Table of Contents
The most noticeable feature of the billfishes is that both of their jaws are prolonged to form a long slim beak well armed with teeth. Their bodies are very slender, and their anal, dorsal, and ventral fins set far back. They have no finlets between the dorsal and anal fins and the caudal, the absence of these being the readiest field mark to separate the billfishes from the needlefishes (Scomberesox, p. 170). They are swift-swimming, predaceous fishes, represented by many species, most of them American. Only two have ever been recorded in the Gulf of Maine.
|KEY TO GULF OF MAINE BILLFISHES|
|Body as thick as it is deep; dorsal, anal, and caudal fins only moderately concave||—||Silver Gar, p. 167|
|Body less than 1/2 as thick as it is deep; dorsal, anal, and caudal fins deeply concave||—||Garfish, p. 168|
 The closely allied houndfish (Tylosurus acus Lacépède 1803) has been taken at Nantucket, but has not been found within the Gulf of Maine. Since it may appear there as a stray from the south, we may point out that it is easily distinguished from the silver gar by its deeply forked tail and by the fact that its dorsal and anal fin are much longer, the former with 23 rays, the latter with 21. The following characters in combination will serve to identify it among the several tropical gars; mouth nearly closable and upper jaw not arched; dorsal and anal fins long; beak at least twice as long as rest of head; greatest depth of body not more than two-thirds as great as length of pectoral fin; no lateral stripe.