Majidae is a
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
of
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, comprising around 200
marine species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
inside 52 genera, with a
carapace
A carapace is a dorsal (upper) 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 unde ...
that is longer than it is broad, and which forms a point at the front. The
legs
A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element cap ...
can be very long in some species, leading to the name "
spider crab
The Majoidea are a superfamily of crabs which includes the various spider crabs.
Taxonomy
In "''A classification of living and fossil genera of decapod crustaceans''" De Grave and colleagues divided Majoidea into six families. The classificati ...
". 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 covered with bristles to which the crab attaches
alga
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, suc ...
e and other items to act as
camouflage
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...
.
Genera
The roughly 200 extant and over 50 extinct species are divided among 52 genera in 5 subfamilies:
*''
Eurynolambrus''
H. Milne-Edwards & Lucas, 1841
Majinae Samouelle, 1819
*''
Ageitomaia''
Griffin & Tranter, 1986
*''
Anacinetops''
Miers, 1879
*''
Choniognathus''
Rathbun, 1932
*''
Cyclax''
Dana, 1851
*''
Entomonyx''
Miers, 1884
*''
Eurynome
Eurynomê (; Ancient Greek: Εὐρυνόμη, from , ''eurys'', "broad" and , ''nomos'', "pasture" or "law") is a name that refers to the following characters in Greek mythology:
* Eurynome, pre-Olympian queen and wife of Ophion
* Eurynome (Oce ...
''
Leach, 1814
*''
Jacquinotia''
Rathbun, 1915
*''
Kasagia''
Richer de Forges & Ng, 2007
*''
Kimbla''
Griffin & Tranter, 1986
*''
Leptomithrax''
Miers, 1876
*''
Maiopsis''
Faxon, 1893
*''
Maja''
Lamarck, 1801
*''
Majella
The Maiella (or Majella) is a massif in the Central Apennines, in Abruzzo, central Italy
Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Penins ...
''
Ortmann, 1893
*''
Microhalimus''
Haswell, 1880
*''
Naxia''
Latreille, 1825
*''
Notomithrax''
Griffin, 1963
*''
Paraentomonyx''
T. Sakai, 1983
*''
Paramithrax''
H. Milne-Edwards, 1837
*''
Pippacirama''
Griffin & Tranter, 1986
*''
Prismatopus''
Ward, 1933
*''
Schizophroida''
T. Sakai, 1933
*''
Schizophrys''
White, 1848
*''
Seiitaoides''
Griffin & Tranter, 1986
*''
Temnonotus''
A. Milne-Edwards, 1875
*''
Teratomaia''
Griffin & Tranter, 1986
*''
Thersandrus''
Rathbun, 1897
*''
Tumulosternum''
McCulloch, 1913
*''
Wilsonimaia'' †
Blow & Manning, 1996
Micromaiinae †
Beurlen, 1930
*''
Micromaia'' †
Bittner, 1875
*''
Mithracia'' †
Bell, 1858
*''
Pisomaja'' †
Lőrenthey, in Lőrenthey & Beurlen, 1929
Mithracinae MacLeay, 1838
*''
Ala''
Lockington, 1877
*''
Antarctomithrax'' †
Feldmann, 1994
*''
Coelocerus''
A. Milne-Edwards, 1875
*''
Cyclocoeloma''
Miers, 1880
*''
Cyphocarcinus''
A. Milne-Edwards, 1868
*''
Leptopisa''
Stimpson, 1871
*''
Macrocoeloma''
Miers, 1879
*''
Micippa''
Leach, 1817
*''
Microphrys''
Milne-Edwards, 1851
*''
Mithraculus''
White, 1847
*''
Mithrax''
A. G. Desmarest, 1823
*''
Nemausa''
A. Milne-Edwards, 1875
*''
Paranaxia''
Rathbun, 1924
*''
Picroceroides''
Miers, 1886
*''
Stenocionops''
A. G. Desmarest, 1823
*''
Teleophrys''
Stimpson, 1860
*''
Thoe''
Bell, 1836
*''
Tiarinia''
Dana, 1851
Planoterginae Števčić, 1991
*''
Hemus''
A. Milne-Edwards, 1875
*''
Planotergum''
Balss, 1935
Image:Majoidea (pe Cyclocoeloma tuberculata) Landaagiraavaru.JPG, '' Cyclocoeloma cf. tuberculata''
Image:Leptomithrax gaimardii P2023255.JPG, '' Leptomithrax gaimardii''
Image:Maja squinado.jpg, ''Maja squinado
''Maja squinado'' (the European spider crab, spiny spider crab or spinous spider crab) is a species of Animal migration, migratory crab found in the Mediterranean Sea. The appearance of the European spider crab is similar to the much larger Japan ...
''
Image:Micippa platipes, sur le dos.jpg, '' Micippa platipes'' (on its back)
Image:Female Mithraculus sculptus Crab.jpg, ''Mithraculus sculptus
''Mithraculus sculptus'', the green clinging crab or emerald crab, is a species of crab in the family Majidae. It is a dark green colour and is found in tropical waters in the Caribbean Sea. It is sometimes kept in reef aquaria.
Description
''Mi ...
''
Image:Mithrax pilosus.jpg, '' Mithrax pilosus''
References
Majoidea
Decapod families
Taxa named by George Samouelle
{{Majoidea-stub