1 Sept. 



13 Sept. 



Nakadosa-machi 



Kaminokae 



Yatabe 



Off Ksaki. Wakayama Pref. 



1417 

 1650 

 1716 



4 POPULATION 



4.1 Structure 



4.11 Sex ratio 



The analysis of catches of A. rochei in April-Decem- 

 ber 1971 from waters off Kochi and Tohoku Prefectures, 

 •Japan, and off Taiwan indicates an inequality in sex 

 ratio. Individual samples show significant deviation 



from a 1:1 ratio, e.g., the set net catches from Shiina, 

 Japan, on 13 December had a ratio of two males to nine 



females. On the other extreme, the pole-and-line catch 

 made off Taiwan on 19 June had a male to female ratio 

 of 7:.5 (Hamada, Morita, Ishida, and Takezawa 1973). 

 Off Sri Lanka, the number of males and females in the 

 catches of A. thazard showed no noticeable difference 



from a 1:1 ratio except in one area (Sivasubramanium 

 1973). Along the southwest coast of the island, the 



41 



