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FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Tetrapturus angustirostris Tanaka 



Shortnose Spearfish 



Furaikajiki (Japan) ; Indian Spearfish (Hawaii) 



Distinguishing characteristics 



This little spearfish is characterized by a snout 

 that extends onlj- slightly beyond the lower jaw, 

 a long, slender, compressed body, the greatest 

 depth of which is less than 13 percent of the fork 

 length, relatively short pectoral fins that are less 

 than 14 percent of the fork length, and an easily 

 visible, single lateral line. It lacks the stripes of 

 most of the other species. 



Unfortunately, we lack data on a sufficient 

 number of specimens of less than 30 pounds of the 

 other species to separate them clearly from 

 Tetrapturus. In very small Makaira ampla the 

 snout is scarcely longer than the mandible, but 

 the body is heavier, rounder, and the middle of the 

 first dorsal fin is probably less than two-thirds of 

 the height of the anterior lobe. In small M. 

 audax, the middle of the first dorsal fin approaches 

 the height of the anterior lobe as it does in Tetrap- 

 turus, but audax may be distinguished by the 

 presence of stripes and a snout markedly longer 

 than the mandible. We have seen no very small 

 specimens of Istiompax marliva, but presumably 

 they may be distinguished unequivocally by the 

 stiff pectoral fin, which in Tetrapturus is flexible. 



The close resemblance of the shortnose spear- 

 fish to the young of the other marlins has led some 

 to suspect (LaMonte and Marcy 1941:21) that it 

 is merely a juvenile form. This view, however, 

 was effectively disproved by the work of Naka- 

 mura (1937) who figured the eggs, ovaries, and 

 testes and described one ripe female taken in 

 November which was 152 cm. in fork length and 

 27 pounds in weight. This fish was taken along with 

 several others with enlarged ovaries. A female 

 with running-ripe ovaries (specimen No. 5 in 

 appendix table 1-A, p. 541) that we captured on 

 March 18, 1954, was 164 cm. fork length. It was 

 not weighed but the weights of other specimens of 

 similar length suggest that its weight should have 

 been about 40 pounds. Such sizes are far below 

 the sizes at which the other species commonly 

 occur and appear to mature. 



Jordan and Evermann (1926) listed four Pacific 

 and one Indian Ocean species of this genus, but it 



appears probable that there is but a single species 

 in this whole area. Two of the species, ectenes and 

 bredrostris, obviously do not belong to the genus 

 Tetrapturus. Two other species, illingworthi and 

 kraussi, were described as new from Hawaii and 

 were separated from the Japanese species angus- 

 tirostris because the latter was described as having 

 a dorsal lobe longer than the pectoral. In the 9 

 specimens from the central Pacific on which we 

 have these measurements we find 8 in which the 

 dorsal lobe is very slightly longer than the pec- 

 toral, and 1 (from Hawaii) in which the opposite 

 is true but the variation in these two characters is 

 such that this comparison of fins is not a good 

 specific character. These authors also distin- 

 guished illingworthi and kraussi on the basis of the 

 separation of the dorsal fins — a character we find 

 highly variable in our specimens. We, therefore, 

 place both species in synonymy with angustirostris. 



There appears to be no valid reason to retain 

 the genus Pseudohistiophorus as proposed by De 

 Buen (1950:170-171). He established this genus 

 because the previous attempts to place hetero- 

 geneous species in Tetrapturus suggested to him 

 that Tetrapturus was the synonym of Makaira. We 

 cannot accept this view because the redescription 

 of Tetrapturus helone Rafinesque given by Cuvier 

 and Valenciennes (1831:205 — the earliest descrip- 

 tion available to us) is excellent and obviously 

 represents a species extremely close to, if not iden- 

 tical with, our Pacific species. 



If Tetrapturus should prove to be monotypic, 

 the species name helone described from a Mediter- 

 ranean specimen would have priority. Jordan and 

 Evermann (1926) separated it on the basis of the 

 short, stiff spines in the interspace between the 

 dorsal and anal fins. We have seen none of these 

 spines in the Pacific form, but in some specimens 

 of M. ampla we have noticed that the first dorsal 

 fin may continue almost to the second dorsal or 

 may be broken up into separate spines, sometimes 

 even in separate fin slots. This appears to be a 

 matter of individual variation, and further ex- 

 amination of the species from several areas is 

 needed to determine whether this is a constant 

 character. 

 Color 



Immediately after death T. angustirostris is a 

 brilliant, deep metallic blue on the back and first 

 dorsal with silvery gray on the sides and white 

 on the belly. In about an hour this rapidly fades 



