''Pisidia longicornis'', the long-clawed porcelain crab, is a

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), ...

porcelain crab Porcelain crabs are decapod crustaceans in the widespread family Porcellanidae, which superficially resemble true crabs. They have flattened bodies as an adaptation for living in rock crevices. They are delicate, readily losing limbs when attacke ...

that lives in the north-eastern

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 ...

. It varies from reddish to white, and grows to 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 ...

width of . It was first named by

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

in 1767, although the etymology remains unclear.

Description

Adult ''Pisidia longicornis'' typically have a

length of . Its colouration is variable, with most individuals being reddish or orange, but some having patches of

pearl A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle (mollusc), mantle) of a living Exoskeleton, shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pear ...

y white, or even being entirely white. One cheliped (claw-bearing

appendage An appendage (or outgrowth) is an external body part or natural prolongation that protrudes from an organism's body such as an arm or a leg. Protrusions from single-celled bacteria and archaea are known as cell-surface appendages or surface app ...

) is usually larger than the other, although this difference is less pronounced in females than in males. The fifth pair of legs is reduced in size and may be difficult to see.

Distribution and ecology

''Pisidia longicornis'' is found in the north-eastern

from

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

Angola Angola, officially the Republic of Angola, is a country on the west-Central Africa, central coast of Southern Africa. It is the second-largest Portuguese-speaking world, Portuguese-speaking (Lusophone) country in both total area and List of c ...

, and throughout the

Mediterranean Sea The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern Eur ...

. It is found from the lower shore down to depths of in the north Atlantic, but at depths of in some locations around the Mediterranean Sea. It lives under boulders and among

bryozoa Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic animal, aquatic invertebrate animals, nearly all living in sedentary Colony (biology), colonies. Typically about long, they have a spe ...

n turfs, and may occasionally be found in

fish market A fish market is a marketplace for selling Fish as food, fish and fish products. It can be dedicated to wholesale trade between Fisherman, fishermen and fish merchants, or to the sale of seafood to individual consumers, or to both. Retail fish ma ...

s among

mussel Mussel () is the common name used for members of several families of bivalve molluscs, from saltwater and Freshwater bivalve, freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other ...

s and

oyster Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but no ...

s. It feeds by

filtering Filtration is a physical process that separates solid matter and fluid from a mixture. Filter, filtering, filters or filtration may also refer to: Science and technology Computing * Filter (higher-order function), in functional programming * Fil ...

suspended material from the sea water. Individuals from the

intertidal zone The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various ...

tend to be larger than those from deeper water, which may be related to the greater churning of the sediment by the

tide Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables ...

Life cycle

Females bear eggs from March to August around the

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

, and from February to September in the Mediterranean Sea. Young ''Pisidia longicornis'' go through two

zoea Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The ...

l (larval) stages before reaching the

megalopa Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow. The ...

(post-larval) stage. The zoea larvae bear "exceptionally long" spines on the

, one directed forwards, and two directed backwards. The second zoeal stage may reach a length of , while the megalopa has a

width of .

Taxonomy

''Pisidia longicornis'' was first described in 1767 by

, originally under the name ''Porcellana longicornis'', in the

12th edition 1 (one, unit, unity) is a number, numeral, and glyph. It is the first and smallest positive integer of the infinite sequence of natural numbers. This fundamental property has led to its unique uses in other fields, ranging from science to sp ...

of his ''

Systema Naturae ' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the syste ...

''. The

specific epithet In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

' is difficult to explain, it being

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

for "long-horned", from ' and '; it may refer to the long chelipeds (claw-bearing appendages). The species was moved from the genus '' Porcellana'' by

William Elford Leach William Elford Leach (2 February 1791 – 25 August 1836) was an English zoologist and marine biologist. Life and work Elford Leach was born at Hoe Gate, Plymouth, the son of an attorney. At the age of twelve he began a medical apprenticesh ...

when he established the genus ''

Pisidia Pisidia (; , ; ) was a region of ancient Asia Minor located north of Pamphylia, northeast of Lycia, west of Isauria and Cilicia, and south of Phrygia, corresponding roughly to the modern-day province of Antalya in Turkey. Among Pisidia's set ...

'' in 1820.

External links

''Pisidia longicornis''
British Marine Life Study Society

References

{{Authority control Porcelain crabs Anomura of the Atlantic Ocean Crustaceans described in 1767 Taxa named by Carl Linnaeus