without the snout, the latter being 3.33 times the eye diameter. Upper jaw slender and short, 

 its length being 1.28 times the length of the lower jaw (both jaws being measured from the poste- 

 rior end of the maxillary). The first dorsal is well developed, with its anterior lobe low, its 

 central portion rather higher, and its rays filamentous. The rays of the dorsal fin are described 

 by Dr. Tanaka as being all soft rays and by Jordan and Evermann as being all spines, but the 

 result of dissection, as shown above, is that the 3 most anterior are spines, the following 8 to 9 

 are clearly soft rays with branched tips, and the remaining more posterior ones are again spines. 

 The pectoral fins are comparatively short, being 0.86 times the body depth (measured as above 

 and likewise in subsequent references). The ventral fins are represented by three rays and they 

 are moderately well developed. The anus is located anterior to the first anal fin, from which it 

 is separated by a distaince roughly equal to the length of the base of that fin. The second dorsal 

 and second anal fins are of approximately the same shape and size. Along the bases of the first 

 dorsal and first anal fins are developed grooves in the skin in which these fins can be accom- 

 modated. The caudal fin is broadly forked, both lobes are narrow, and there are two pairs of 

 keels on the peduncle. The body has a steely color on the back, the belly is silvery white, and 

 the boundary between these two colorations is comparatively well marked and runs somewhat 

 dorsal of the center of the sides of the body in an approximately straight line with small serra- 

 tions along the boundary. There are no markings on the sides of the body. The lateral line is 

 clearly apparent and forms rather complex curves anteriorly while in the posterior part it runs 

 almost straight along the center of the sides of the body. 



The upper and lower jaws have rasp-like teeth, and there is a broad area of sharp, long 

 teeth on the palatines. The cranium is rather narrow and the vertebrae are rather delicate, 

 there being 12 ventral and 12 caudal vertebrae. 



The gonads have a characteristic form, being Y-shaped as a whole, the left side being 

 remarkably developed and extending far posterior beyond the anus. In mature ripe specimens 

 the left gonad together with the air bladder reach to the vicinity of the posterior end of the body 

 cavity. The right gonad is small and is joined to the left one in the vicinity of the anus with the 

 reproductive duct attached at the point of juncture. In the male the posterior portion of the left 

 gonad is poorly developed so that the gonads form roughly a V-shape. 



Habits 



This species has hitherto been so rare in Formosa that it had no particular name, but 

 through the fishing experiments of the Forn:iosan Government-General's fishery research vessel 

 Shonan Maru from October to December of 1935 and from October to December 1936 it was 

 found that the species occurs in rather dense concentrations far off to the east of the island (30 to 

 300 miles off shore) in the area of the Japan Current, and at the same time it was learned that it 

 spawns in that area at this season. 



Genus Istiophorus Lacep^de*, bashokajiki genus 



Nine species are recorded for this genus, five of them fronn the Indo-Pacific region; only 

 one species is known from Japan and only one from Formosa. Its study was undertaken with 

 particular care because it was thought that there was ample possibility of the fishing vessels based 

 at Takao taking some other species, since they fish on far southern grounds, however, none was 

 found in the catch other than the same species found in Japan. It is thought that the three genera 

 and 31 species of Istiophorus recorded by Jordan and Evermann may perhaps be reduced to a far 

 smaller number of species through detailed studies. Only the following single species occurs in 

 Formosa. 



2) Istiophorus orientalis Temminck and Schlegel, bashokajiki ^sailfish/; basho, baren 



(throughout the island); Formosan names i^ ^ ,f, (Keelung), "^ ^ -^ ^ (Suo). 



Plate 13, figure 2 



* Lac^p^de. Hist. Nat. Poiss. , III, 274, 1803. 



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