FISHES OF THE GULF OF MAINE 211 



76. Striped bonito (Gymnosarda pelamis Linnaeus) 

 Oceanic bonito 



Jordan and Evermann, 1896-1900, p. 868. 



Description. — This bonito is separable at a glance from the mackerel by its 

 much stouter and more robust form, it being one-fourth as deep as long, though 

 similarly fusiform and tapering to pointed snout and slender caudal peduncle, and 

 by the fact that its dorsal fins are practically contiguous. The concave outline of 

 the first dorsal marks it off from the Spanish mackerel (p. 217), common bonito 

 (p. 215), and tuna (p. 212), which resemble it in the close apposition of the two dor- 

 sals. More diagnostic, however, is the fact that the striped bonito has no body 

 scales except for a very prominent "corselet" on the forward and upper part of the 

 trunk, which is outlined in the illustration (fig. 95). The fact that the lateral line 

 curves downward suddenly below the second dorsal separates it from its genus mate, 

 the "little tunny" ((t. alleterata), a fish to be expected, though not yet actually re- 

 corded, in the Gulf of Maine. 



Fig. 95. — Striped bonito {Gymnosarda pelamis). After Schmidt 



The first dorsal (about 15 spines) is not only much longer than that of the mack- 

 erel, but of rather diagnostic form, being abruptly concave behind the second spine 

 with the last 9 or 10 spines much shorter. Almost the whole of the second dorsal, 

 triangular in form but with concave rear margin, stands in front of the anal, which 

 about equals it in size and is of similar outline. There are about 8 little finlets 

 behind the second dorsal, and 7 behind the anal. The pectoral is of moderate size, 

 reaching back only about midway of the first dorsal. The tail fin is very short but 

 broad and lunate in outline, and there is a conspicuous median keel on either side 

 of the caudal peduncle. 



Color. — Deep steel blue above, with lower sides, throat, and belly shining white. 

 Each side is barred behind the corselet with 4 to 6 longitudinal blue or brown stripes, 

 the upper ones terminating at their intersection with the lateral line, the lower 3 

 or 4 fading out as they near the caudal peduncle. 71 



71 The number of stripes is variable in different regions, for whereas American fish usually show 4 only, 7 hive been described 

 in Japanese specimens, while in the European bonito there are usually 4 and sometimes 5 or 6 on each side. 



