(page 167)

Silver gar Tylosurus marinus (Walbaum) 1792 [4]

BILLFISH; SALT-WATER GAR; SEA PIKE; AND VARIOUS OTHER LOCAL NAMES

[Jordan and Evermann, 1896-1900, p. 714.]

Silver gar (Tylosurus marinus)

Figure 79.—Silver gar (Tylosurus marinus).

Description—

Its long bill and slender body give the gar so peculiar an aspect that it is not likely to be confused with any other Gulf of Maine fish other than the half beak (p. 169), the needle fish (p. 170), or its own close relative Ablennes (p. 168). And it is easily distinguishable from the first of these by the fact that both of its jaws are prolonged instead of only the lower; from the second by lacking detached finlets on its back between its dorsal and caudal fins. The most conspicuous differences between the silver gar and Ablennes (p. 168) is that the body of the former is thicker than it is deep, and that its fins are only moderately concave, whereas the latter is so strongly flattened sidewise that it is less than one-half as thick as it is deep with deeply concave fins.

The head of the adult silver gar occupies nearly one-third of the total length of the fish; the upper jaw, from the eye forward, is twice as long as the rest of the head; both jaws are armed with sharp teeth; and the eyes are large. The long, slender body is only about one-twentieth as deep as long, rounded (not laterally flattened) in cross section, and thicker than deep. Both the body and the sides of the head are scaly. The dorsal fin, with 13 to 17 rays, and the anal fin, with 17 to 21 rays, are alike in outline, the anterior rays of both being much longer than those toward the rear, and the rear two-thirds of each can be depressed along the back and nearly concealed in a groove, while the forward one-third continues erect. Both fins, too, are situated far back, with the dorsal arising a little behind the forward end of the anal.

The ventral fins stand about halfway between a point below the eye and the base of the caudal. The margin of the caudal fin is only moderately concave, this fact being the readiest field mark to separate this particular gar from the only other species of its genus (Tylosurus acus) taken yet near the Gulf of Maine (see footnote, p. 167), for the tail of the latter is deeply forked. There is a distinct [page 168] longitudinal ridge, or low keel, along either side of the caudal peduncle.[5]

Color—

Greenish above, silvery on the sides, white below; a bluish silvery stripe along each side becoming broader and less distinct toward the tail; snout dark green; there is a blackish blotch deeper than long on the upper part of the cheek. The fins are without markings for the most part; the dorsal may be somewhat dusky, and the caudal bluish at its base.

Size—

The silver gar grows to a length of about 4 feet.

General range—

Maine to Texas; abundant along the South Atlantic and Gulf coasts of the United States, often running up fresh rivers above tide water.

Occurrence in the Gulf of Maine—

The silver gar is common enough along the southern shores of New England, e. g., in Rhode Island waters and at Woods Hole where quite a few are found from June to October. Like many other southern fishes, however, it seldom journeys eastward past Cape Cod, the only definite records of it within the Gulf of Maine being of several collected by Dr. William C. Kendall at Monomoy Island, forming the southern elbow of Cape Cod; at Wolfs Neck, Freeport, and Casco Bay, Maine, and of one found by Crane[6] in the stomach of a tuna that she examined at Portland, Maine, in July 1936. We have not seen it in the Gulf, nor have we heard even a rumor of its presence there from fishermen, good evidence that it is as rare a straggler as the few records indicate, for large silver gars are not fish to be overlooked. With so little claim to mention here, we need merely note that it is voracious, feeding on all sorts of smaller fishes, and that it runs inshore, possibly even into river mouths, to spawn. The eggs, described by Ryder,[7] are about 3.6 mm. (one-seventh of an inch) in diameter, and stick together and to any object they may touch, by long threads scattered over their surface.



[4] Jordan, Evermann, and Clark (Rept. U. S. Comm. Fish., (1928) Pt. 2. 1930, p. 196) place this species in the genus Strongylura Van Hasselt 1824.

[5] There are many other species of gars; in tropical seas, any one of which might stray northward with the Gulf Stream and so to the Gulf of Maine. The silver gar is identifiable among them by the following combination of characters (no one character alone marks it out among its relatives): mouth capable of being nearly closed; caudal peduncle with keels; dorsal and anal fins short, the former with 13-17 rays, the latter with 17-21 rays; caudal fin only moderately concave; eyes at least one-third as broad as the head is long behind the eyes; body not excessively slender but at least one-fifth to one-sixth as deep as head (including jaws) is long; body not very strongly compressed sidewise; Jordan and Evermann (Bull. 47, U. S. Nat. Mus., Pt. 1, 1896. p. 709) gives a useful key to the species of the family.

[6] Zoologica, New York Zool. Soc., vol. 21, No. 16, 1936, p. 211.

[7] Bull. U. S. Fish Comm., vol 1, 1882, p. 283.