Table of Contents
The ocean pouts and wolf eels are slender eel-like fishes with the anal fin continuous with the caudal. In most of the members of the family the dorsal fin, also, joins the caudal equally, making one continuous fin extending around the tip of the tail, but in the only common Gulf of Maine species the rear portion of the dorsal is so low that there seems to be a bare space between it and the caudal. All the members of the family, however, known definitely, either from the Gulf of Maine, or from the outer coast of Nova Scotia, are readily separable from the true eels by having ventral fins (small but unmistakable) situated a [page 509] little in advance of the pectorals. But the green ocean pout (Gymnelis viridis Goode and Bean) of arctic seas has no ventrals; it ranges southward as far as the estuary of the St. Lawrence River,[24] and perhaps as far as northern Nova Scotia.[25] The closest affinities of the ocean pouts, among Gulf of Maine fishes are with the blennies (p. 491), the wolffishes (p. 502), and the wrymouths (p. 500). But they are easily separable from the blennies and wrymouths by the fact that at least the major part of the dorsal fin is soft-rayed, not spiny; and from the wolffish by their more slender form and smaller teeth.
Only two species are known definitely from our Gulf, one, the common ocean pout (p. 510) very plentiful; the other, the wolf eel (p. 515), much less so. A third, the Arctic Ocean pout (p. 516) has been reported from shoal water to the west of our Gulf as well as from the Nova Scotian Banks to the east, though not from the Gulf itself. A fourth species (Lycodes esmarkii Collett 1875) has been credited to the Bay of Fundy.[26] But the specimen in question was trawled by the Albatross I, on the southern slope of the Grand Banks in 244 fathoms of water.[27] Two others that have been reported from the Nova Scotian Banks are also included in the following key, as they are likely to be found in our Gulf sooner or later.
Still another species, Lycodes atlanticus Jensen 1904, has been reported from a number of stations along the continental slope from the offing of southern Nova Scotia to the offing of northern North Carolina, in depths of 543 to 1,423 fathoms.[28] But being a deep-water form, it is not to be expected either within the limits of the Gulf of Maine, or on the Nova Scotian Banks.
The various species of the genus Lycodes resemble one another so closely that their identification is very difficult. If one should be taken in the Gulf that does not agree with either of these that are described on the following pages, we suggest that it be sent either to the laboratory of the U. S. Fish and Wildlife Service, Woods Hole, Mass.; the Division of Fishes, U. S. National Museum, Washington, D. C.; or to the Department of Fishes, Museum of Comparative Zoology, Cambridge, Mass., to be named.[29]
| KEY TO GULF OF MAINE AND NOVA SCOTIAN OCEAN POUTS AND WOLF EELS | |||
|---|---|---|---|
| 1. | The dorsal fin seems to be separated from the caudal fin by a considerable gap | — | Ocean pout, p. 510 |
| The dorsal, caudal and anal fins form one continuous fin | 2 | ||
| 2. | The trunk is extremely slender, at least 14-16 times as long as it is deep; the dorsal fin originates over the tips of the pectoral fins | 3 | |
| The trunk is stouter, less than 12 times as long as it is deep | 4 | ||
| 3. | Dorsal fin with only about 92 rays and anal fin with about 88 rays; lower surface of body with only a few scales. | — | Wolf eel, p. 515 |
| Dorsal fin with about 118 rays and anal fin with about 110 rays; lower surface of body uniformly scaly, like upper surface | — | Lycenchelys paxillus, Goode and Bean 1879[30] | |
| 4. | The lateral line runs along the middle of the sides; the vent is only a little nearer to the snout than to the tip of the tail; there are no scales on the belly or on the forward part of the back | — | Arctic eelpout, p. 516 |
| The lateral lines (or their lower branch if double) run along the lower part of the sides; the vent is considerably nearer to the snout than it is to the tip of the tail; the body is covered with scales | 5 | ||
| 5. | Lateral line single, running along lower part of side of body; forward part of dorsal fin marked with one or more sooty patches | — | Lycodes vahlii Reinhardt 1838[31] |
| Lateral line double, with the more distinct branch of the two running along the lower edge of the side of the body; the forward part of the dorsal fin is not marked with dark patches | — | Lycodes esmarkii, Collett 1875[32] | |
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[30] Known from several stations on the continental slope abreast of our Gulf and off southern New England at depths of 365-904 fathoms; also from the deep gully between LaHave and Sable Island Banks at 200 fathoms (see Goode and Bean 1895, p. 311 for list). [31] Originally described from Greenland; reported from Banquereau Bank, at 130-190 fathoms by Goode and Bean (Smithsonian Contrib. Knowl., vol. 30, p. 308, as Lycodes zoarchus.) See Vladykov and McKenzie, Proc. Nova Scotian Inst. Sci., vol. 19, pt. 1, 1935, p. 109. [32] Spitzbergen and Northern Norway; Grand Banks; LaHave Bank, and southward along the continental slope in depths of 300-420 fathoms to the offing of Rhode Island. |
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[24] Vladykov and Tremblay, Natural. Canad., vol. 62 (Ser. 3, vol. 6), 1935, p. 82.
[25] Goode and Bean (Smithsonian Contrib. Knowl., vol. 30, 1895, p. 313) credit it to Nova Scotia but give no definite locality.
[26] By Vladykov and McKenzie, Proc. Nova Scotian Inst. Sci., vol. 19, 1935, p. 109.
[27] Reported by Goode and Bean (Smithsonian Contrib. Knowl., vol. 30, 1895, p. 305) as from lat. 44° 47' N.; long. 66° 33' W., Albatross Station 2470; but the actual position of this station was lat. 44° 47' N.; long. 56° 33' W. See Townsend, Rept. U. S. Comm. Fish., (1900), 1901, p. 399.
[28] Reported by Goode and Bean (Smithsonian Contrib. Knowl., vol. 30, 1895. pp. 305-306) as L. frigidus Collett 1875, with list of stations.
[29] Jensen's monograph of the Lycodids of Northern Europe and of Greenland (Danish Ingolf Exped., vol. 2, Pt. 4, 1904) includes descriptions, and beautiful illustrations of all the species of Lycodes that have been reported from the Gulf of Maine, or from the Nova Scotian Banks. And Vladykov and Tremblay (sta. Biol. Saint Laurent. Fauna and Flora Laurent, No. 1, 1936) have given a revision of the genus in the western Atlantic with descriptions and photographs of several new species and subspecies from the Gulf of St. Lawrence and northward.