The witch (''Glyptocephalus cynoglossus''), known in English by a variety of other common names including the witch flounder, pole flounder, craig fluke, Torbay sole and grey sole, is a species of

flatfish A flatfish is a member of the ray-finned demersal fish order Pleuronectiformes, also called the Heterosomata, sometimes classified as a suborder of Perciformes. In many species, both eyes lie on one side of the head, one or the other migrating ...

from the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Pleuronectidae Pleuronectidae, also known as righteye flounders, are a family of flounders. They are called "righteye flounders" because most species lie on the sea bottom on their left sides, with both eyes on their right sides. The Paralichthyidae are the op ...

. It occurs on both sides of the North Atlantic Ocean on muddy sea beds in quite deep water. In northern Europe it has some importance in fisheries as a food fish.

Description

The witch is a right-eyed flatfish with a small mouth which reaches the forward edge of the lower eye. The mouth contains a single series of small, incisor like teeth. It has a small head which takes up a fifth of the total length with large, open blister-like mucous pits on its blind side Its body is strongly, dorsally compressed and oval in shape. The body is elongated and has a standard length which is 2.5-3.5 times longer than it is broad. The

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

is relatively straight and runs the length of its body with 110-140 scales. The

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...

has 95-120 rays and the

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as see ...

has 85-102 rays, and there is a short, sharp spine pointing forward in front of the anal fin, which is created by an elongated first interhaemal spine of the post-abdominal bone, although this is sometimes so small that it is hidden. The

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

on the eyed side is shorter than the head and the pectoral fins are blackish towards their tips. Almost all of the head and body, apart from the tip of the snout and the lower jaw is covered in smooth

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

which make the fish slippery when held. They are brownish grey to greyish brown in colour on their eyed side, with less variation in colour than other flatfish, with the body and fins densely spotted with muted black spots; the median fins become duskier towards their margins. The blind side is white, marked with tiny black dots, although occasionally fish are recorded with the blind side a similar colour to the eyed side. They grow to a maximum size of 60 cm standard length but are normally no more than 40 cm.

Distribution

The witch occurs on both sides of the North Atlantic Ocean. In the northeastern Atlantic Ocean it is found from the northernmost part of the

Bay of Biscay The Bay of Biscay (), known in Spain as the Gulf of Biscay ( es, Golfo de Vizcaya, eu, Bizkaiko Golkoa), and in France and some border regions as the Gulf of Gascony (french: Golfe de Gascogne, oc, Golf de Gasconha, br, Pleg-mor Gwaskogn), ...

to the

Kattegat The Kattegat (; sv, Kattegatt ) is a sea area bounded by the Jutlandic peninsula in the west, the Danish Straits islands of Denmark and the Baltic Sea to the south and the provinces of Bohuslän, Västergötland, Halland and Skåne in Sweden ...

and into the westernmost part of the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

, northwards along the entire coast of Norway and east in to the Murmansk region of Russia and west to the southern and western coasts of Iceland.. In the western North Atlantic their range runs from

Newfoundland Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...

and

Labrador , nickname = "The Big Land" , etymology = , subdivision_type = Country , subdivision_name = Canada , subdivision_type1 = Province , subdivision_name1 ...

south as far as

North Carolina North Carolina () is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. The state is the List of U.S. states and territories by area, 28th largest and List of states and territories of the United ...

, including the

Grand Banks The Grand Banks of Newfoundland are a series of underwater plateaus south-east of the island of Newfoundland on the North American continental shelf. The Grand Banks are one of the world's richest fishing grounds, supporting Atlantic cod, sword ...

, Gulf of Maine,

Gulf of St Lawrence , image = Baie de la Tour.jpg , alt = , caption = Gulf of St. Lawrence from Anticosti National Park, Quebec , image_bathymetry = Golfe Saint-Laurent Depths fr.svg , alt_bathymetry = Bathymetry ...

and the

Scotian Shelf The Scotian Shelf is a geological formation, part of the Continental shelf, located southwest of Nova Scotia, Canada. It covers an area of , is long and ranges in width from . It has an average depth of . The Scotian Shelf contains the ecological ...

Habitat

Witch adults are found on the

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

and upper

continental slope A continental margin is the outer edge of continental crust abutting oceanic crust under coastal waters. It is one of the three major zones of the ocean floor, the other two being deep-ocean basins and mid-ocean ridges. The continental margin ...

with a preference for fine sediments such as clay, muddy sand, and pure mud. They also occur where there are deep holes and channels on the continental shelf. They are

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning " ...

and occur in fairly deep water, ranging between 45m and 1460m, but mainly at depths between 184m and 366m. This species prefers temperatures of 2-6 °C. The juvenile fish cease to be

nektonic Nekton or necton (from the ) refers to the actively swimming aquatic organisms in a body of water. The term was proposed by German biologist Ernst Haeckel to differentiate between the active swimmers in a body of water, and the passive organisms t ...

when they grow to lengths of 5–6 cm and adopt a benthic habit at shallower depths than the adults.

Biology

The witch feeds on invertebrates and in European waters the main prey items are small crustaceans, starfish, small molluscs, and worms. Fish are rarely taken, if at all, and it does not take baits. Spawning occurs between May and September. and can take place in temperatures ranging from near freezing to 8.8-10 °C, experiments have demonstrated that the eggs continue to incubate normally in water which is as cold as 7.2C. and as warm as 12.77 °C. The eggs take around a week to hatch, the newly hatched

larvae A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. T ...

being about 4.9mm in length with a relatively large yolk sac. As the larvae grow they develop five transverse bands on their body, the reduced yolk and the fin folds. The entire yolk is absorbed when the larva is around 10 days old. At around 40mm the left eye has migrated to the dorsal surface of the head, the migration of the eye is completed at lengths of between 40 and 50 mm. and it is at this point that the young fish adopts a benthic habit. It is a slow growing species, sexual maturity is reached at 3–4 years and they have a lifespan of up to 14 years, although the maximum reported age is 25 years. Off Norway a sex ratio of 1:1 was found for fish up to the age of 9 years but in older fish this was skewed towards females. Abstract The fecundity of females varies with size with 48,800 eggs borne by a fish of 31 cm in length to 508,300 eggs in one of 60 cm.

Fisheries

The witch is commercially important as a bycatch and there are fisheries directed at this species, except that it is occasionally targeted in the Skagerrak. It is an important bycatch species in some fisheries which target the langoustine (''

Nephrops norvegicus ''Nephrops norvegicus'', known variously as the Norway lobster, Dublin Bay prawn, ' (compare langostino) or ''scampi'', is a slim, orange-pink lobster which grows up to long, and is "the most important commercial crustacean in Europe". It is n ...

''). There was a notable increase in the landings of this species in the 1980s as a result of increased fishing effort by Iceland, Spain, and Norway. The North Sea is where most of the commercial landings in the northeast Atlantic are made and this species is rarely landed in Norway. The

FAO The Food and Agriculture Organization of the United Nations (FAO)french: link=no, Organisation des Nations unies pour l'alimentation et l'agriculture; it, Organizzazione delle Nazioni Unite per l'Alimentazione e l'Agricoltura is an intern ...

reported a total catch for ''G. cynoglossus'' in 1999 of 18,969 tonnes, while more recent statistics are that approximately 13,600 tonnes are taken by European fisheries annually with United Kingdom vessels taking around 3,600 tonnes of this total catch. In North America commercial fisheries take around 2,700 tonnes annually. They are caught with bottom trawls using techniques known as "demersal bottom trawling" and "small flatfish (flounders, soles) bottom trawling". The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

classifies this species as

Least Concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. ...

, but the damaging bottom trawling methods used to catch it may cause issues, and the large number discarded as bycatch by commercial vessels which are targeting other species is unknown. The flesh is marketed fresh or frozen and is eaten steamed, fried, microwaved and baked. The name ''Torbay sole'' appears to be a mainly culinary term,Witch , InterSites
/ref> following the habit of renaming certain fish to broaden their appeal. Glyptocephalus cynoglossus

References

{{DEFAULTSORT:flounder, witch witch flounder Commercial fish Fish of the North Atlantic witch flounder witch flounder Taxobox binomials not recognized by IUCN