[Jordan and Evermann, 1896-1900, p. 2439.]
This shanny suggests the rock eel in its color pattern. But it is easily distinguished from it by having well developed ventral fins and considerably larger pectorals, but fewer dorsal fin [page 498] spines (only 48 or 49). The presence of a series of large roundish spots on the dorsal fin separates it at a glance from the radiated shanny, which is similar to it in form, but which has only a single large blotch on its dorsal; its spotted dorsal and its evenly rounded pectorals mark it off from the shanny; and its much less slender body (only about one-seventh as deep as it is long) from the snake blenny.
The single long dorsal fin originates directly over the edge of the gill cover, and is of uniform height throughout its length, except that the first 2 or 3 spines, and the last 2 or 3, are shorter than the others. It extends backward nearly to the caudal, but the fins are separated by a conspicuous notch. The anal fin (one short spine, closely followed by about 35 rays) is about two-thirds as long as the dorsal fin, is of approximately the same height as the latter, and bears a similar relation to the caudal. The caudal fin is gently rounded in outline. The pectorals are broadly rounded, a little longer than the depth of the body; the ventral fins are somewhat less than half as long as the pectorals. The straight dorsal profile of the head, from tip of snout to origin of dorsal fin, is an outstanding feature, and the lateral line is single (double in the radiated shanny, p. 499), conspicuous, and ends at about the mid-length of the body.
Grows to a length of at least 7 inches.
The single row of 5 to 9 round black spots with pale margins on the dorsal fin, and irregular dark bars on the cheeks and chin are the most conspicuous markings of this shanny. The ground color of the body of an Alaskan specimen is described as bright scarlet, but is brownish (after preservation) on a Gulf of Maine specimen, with darker cloudings extending from close behind the head to the base of the caudal fin. The lower surface of the body (except the head) is plain whitish. The anal fin is dusky, edged with white; the pectorals and caudal are crossed by pale bars, and the ventrals are plain yellow.
Arctic and circumpolar, from Greenland to northern Siberia and the Arctic Coast of America; southward to Bristol Bay and Prince of Wales Island, Alaska, in the Pacific, and to Mount Desert, Maine on the Atlantic coast of America.
A specimen 41/3 inches (109 mm.) long, of this Arctic species, taken one-half mile off Little Duck Island near Mount Desert, Maine, from the stomach of a cod, on April 30, 1930, was in such good condition that it unquestionably had been living in the immediate vicinity.
The next most southerly records are of two specimens from Chedabucto Bay, Nova Scotia, near the Atlantic entrance to the Strait of Canso; and of one taken off Cheticamp, on the Nova Scotian shore, within the Gulf of St. Lawrence, where Huntsman classes it as a characteristic of the icy-cold water on the banks; and of one from Battle Harbor, on the outer coast of Labrador, a few miles north of the eastern entrance to the Strait of Belle Isle.
 Jordan and Evermann, Bull. 47, U. S. Nat. Mus., Pt. III, 1898, p. 2439.
 Reported from Hudson Bay by Vladykov, Contrib. Canadian Biol., N. Ser., vol. 8, No. 3, 1933, p. 35.
 Cornish, Contrib. Canadian Biol. (1902-1905) 1907, p. 87.
 Cox, Contrib. Canadian Biol. (1918-1920) 1921, p. 112.
 Huntsman, Trans. Roy. Soc. Canada, Ser. 3, vol. 12, Sect. 4, 1918, p. 63.