ON THE LIFE HISTORY OF AN ECONOMIC 
CUTTLEFISH OF JAPAN, OMMASTREPHES SLOANI 
PACIFICUS 
By MADOKA SASAKI 
The Hokkaidé Imperial University, Sapporo, Japan 
(With nine figures) 
INTRODUCTORY 
MONG the Japanese marketable cuttlefishes the species of the most 
A economic importance is Ommastrephes sloani pacificus Steenstrup, 
which is popularly known as “Surumé-ika” or ‘“‘Nibanzurumé.”’ Ac- 
cording to the statistical reports of the Agricultural and Commercial Depart- 
ment of the Japanese Imperial Government, the total annual catch of the 
species has often exceeded 70,000,000 kilos. 
Rather suddenly there occurred a marked decrease of catch, as it took 
place in certain provinces some years ago. The condition is often repeated, 
so that villages which have been living upon this fishing industry suffer serious 
loss. The people of these localities are anxious to learn what causes this de- 
crease, hence investigation is urgent. This condition caused me to undertake 
the present investigation at the request of one of the provinces which has 
suffered since some twelve years ago. 
I have had several opportunities to visit the villages where cuttlefish 
catching is carried on, and to be on board fishing vessels. I spent the summer 
of the year 1919 in Sado, Oki, Tsushima, and Utsuryoté (Dagelet I.), islands 
scattered in the Japan Sea and the most famous places in all Japan for the 
cuttlefish industry and enjoyed special advantages for observing conditions. 
I have occupied myself in angling for the animal, in order to observe at the 
same time the physical conditions of the sea. The present paper embodies the 
results thus obtained except some parts, of which the investigation is still in 
progress to be published on a future occasion.* 
*Tn this connection I wish to express my warmest thanks to Prof. S. Hatta and Dr. L. Balder- 
ston for their courtesies. My thanks are also due to Mr. Kitahara, leader of the Oceanographic 
Institute of the Agricultural and Commercial Bureau, Tokyo, for his kind advice and help in the 
course of the present investigation. Further, I am also indebted to Mr. S. Takarabé, Governor of 
Shimané-ken, and Vice-governor K. Iwamoto for their assistance in my work. 
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