Thornback ray

Thornback ray

Taxobox
name = Thornback ray


status = LR/nt | status_system = IUCN2.3
regnum = Animalia
phylum = Chordata
classis = Chondrichthyes
ordo = Rajiformes
familia = Rajidae
genus = "Raja"
species = "R. clavata"
binomial = "Raja clavata"
binomial_authority = Linnaeus, 1758

The Thornback ray ("Raja clavata") or Thornback skate is a species of fish in the Rajidae family. it is found in coastal waters of Europe and the Atlantic coast of Africa, possibly as far south as Namibia and even South Africa. Its natural habitats are open seas and shallow seas. It is sometimes seen trapped in large estuarine pools at low tide.

Description

The thornback ray is probably one of the commonest rays encountered by divers. Like all rays it has a flattened body with broad, wing-like pectoral fins. The body is kite-shaped with a long, thorny tail. The back is covered in numerous thorny spines, as is the underside in older females. ["Morpholgy" in [http://filaman.ifm-geomar.de/Summary/SpeciesSummary.php?id=2059] ] Adult fish can grow to 1 m (3.3 ft) in length although most are less than 85 cm (33.67 in). This ray can weigh from 4.5 to 8.75 lb (2 to 3.98 lb).cite book |last=Kindersley |first= Dorling |year=2001,2005 |title=Animal |location=New York City |publisher=DK Publishing |isbn=0-7894-7764-5]

In sexually mature fish some of the spines are thickened with button-like bases (known as bucklers). These are particularly well developed on the tail and back of sexually mature females. The colour varies from light brown to grey with darker blotches and numerous small darker spots and yellow patches. Sometimes the yellow patches are surrounded by small dark spots. The underside is creamy-white with a greyish margin.

Habitat

The thornback ray is usually found on sediment type seabeds such as mud, sand or gravel at depths between 10-60m. Juvenile fish feed on small crustaceans, particularly amphipods and bottom-living shrimps, Adults feed on crabs, shrimps and small fish.

References

* Ellis, J. & Walker, P. 2000. [http://www.iucnredlist.org/search/details.php/39399/all Raja clavata] . [http://www.iucnredlist.org 2006 IUCN Red List of Threatened Species. ] Downloaded on 03 August 2007.
* Picton, B.E. & Morrow, C.C., 2005. [In] Encyclopedia of Marine Life of Britain and Irelandhttp://www.habitas.org.uk/marinelife/species.asp?item=ZF1360


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Look at other dictionaries:

  • thornback ray — dyglioji raja statusas T sritis zoologija | vardynas taksono rangas rūšis atitikmenys: lot. Raja clavata angl. buckler skate; maid ray; roker; rough ray; thornback ray; thorny rus. колючий скат; морская лисица ryšiai: platesnis terminas –… …   Žuvų pavadinimų žodynas

  • thornback ray — noun a prickly skinned ray which is often eaten as ‘skate’. [Raja clavata.] …   English new terms dictionary

  • thornback ray — noun : a common European ray (Raja clavata) having several large curved spines on the back and tail …   Useful english dictionary

  • Thornback — may refer to:* the Thornback ray or Thornback skate, a species of fish * the Banjo shark or Thornback, another species of fish * USS Thornback (SS 418), a submarine * the Phaerimm, a fictional species of creatures in the Forgotten Realms setting …   Wikipedia

  • thornback — noun Date: 14th century any of various ray fishes having spines on the back …   New Collegiate Dictionary

  • thornback — /thawrn bak /, n. 1. a skate, Raja clavata, of European waters, having short spines on the back and tail. 2. a California ray, Platyrhinoidis triseriatus, belonging to the guitarfish group. [1250 1300; ME; see THORN, BACK1] * * * …   Universalium

  • thornback — thorn•back [[t]ˈθɔrnˌbæk[/t]] n. 1) ich a skate, Raja clavata, of European waters, having short spines on the back and tail 2) ich a California ray, Platyrhinoidis triseriatus, belonging to the guitarfish group • Etymology: 1250–1300 …   From formal English to slang

  • thornback — n. a ray, Raja clavata, with spines on the back and tail …   Useful english dictionary

  • maid ray — dyglioji raja statusas T sritis zoologija | vardynas taksono rangas rūšis atitikmenys: lot. Raja clavata angl. buckler skate; maid ray; roker; rough ray; thornback ray; thorny rus. колючий скат; морская лисица ryšiai: platesnis terminas –… …   Žuvų pavadinimų žodynas

  • rough ray — dyglioji raja statusas T sritis zoologija | vardynas taksono rangas rūšis atitikmenys: lot. Raja clavata angl. buckler skate; maid ray; roker; rough ray; thornback ray; thorny rus. колючий скат; морская лисица ryšiai: platesnis terminas –… …   Žuvų pavadinimų žodynas

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