378 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



Family ISTIOPHORIDAE: Sailfishes and Spearfishes 



Body elongate, deepest in region of shoulders, tapering gradually 

 posteriorly; caudal peduncle, with two rather low keels on side; 

 upper jaw produced, though shorter, narrower, and with rounder 

 edges than in the swordfish; teeth in jaws small, persistent; gills, 

 four; scales present, long, narrow, more or less embedded; two dorsal 

 fins, the first very long, generally occupying fully two-thirds of length 

 of back, second dorsal small; two anal fins, the second smaller than 

 the first, about opposite second dorsal; ventral fins present, thoracic, 

 with one to three rays; pectorals generally rather long, and narrow. 



Two genera no doubt occur from time to time on the coast of Peru. 

 In the report of the Mission (1943, p. 248) the swordfish and the 

 marlin {''Makaira sp.") are discussed together. The marlin was 

 seen, but efforts to catch examples failed. No record of specific 

 identifications of marlins taken on the coast of Peru has come to my 

 attention. In any event, the species are not well known. There- 

 fore, no specific name or names can be supplied. The Mission has 

 not reported sailfish. However, Walford (1937, p. 49) gave the 

 usual range of the Pacific sailfish, Istiophorus greyi Jordan and Ever- 

 mann, as extending from "Cape San Lucas to Peru." A key to the 

 two genera that seemingly occur on the coast of Peru is offered, but 

 no descriptions of the species are included. If examples are taken, 

 the species probably can be identified from the work by Jordan and 

 Evermann (1926), or from the book by Walford (1937). 



KEY TO THE GENERA 



a. First dorsal very large, forming a "sail" Istiophorus 



aa. First dorsal elevated anteriorly only, the rest of fin low, not forming a 

 ' 'sail' ' Makaira 



Family XIPHIIDAE: Swordfishes 



Body elongate, robust; caudal peduncle slender, with a strong 

 lateral keel; upper jaw greatly produced, forming a "sword"; teeth 

 wanting in adults, though present in young; gills four; scales wanting; 

 two dorsal fins in adults, single, high, and continuous in young, the 

 first beginning over gill opening, the second situated far back, very 

 small; caudal fin broadly forked; two anal fins in adults, single and 

 continuous in young, the first rather large, the second small and 

 opposite the second dorsal; ventrals wanting; pectorals long, narrow, 

 pointed. 



A single genus and species is known. 



Genus XIPHIAS Linnaeus, 1758 



SWOBDFISHES 



The characters of the genus are those of the family. 



