The thorny skate (Amblyraja radiata) is a species of fish in the family Rajidae. This bottom-living skate lives in the North and south-eastern Atlantic Ocean in depths ranging from 20 to 1,000 m (66–3,281 ft) and water temperatures from −1 to 14 °C (30–57 °F).
Fish are gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming the olfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Tetrapods emerged within lobe-finned fishes, so cladistically they are fish as well. However, traditionally fish are rendered paraphyletic by excluding the tetrapods. Because in this manner the term "fish" is defined negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology, unless it is used in the cladistic sense, including tetrapods. The traditional term pisces is considered a typological, but not a phylogenetic classification.
Skates are cartilaginous fish belonging to the family Rajidae in the superorder Batoidea of rays. More than 150 species have been described, in 17 genera. Softnose skates and pygmy skates were previously treated as subfamilies of Rajidae, but are now considered as distinct families. Alternatively, the name "skate" is used to refer to the entire order of Rajiformes.
The thorny skate reaches up to 1.05 m (3.4 ft) in total length and 11.4 kg (25 lb) in weight. Its underside is smooth, but the upper side, as the name suggests, is very rough with many small thorns all over and 13-17 larger ones in line from the back of the head to end of the tail. The top side is brown with possibly black spots and the underside is white. It has a hard, roughly triangular snout and a tail, which is shorter than its body. It eats crustaceans, small fishes, and worms. It produces egg capsules, which are 3.4-8.9 cm long and 2.3-6.8 cm wide, which hatch outside the body.
An egg case or egg capsule is the casing that surrounds the eggs of oviparous sharks, skates, and chimaeras. Egg cases typically contain one embryo, except for big skate and mottled skate egg cases, which contain up to 7 embryos. Oviparity is completely absent in the superorder Squalomorphii.
Thorny skate are taken as bycatch in some fisheries. It is a U.S. National Marine Fisheries Service species of concern, which are those species about which the U.S. National Oceanic and Atmospheric Administration, National Marine Fisheries Service, has some concerns regarding status and threats, but for which insufficient information is available to indicate a need to list the species under the U.S. Endangered Species Act.
The National Marine Fisheries Service (NMFS) is the United States federal agency responsible for the stewardship of national marine resources. The agency conserves and manages fisheries to promote sustainability and prevent lost economic potential associated with overfishing, declining species, and degraded habitats.
The National Oceanic and Atmospheric Administration is an American scientific agency within the United States Department of Commerce that focuses on the conditions of the oceans, major waterways, and the atmosphere.
The Atlantic wolffish, also known as the seawolf, Atlantic catfish, ocean catfish, devil fish, wolf eel, woof or sea cat, is a marine fish of the wolffish family Anarhichadidae. The numbers of the Atlantic wolffish in US waters are rapidly being depleted, most likely due to overfishing and bycatch, and is currently a Species of Concern according to the U.S. National Oceanic and Atmospheric Administration's National Marine Fisheries Service.
The sandbar shark is a species of requiem shark, and part of the family Carcharhinidae, native to the Atlantic Ocean and the Indo-Pacific. It is distinguishable by its very high first dorsal fin and interdorsal ridge. It is not to be confused with its similarly named shark, the sand tiger shark, Carcharias taurus.
Rajiformes is one of the four orders in the superorder Batoidea, flattened cartilaginous fishes related to sharks. Rajiforms are distinguished by the presence of greatly enlarged pectoral fins, which reach as far forward as the sides of the head, with a generally flattened body. The undulatory pectoral fin motion diagnostic to this taxon is known as rajiform locomotion. The eyes and spiracles are located on the upper surface of the head and the gill slits are on the underside of the body. Most species give birth to live young, although some lay eggs with a horny capsule.
The cusk or tusk is a North Atlantic cod-like fish in the ling family Lotidae. It is the only species in the genus Brosme. Other common names include brismak, brosmius, torsk and moonfish.
The North Pacific hake, Pacific hake, Pacific whiting, or jack salmon is a ray-finned fish in the genus Merluccius, found in the northeast Pacific Ocean from northern Vancouver Island to the northern part of the Gulf of California. It is a silver-gray fish with black speckling, growing to a length of 90 cm (3 ft). It is a migratory offshore fish and undergoes a daily vertical migration from the surface to the seabed at depths down to about 1,000 m (3,300 ft). It is the object of an important commercial fishery off the West Coast of the United States, and annual quotas are used to prevent overfishing.
The longnose pygmy shark is a rare species of squaliform shark in the family Dalatiidae and the only member its genus. It is known only from a handful of specimens collected from the cold oceanic waters of the Southern Hemisphere, between the surface and a depth of 502 m (1,647 ft). Reaching 37 cm (15 in) in length, this diminutive shark is characterized by a slender, dark brown body with a very long, bulbous snout. In addition, it has two spineless dorsal fins of nearly equal size, with the origin of the first lying over the pectoral fin bases. The longnose pygmy shark does not appear substantially threatened by fisheries, and has been assessed as Least Concern by the International Union for Conservation of Nature (IUCN).
Raja is a genus of skates in the family Rajidae containing 16 species. Formerly a wastebasket genus, many species historically placed here have been moved to other genera in the family, such as Amblyraja, Beringraja, Dipturus, Leucoraja and Rostroraja. Raja are flat-bodied, cartilaginous fish with a rhombic shapes due to their large pectoral fins extending from or nearly from the snouts to the bases of their tails. Their sharp snouts are produced by a cranial projection of rostral cartilage. The mouth and gills are located on underside of the body. They may be either solid-coloured or patterned, and most skates have spiny or thorn-like structures on the upper surface, and some species contain weak electrical organs within their tails. Mating typically occurs in the spring and the female lays numerous eggs per clutch which are encapsulated in leathery cases, commonly known as "mermaid’s purses". Species vary in size, ranging from about 40 to 140 cm (1.3–4.6 ft) in length. These bottom-dwellers are active during both day and night, and typically feed on molluscs, crustaceans and fish. Raja skates are found in the East Atlantic, including the Mediterranean, and western Indian Ocean, ranging from relatively shallow water to a depth of 800 m (2,600 ft). Skates and related species have fossil records dating from the Upper Cretaceous period, thus this well adapted species is quite ancient.
The barndoor skate is a species of marine cartilaginous fish in the skate family Rajidae of the order Rajiformes. It is native to the northwestern Atlantic Ocean, and is found from the Grand Banks of Newfoundland and the southern side of the Gulf of St. Lawrence south to North Carolina. The fish is one of the largest skates found in the North Atlantic Ocean, reaching lengths up to 1.5 m (5 ft). It is carnivorous, feeding on invertebrates and other fish found near the sea floor.
The thornback ray, or thornback skate, is a species of ray fish in the family Rajidae.
The big skate is the largest species of skate in the waters off North America. They are found along the Pacific Coast from Alaska to Baja California, typically from the intertidal zone to a depth of 120 m (390 ft), and feed on benthic invertebrates and small fishes. They are unusual among skates in that their egg cases may contain up to seven eggs each. This species is one of the most commercially important skates off California and is sold for food.
The bottlenose skate, spearnose skate, or white skate is a species of skate in the family Rajidae. It is a benthic fish native to the coastal eastern Atlantic Ocean. Due to overfishing, it has been depleted or extirpated in many parts of its former range in the northeastern Atlantic and the Mediterranean Sea, and is now endangered.
The broad skate is a poorly known species of skate in the family Rajidae. It occurs at depths of 846 to 2,324 metres, and has been observed via remotely operated underwater vehicle by the Monterey Bay Aquarium Research Institute as deep as 3,167 metres (10,390 ft), making it one of the deepest-occurring skates known. It is sporadically distributed in the Pacific Ocean, from the Gulf of Panama to British Columbia and the Bering Sea, to the Tohoku Slope off northern Honshu and the Okhotsk Slope off Hokkaido. The species name, badia, comes from the Latin batius meaning "brown", referring to its color.
Sebastes levis, the cowcod, is a member of the Sebastidae (rockfish) family. In Greek, Sebastes means "magnificent," and levis is Latin for "capricious" or "fantastic".
The undulate ray is a species of ray and cartilaginous fish found in the Mediterranean and East Atlantic from southern Ireland and England to the Gulf of Guinea. It is found in areas with mud or sand, and may occur as deep as 200 m (660 ft), though it prefers shallower depths. It is considered endangered due to overfishing.
The bigmouth skate is a species of fish in the family Rajidae. It lives near the bottom in deep waters in Southeast Atlantic in depths below 1000 m. Its maximum size is 77 cm. It has a hard, roughly triangular snout and smooth body with star-based thorns around its eyes, tail, and elsewhere. Its top side is dark gray and underside has white spots. As the name suggests, it has a large mouth.
The Arctic skate is a species of fish in the family Rajidae. It lives near the seabed between 140 and 2,500 m deep in the Arctic Ocean and waters around Canada and northern and north-western Europe, in the northern Pacific Ocean, and in waters surrounding Antarctica and New Zealand.
Jensen's skate, also known as the shortail skate, is a poorly known species of fish discovered in 2004 during a study of bottom ichthyofauna aboard the Norwegian RV G.O. Sars, where four species were identified, including A. jensieni.
Eudactylina corrugata is a species of parasitic copepod found on the little skate and the thorny skate that is only known from St. Andrews, New Brunswick and Woods Hole, Massachusetts.
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