rough estimate,! Such questions as what proportion of these eggs 

 hatch, what percentage reach full maturity,, and what is their 

 rate of development remain to be investigatedo 



The spawning season of the broadbill swordfish in Japanese 

 waters is thought to be around Augu st=Sept ember , Its develop- 

 ment is known to include marked changes in forme NakamuraC^y 

 has reported the collection in the spring of 1933 near Ominato, 

 Chiba Prefecture, of two specimens measuring 660 and 860 ramo in 

 total lengtht The 660 mm^ individual in form had the outline 

 of a mature fish, but both the dorsal and anal fins were single, 

 the former with 2 spines and 4E rays and the latter with 1 spine 

 and 15 raysc The mature fish have no teeth, but larval fish at 

 this stage have setiform teetho There are keels on the caudal 

 peduncle, but they are not as conspicuous as in the adultc There 

 are hard scales forming rows on the sides of the body, and the 

 dorsal surfaces are deep indigo in color, the sides paler^ and 

 the belly is whitec The yellow bands on the fins and body pic- 

 tured by Ijjtken on a 37 mmo larva hav© already faded out and 

 cannot be seen,, In the 860 mmo specimen the lower jaw has 

 become rather short„ The dorsal and anal fins both are still 

 single, but in the dorsal the fifth to the sixth rays from the 

 posterior end have become shortened, and in the anal fin the 

 fifth to the seventh rays from the posterior end have become 

 buried in the muscles £, cleso-ly indicating a tendency toward 

 separation into two fins, 



ivo Distribution and migrations 



These fishes are present at all times in tropical seaSo 

 In the coastal waters of Japan they begin to migrate gradually 

 north as the water temperature rise in the springo The season 

 of the northward migration is somewhat later than that of the 

 black tuna and about the same time as that of the albacoreo 



The short -nosed speao'fish is very pelagic in nature, and 

 it hardly ever comes into coastal waters nor is it seen in 

 enclosed saasc Its distribution in the waters adjacent to 

 Japan is in general south of Sagami Wano Many of these fish 

 spawn in the waters east of Fonnosa in an area centered about 

 150 miles offshore from October to December c When the Sh'onan 

 Maru'5; conducted a survey in the central part of the East 

 Philippine Sea (lO° No - 15° No) in July, 193?^ not one fish 

 was takenj, and only one was caught in the southern part of that 

 sea (3° No - 10° No) in Augusto In the survey made by the 



^^'Nakamura, Hidenario 1935-36o_ Larval Stages of Shorefishes 

 Appearing in the Vicinity of Ominato (Parts 12, 14)o 

 Yoshokukai Shi 5. pp„ 191^195; 6o ppo 133-139. 



wJOriginally the Taiwan Government-General *s research vesselo 



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