The spawning of the sailfish occurs over wide areas of the Pacific 

 and the South China Sea and covers a rather long period of time with June 

 as the peako Around this time this species occurs densely in these sea 

 areas, and mature and immature fish occur mixed together „ It is interest- 

 ing that spawning proceeds gradually as the fish become ripe, the males 

 and females forming pairs and following each other around in the same way 

 goldfish doo On this point they differ completely from such fishes as 

 the herring., lith herring the whole school becomes ripe, and spawning 

 and fertilization are accomplished within an extremely short timCo These 

 spawning habits of the herring are the sort generally possessed by 

 pelagic species and they make the reproductive activity most effectiveo 

 It is very interesting then that the spearfishes which are the most 

 markedly pelagic of fishes, have the habits described above „ Since 

 spawning habits of this type appear to be common to the fishes of the 

 south in general, this is thought to be an important matter to consider 

 with regard to the future of the southern fisherieSo 



The diameter of the eggs is from 0o8 mm to a little less than 1 mm, 

 and the ovaries of a large individual contain over 1 million eggs„ 



The larval fish have a form altogether different from their parents, 

 and their heads are armed with conspicuous spines„ It is thought that 

 these are for the purpose of increasing the surface area of the larvae, 

 whose swimming powers are weak, in order to facilitate their floating. 

 The smallest specimen which the author has been able to obtain to date 

 is about 3 mm long, and it is thought to have been collected not too long 

 after hatching, hardly any pigment having appeared on its body„ Several 

 specimens ranging from this size up to about 12 mm have been collected, 

 but we have not as yet been able to collect any larger than that until we 

 get up to the range of 1^,0 mm to 260 mm, where we have obtained several 

 specimenSo (Figure 6) 



As far as the true marlin /Mo mitsukurii / is concerned, we have 

 recently had two opportunities to collect ripe eggs and can therefore make 

 some conjectures about its spawning season in Formosan waters (the South 

 China Sea). Both of the specimens ^nere landed at the Takao fish market in 

 May, one in 19/U. and the other in 19A3o Unfortunately it is not clear 

 just where these fish were taken, but in any case it can be considered 

 fairly certain that this species spawns about May. 



For the black marlin /^o mazara 7 we have ripe eggs collected in 

 the East Philippines Sea in Kay so it can be thought that they probably 

 spawn around that month. (Figure 5) 



For the white marlin / M. marlina 7 we have as yet no concrete data 

 from which to deduce their spawning season and spawning grounds, but it is 

 wondered 'Thether they may not spawn in April and May in the area from 

 Annam to Hainan lo 



As indicated above, our knowledge of the tunas and spearfishes is 

 extremely poor. In the near future, when the fisheries of Greater East 

 Asia come to be seriously developed, many new facts will probably come to 



39 



