Stingray
Overview
 
The stingrays are a group of rays
Batoidea
Batoidea is a superorder of cartilaginous fish commonly known as rays and skates, containing more than 500 described species in thirteen families...

, which are cartilaginous fishes related to shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

s. They are classified in the suborder Myliobatoidei of the order Myliobatiformes
Myliobatiformes
Myliobatiformes is one of the four orders of batoids, cartilaginous fishes related to sharks. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown that the myliobatiforms are a monophyletic group, and that its more derived members evolved their...

, and consist of eight families: Hexatrygonidae (sixgill stingray), Plesiobatidae (deep water stingray), Urolophidae (stingarees), Urotrygonidae
Urotrygonidae
Urotrygonidae is a family of rays in the order Myliobatiformes, commonly referred to as the American round stingrays or round rays. They are native to the tropical and warm temperate marine waters of the Americas. The two genera in this family were formerly placed within the family Urolophidae,...

 (round rays), Dasyatidae (whiptail stingrays), Potamotrygonidae
Potamotrygonidae
River stingrays are Neotropical freshwater fishes of the Potamotrygonidae family .They are native to northern, central and eastern South America, living in rivers that drain into the Caribbean, and into the Atlantic as far south as the Río de la Plata in Argentina...

 (river stingrays), Gymnuridae (butterfly rays), and Myliobatidae (eagle rays).

Most stingrays have one or more barbed stings (modified from dermal denticles) on the tail, which is used exclusively in self-defense.
Encyclopedia
The stingrays are a group of rays
Batoidea
Batoidea is a superorder of cartilaginous fish commonly known as rays and skates, containing more than 500 described species in thirteen families...

, which are cartilaginous fishes related to shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

s. They are classified in the suborder Myliobatoidei of the order Myliobatiformes
Myliobatiformes
Myliobatiformes is one of the four orders of batoids, cartilaginous fishes related to sharks. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown that the myliobatiforms are a monophyletic group, and that its more derived members evolved their...

, and consist of eight families: Hexatrygonidae (sixgill stingray), Plesiobatidae (deep water stingray), Urolophidae (stingarees), Urotrygonidae
Urotrygonidae
Urotrygonidae is a family of rays in the order Myliobatiformes, commonly referred to as the American round stingrays or round rays. They are native to the tropical and warm temperate marine waters of the Americas. The two genera in this family were formerly placed within the family Urolophidae,...

 (round rays), Dasyatidae (whiptail stingrays), Potamotrygonidae
Potamotrygonidae
River stingrays are Neotropical freshwater fishes of the Potamotrygonidae family .They are native to northern, central and eastern South America, living in rivers that drain into the Caribbean, and into the Atlantic as far south as the Río de la Plata in Argentina...

 (river stingrays), Gymnuridae (butterfly rays), and Myliobatidae (eagle rays).

Most stingrays have one or more barbed stings (modified from dermal denticles) on the tail, which is used exclusively in self-defense. The stinger may reach a length of approximately 35 cm (13.8 in), and its underside has two grooves with 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...

 gland
Gland
A gland is an organ in an animal's body that synthesizes a substance for release of substances such as hormones or breast milk, often into the bloodstream or into cavities inside the body or its outer surface .- Types :...

s. The stinger is covered with a thin layer of skin, the integumentary sheath, in which the venom is concentrated. A few members of the suborder, such as the manta ray
Manta ray
The manta ray is the largest species of the rays. The largest known specimen was more than across, with a weight of about . It ranges throughout waters of the world, typically around coral reefs...

s and the porcupine ray
Porcupine ray
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 habitats in inshore waters to a depth of...

, do not have stings.

Stingrays are common in coastal tropical and subtropical marine waters throughout the world, and also includes species found in warmer temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...

 oceans such as Dasyatis thetidis
Thorntail stingray
The thorntail stingray, black stingray, or longtail stingray is a species of stingray in the family Dasyatidae. It is found off southern Africa, Australia, and New Zealand from the intertidal zone to a depth of . This bottom-dweller inhabits soft-bottomed habitats such as lagoons, estuaries, and...

, and those found in the deep ocean such as Plesiobatis daviesi. The river stingrays, and a number of whiptail stingray
Whiptail stingray
The whiptail stingrays are a family, Dasyatidae, of rays in the order Myliobatiformes. They are found worldwide in tropical to temperate marine waters, and a number of species have also penetrated into fresh water in North America, Africa, Asia, and Australia. Members of this family have flattened...

s (such as the Niger stingray
Niger stingray
The Niger stingray or smooth freshwater stingray, Dasyatis garouaensis, is a species of stingray in the family Dasyatidae, native to rivers in Nigeria and Cameroon. Attaining a width of , this species can be distinguished by its thin, almost circular pectoral fin disk, slightly projecting snout...

), are restricted to fresh water
Fresh Water
Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...

. Most myliobatoids are demersal, but some, such as the pelagic stingray
Pelagic stingray
The pelagic stingray is a species of stingray in the family Dasyatidae, and the sole member of its genus. It is characterized by the wedge-like shape of its pectoral fin disc, which is much wider than long, as well as by the pointed teeth in both sexes, whip-like tail with extremely long tail...

 and the eagle ray
Eagle ray
The eagle rays are a group of cartilaginous fishes in the family Myliobatidae, consisting mostly of large species living in the open ocean rather than on the sea bottom....

s, are pelagic.

While most stingrays are relatively widespread and not currently threatened
Threatened species
Threatened species are any speciesg animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future.The World Conservation Union is the foremost authority on threatened species, and treats threatened species not as a single category, but as a group of three categories,...

, there are several species (for example Taeniura meyeni
Blotched fantail ray
The blotched fantail ray is a species of stingray in the family Dasyatidae, found throughout the nearshore waters of the tropical Indo-Pacific, as well as off islands in the eastern Pacific. It is a bottom-dwelling inhabitant of lagoons, estuaries, and reefs, generally at a depth of...

, D. colarensis
Colares stingray
The Colares stingray, Dasyatis colarensis, is a species of stingray in the family Dasyatidae, native to the shallow brackish waters of the Amazon River estuary in northern Brazil. This species inhabits inshore bays during the dry season and moves away from the coast in the rainy season...

, D. garouaensis
Niger stingray
The Niger stingray or smooth freshwater stingray, Dasyatis garouaensis, is a species of stingray in the family Dasyatidae, native to rivers in Nigeria and Cameroon. Attaining a width of , this species can be distinguished by its thin, almost circular pectoral fin disk, slightly projecting snout...

, and D. laosensis) where the conservation status is more problematic, leading to them being 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:...

 or endangered
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...

 by IUCN. The status of several other species are poorly known, leading to them being listed as Data Deficient
Data Deficient
Data Deficient is a category applied by the IUCN, other agencies, and individuals to a species when the available information is not sufficient for a proper assessment of conservation status to be made...

.

Behavior

The flattened bodies of stingrays allow them to effectively conceal themselves in their environment. Stingrays do this by agitating the sand and hiding beneath it. Because their eyes are on top of their bodies and their mouths on the undersides, stingrays cannot see their prey; instead, they use smell and electro-receptors (ampullae of Lorenzini
Ampullae of Lorenzini
The ampullae of Lorenzini are special sensing organs called electroreceptors, forming a network of jelly-filled pores. They are mostly discussed as being found in cartilaginous fishes ; however, they are also reported to be found in Chondrostei such as Reedfish and sturgeon. Lungfish have also been...

) similar to those of shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

s. Stingrays feed primarily on mollusc
Mollusca
The Mollusca , common name molluscs or mollusksSpelled mollusks in the USA, see reasons given in Rosenberg's ; for the spelling mollusc see the reasons given by , is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. Mollusca is the largest...

s, crustacean
Crustacean
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 occasionally on small fish. Some stingrays' mouths contain two powerful, shell-crushing plates, while other species only have sucking mouthparts. Stingrays settle on the bottom while feeding, often leaving only their eyes and tail visible. Coral reef
Coral reef
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...

s are favorite feeding grounds and are usually shared with sharks during high tide.

Reproduction

When a male is courting a female, he will follow her closely, biting at her pectoral disc. He then places one of his two claspers into her valve.

Stingrays are ovoviviparous
Ovoviviparity
Ovoviviparity, ovovivipary, or ovivipary, is a mode of reproduction in animals in which embryos develop inside eggs that are retained within the mother's body until they are ready to hatch...

, bearing live young in "litters" of five to thirteen. The female holds the embryos in the womb without a placenta. Instead, the embryos absorb nutrients from a yolk sac
Yolk sac
The yolk sac is a membranous sac attached to an embryo, providing early nourishment in the form of yolk in bony fishes, sharks, reptiles, birds, and primitive mammals...

, and after the sac is depleted, the mother provides uterine "milk".

At the Sea Life London Aquarium 2 female stingrays have delivered 7 baby stingrays, although the mothers have not been near a male for 2 years. "Rays have been known to store sperm and not give birth until they decide the timing is right".

Stingray injuries

Stingrays do not aggressively attack humans (a notable exception being the death of Steve Irwin), though stings do normally occur if a ray is accidentally stepped on. To avoid stepping on a stingray in shallow water, the water should be waded through with a shuffle. Alternatively, before wading, stones can be thrown into the water to scare stingrays away. Contact with the stinger causes local trauma (from the cut itself), pain, swelling, muscle cramps from the venom, and later may result in infection from bacteria. The injury is very painful, but seldom life-threatening unless the stinger pierces a vital area. The barb usually breaks off in the wound, and surgery may be required to remove the fragments.

As food

Rays are edible, and may also be caught as food by fishing lines or spears. Stingray recipes abound throughout the world, with dried forms of the wings being most common. For example, in Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...

 and Malaysia, stingray is commonly barbecue
Barbecue
Barbecue or barbeque , used chiefly in the United States, Canada, the United Kingdom, New Zealand and Australia is a method and apparatus for cooking meat, poultry and occasionally fish with the heat and hot smoke of a fire, smoking wood, or hot coals of...

d over charcoal, then served with spicy sambal
Sambal
Sambal is a chili based sauce which is normally used as a condiment. Sambals are popular in Indonesia, Malaysia, Singapore, the southern Philippines and Sri Lanka, as well as in the Netherlands and in Suriname through Javanese influence. It is typically made from a variety of chili peppers and is...

sauce. Generally, the most prized parts of the stingray are the wings (flaps is the proper terminology), the "cheek" (the area surrounding the eyes), and the liver. The rest of the ray is considered too rubbery to have any culinary uses.

While not independently valuable as a food source, the stingray's capacity to damage shell fishing grounds can lead to bounties being placed on their removal.

Eco-tourism

Stingrays are usually very docile and curious, their usual reaction being to flee any disturbance, but will sometimes brush their fins past any new object they come across. Nevertheless, certain larger species may be more aggressive and should be approached with caution, as the stingray's defensive reflex (use of its poisoned stinger) may result in serious injury or death.

Dasyatids are not normally visible to swimmers, but divers and snorkelers may find them in shallow sandy waters, more so when the water is warm. In the Cayman Islands
Cayman Islands
The Cayman Islands is a British Overseas Territory and overseas territory of the European Union located in the western Caribbean Sea. The territory comprises the three islands of Grand Cayman, Cayman Brac, and Little Cayman, located south of Cuba and northwest of Jamaica...

 there are several dive sites called Stingray City, Grand Cayman
Stingray City, Grand Cayman
Stingray City is a series of shallow sandbars found in the North Sound of Grand Cayman, Cayman Islands. It is a tourist attraction, where southern stingrays are found in abundance and visitors can pet and interact with the animals.- Location :...

, where divers and snorkelers can swim with large southern stingray
Southern stingray
The southern stingray, Dasyatis americana, is a stingray of the family Dasyatidae found in tropical and subtropical waters of the Western Atlantic Ocean from New Jersey to Brazil. It has a flat, diamond-shaped disc, with a mud brown, olive, and grey dorsal surface and white underbelly...

s (D. americana) and feed them by hand. There is also a "Stingray City" in the sea surrounding the Caribbean
Caribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...

 island of Antigua
Antigua
Antigua , also known as Waladli, is an island in the West Indies, in the Leeward Islands in the Caribbean region, the main island of the country of Antigua and Barbuda. Antigua means "ancient" in Spanish and was named by Christopher Columbus after an icon in Seville Cathedral, Santa Maria de la...

. It consists of a large, shallow reserve where the rays live, and snorkeling is possible, since the rays are used to the presence of humans.

In Belize
Belize
Belize is a constitutional monarchy and the northernmost country in Central America. Belize has a diverse society, comprising many cultures and languages. Even though Kriol and Spanish are spoken among the population, Belize is the only country in Central America where English is the official...

, off the island of Ambergris Caye
Ambergris Caye
Ambergris Caye, pronounced "am-BER-gris", is the largest island of Belize located northeast of the country in the Caribbean Sea. Though administered as part of the Belize District, the closest point on the mainland is part of the Corozal District....

, there is a popular marine sanctuary called Hol Chan
Hol Chan Marine Reserve
Hol Chan Marine Reserve is a marine reserve close to Ambergris Caye and Caye Caulker, off the coast of Belize. It covers approximately 18 km² of coral reefs, seagrass beds, and mangrove forest...

. Here, divers and snorkelers often gather to watch stingrays and nurse shark
Nurse shark
The nurse shark, Ginglymostoma cirratum, sometimes referred to as the Nur Shark is a shark in the nurse sharks family, the only member of its genus Ginglymostoma...

s that are drawn to the area by tour operators who feed the animals.

Many Tahiti
Tahiti
Tahiti is the largest island in the Windward group of French Polynesia, located in the archipelago of the Society Islands in the southern Pacific Ocean. It is the economic, cultural and political centre of French Polynesia. The island was formed from volcanic activity and is high and mountainous...

an island resorts regularly offer guests the chance to "feed the stingrays and sharks". This consists of taking a boat to the outer lagoon reefs then standing in waist-high water while habituated stingrays swarm around, pressing right up against tourists seeking food from their hands or that being tossed into the water. The boat owners also "call in" sharks which, when they arrive from the ocean, swoop through the shallow water above the reef and snatch food offered to them.

Other uses

The skin of the ray (same in Japanese
Japanese language
is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...

) is used as an under layer for the cord or leather wrap (known as ito in Japanese
Japanese language
is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...

) on Japanese swords
Katana
A Japanese sword, or , is one of the traditional bladed weapons of Japan. There are several types of Japanese swords, according to size, field of application and method of manufacture.-Description:...

 due to its hard, rough, skin texture that keeps the braided wrap from sliding on the handle during use. They are also used to make exotic shoes, boots, belts, wallets, jackets, and also cellphone cases.

Several ethnological sections in museums such as the British Museum
British Museum
The British Museum is a museum of human history and culture in London. Its collections, which number more than seven million objects, are amongst the largest and most comprehensive in the world and originate from all continents, illustrating and documenting the story of human culture from its...

 display arrowheads and spearheads made of stingray stingers, used in Micronesia
Micronesia
Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....

 and elsewhere. Henry de Monfreid
Henry de Monfreid
Henry de Monfreid was a French adventurer and author. Born in Leucate, Aude, France, he was the son of artist painter Georges-Daniel de Monfreid and knew Paul Gauguin as a child....

 states in his books that before World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, in the Horn of Africa
Horn of Africa
The Horn of Africa is a peninsula in East Africa that juts hundreds of kilometers into the Arabian Sea and lies along the southern side of the Gulf of Aden. It is the easternmost projection of the African continent...

, whip
Whip
A whip is a tool traditionally used by humans to exert control over animals or other people, through pain compliance or fear of pain, although in some activities whips can be used without use of pain, such as an additional pressure aid in dressage...

s were made from the tail of big stingrays, and that this device inflicted cruel cuts, so in Aden
Aden
Aden is a seaport city in Yemen, located by the eastern approach to the Red Sea , some 170 kilometres east of Bab-el-Mandeb. Its population is approximately 800,000. Aden's ancient, natural harbour lies in the crater of an extinct volcano which now forms a peninsula, joined to the mainland by a...

 the British forbid its use on women and slaves. In former Spanish colonies a stingray is called raya làtigo ("whip ray").

Monfreid also writes in several places about men of his crew suffering stingray wounds while stranding and wading into 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...

 shallows to load or unload smuggled wares: he wrote that to "save the man's life" searing the wound with a red-hot iron was necessary.

Fossils

Although stingray teeth are rare on sea bottoms compared to the similar shark teeth, scuba divers searching for the latter do encounter the teeth of stingrays. Permineralized
Permineralization
Permineralization is a process of fossilization in which mineral deposits form internal casts of organisms. Carried by water, these minerals fill the spaces within organic tissue...

 stingray teeth have been found in sedimentary deposits around the world, including fossiliferous
Fossil collecting
Fossil collecting is the collection of fossils for scientific study, hobby, or profit. Fossil collecting, as practiced by amateurs, is the predecessor of modern paleontology and many still collect fossils and study fossils as amateurs...

 outcrops in Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...

.

External links

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