366 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



the posterior rays being very short, its origin about equidistant from 

 origin of first dorsal and base of next to last dorsal finlet; anal similar 

 to second dorsal, its origin a little in advance of vertical from base of 

 last ray of second dorsal; ventral somewhat shorter than pectoral, 

 inserted slightly posterior to pectoral, its distance from tip of mandible 

 2.7 to 2.9 in length; pectoral moderately pointed, 1.9 to 2.1 in head. 



Color very dark blue above, with metallic reflections; silvery below; 

 lower part of head, chest, and area around ventral fins dirty white; 

 lower half of side with two to four dark longitudinal stripes ; spines of 

 first dorsal dusky, anterior margin of first spine and membranes pale 

 or white; second dorsal, dorsal and anal finlets, caudal, anal, and 

 pectoral all more or less dusky; pectoral much darker on inner side 

 than outside, the upper rays generally silvery; ventral fins white on 

 outside, inner side dusky; inside of mouth largely dusky. 



The Mission preserved 10 examples of the many that were caught. 

 These specimens, which range in length from 485 to 595 mm. (425 to 

 525 mm. to base of caudal), form the basis for the description. The 

 specimens were all taken b}'- trolhng, though it is stated in the report 

 by the Mission (1943, p. 181) that this fish also was taken from the 

 stern of the vessel with poles, "rigged with a short line and feather jig." 

 The specimens preserved were caught at points 5 miles off Lobos de 

 Afuera Island, 16 miles west of Hormigas de Afuera, 25 miles south- 

 west of Punta Fraile, and 55 miles southwest of Ilo. This common 

 species was observed and also caught elsewhere. The report (p. 235) 

 stated further: "More skipjack were caught by the Mission than any 

 other species." The largest individual listed in the report was 650 

 mm. long. The species was found principally in rather warm water, 

 as 99.8 percent of all the fish caught were from water varying from 17° 

 to 25.4° C. In another paragraph (p. 238) it is stated, "Skipjack are 

 found in the transitional zones Uke the yellowfin (tuna) but they are 

 more abundant than this species in the warm oceanic waters." 



Although the skipjack (barrilete) was associated in a general way 

 with the yellowfin tuna (atun) the report of the Mission (p. 239) said, 

 "In contrast to the yellowfin tuna, a number of compact schools were 

 seen. * * * They appeared at the surface more frequently." 

 It is stated (p. 244) also that the food of the skipjack is about the same 

 as that of the yellowfin tuna, which according to contents of stomachs 

 examined aboard the vessel consisted of fish (especially anchovies) 

 and squids. The skipjack (barrilete), according to the report (pp. 

 245, 246), is considered as of inferior quality, and consequently is of 

 little commercial value in Peru. 



Range. — Cosmopolitan, in temperate and tropical seas. I have 

 found no previously published record of its occurrence on the coast of 

 Peru, 



