Porcupine ray
Encyclopedia
The porcupine ray is a rare species
of stingray
in the family
Dasyatidae and the only member of its genus
. This bottom-dweller is found throughout the tropical Indo-Pacific
, as well as off West Africa
. It favors sand, coral
rubble, and seagrass
habitat
s in inshore waters to a depth of 30 m (98.4 ft). A large and heavy-bodied species reaching 1.2–1.5 m (3.9–4.9 ft) in width, the porcupine ray has a nearly circular, plain-colored pectoral fin disc and a thin tail without any fin folds. Uniquely within its family, it lacks a venom
ous stinging spine. However, an adult ray can still defend itself ably with the many large, sharp thorns found over its disc and tail.
The diet of the porcupine ray consists mainly of benthic invertebrate
s and bony fishes, which it digs up from the sea floor. It is aplacental viviparous, in which the developing embryo
s are nourished by histotroph ("uterine milk") produced by the mother. The porcupine ray has long been valued for its rough and durable skin, which was made into a shagreen
leather
once used for various utilitarian and ornamental purposes, such as to cover sword
hilt
s and shield
s. It is caught incidentally
by coastal fisheries. Because it must be handled carefully due to its thorns, its commercial significance is limited. Unregulated fishing has led to this species declining in many parts of its range, and thus has been listed as Vulnerable
by the International Union for Conservation of Nature (IUCN).
German naturalists Marcus Elieser Bloch
and Johann Gottlob Schneider
described the porcupine ray in their 1801 work Systema Ichthyologiae, based on a partial dried skin obtained from Mumbai
, India
. They placed it in the genus Raja
and named it asperrima, meaning "roughest" in Latin
. In the same work, they also described a West Africa
n form, Raja africana. Later authors have regarded the two as synonymous
. However, since the two names were published simultaneously, there is uncertainty about which name has priority. Some works give the ray's specific epithet as asperrimus, and others as africanus.
In 1837, Johannes Peter Müller
and Friedrich Gustav Jakob Henle
placed the porcupine ray in a new genus, Gymnura. As the name Gymnura was already in use, referring to the butterfly ray
s, later that year Müller and Henle replaced it with Urogymnus. Both names are derived from the Ancient Greek
oura ("tail") and gymnos ("naked" or "unarmed"), referring to the lack of a tail sting. Other common name
s for this species include black spotted ray, rough-skinned ray, roughback stingaree, Solander's ray, and thorny ray. There may be more than one species of porcupine ray, as is currently recognized.
, from South Africa
to the Arabian Peninsula
to Southeast Asia
to Ningaloo Reef
off western Australia
, including Madagascar
, the Seychelles
, and Sri Lanka
; it has colonized the eastern Mediterranean Sea
through the Suez Canal
. In the Pacific Ocean
, its range continues through Indonesia
and New Guinea
, north to the Philippines
, east to the Gilbert Islands
and Fiji
, and south to Heron Island off eastern Australia. This species is also found in the eastern Atlantic Ocean
off Senegal
, Guinea
, and Côte d'Ivoire
. Bottom-dwelling in nature, the porcupine ray is found close to shore at depths of 1–30 m (3–100 ft). It inhabits sandy flats, coral
rubble, and seagrass
beds, often near reef
s, and also enters brackish water
.
s. Between the narrow nostrils is a skirt-shaped curtain of skin; the posterior margin of the curtain is strongly fringed and overhangs the mouth. The mouth bears 3–5 papillae on the floor and prominent furrows at the corners. The area around the mouth, including the curtain, are heavily covered by more papillae. There are around 48 tooth rows in either jaw. The teeth are small and flattened. Five pairs of gill slit
s are located on the underside of the disc.
The pelvic fins are small and narrow. The thin, rapidly tapering tail is about equal to the disc in length and has an almost cylindrical cross-section, without fin folds. The tail also has no venom
ous stinging spine, unlike other members of the family. A dense patch of flattened, heart-shaped dermal denticles covers the center of the disc and extends onto the tail. Larger individuals additionally have numerous tall, sharp thorns over the entire upper surface of the disc. The porcupine ray is plain light to dark gray or brown above, darkening to blackish towards the tail tip, and white below. This large species grows to at least 1.2 m (3.9 ft) across and 2.2 m (7.2 ft) long, and may reach 1.5 m (4.9 ft) across.
s, and bony fishes. When feeding it plows deeply into the bottom, expelling excess sediment from its spiracles in a plume visible from a long distance away. Parasites documented from this ray include the tapeworm Rhinebothrium devaneyi, the nematode
Echinocephalus overstreeti, and the monogenea
ns Dendromonocotyle urogymni and Neoentobdella baggioi. The porcupine ray is aplacental viviparous, with the developing embryo
s sustained to term by histotroph ("uterine milk") secreted by the mother. Mangrove forests serve as important habitat for juvenile rays. Males and females mature sexually
at about 90 and 100 cm (35.4 and 39.4 in) across respectively.
called shagreen
, had many historical uses. In particular, it was used to cover the hilt
s of various melee weapon
s, as its extremely rough texture prevented slippage during battle. For example, the Japanese deemed it the only species whose skin was acceptable for covering sword
grips. The Malayans used it to cover shield
s. The skin was also used ornamentally, such as by the Chinese, who dye
d it and ground down the thorns to yield a mottled pattern. The native inhabitants of Funafuti Atoll used dried portions of the ray's tail as a rasp
-like tool.
Presently, the porcupine ray is caught incidentally
in trawls, tangle net
s, and beach seines. Its skin continues to be highly valued, while the meat and cartilage
may also be utilized. In the Farasan Islands
and some other places in the Red Sea
, its liver
is eaten as a seasonal dish. However, the economic importance of this ray is limited by how difficult it is to handle. The multi-species coastal fisheries that catch the porcupine ray are largely unregulated, which seems to have resulted in its dramatic decline or local extinction
in the Bay of Bengal
, the Gulf of Thailand
, and likely elsewhere in its range. Potential additional threats to this species include habitat degradation from coastal development, and depletion of its food supply from overfishing
. As a result, the International Union for Conservation of Nature (IUCN) has assessed it as Vulnerable
.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of stingray
Stingray
The stingrays are a group of rays, which are cartilaginous fishes related to sharks. They are classified in the suborder Myliobatoidei of the order Myliobatiformes, and consist of eight families: Hexatrygonidae , Plesiobatidae , Urolophidae , Urotrygonidae , Dasyatidae , Potamotrygonidae The...
in the family
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...
Dasyatidae and the only member of its genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
. This bottom-dweller is found throughout the tropical Indo-Pacific
Indo-Pacific
The Indo-Pacific is a biogeographic region of the Earth's seas, comprising the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the seas connecting the two in the general area of Indonesia...
, as well as off West Africa
West Africa
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...
. It favors sand, coral
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
rubble, and seagrass
Seagrass
Seagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully saline environments.-Ecology:...
habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s in inshore waters to a depth of 30 m (98.4 ft). A large and heavy-bodied species reaching 1.2–1.5 m (3.9–4.9 ft) in width, the porcupine ray has a nearly circular, plain-colored pectoral fin disc and a thin tail without any fin folds. Uniquely within its family, it lacks a venom
Venom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...
ous stinging spine. However, an adult ray can still defend itself ably with the many large, sharp thorns found over its disc and tail.
The diet of the porcupine ray consists mainly of benthic invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s and bony fishes, which it digs up from the sea floor. It is aplacental viviparous, in which the developing embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s are nourished by histotroph ("uterine milk") produced by the mother. The porcupine ray has long been valued for its rough and durable skin, which was made into a shagreen
Shagreen
Shagreen is a type of leather or rawhide consisting of rough untanned skin, formerly made from a horse's back or that of an onager . Shagreen is now commonly made of the skins of sharks and rays....
leather
Leather
Leather is a durable and flexible material created via the tanning of putrescible animal rawhide and skin, primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage industry to heavy industry.-Forms:...
once used for various utilitarian and ornamental purposes, such as to cover sword
Sword
A sword is a bladed weapon used primarily for cutting or thrusting. The precise definition of the term varies with the historical epoch or the geographical region under consideration...
hilt
Hilt
The hilt of a sword is its handle, consisting of a guard,grip and pommel. The guard may contain a crossguard or quillons. A ricasso may also be present, but this is rarely the case...
s and shield
Shield
A shield is a type of personal armor, meant to intercept attacks, either by stopping projectiles such as arrows or redirecting a hit from a sword, mace or battle axe to the side of the shield-bearer....
s. It is caught incidentally
Bycatch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...
by coastal fisheries. Because it must be handled carefully due to its thorns, its commercial significance is limited. Unregulated fishing has led to this species declining in many parts of its range, and thus has been listed as Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
by the International Union for Conservation of Nature (IUCN).
Taxonomy
Marcus Elieser Bloch
Marcus Elieser Bloch was a German medical doctor and naturalist. He is generally considered one of the most important ichthyologists of the 18th century.- Life :...
and Johann Gottlob Schneider
Johann Gottlob Schneider
Johann Gottlob Theaenus Schneider was a German classicist and naturalist.-Biography:Schneider was born at Collm in Saxony...
described the porcupine ray in their 1801 work Systema Ichthyologiae, based on a partial dried skin obtained from Mumbai
Mumbai
Mumbai , formerly known as Bombay in English, is the capital of the Indian state of Maharashtra. It is the most populous city in India, and the fourth most populous city in the world, with a total metropolitan area population of approximately 20.5 million...
, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
. They placed it in the genus Raja
Raja (genus)
Raja is a genus of skates in the family Rajidae, containing nearly thirty species. They are flat-bodied cartilaginous fish with a rhombic shape due to their large pectoral fins extending from or nearly from the snout to the base of their tail. Their sharp snouts produced by a cranial projection of...
and named it asperrima, meaning "roughest" in Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
. In the same work, they also described a West Africa
West Africa
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...
n form, Raja africana. Later authors have regarded the two as synonymous
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
. However, since the two names were published simultaneously, there is uncertainty about which name has priority. Some works give the ray's specific epithet as asperrimus, and others as africanus.
In 1837, Johannes Peter Müller
Johannes Peter Müller
Johannes Peter Müller , was a German physiologist, comparative anatomist, and ichthyologist not only known for his discoveries but also for his ability to synthesize knowledge.-Early years and education:...
and Friedrich Gustav Jakob Henle
Friedrich Gustav Jakob Henle
Friedrich Gustav Jakob Henle was a German physician, pathologist and anatomist. He is credited with the discovery of the loop of Henle in the kidney. His essay "On Miasma and Contagia" was an early argument for the germ theory of disease...
placed the porcupine ray in a new genus, Gymnura. As the name Gymnura was already in use, referring to the butterfly ray
Butterfly ray
The butterfly rays are a group of rays forming the genus Gymnura and the family Gymnuridae. They are found in warm oceans worldwide, and occasionally in estuaries....
s, later that year Müller and Henle replaced it with Urogymnus. Both names are derived from the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
oura ("tail") and gymnos ("naked" or "unarmed"), referring to the lack of a tail sting. Other common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
s for this species include black spotted ray, rough-skinned ray, roughback stingaree, Solander's ray, and thorny ray. There may be more than one species of porcupine ray, as is currently recognized.
Distribution and habitat
The porcupine ray is widely distributed, but uncommon compared to other stingrays that share its range. It is found all along the continental periphery of the Indian OceanIndian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
, from South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
to the Arabian Peninsula
Arabian Peninsula
The Arabian Peninsula is a land mass situated north-east of Africa. Also known as Arabia or the Arabian subcontinent, it is the world's largest peninsula and covers 3,237,500 km2...
to Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
to Ningaloo Reef
Ningaloo Reef
Ningaloo Reef is a fringing coral reef located off the west coast of Australia, approximately 1200 km north of Perth. The reef is 260 km long and is Australia's largest fringing coral reef and the only large reef positioned very close to a landmass....
off western Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, including Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
, the Seychelles
Seychelles
Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
, and Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
; it has colonized the eastern Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
through the Suez Canal
Suez Canal
The Suez Canal , also known by the nickname "The Highway to India", is an artificial sea-level waterway in Egypt, connecting the Mediterranean Sea and the Red Sea. Opened in November 1869 after 10 years of construction work, it allows water transportation between Europe and Asia without navigation...
. In the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
, its range continues through Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
and New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
, north to the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, east to the Gilbert Islands
Gilbert Islands
The Gilbert Islands are a chain of sixteen atolls and coral islands in the Pacific Ocean. They are the main part of Republic of Kiribati and include Tarawa, the site of the country's capital and residence of almost half of the population.-Geography:The atolls and islands of the Gilbert Islands...
and Fiji
Fiji
Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...
, and south to Heron Island off eastern Australia. This species is also found in the eastern Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
off Senegal
Senegal
Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...
, Guinea
Guinea
Guinea , officially the Republic of Guinea , is a country in West Africa. Formerly known as French Guinea , it is today sometimes called Guinea-Conakry to distinguish it from its neighbour Guinea-Bissau. Guinea is divided into eight administrative regions and subdivided into thirty-three prefectures...
, and Côte d'Ivoire
Côte d'Ivoire
The Republic of Côte d'Ivoire or Ivory Coast is a country in West Africa. It has an area of , and borders the countries Liberia, Guinea, Mali, Burkina Faso and Ghana; its southern boundary is along the Gulf of Guinea. The country's population was 15,366,672 in 1998 and was estimated to be...
. Bottom-dwelling in nature, the porcupine ray is found close to shore at depths of 1–30 m (3–100 ft). It inhabits sandy flats, coral
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...
rubble, and seagrass
Seagrass
Seagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully saline environments.-Ecology:...
beds, often near reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s, and also enters brackish water
Brackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
.
Description
The pectoral fin disc of the porcupine ray is evenly oval, almost as wide as long, and very thick at the center, giving it a domed appearance. The tip of the snout is rounded and barely protruding. The small eyes are closely followed by much larger spiracleSpiracle
Spiracles are openings on the surface of some animals that usually lead to respiratory systems.-Vertebrates:The spiracle is a small hole behind each eye that opens to the mouth in some fishes. In the primitive jawless fish the first gill opening immediately behind the mouth is essentially similar...
s. Between the narrow nostrils is a skirt-shaped curtain of skin; the posterior margin of the curtain is strongly fringed and overhangs the mouth. The mouth bears 3–5 papillae on the floor and prominent furrows at the corners. The area around the mouth, including the curtain, are heavily covered by more papillae. There are around 48 tooth rows in either jaw. The teeth are small and flattened. Five pairs of gill slit
Gill slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of Cartilaginous fish such as sharks, rays, sawfish, and guitarfish. Most of these have five pairs, but a few species have 6 or 7 pairs...
s are located on the underside of the disc.
The pelvic fins are small and narrow. The thin, rapidly tapering tail is about equal to the disc in length and has an almost cylindrical cross-section, without fin folds. The tail also has no venom
Venom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...
ous stinging spine, unlike other members of the family. A dense patch of flattened, heart-shaped dermal denticles covers the center of the disc and extends onto the tail. Larger individuals additionally have numerous tall, sharp thorns over the entire upper surface of the disc. The porcupine ray is plain light to dark gray or brown above, darkening to blackish towards the tail tip, and white below. This large species grows to at least 1.2 m (3.9 ft) across and 2.2 m (7.2 ft) long, and may reach 1.5 m (4.9 ft) across.
Biology and ecology
The porcupine ray can sometimes be observed lying still on the bottom in the open or inside caves. It is known to form groups at Ningaloo Reef. Its diet consists primarily of sipunculids, polychaete worms, crustaceanCrustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, and bony fishes. When feeding it plows deeply into the bottom, expelling excess sediment from its spiracles in a plume visible from a long distance away. Parasites documented from this ray include the tapeworm Rhinebothrium devaneyi, the nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
Echinocephalus overstreeti, and the monogenea
Monogenea
Monogenea are a group of largely ectoparasitic members of the flatworm phylum Platyhelminthes, class Monogenea.-Characteristics:Monogenea are very small parasitic flatworms mainly found on skin or gills of fish....
ns Dendromonocotyle urogymni and Neoentobdella baggioi. The porcupine ray is aplacental viviparous, with the developing embryo
Embryo
An embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
s sustained to term by histotroph ("uterine milk") secreted by the mother. Mangrove forests serve as important habitat for juvenile rays. Males and females mature sexually
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
at about 90 and 100 cm (35.4 and 39.4 in) across respectively.
Human interactions
Despite not having a sting, the porcupine ray is capable of injuring humans with its many sharp thorns. It is reportedly bold and tolerant of being approached closely underwater. The tough, thorny skin of this ray, made into a form of leatherLeather
Leather is a durable and flexible material created via the tanning of putrescible animal rawhide and skin, primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage industry to heavy industry.-Forms:...
called shagreen
Shagreen
Shagreen is a type of leather or rawhide consisting of rough untanned skin, formerly made from a horse's back or that of an onager . Shagreen is now commonly made of the skins of sharks and rays....
, had many historical uses. In particular, it was used to cover the hilt
Hilt
The hilt of a sword is its handle, consisting of a guard,grip and pommel. The guard may contain a crossguard or quillons. A ricasso may also be present, but this is rarely the case...
s of various melee weapon
Mêlée weapon
A melee weapon is any weapon that does not involve a projectile — that is, both the user and target of the weapon are in contact with it simultaneously in normal use...
s, as its extremely rough texture prevented slippage during battle. For example, the Japanese deemed it the only species whose skin was acceptable for covering sword
Sword
A sword is a bladed weapon used primarily for cutting or thrusting. The precise definition of the term varies with the historical epoch or the geographical region under consideration...
grips. The Malayans used it to cover shield
Shield
A shield is a type of personal armor, meant to intercept attacks, either by stopping projectiles such as arrows or redirecting a hit from a sword, mace or battle axe to the side of the shield-bearer....
s. The skin was also used ornamentally, such as by the Chinese, who dye
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
d it and ground down the thorns to yield a mottled pattern. The native inhabitants of Funafuti Atoll used dried portions of the ray's tail as a rasp
Rasp
A rasp is a tool used for shaping wood or other material. It consists of a point or the tip, then a long steel bar or the belly, then the heel or bottom, then the tang. The tang is joined to a handle, usually made of plastic or wood. The bar has sharp teeth...
-like tool.
Presently, the porcupine ray is caught incidentally
Bycatch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...
in trawls, tangle net
Tangle net
Similar to a gillnet, the tangle net, or tooth net, is a type of nylon fishing net. Left in the water for no more than two days, and allowing bycatch to be released alive, this net is considered to be less harmful that other nets. The tangle net is used in the Philippines by commercial fishermen,...
s, and beach seines. Its skin continues to be highly valued, while the meat and cartilage
Cartilage
Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...
may also be utilized. In the Farasan Islands
Farasan Islands
Farasan Islands is a large coral island group in the Red Sea, belonging to Saudi Arabia. It is located some 40 km offshore from Jizan, in the far southwestern part of the country. It is located at around . It is a protected area and was home to the extinct Arabian gazelle and, in winter, migratory...
and some other places in the Red Sea
Red Sea
The Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...
, its liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
is eaten as a seasonal dish. However, the economic importance of this ray is limited by how difficult it is to handle. The multi-species coastal fisheries that catch the porcupine ray are largely unregulated, which seems to have resulted in its dramatic decline or local extinction
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
in the Bay of Bengal
Bay of Bengal
The Bay of Bengal , the largest bay in the world, forms the northeastern part of the Indian Ocean. It resembles a triangle in shape, and is bordered mostly by the Eastern Coast of India, southern coast of Bangladesh and Sri Lanka to the west and Burma and the Andaman and Nicobar Islands to the...
, the Gulf of Thailand
Gulf of Thailand
The Gulf of Thailand , also known in to Malays as Teluk Siam literally meant Gulf of Siam, is a shallow arm of the South China Sea.-Geography:...
, and likely elsewhere in its range. Potential additional threats to this species include habitat degradation from coastal development, and depletion of its food supply from overfishing
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
. As a result, the International Union for Conservation of Nature (IUCN) has assessed it as Vulnerable
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
.