''Neohelice granulata'' is a species 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 ...

in the family

Varunidae The Varunidae are a family (biology), family of thoracotrematan crabs. The delimitation of this family, part of the taxonomically confusing Grapsoidea, is undergoing revision. For a long time, they were placed at the rank of subfamily in the Grap ...

, and the only species in the genus ''Neohelice''. In 2009, it was estimated that ''N. granulata'' was the sixth most studied species of crab.

Distribution and ecology

''Neohelice'' is found in the south-western

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

, from the Laguna Araruama in

Rio de Janeiro state Rio de Janeiro () is one of the 27 federative units of Brazil. It has the second largest economy of Brazil, with the largest being that of the state of São Paulo. The state, which has 8.2% of the Brazilian population, is responsible for 9.2% of ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

to the Golfo San José (on the north side of the

Valdes Peninsula Valdez or Valdés may refer to: People *Valdez (surname) *Valdés (surname) * Valdez (Brazilian footballer) (born 1943), a Brazilian former footballer * Valdez Demings, U.S. politician Geography * Valdés, Asturias, Spain *Valdez, Alaska Vald ...

Patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

). The diet of ''Neohelice'' in the wild most consists of sediment, ''

Spartina ''Spartina'' is a genus of plants in the grass family, frequently found in coastal salt marshes. Species in this genus are commonly known as cordgrass or cord-grass, and are native to the coasts of the Atlantic Ocean in western and southern Eu ...

'' and plant-derived

detritus In biology, detritus ( or ) is organic matter made up of the decomposition, decomposing remains of organisms and plants, and also of feces. Detritus usually hosts communities of microorganisms that colonize and decomposition, decompose (Reminera ...

Taxonomic history

The first report of ''Neohelice'' was probably that made by

Alcide d'Orbigny Alcide Charles Victor Marie Dessalines d'Orbigny (6 September 1802 – 30 June 1857) was a French naturalist who made major contributions in many areas, including zoology (including malacology), palaeontology, geology, archaeology and anthropol ...

during an expedition to South America between 1826 and 1834. He included details of the crab's ecology, including their burrows, but did not name the species. The first person to describe the species taxonomically was

James Dwight Dana James Dwight Dana Royal Society of London, FRS FRSE (February 12, 1813 – April 14, 1895) was an American geologist, mineralogist, volcanologist, and zoologist. He made pioneering studies of mountain-building, volcano, volcanic activity, and the ...

, who named it ''Chasmagnathus granulatus'' in his 1851 work reporting the results of the

United States Exploring Expedition The United States Exploring Expedition of 1838–1842 was an exploring and surveying expedition of the Pacific Ocean and surrounding lands conducted by the United States. The original appointed commanding officer was Commodore Thomas ap Catesby ...

(also known as the "Wilkes expedition"). In 1918, Mary J. Rathbun redescribed the species under the modified name "''Chasmagnathus granulata''", which remained in occasional use along Dana's name until 2006, when Katushi Sakai, Michael Türkay and Si-Liang Yang revised the genera '' Helice'' and ''

Chasmagnathus ''Chasmagnathus convexus'' is a common mud-flat crab of the family (biology), family Varunidae, which is endemism, endemic to East Asia. In Japan, this crab is commonly called ''hamagani''. This crab has two forms that differ in color; one is ol ...

''. They restricted both genera to those species occurring in

East Asia East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of Economy of China, China, Economy of Ja ...

, and erected a new genus for ''C. granulatus'', which thus became ''Neohelice granulata'', as well as the genera '' Austrohelice'' and '' Pseudohelice''.

Importance

''Neohelice granulata'' has emerged since the 1980s as a model species in a variety of biological fields. Much of the

scientific research The scientific method is an empirical method for acquiring knowledge that has been referred to while doing science since at least the 17th century. Historically, it was developed through the centuries from the ancient and medieval world. The ...

has focused on the species' tolerance of both fresh water and brine (euryhalinity) and its semiterrestrial habit. It has also been investigated for research into

neurophysiology Neurophysiology is a branch of physiology and neuroscience concerned with the functions of the nervous system and their mechanisms. The term ''neurophysiology'' originates from the Greek word ''νεῦρον'' ("nerve") and ''physiology'' (whic ...

, neurobiology of learning and memory,Lessons from a crab: molecular mechanisms in different memory phases of Chasmagnathus. Romano A, Locatelli F, Freudenthal R, Merlo E, Feld M, Ariel P, Lemos D, Federman N, Fustiñana MS. Biol Bull. 2006 Jun;210(3):280-8. doi: 10.2307/4134564.

toxicology Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine, that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating ex ...

and ecosystem dynamics. Such breadth of study is unusual for a model organism. In 2009, Eduardo Spivak tallied the number of

scientific paper Scientific literature encompasses a vast body of academic papers that spans various disciplines within the natural and social sciences. It primarily consists of academic papers that present original empirical research and theoretical ...

s published about different crab species over the previous 23 years, and found that ''Neohelice granulata'' was the sixth most studied crab species, after ''

Carcinus maenas ''Carcinus maenas'' is a common littoral crab. It is known by different names around the world. In the British Isles, it is generally referred to as the shore crab or green shore crab. In North America and South Africa, it bears the name Europe ...

'', ''

Callinectes sapidus ''Callinectes sapidus'' (from the Ancient Greek language, Ancient Greek ,"beautiful" + , "swimmer", and Latin , "savory"), the blue crab, Atlantic blue crab, or, regionally, the Maryland blue crab, is a species of crab native to the waters of t ...

'', ''

Scylla serrata ''Scylla serrata'' (often called mud crab or mangrove crab, although both terms are highly ambiguous, and black crab) is an ecologically important species of crab found in the estuaries and mangroves of Africa, Australia, and Asia. In their ...

'', ''

Cancer pagurus ''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 wit ...

'' and ''

Metacarcinus magister The Dungeness crab (''Metacarcinus magister'') makes up one of the most important seafood industries along the west coast of North America. Its typical range extends from Alaska's Aleutian Islands to Point Conception, near Santa Barbara, Califor ...

'', but ahead of the invasive and edible

Chinese mitten crab The Chinese mitten crab (''Eriocheir sinensis''; ; Jyutping: daai6 zaap6 haai5; Shanghainese: ''du6-zaq8-ha5'', "big sluice crab"), also known as the Shanghai hairy crab (, p ''Shànghǎi máoxiè''), is a medium-sized burrowing cr ...

(''Eriocheir sinensis'') and the commercially important "snow crab", ''

Chionoecetes opilio ''Chionoecetes opilio'', a species of snow crab, also known as opilio crab or opies, is a predominantly epifaunal crustacean native to shelf depths in the northwest Atlantic Ocean and north Pacific Ocean. It is a well-known commercial species ...

''.

Distribution and ecology

Taxonomic history

Importance

References

Further reading