i. The coastal waters of the Lesser Sundas are cut off from the 

 coastal waters of Java to the west, while they are intimately 

 related to the Banda Sea and Flore s Sea area. 



ii. The coastal waters of Java are cut off from the west in the 

 vicinity of Sunda Strait, and the occurrence of fish in these 

 waters is sparse. 



iii. The population from the vicinity of Sunda Strait to the 

 neighborhood of the Equator is different from that found 

 north of the Equator. 



iv. North of the Equator in the coastal waters of the Nicobar 

 Is. the population appears to be different from that occur- 

 ring north of the Nicobar Is. 



V. It further appears that there is a distributional boundary 

 in the vicinity of 9°N. 



5. The relationships between these populations and the ocean currents 

 are extremely intimate (Figure 2), 



6. Big-eyed tuna are generally more abundant in the low latitudes and 

 scarcer in the high latitudes; the peak density of their occurrence is 

 reached around December and thereafter their abundance gradually declines, 



7. In contrast to the big-eyed tuna, the spearfishes tend to be 

 least abundant around December, gradually increasing thereafter and 

 reaching their peak around February. 



III. Vertical Distribution 



The study of the vertical distribution of the fishes of these popu- 

 lations is even more difficult than the study of their horizontal distri- 

 bution. 



According to Dr. Kishinouye, the vertical distribution of the tunas 

 is as shown in Figure 3. 



Om 



20m 



4.0m 60m 



80m 



100m 



120m 



Figure 3 Vertical distribution of tunas 



32 



