Viperfish Chauliodus sloani Bloch and Schneider 1801
[Jordan and Evermann, 1896-1900, p. 585.]
Figure 63.—Viperfish (Chauliodus sloani), Southern slope of Browns Bank. After Goode and Bean.
Description—
The viperfish not only has luminescent organs, but it is very different in general appearance from all the fishes that are regular inhabitants of the Gulf of Maine. Most obvious of its characteristics is its bulldog-like mouth. It shares this with its fellow strays, Stomias (p. 147), Stomioides (p. 147) and Trigonolampa (p. 148) and the general form is much alike in the three. But there is no danger of confusing it with any one of these if one looks closely, for the viperfish has an adipose fin and its rayed dorsal fin is far forward, whereas Stomias, Stomioides, and Trigonolampa have no adipose fin and their rayed dorsal fin stands far rearward.
In the viperfish the lower jaw is longer than the upper, the upper is armed with four long fangs on each side, while the lower has a series of pointed teeth set far apart, those in front very elongate and all of them so long that they project when the mouth is closed. Furthermore, the snout is so short that the very wide mouth gapes far back of the eye. The body is about seven times as long as deep, flattened sidewise, deepest close behind the head, and tapering evenly to the tail. The very short dorsal fin (6 or 7 rays) stands far forward and its first ray is separate, very slender, and about half as long as the fish when not broken off, as it usually is. The ventrals are about midway between the snout and the origin of the anal fin, variously pictured as either larger or smaller than the dorsal. The small anal is close to the caudal, with the adipose fin over it. The [page 146] body is clothed with large but very thin scales. There are several longitudinal rows of small luminescent spots on the ventral surface, running from throat to tail; several more such spots on each side of the head; and many tiny unpigmented dots scattered over the trunk.[39]
Color—
Greenish above, the sides with metallic gloss; blackish below.
Size—
Up to about one foot long.
Habits—
Nothing is known of its habits except that it is an inhabitant of the mid-depths of the Atlantic Basin and that it probably does not rise closer to the surface than 150 or 200 fathoms except, perhaps, during its larval stages. Its teeth suggest a rapacious habit but there is no actual record of its diet.
Occurrence in the Gulf of Maine—
The only definite Gulf of Maine records are of one specimen found in the stomach of a cod caught on Georges Bank in 1874, and of a second found in the stomach of a swordfish that was harpooned in the gully between Browns and Georges Banks in 1931.[40] But the viperfish may be expected on the offshore banks as a stray at any time, for several have been taken off the continental slope abreast of southern New England[41] in deep water.