Porcupine ray - Wikipedia. The porcupine ray (Urogymnus asperrimus) 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 seagrasshabitats in inshore waters to a depth of 3. A large and heavy- bodied species reaching 1. Uniquely within its family, it lacks a venomous 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 benthicinvertebrates and bony fishes, which it digs up from the sea floor. It is aplacental viviparous, in which the developing embryos are nourished by histotroph (. The porcupine ray has long been valued for its rough and durable skin, which was made into a shagreenleather once used for various utilitarian and ornamental purposes, such as to cover swordhilts and shields. 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). Taxonomy. They placed it in the genus Raja and named it asperrima, meaning . In the same work, they also described a West African form, Raja africana. 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. As the name Gymnura was already in use, referring to the butterfly rays, later that year M. It is found all along the continental periphery of the Indian Ocean, 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. It inhabits sandy flats, coral rubble, and seagrass beds, often near reefs, and also enters brackish water. The tip of the snout is rounded and barely protruding. The small eyes are closely followed by much larger spiracles. 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 area around the mouth, including the curtain, are heavily covered by more papillae. Five pairs of gill slits are located on the underside of the disc. 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 venomous 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. Es som elgruppe hastighet es som: «All e tningshastigheter» e og langsomme simal ed langsomme an er p? Planning and periodization are assumed to be crucial phases directly implied in the efficiency, consistency and game quality of the teams. 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. In particular, it was used to cover the hilts of various melee weapons, 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. 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.
Fases del viraje o volteo de crol: Las fases del viraje son: aproximaciPotential 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. IUCN Red List of Threatened Species. International Union for Conservation of Nature. Sharks and Rays of Australia (second ed.). Harvard University Press. Systema Ichthyologiae iconibus cx illustratum. Berolini: Sumtibus auctoris impressum et Bibliopolio Sanderiano commissum. Catalog of Fishes electronic version (2. March 2. 01. 1).^ ab. Randall, J. E.; Allen, G. R.; Steene, R. C. Fishes of the Great Barrier Reef and Coral Sea. University of Hawaii Press. Catalog of Fishes electronic version (2. March 2. 01. 1).^Hunter, R. April 2. 01. 1 version.^ ab. Smith, J. L. B.; Smith, M. M.; Heemstra, P. Sharks & Rays: Elasmobranch Guide of the World (second ed.). FAO species identification guide for fishery purposes: Field identification guide to the sharks and rays of the Red Sea and Gulf of Aden. Food and Agriculture Organization of the United Nations. Coastal fishes of Oman. University of Hawaii Press. In Carpenter, K. E.; Niem, V. H. FAO species identification guide for fishery purposes: The living marine resources of the Western Central Pacific. Food and Agricultural Organization of the United Nations. The Journal of Parasitology. In Carrier, J. C.; Musick, J. A.; Heithaus, M. R. Sharks and Their Relatives 2. Reef Sharks & Rays of the World. A Glossary of the Construction, Decoration and Use of Arms and Armor in All Countries and in All Times. Courier Dover Publications. Journal of the Bombay Natural History Society, Volume 2. Bombay Natural History Society. The Riverside Natural History. Sharks, Rays and Chimaeras: The Status of the Chondrichthyan Fishes. International Union for Conservation of Nature and Natural Resources. Autores y titulos de bibliografia oposiciones.
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