CONGO EEL; BASTARD CUSK; GHOSTFISH
[Jordan and Evermann, 1896-1900, p. 2443.]
The wrymouth is eel-like in form, about thirteen times as long as it is deep but much flattened sidewise, and (eel-like) it lacks ventral fins. And (as in the eel) there is no definite demarcation between dorsal fin and the caudal fin or between the anal fin (about 47 to 50 rays) and the caudal, the one merging into the other to form a continuous fin around the tail, with no interspaces. [page 501] But its dorsal fin (which extends from close behind the pectorals back to the caudal fin) is spiny (about 75 to 77 spines) for its entire length like that of its close relatives the blennies. But the absence of ventral fins separates it from all of our local blennies, and its peculiar profile is an equally useful field mark, the head being flat-topped, the eyes set high up in very prominent orbits, and the mouth strongly oblique with so heavy a lower jaw that it gives the face a bulldog-like expression when the mouth is closed. The wide gill openings, running forward under the throat, and the small size and rounded outline of the pectorals are distinctive, also, as is the fact that both the dorsal fin and the anal fin are low (less than half as high as the body is deep in large specimens, relatively higher in small), and of uniform heights throughout most of their lengths, with the anal about two-thirds as long as the dorsal. The caudal fin is oval.
Described (and the few preserved specimens we have seen correspond with this) as of varying shades of brown or reddish brown, with the upper part of the sides marked with two or three irregular rows of small darker brown spots that run from head to tail; the top of the head is thickly speckled; the dorsal and anal fins are spotted with similar but smaller dots, and the belly is grayish white. A few spotless specimens have been seen.
Maximum length about 3 feet.
Very little was known of the habits of the wrymouth until recently, except that it is a bottom fish living from the intertidal zone down to considerable depths (where it is sometimes taken on line trawls in the Bay of Fundy). But in 1910 and again in 1920 Willey and Huntsman found full-grown wrymouths living in burrows in the mud on the flats at the mouth of the Magaguadavic River, a tributary of Passamaquoddy Bay. These burrows, to quote from their account, "were found in very soft mud from the lower part of the Fucus zone downward; that is, as far up as 4 feet above low-water mark," and "each system of burrows, inhabited by only one fish, consisted of branching tunnels about 5 cm. in diameter and from 3 to 8 cm. below the surface" of the mud, originating from a more or less centrally placed mound, where the main entrance was, with other smaller openings along the tunnels and at their terminations.
It seems that the burrowing instinct is strong, for one fish kept in a tank constantly inhabited a piece of hard rubber tubing. Hence it is probable that wrymouths in other parts of the Gulf likewise live in burrows or perhaps under stones. And they seem as likely to be inshore in shoal water in winter as in summer, for one was speared in Marblehead Harbor in December many years ago. Within our Gulf wrymouths have been found from a little above low water mark, as just remarked, down to about 100 fathoms; and to somewhere between 245 and 325 fathoms off New Jersey (see footnote 89, p. 502).
Huntsman and Willey found "beach fleas" or "sand-hoppers" (Gammarus), shrimps (Crago) and fragments of winter flounders in several wrymouths which they opened, and the one kept in captivity ate sand-hoppers, hermit crabs, small herring, and mollusks such as limpets, periwinkles, whelks, clams, and mussels. Apparently it located food as much by sight as by smell.
Ripe wrymouths are yet to be seen; but the presence of the larvae early in spring in Passamaquoddy Bay, as reported by Huntsman, with the seasonal occurrence of the fry mentioned below (p. 502), proves it a winter spawner in the Gulf of Maine. It may breed later in the Gulf of St. Lawrence, for Dannevig records a young wrymouth only 38 mm. long that was taken there as late as June 10. The localities where the young fish have been taken (see p. 502) suggest that wrymouths spawn all around the coast of the Gulf of Maine and wherever they occur on the offshore banks.
Neither the eggs nor the early larval stages are known. But by the time the young have grown to a length of 21 to 22 mm. they show the long dorsal and anal fins, and the lack of ventral fins characteristic of their parents, though they are much less slender, relatively, their caudal fins are larger and square instead of rounded and their mouths are nearly horizontal. The pigmentation of the fry is likewise extremely characteristic, the upper sides from the eye back to the caudal fin [page 502] being thickly speckled with dark brown dots, which are sparser on the lower part of the sides.
Atlantic Coast of North America, from southeastern Labrador, the coasts and banks of Newfoundland, and the Gulf of St. Lawrence to Long Island Sound and to the offing of central New Jersey.
Published records locate this fish in the Bay of Fundy; at Eastport; in Casco Bay; at Portland; in the mouth of the Piscataqua River; at Gloucester; in Marblehead Harbor; at Swampscott; Nahant; and Dorchester in Boston Harbor; and in the outer waters of Massachusetts Bay; there are specimens in the Museum of Comparative Zoology from Trenton, Maine; from outer Boston Harbor; and from near Provincetown. Two were taken in the central basin of the Gulf in July 1931 at a depth of 88-95 fathoms; one was trawled by the Atlantis in the deep trough west of Jeffreys Ledge at 72-78 fathoms, and another in the southwestern basin of the Gulf off Cape Cod at about 100 fathoms (183 meters), in August 1936; the Albatross II trawled one on the eastern slope of Nantucket Shoals at 52 fathoms, in May 1950. And one of the crew of the dragger Eugene H reports the capture of 4 of them on the northeastern part of Georges Bank on October 12, 1951. We have also taken its late larvae and fry in tow nets (11 specimens 18 to 40 mm. long) in Massachusetts Bay off Boston Harbor; over Jefferys Bank; in the trough near the Isles of Shoals; in the western basin a few miles west of Cashes Ledge; off Penobscot Bay; near Mount Desert Island; and in the deep basin off Machias, Maine, in May 1915, and in March and April 1920. These localities are sufficiently scattered to show that it is to be found, not only all around the coasts of the Gulf, but on the offshore grounds as well.
However, it seems to be rare or at least very local, for we have caught few adults ourselves, nor have we seen it brought in by fishing boats. In fact, few of the fishermen of whom we have inquired have been aware of its existence, a fact no doubt associated with its burrowing habit. And it has not been reported as yet from Browns Bank though it is to be expected there.
Following its range to the eastward and northward, we find it described as "rather common" all along Nova Scotia (taken at 60 fathoms on Western Bank off Halifax); it has been reported from a number of stations on the eastern half of the Grand Banks region, from the southern and southeastern coasts of Newfoundland, and from the outer Labrador coast some 20 miles north of the Strait of Belle Isle (see footnote 89, p. 502); also within the Gulf of St. Lawrence from the Bay of Chaleur in the southwest, and from the entrance to the Strait of Belle Isle in the northeast.
 Canad. Field Natural, vol. 35, 1921, p. 4.
 Putnam, Bull. Essex Inst., vol. 6, 1874, pp. 11-13.
 Willey and Huntsman also give interesting data on its respiration and on its response to various stimuli.
 Canadian Fisheries Expedition, 1914-1915 (1919), p. 16. He gives an excellent figure of this specimen on pl. 2, fig. 10.
 The most northern locality-record which we have found is for its drifting larvae off the outer coast of Labrador, about 20 miles north of Belle Isle (Rept. Newfoundland Fish. Res. Lab., vol. 2, No. 3, 1935, p. 79, Sta. 422); the most southern are for one trawled by the Albatross II off northern New Jersey, lat. 40° 04' N., long. 73° 32' W., August 1936, at 35 fathoms; and of another dredged by the Atlantis 30 miles farther south (lat. 39° 31' N., long. 72° 16' W.) between 245 and 325 fathoms, that same year.
 Lat. 40° 05' N., long. 69° 22' W.
 Vladykov and McKenzie, Proc. Nova Scotian Inst. Sci., vol. 19, 1935, p. 104.
 Halkett, Checklist Fishes Canada, 1913, p. 112, "Gaspé Bay."
 Rept. Newfoundland Fish. Res. Lab., vol. 2, No. 3, 1935, p. 79, Sta. 370.