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Witch Flounder fish identification, Gray Sole fish characteristics, its habitats, fishing methods
The witch or Torbay sole (Glyptocephalus cynoglossus) is a right-eyed flatfish found in rather deep water on sandy bottoms in the North Atlantic, on both coasts, Eastern Atlantic, from northern Spain (Bay of Biscay) to northern Norway, also Iceland, Western Atlantic southwards to Cape Cod and France. It reaches a length of 12 to 18 inches, grows to maturity in 3 or 4 years, and may live up to 14 years. The species lives on soft bottoms between 45 and 1460 m, predominant from 184 to 366 m and prefers temperatures of 2–6 °C. It eats mostly crustaceans, worms and brittle stars. It spawns from May to September. The name Torbay sole appears to be a mainly culinary term, following the habit of renaming certain fish to broaden their appeal. It is also called gray flounder or witch flounder. The lefteye flounder Arnoglossus scapa is also known as witch.
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The witch or Torbay sole, Glyptocephalus cynoglossus, is flatfish of the family Pleuronectidae, also known as Gray flounder, Gray Sole, Craig Fluke, Pole Flounder, Камбала Длинная Атлантическая or Камбала Красная in Russian, are found in the North Atlantic Ocean from Labrador southward to Virginia. In the eastern Atlantic, they occur from Norway to northern Spain. In the western Atlantic, they are distributed from the Gulf of St. Lawrence and Grand Banks in Canada to North Carolina. It is found in European waters from Murmansk in the north to the Bay of Biscay in the south. In US waters, Witch flounder are common throughout the Gulf of Maine and in deeper areas on and adjacent to Georges Bank and along the shelf edge as far south as Cape Hatteras.
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Description
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Witch flounder, or grey sole, is a medium sized rather long and thin flatfish having eyes and color on the right side. Body is extremely elongate, fusiform, more than twice as long as deep, much compressed. Head is ovate, very small and short, 1/5th in body length. The dorsal (left-hand) profile of its head slightly curved; its blind side with many excavations and mucous blister-like cavities in the skull, mandible, and preopercle. Head with about 12 open mucous pits or depressions, flat poles on a blind side and less obvious ones on the eyed side; the small oral aperture located on the end of a snout. Mouth very small, with the cleft oblique, reaching anterior edge of lower eye; teeth small, moderate, incisor-like, broad, equal, close set on a blind side, in a single series, 17 blind side, 20 on the eyed side, distant, obtusely conic; no teeth on vomer or palatines. Lower pharyngeals are narrow, with 1 or 2 rows of conical teeth. Eyes moderate, the lower advanced, close together, 1/3rd in head. Gill rakers are short, weak.
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Lateral line nearly straight, simple, but in some species it is slightly arched abreast the pectoral fin; there are 110-140 scales on lateral line, scales very small, smooth. Dorsal and anal fin rays are very long, highest dorsal and, anal rays 2 in head. Origin of dorsal begins above middle of upper eye. The anal fin is preceded by a short, sharp spine pointing forward, which is a prolongation of the post-abdominal bone, sometimes very small and hidden in the skin. The two long fins are of about uniform width throughout most of their lengths, except that they narrow gradually toward head and tail. Pectoral fin of eyed side is shorter than head, falcate, that of eyed side about half length of head. Caudal fin rounded; anal spine present. The pectoral fins and the ventral fins are alike on the two sides, or nearly so, while the caudal fin is much smaller, relatively, than that of the yellowtail, of the winter flounder, or of the smooth flounder, though similarly rounded in rear outline.
Key characters
Body is oval and very thin with complete straight lateral line. Very small head is occupying only about one fifth of the total body length. It has a very small mouth. On the blind side of the head are about a dozen large open mucous pores which are very noticeable. Pectoral fin of eyed side is shorter than head. Distal part of pectoral fin blackish. Uniform coloration, rough scales.
95-120 Dorsal fin rays
85-102 Anal fin rays
58-65 Vertebrae
110-140 scales on Lateral Line
Max length: 31in (78 cm), common 45cm.
Max weights: 4kg, common 2 kg (4.5 lb)
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The witch is less variable in color than most other flatfishes. Most of them are grayish brown, brownish or russet gray on the eyed side, either uniform or with darker transverse bars, with the vertical fins of the general body hue, tinted or tinged with violet, and either plain or spotted. Fins are with dark spots. Median fins more or less dusky towards their margins. The pectoral fin membrane on the eyed side is dusky or even black, a feature distinctive of this particular flatfish. The blind side is white, and more or less dotted with minute dark points. An occasional fish is colored on the underside as well as on the upper side.
This species is one of the most strongly marked in the family, being easily distinguished from most flatfishes by the greatly increased number of vertebrae, and from all of them by the remarkable cavernous structure of the bones of the head. The body is relatively narrow compared to other flatfishes, with a very small head. It is small-mouthed like the
Winter Flounder, Pseudopleuronectes Americanus, the Smooth flounder, Liopsetta putnami and the
Yellowtail Flounder, Lvnanda Ferruginea. Distinguishing characteristics from all 3 are: Witch flounder’s fin rays are much more numerous, its body narrower relatively, its head much smaller, and the open mucous pits on the blind side of its head large and conspicuous. It is 2 ½ to 3 times as long as it is deep, elliptical in outline, very thin but with its head occupying only about one-fifth of the total body length, and it has a very small mouth. The whole body and head (except for the tip of the snout and the lower jaw) are scaly, but the scales are smooth to the touch, which make the witch as slippery to hold as a female Smooth flounder.
Habitat and Habits
They prefer living in gullies where the bottom is usually of clay, muddy sand or pure mud rather than the hard tops of the banks and inshore ground. In summer they usually move up onto the soft mud and in winter move down into the deeper gullies. The witch flounder is rather a deepwater fish, usually caught as deep as 1100 - 1500 m. Witch flounder have been caught in a bottom temperature range of -1° to 11°C. However; they are most abundant within a bottom temperature range of 2 to 6°C. However, the depth of highest abundance of witch flounder in Canadian waters is between 185 and 400 m. The reason for this wide variation in depths is that colder waters in upper water layers in certain areas at certain times generally force these fish deeper until they find suitable temperature conditions conducive to their survival. Witch flounder are not normally found on the shallower parts where bottom water temperatures are less than 1°C.
Witch flounder are associated with deep holes and channels between the coastal banks and along the deep edges of the banks where water temperatures are usually in a range suitable for their habitation. These localized areas of high abundance are habitually more prominent in the winter-spring time when this species forms rather dense prespawning concentrations.
Due to the very small mouth of the Witch flounder, the type of food it can eat is obviously restricted to very small animals. The main food item is marine worms of many varieties. They also eat small crustaceans or shellfish similar in shape to shrimp, though by volume, many less than marine worms. It feeds on invertebrates, like other small-mouthed flatfishes, starfish, small mollusks, and worms, as its chief diet. The distribution and biology of the witch flounder is remarkably similar as for lemon sole except that they prefer somewhat different bottom types.
Witch flounder are a rather sedentary species and do not appear to undertake long-distance migrations. They concentrate in selected water suitable for spawning, and then disperse in the surrounding areas for feeding. Young witch flounder are either pelagic (midwater) or they live in very deepwater areas where the only probable threat to them is the redfish fishery. The deepwater phase of the very young also reduces direct competition for food from such groundfish species as the Atlantic cod and the American Plaice.
Spawning
Spawning usually takes place in very deep water where temperature conditions are rather high, with the spawning period being less extensive in the north than in the south. They spawn over the continental shelf in late spring to late summer depending upon the geographical area of the spawning grounds. The spawning period in the southern Labrador-northeast Newfoundland Shelf area continues from March to July, with the pick in March-April at depths of 500-700 m. In the Grand Banks and St. Pierre Bank regions the spawning continues up to September, even as late as October with the pick spawning in July-August, with a possible earlier most intensive peak in April. Spawning occurs in shallow water and on the slopes; however the most intensive spawning is associated with the slopes of the bank greater than 500 m. The witch spawns in temperatures ranging from close to the freezing point of salt water up to 48°-50° F.
Female witch flounder reach maturity between ages 5 and 7 at lengths of 40-45 cm, most of the males are sexually mature at 4 to 5 at lengths of 30-34 cm. Witch flounder form a large pre-spawning concentration in the spawning areas. The females are highly fertile, releasing as many as 500,000 eggs in a single spawn.
The pelagic larval stage is longer compared with other flounders, lasting from 4-6 months to 12 months. During this time, eggs and larvae from spawning grounds in the northern areas drift southward in the fast current over great distances to settle in water where temperatures are suitable for survival. Eggs and larvae on the southern banks probably do not drift far because of the slow currents which move in a more circular fashion.
The eggs are buoyant, spherical, transparent, without oil globule, and 0.7 to 1.45 mm. in diameter (average 1.27mm). As noted, there is danger of confusing newly spawned witch eggs with those of the cod and haddock, for they overlap these in size and in season. But identity is easily recognizable after a few days' incubation; for black pigment is to be seen in the gadoid eggs soon after the embryo is visible as such, but does not appear in the witch flounder eggs until after hatching.
The fertilized eggs float and hatching occurs after 7 to 8 days at temperatures varying from 46° to 49° F., and the newly hatched larvae are about 4.9 mm. long, with a yolk sac larger than of other flatfishes. The yellow and black pigment becomes aggregated into five transverse bands on body, yolk, and fin folds within a few days after hatching, when the larva is 5 to 6 mm. long. One of these bands is at the region of the pectoral fin, one at the vent, and three of them on the trunk rearward from the vent. The yolk is entirely absorbed in about 10 days after hatching, the caudal rays have begun to appear at a length of 15 mm. the rays of the vertical fins are well advanced at 21 mm. and they are complete in their final number at about 30 mm. The eyes are still symmetrical, or nearly so, up to this stage. But the left eye has moved to the dorsal surface of the head in larvae of about 40 mm. And the migration of the eye is complete at a length of 40 to 50 mm. when the young fish takes to the bottom.
Juveniles eventually settle to the bottom in deep waters. In northern areas of their range, including the Gulf of St. Lawrence, witch flounder move into deep water during winter months and cease feeding. Witch grow faster in the Gulf of Maine and Georges Bank, where water temperature is higher and feeding occurs year-round.
Fishing Methods
Witch flounder caught mainly on hook-and-line, and with harpoons and beach nets, occasionally in traps. It is a very good-eating fish but not taken in sufficient quantities to be commercially important. Once cooked, the meat is pure white, lean, boneless and flaky with a mild flavor. It has no commercial value due to its thin watery flesh and many fine bones. Witch flounder is sold fresh and frozen as whole fish, fillets and blocks as well as fully prepared in various value-added presentations.
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