Shagreen ray
Encyclopedia
The shagreen ray or fuller's ray, Leucoraja fullonica, is a species
of skate
in the family Rajidae. This ray is found in the eastern Atlantic Ocean
, from Murmansk
, Russia
through Norway
, southern Iceland
, the Faroe Islands
, the Celtic Sea
, the northern North Sea
and Skagerrak
, to northern Morocco
, including (infrequently) the western Mediterranean Sea
and the Madeira Islands. It is absent from the shallow waters off England
and Wales
.
Shagreen
is a form of roughened untanned leather, typically dyed green and commonly made of the skins of sharks and rays. The common name
"fuller's ray" comes from an instrument used by fullers
to smooth cloth, referring to its rough and spiny back.
The pectoral fin disc of the shagreen ray is somewhat wider than it is long. The forward margin concave
and undulated, and about one-third longer than the rear margin. The snout
is cone-shaped and pointed. The tail
is shorter than the disc, with two small, equally sized dorsal fin
s and a rudimentary caudal fin. The eye
s and mouth
are large; the teeth are pointed and number about 64 in the upper jaw and 56 in the lower. The upper surface is rough in texture, with patches of large spines on the snout, around the eyes, and on the shoulder. There are two rows of about 50 spines each running from the center of the back to the first dorsal fin, and no interdorsal spine. The underside is smooth except for the front edge of the disc, base of the tail, and tail. The coloration is a uniform gray or brown with smaller darker dots above, and white below. The maximum size is to 120 cm long.
This species occurs in relatively cold water on the upper continental slopes at a depth of 30-550 m. It is most common at depths of 200 m, but is found deeper in southern areas. It favors sand
y and possibly also rocky habitat
s. The shagreen ray feeds on a variety of benthic animal
s, mainly fish
es but also crustacean
s. Like other skates reproduction is oviparous; the egg
capsules are amber in color and oblong-shaped, with long, stiff horns at each corner. One pair of horns are longer than the capsule. The capsules measure 7.5-9.9 cm long and 4.5-4.7 cm wide. Historically this ray was considered of "inferior" quality for consumption. It is caught commercially by longlines and trawls.
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 skate
Skate
Skates are cartilaginous fish belonging to the family Rajidae in the superorder Batoidea of rays. There are more than 200 described species in 27 genera. There are two subfamilies, Rajinae and Arhynchobatinae ....
in the family Rajidae. This ray is 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...
, from Murmansk
Murmansk
Murmansk is a city and the administrative center of Murmansk Oblast, Russia. It serves as a seaport and is located in the extreme northwest part of Russia, on the Kola Bay, from the Barents Sea on the northern shore of the Kola Peninsula, not far from Russia's borders with Norway and Finland...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
through Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
, southern Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
, the Faroe Islands
Faroe Islands
The Faroe Islands are an island group situated between the Norwegian Sea and the North Atlantic Ocean, approximately halfway between Scotland and Iceland. The Faroe Islands are a self-governing territory within the Kingdom of Denmark, along with Denmark proper and Greenland...
, the Celtic Sea
Celtic Sea
The Celtic Sea is the area of the Atlantic Ocean off the south coast of Ireland bounded to the east by Saint George's Channel; other limits include the Bristol Channel, the English Channel, and the Bay of Biscay, as well as adjacent portions of Wales, Cornwall, Devon, and Brittany...
, the northern North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
and Skagerrak
Skagerrak
The Skagerrak is a strait running between Norway and the southwest coast of Sweden and the Jutland peninsula of Denmark, connecting the North Sea and the Kattegat sea area, which leads to the Baltic Sea.-Name:...
, to northern 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...
, including (infrequently) the western 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...
and the Madeira Islands. It is absent from the shallow waters off England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
and Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
.
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....
is a form of roughened untanned leather, typically dyed green and commonly made of the skins of sharks and rays. The 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...
"fuller's ray" comes from an instrument used by fullers
Fulling
Fulling or tucking or walking is a step in woolen clothmaking which involves the cleansing of cloth to eliminate oils, dirt, and other impurities, and making it thicker. The worker who does the job is a fuller, tucker, or walker...
to smooth cloth, referring to its rough and spiny back.
The pectoral fin disc of the shagreen ray is somewhat wider than it is long. The forward margin concave
Concave
The word concave means curving in or hollowed inward, as opposed to convex. The former may be used in reference to:* Concave lens, a lens with inward-curving surfaces.* Concave polygon, a polygon which is not convex....
and undulated, and about one-third longer than the rear margin. The snout
Snout
The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...
is cone-shaped and pointed. The tail
Tail
The tail is the section at the rear end of an animal's body; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, reptiles, and birds...
is shorter than the disc, with two small, equally sized dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s and a rudimentary caudal fin. The eye
Eye
Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...
s and mouth
Mouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....
are large; the teeth are pointed and number about 64 in the upper jaw and 56 in the lower. The upper surface is rough in texture, with patches of large spines on the snout, around the eyes, and on the shoulder. There are two rows of about 50 spines each running from the center of the back to the first dorsal fin, and no interdorsal spine. The underside is smooth except for the front edge of the disc, base of the tail, and tail. The coloration is a uniform gray or brown with smaller darker dots above, and white below. The maximum size is to 120 cm long.
This species occurs in relatively cold water on the upper continental slopes at a depth of 30-550 m. It is most common at depths of 200 m, but is found deeper in southern areas. It favors sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
y and possibly also rocky 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. The shagreen ray feeds on a variety of benthic animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s, mainly fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
es but also 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. Like other skates reproduction is oviparous; the egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
capsules are amber in color and oblong-shaped, with long, stiff horns at each corner. One pair of horns are longer than the capsule. The capsules measure 7.5-9.9 cm long and 4.5-4.7 cm wide. Historically this ray was considered of "inferior" quality for consumption. It is caught commercially by longlines and trawls.