[Jordan and Evermann, 1896-1900, p. 2271.]
The chief distinctions between the remora and the swordfish sucker is that it has a larger number of ridges in its sucking plate on the average (16 to 20, as against 14 to 17), and that there are only 22 to 25 rays in its dorsal fin, whereas the swordfish sucker has 29 to 32. Like the latter, it is a stouter fish than the shark sucker (p. 485), and its ventral fins are similarly attached to the skin of the abdomen along their inner edges.
Uniform brownish, blackish, or sooty, both above and below.
Maximum length about 18 inches.
Very little is known of the life history of the remoras. The young fry of this, and of other species of Remora have been taken in the open Atlantic, usually in June or July which suggests a sharply limited spawning period. A remora may join a shark, or other host, when only about 1½ inches (3 to 4 cm.) long.[26] But we have yet to learn how long or how constantly one may accompany a single shark, or how often it may transfer from one host to another.
Tropical seas generally; very common in the West Indies, occasionally north to New York and to Woods Hole, and only a stray north of Cape Cod. It is usually attached to large sharks or to sea turtles.
The only Gulf of Maine records for the remora, up to 1925, were of one taken many years ago in Salem Harbor, no doubt brought thither clinging to the bottom of some ship in from a southern voyage, as Goode and Bean[27] remarked; and of one in the Museum of Comparative Zoology that was taken at Provincetown long past. More recent records are of one found clinging to the bottom of a lobster trap in Portland Harbor in 1931, probably brought in by some West Indian schooner, several of which had recently been in the harbor;[28] of a second found sucking to the gills of a blue shark Prionace glauca caught on the northeast edge of Georges Bank, August 1 of that same year; and of a third fastened to a shark of the genus Carcharhinus that was caught at the surface over the southeast slope of Georges Bank in July 1939.[29]
Records from farther east and north along the American coast are of one taken from a blue shark, 10 miles off Cape Sable, June 1, 1933;[30] of another (also from a blue shark) west of Sable Island, September 9, 1934; and of two taken from sharks on St. Pierre Bank, south of Newfoundland, one of them on August 13, 1936,[31] the other on October 7, 1937.[32]
[26] Tåning, Nature, vol. 20, 1927, p. 224.
[27] Bull. Essex Inst., vol. 11, 1879, p. 21.
[28] Reported to us by the late Walter H. Rich, of the U. S. Bureau of Fisheries.
[29] The last 2 are in the collection of the Museum of Comparative Zoology.
[30] Vladykov, Proc. Nova Scotian Inst. Sci., vol. 19, 1935, p. 7.
[31] McKenzie and Homans, Proc. Nova Scotian Inst. Sci., vol. 19. 1938, p. 279.
[32] McKenzie, Proc. Nova Scotian Inst. Sci., vol. 20, 1939, p. 18.