''Orithyia sinica'', sometimes called tiger crab or the tiger face crab, is a "singularly unusual"

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), ...

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 ...

, whose characteristics warrant its separation into a separate

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 ...

and even

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

, having previously been included in the Dorippoidea or

Leucosioidea Leucosioidea is a superfamily 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 ...

. Its

larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

, for instance, are unlike those of any other crab.

Description

''Orithyia sinica'' is a distinctive species, with stripes on 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 ...

, and prominent eyespots on the

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 ...

; the females'

abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...

is unusually narrow, leaving the vulvae exposed. The legs are flattened at the end, and this is an adaptation to digging, not

swimming Swimming is the self-propulsion of a person through water, such as saltwater or freshwater environments, usually for recreation, sport, exercise, or survival. Swimmers achieve locomotion by coordinating limb and body movements to achieve hydrody ...

Distribution and fishery

''Orithyia sinica'' is found along the coast of mainland

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

from

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

Hong Kong Hong Kong)., Legally Hong Kong, China in international treaties and organizations. is a special administrative region of China. With 7.5 million residents in a territory, Hong Kong is the fourth most densely populated region in the wor ...

, but is missing from the nearby

island An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been ...

s, such as

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

, the

Ryukyu Islands The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Geography of Taiwan, Taiwan: the Ryukyu Islands are divided into the Satsunan Islands (Ōsumi Islands, Ōsumi, Tokara Islands, Tokara and A ...

and

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, even though the intervening waters are shallow and the crab's

are

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

ic. Throughout its range, ''O. sinica'' is fished on a small scale and commands high prices.

Etymology

The name ''Orithyia'' (also spelt ''Orithuja'') commemorates

Orithyia In Greek mythology, Orithyia or Oreithyia (; ; ) was the name of the following women: *Orithyia or Orythya, the Nereid of raging seas and one of the 50 marine-nymph daughters of the ' Old Man of the Sea' Nereus and the Oceanid Doris. She and he ...

, daughter of

Erechtheus Erechtheus (; ) in Greek mythology was a king of Athens, the founder of the ''polis'' and, in his role as god, attached to Poseidon, as "Poseidon Erechtheus". The name Erichthonius is carried by a son of Erechtheus, but Plutarch conflated the tw ...

King of Athens Before the Athenian democracy, the tyrants, and the Archons, the city-state of Athens was ruled by kings. Most of these are probably mythical or only semi-historical. The following lists contain the chronological order of the title King of Athens ...

References

External links

* {{Taxonbar, from1=Q1060688, from2=Q18585208, from3=Q15144458, from4=Q16344755 Crabs Edible crustaceans Commercial crustaceans Crustaceans described in 1771 Crabs of the Pacific Ocean Crustaceans of Korea Crustaceans of China Marine fauna of East Asia Invertebrates of Hong Kong Taxa named by Carl Linnaeus