Preliminary Studies on the Rotatorian Fauna of Korea^ 
Kokichi Yamamoto^ 
INTRODUCTION 
Thorough limnological surveys in Korea 
have not been carried out up to the present 
time; only a few brief studies on the plankton, 
especially on the rotatorian fauna, have been 
made in several districts. There are papers 
relating to the Korean rotatorians published 
by five authors, namely, Kawamura (1917), 
Hada (1936), Ueno (1941), Sato (1939, 1941), 
and Yamamoto (1941). One of the reasons 
why such studies have been neglected is the 
paucity of lakes and ponds suitable for col- 
lections, except for a series of brackishrwater 
lakes on the coast of the Japan Sea and reser- 
voirs recently built for hydroelectric plants. 
The studies of the fresh-water fauna of Korea 
are quite incomplete when compared with 
those made on the fauna of Manchuria, which 
has been clarified by several researches under 
the direction of Professor T. Kawamura and 
summarized by Yamasaki (1940). 
The author, accompanied by M. Ueno, 
made a trip for limnological work to the mid- 
dle, eastern, and western districts of Korea 
from November 19 to 26, 1941. Since return- 
ing to the laboratory the author has engaged 
in a microscopical study of the rotatorians in 
the plankton obtained. At the same rime, 
collections made by us in the preceding year 
in the northern part of Korea, as well as ma- 
terials preserved in our laboratory, were ex- 
amined. These latter consist of specimens 
which were collected by T. Kawamura during 
1 Contribution No. 133 from the Otsu Hydrobio- 
logical Station of the University of Kyoto. 
^ Otsu Hydrobiological Station, University of Kyo- 
to. Manuscript received March 23, 1949. 
June, 1936, and by A. Tanaka in Lake Puchon- 
ho in 1931. 
Through the courtesy of T. Kamita of Kei- 
jo Normal School, some plankton samples 
collected by T. Sato in the City of Keijo 
(Seoul) and the neighborhood were placed at 
my disposal for study. The rotatorians found 
in all these collections are reported upon in 
the following pages. Previous records are in- 
cluded in the list. 
As the specimens treated here have been 
collected not only in a limited season but also 
from comparatively confined localities, they 
are not sufficient basis for a full discussion of 
the rotatorian fauna of Korea. The survey was 
to include different seasons and additional 
various localities, but the program was of 
necessity changed by the outbreak of war. 
Difficulties of travel had increased day by day, 
and finally the war made continuation of our 
survey in this peninsula impossible. There- 
fore, this report is based on limited material. 
I wish to express my thanks to Doctor 
Ueno for his kind advice during the journey 
and in the research room. 
LOCALITIES 
The specimens examined were obtained 
from 16 bodies of water, which included all 
localities from which there are previous rec- 
ords. They are placed in four regions — 
northern, middle, eastern, and western — no 
collections having been made in the southern 
portion of the peninsula. The stations are 
shown on the sketch map in Figure 1. Table 
1 shows some ecological data for the stations 
examined by Ueno and Yamamoto; such data. 
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