FISHES OF THE GULF OF MAINE 



373 



the gill cover is rounded in the adult but it bears 

 a spine in young fry. 



Color. — Bluish, cross-barred with 5 to 7 dark 

 bands, 2 or 3 of which run up on the dorsal fin 

 and down on the anal. The outer margins of 

 caudal, ventral, and pectoral fins are nearly black 

 The caudal is white-tipped. 



Size. — Maximum length about 2 feet. 



General range. — A tropical fish of the high seas, 

 rarely straying as far north as outer Nova Scotia. 48 



Occurrence in the Gulf oj Maine.- — -The only 

 records of this species from within the Gulf are 

 of one taken in a mackerel net in Provincetown 

 Harbor in October 1858, the fish probably having 

 followed a whale ship that arrived a few days pre- 

 vious; one caught near Seguin Island in 1906; one 

 off Portland in September 1921; one taken from a 

 mackerel net at Provincetown in August 1924; 

 three in 1929; one of them from the northern 

 edge of Georges Bank in October, the other two 

 from the South Channel to the southeast of Cape 

 Cod (one in August, one in November) ; one off 

 Portland, July 1931 ; and one picked up in a trawl 

 on the northern slope of Georges Bank Oat. 42°10' 

 N., long. 66°32' W.) October 10, 1933. 49 We need 

 only add that this is the fish that so commonly 

 attends sharks in tropic seas, either picking up a 

 living from the scraps left by the latter, or feeding 

 on the parasites with which their protectors are 

 infested. They often follow sailing vessels, also. 



*' Vladykov (Proc. Nova Scotian Inst. Scl., vol. 19, 1935, p. 0), reports two 

 specimens taken on Sable Island Bank, and one from Sambro near Halifax, 

 during the period 1932-34. 



"Reported to us by W. C. Neville of the U. S. Bur. Fish. 



Rudderfish Seriola zonata (Mitchill) 181 5. M 

 Amberjack; Pilotfish 

 Jordan and Evermann, 1896-1900, p. 902. 



Description. — The rudderfish is deeper bodied, 

 relatively, than the pilotfish (body about three and 

 one-half times as long as deep), so much flattened 

 sidewise that it is almost as thin as a butterfish 

 (p. 363), and with a pointed nose. Its first (spiny) 

 dorsal fin is well developed, with 7 spines. There 

 are 36 to 38 rays in the second dorsal fin (only 26 

 or 27 in the pilotfish) and the ventrals are relatively 

 much longer than in the pilot. In young fry of 

 2 to 3 inches the second dorsal originates a little 

 in front of the tips of the pectorals, but it origi- 

 nates slightly behind the tips of the pectorals by 

 the time the fish has grown to 8 or 9 inches, and 

 still farther back in larger specimens. 61 



The anal fin (20 or 21 rays) is a little more than 

 half as long as the second dorsal in the rudderfish, 

 as it is in the pilotfish also. And in young fish 

 it is preceded by one or two short spines which 

 adults lack. 



The ventrals are a little longer than the pec- 

 torals, and more pointed in large fish than in 

 small; the caudal is deeply forked, its slender 

 peduncle with a longitudinal keel on each side; 

 the mouth gapes back to the forward margin of 

 the eye and is armed with broad bands of hairlike 

 teeth. The body is clad with small scales. 



" The interrelationships of the several Seriola! that have been described 

 from our South Atlantic coast still remain in doubt. 



" We have examined specimens ranging from 3 to 9 inches In length taken 

 in Cape Cod Bay, at Woods Hole, Now Bedford, and other localities. 

 Storer's illustration, reproduced here, was of a 2-inch fish. 





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Figure 198.— Rudderfish (Seriola zonata), young, in striped stage, Wellfleet, Mass. After Storer. 



