FISHES OF THE GULF OF MAINE 



169 



General range and occurrence in the Gulf of 

 Maine.- — Widespread in tropical seas; 10 Brazil to 

 Chesapeake Bay in the western Atlantic, and 

 northward as a stray to Cape Cod. A specimen 



of this tropical fish, about 23% inches (594 mm.) 

 long to the fork of the tail, was taken in a fisb 

 trap on the shore of Cape Cod Bay at North 

 Truro, Mass., on August 15, 1949." 



THE HALFBEAKS. FAMILY HEMIRAMPHIDAE 



The halfbeaks are close allies of the billfishes 

 (Belonidae, p. 167), but it is only the lower jaw 

 that is greatly prolonged while the upper jaw is 

 short in the only species of present concern. They 

 are largely herbivorous, feeding mainly on green 

 algae. There are many species in warm seas, 

 only one of which is known to reach the Gulf of 

 Maine. 



Halfbeak Hyporhamphus unifasciatus 



(Ranzani) 1842 



Skipjack 



Jordan and Evermann, 1896-1900, p. 721 (Hyporham- 

 phus roberti (Cuvier and Valenciennes) 1846. 



Description. — The most striking feature of this 

 halfbeak and one which is enough of itself to mark 

 it off from every other fish known from the Gulf 

 of Maine, is the fact that while the lower jaw is 

 very long, the upper jaw is short. 12 



This is a slender fish, its body only one-sixth to 

 one-tenth as deep as long (younger fish are still 

 more slender), tapering slightly toward head and 

 tail. Its dorsal (14 to 16 rays) and anal (15 to 

 17 rays) fins are situated far back and opposite 

 each other, as in the silver gar, and are about 

 equal in length and alike in outline. There are 

 no detached finlets between them and the caudal 



'• We have seen specimens from Acapulco, west coast of Mexico; Panama; 

 Mauritius; and Zanzibar. 



" This specimen was presented to the Museum of Comparative Zoology hy 

 John Worthlngton of the Pond Village Cold Storage Co., North Truro, 

 Mass. 



13 Should a halfbeak be taken in the Gulf of Maine It would be well to con- 

 sult Meek and Hlldebrand (Field Museum of Natural History, Znol. Scries, 

 vol. 15, Pt. 1, p. 232, 1923) for there are several other species that might reach 

 us as strays, either via the Gulf Stream route or from offshore. One, Indeed 

 (Euleptorhamphus velox) , has been taken at Nantucket. Its lower Jaw is oven 

 longer and more slcndor than that of the halfbeak. its body Is more flattened 

 sidewlse, and its pectoral fins are longer. 



fin. The ventrals stand about midway between 

 a point below the eye and the base of the caudal. 

 The teeth are small and the scales are largest on 

 the upper surface of the head. The beak is much 

 shorter in young fish than it is in adults. 



Color. — Translucent bottle green above with 

 silvery tinge, each side with a narrow but well- 

 defmed silvery band running from the pectoral fin 

 to the caudal fin, the sides darkest above and 

 paler below this band. The tip of the lower jaw is 

 crimson in life, with a short filament, and three 

 narrow dark streaks run along the middle of the 

 back. The forward parts of the dorsal and anal 

 fins and the tips of the caudal fins are dusky. 

 The lining of the belly is black. 



Size.— Adults are seldom more than 1 foot long. 



General range. — Tropical and subtropical on 

 both coasts of America and in the Gulf of Mexico; 

 abundant off the South Atlantic United States, 

 not uncommon northward to Cape Cod, and stray- 

 ing to the coast of Maine. 



Occurrence in the Gulf of Maine. — In our cool 

 boreal waters the halfbeak is only a rare stray 

 from the south, previously recorded only twice in 

 the Gulf of Maine, i. e., from Machias and from 

 Casco Bay, Maine, many years ago in each case. 

 We can now add one taken in Quincy Bay, Boston 

 Harbor, July 10, 1951, by Gordon Faust; another 

 off Revere (also in Boston Harbor) on the 19th of 

 the month, by John M. Hodson; a third, taken 

 in a trap at Sandwich, September 24 of the same 

 year, 13 and several dozen taken in a pound net at 

 Small Point, Maine, July 14-15, reported by Leslie 

 Scattergood. 



11 These specimens are In the Harvard Museum of Comparative Zoology. 



Figure 81. — Halfbeak (Hyporhamphus unifasciatus), Chesapeake Bay. From Jordan and Evermann. Drawing by 



H. L. Todd. 



