Matutidae
Encyclopedia
Matutidae is a family
of crab
s, sometimes called moon crabs, adapted
for swimming or digging. They differ from the swimming crabs of the family Portunidae
in that all five pairs of legs
are flattened, rather than just the last pair, as in Portunidae. Crabs in the Matutidae are aggressive
predators.
, and was considered a subfamily of the Calappidae
. Now, the group is ranked
as a family and six genera (four extant and two fossil) are now recognised. Although placed in the Calappoidea
, it is not clear that Matutidae and Calappidae are closely related.
fossil
deposits of Middle Miocene
age. Eomatuta was described from the Middle Eocene of Italy
in 2009. Fossils of Ashtoret
have also been found in Miocene
deposits in Japan
.
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of crab
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...
s, sometimes called moon crabs, adapted
Adaptation
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....
for swimming or digging. They differ from the swimming crabs of the family Portunidae
Portunidae
Portunidae is a family of crabs which contains the swimming crabs.-Description:Portunid crabs are characterised by the flattening of the fifth pair of legs into broad paddles, which are used for swimming...
in that all five pairs of legs
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 ,...
are flattened, rather than just the last pair, as in Portunidae. Crabs in the Matutidae are aggressive
Aggression
In psychology, as well as other social and behavioral sciences, aggression refers to behavior between members of the same species that is intended to cause humiliation, pain, or harm. Ferguson and Beaver defined aggressive behavior as "Behavior which is intended to increase the social dominance of...
predators.
Taxonomy
Traditionally, this taxon contained the single genus MatutaMatuta
Matuta is a genus of crabs in the family Matutidae, containing the following species:* Matuta banksi Leach, 1817* Matuta circulifera Miers, 1880* Matuta planipes Fabricius, 1798* Matuta purnama Lai & Galil, 2007...
, and was considered a subfamily of the Calappidae
Calappidae
Calappidae is a family of crabs containing 16 genera, of which 7 are only known as fossils:*Acanthocarpus Stimpson, 1871*Calappa Weber, 1795*† Calappella Rathbun, 1919*† Calappilia A. Milne-Edwards, 1873*Calappula Galil, 1997...
. Now, the group is ranked
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...
as a family and six genera (four extant and two fossil) are now recognised. Although placed in the Calappoidea
Calappoidea
Calappoidea is a superfamily of crabs comprising the two families Calappidae and Matutidae. The earliest fossils attributable to the Callpoidea date from the Aptian....
, it is not clear that Matutidae and Calappidae are closely related.
- AshtoretAshtoretAshtoret is a genus of crabs in the family Matutidae, containing the following species:* Ashtoret granulosa * Ashtoret lunaris * Ashtoret maculata * Ashtoret miersii...
Galil & P. F. Clark, 1994 - † Eomatuta De Angeli & Marchiori, 2009
- IzanamiIzanami (crab)Izanami is a genus of crabs in the family Matutidae, containing the following species:* Izanami curtispina * Izanami inermis...
Galil & P. F. Clark, 1994 - MatutaMatutaMatuta is a genus of crabs in the family Matutidae, containing the following species:* Matuta banksi Leach, 1817* Matuta circulifera Miers, 1880* Matuta planipes Fabricius, 1798* Matuta purnama Lai & Galil, 2007...
Weber, 1795 - MebeliMebeliMebeli michaelseni is a species of crab in the family Matutidae, the only species in the genus Mebeli....
Galil & P. F. Clark, 1994 - † Szaboa Müller & Galil, 1998
Fossil record
Szaboa is known only from HungarianHungary
Hungary , officially the Republic of Hungary , is a landlocked country in Central Europe. It is situated in the Carpathian Basin and is bordered by Slovakia to the north, Ukraine and Romania to the east, Serbia and Croatia to the south, Slovenia to the southwest and Austria to the west. The...
fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
deposits of Middle Miocene
Middle Miocene
The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene....
age. Eomatuta was described from the Middle Eocene of Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
in 2009. Fossils of Ashtoret
Ashtoret
Ashtoret is a genus of crabs in the family Matutidae, containing the following species:* Ashtoret granulosa * Ashtoret lunaris * Ashtoret maculata * Ashtoret miersii...
have also been found in Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
deposits in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
.