history in general, and specifically that of crustaceans and insects"). [3] Latreille designated C. pagurus to be the type species in 1817. [1]

In 1975, J. Dale Nations divided the genus Cancer into four subgenera: Cancer (Cancer), Cancer (Glebocarcinus), Cancer (Metacarcinus) and Cancer (Romaleon). [3] [5] Each of these is now treated as a separate genus, as is the genus Platepistoma , erected by Mary J. Rathbun and resurrected in 1991. [3] Since that time, further genera have been described to accommodate species previously included in Cancer, and the genus Cancer now contains only eight extant species. [3]

Evolutionary history

The earliest fossils that can be confidently ascribed to the genus Cancer are those of C. fujinaensis from the Japanese Miocene. [2] The genus is therefore thought to have evolved in the northern Pacific Ocean, perhaps during the Miocene, and have spread across that ocean and into the Atlantic Ocean by the Pliocene or Pleistocene, having crossed the equator and the Straits of Panama. [2]

Related Research Articles

<i>Cancer pagurus</i> Species of crustacean

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 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 up to 25 centimetres and weigh up to 3 kilograms. 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 on the coasts of the British Isles, with more than 60,000 tonnes caught annually.

<i>Nephrops</i> Genus of lobsters

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.

<i>Calappa</i> (crab) Genus of crabs

Calappa is a genus of crabs known commonly as box crabs or shame-faced crabs. The name box crab comes from their distinctly bulky carapace, and the name shame-faced is from anthropomorphising the way the crab's chelae (claws) fold up and cover its face, as if it were hiding its face in shame.

<span class="mw-page-title-main">Portunidae</span> Family of crabs

Portunidae is a family of crabs which contains the swimming crabs.

<i>Metacarcinus gracilis</i> Species of crab

The graceful rock crab or slender crab, Metacarcinus gracilis or Cancer gracilis, is one of only two members of the genus Metacarcinus, recognized by WoRMS, whose chelae (claws) are white tipped, the other crab being M. magister. Both of these eastern Pacific crab species are recognized by ITIS as belonging to the much larger genus Cancer. M. gracilis has been caught from Alaska to Bahía Magdelena, Baja California. Although M. gracilis is only found in the Pacific Ocean, it has cousins in the Atlantic Ocean. The genus Cancer apparently evolved in the Pacific Ocean and later migrated to the Atlantic Ocean. Larvae and small juveniles of this species are often seen riding jellyfish, especially Phacellophora camtschatica. The juvenile crabs steal food from the jellyfish and also clean off parasitic amphipods.

<span class="mw-page-title-main">Pie crust crab</span> Species of crab

The pie crust crab, is a species of crab found around New Zealand and south-eastern Australia.

<span class="mw-page-title-main">Cancridae</span> Family of crabs

Cancridae is a family of crabs. It comprises six extant genera, and ten exclusively fossil genera, in two subfamilies:

<span class="mw-page-title-main">Retroplumidae</span> Family of crabs

Retroplumidae is a family of heterotrematan crabs, placed in their own (monotypic) superfamily, Retroplumoidea.

Metacarcinus starri is an extinct species of crab in the family Cancridae, subfamily Cancrinae. The species is known solely from the early Miocene, Clallam Formation and the underlying Pysht Formation deposits on the Olympic Peninsula of Washington state, United States.

<span class="mw-page-title-main">Goneplacidae</span> Family of crabs

Goneplacidae is a family of crabs of the order Decapoda and the superfamily Goneplacoidea. It includes the following genera:

Hexapodidae is a family of crabs, the only family in the superfamily Hexapodoidea. It has traditionally been treated as a subfamily of the family Goneplacidae, and was originally described as a subfamily of Pinnotheridae. Its members can be distinguished from all other true crabs by the reduction of the thorax, such that only seven sternites are exposed, and only four pairs of pereiopods are present. Not counting the enlarged pair of claws, this leaves only six walking legs, from which the type genus Hexapus, and therefore the whole family, takes its name. Some anomuran "crabs", such as porcelain crabs and king crabs also have only four visible pairs of legs. With the exception of Stevea williamsi, from Mexico, all the extant members are found either in the Indo-Pacific oceans, or around the coast of Africa.

<i>Metacarcinus</i> Genus of crabs

Metacarcinus is a genus of crabs formerly included in the genus Cancer. It includes nine exclusively fossil species and five extant species, of which four are also known from the fossil record. A molecular study using the cytochrome oxidase I gene does not support the monophyly of this genus.

<i>Romaleon</i> Genus of crabs

Romaleon is a genus of marine crabs formerly considered in the genus Cancer.

<i>Actumnus</i> Genus of crabs

Actumnus is a genus of crabs in the family Pilumnidae. Alongside the 28 extant species, it has a fossil record extending back into the Miocene.

<i>Planes</i> (genus) Genus of crabs

Planes is a genus of crabs in the family Grapsidae that currently comprises three extant species: Planes minutus, Planes marinus Rathbun, 1914, and Planes major (=cyaneus). A further fossil species is known from the Middle Miocene of the Caucasus.

Anatolikos is a genus of two species of crabs in the family Cancridae. They are recorded from Japan and Taiwan. Two fossil species are known, one from Japan and one from Mexico.

<i>Hepatus</i> Genus of crabs

Hepatus is a genus of crabs in the family Aethridae, containing seven extant species, plus some fossil species:

<i>Speocarcinus</i> Genus of crabs

Speocarcinus is a genus of crabs in the family Xanthidae, containing six extant species, one fossil species from the Late Miocene, one fossil species from the Eocene (Lutetian) and one fossil species from the Early Eocene (Ypresian):

<i>Zosimus</i> (crab) Genus of crabs

Zosimus is a genus of crabs in the family Xanthidae, containing the following species:

<i>Oregonia</i> (genus) Genus of crabs

Oregonia is a genus of crabs, comprising two extant species and one fossil species: It is classified in the family Oregoniidae under the spider crab superfamily Majoidea.

References

  1. 1 2 3 4 P. K. L. Ng, D. Guinot & P. J. F. Davie (2008). "Systema Brachyurorum: Part I. An annotated checklist of extant Brachyuran crabs of the world" (PDF). Raffles Bulletin of Zoology . 17: 1–286. Archived from the original (PDF) on 2011-06-06.
  2. 1 2 3 4 5 6 7 Carrie E. Schweitzer & Rodney M. Feldmann (2000). "Re-evaluation of the Cancridae Latreille, 1802 (Decapoda: Brachyura) including three new genera and three new species". Contributions to Zoology . 69 (4): 223–250. doi: 10.1163/18759866-06904002 . Also available as PDF.
  3. 1 2 3 4 5 6 Frederick R. Schram & Peter K. L. Ng (2012). "What is Cancer?". Journal of Crustacean Biology . 32 (4): 665–672. doi: 10.1163/193724012X640650 .
  4. Boxshall, Geoff A. (2007). "Crustacean classification: on-going controversies and unresolved problems". Zootaxa. 1668 (1): 313–325. doi:10.11646/zootaxa.1668.1.16.
  5. J. Dale Nations (1975). "The genus Cancer (Crustacea: Bachyura): systematics, biogeography, and fossil record" (PDF). Natural History Museum of Los Angeles County Science Bulletin. 23: 1–104.