390 
KAMAKICHI KLSHINOUYE : 
DISTRIBUTION. 
Scombroid fishes are generally widely distributed, and many of them 
are really cosmopolitan ; but some of them are confined to limited districts. 
For instance Gybium korcanum and Neoihunnus varus have restricted distribu¬ 
tion. Generally speaking the mackerels and seerfishes which have a wider 
range in vertical distribution have a narrower range in horizontal distribution. 
Scomber japonicus is very widely distributed. It is said to occur in the 
Pacific as well as in the Atlantic. In the Pacific it is found on the Asiatic as 
well as on the American coasts. However, the fish is not found round the oceanic 
islands, such as the Ryukyu Islands, Ogasawara Islands, and South Sea Mandates. 
Adult mackerels migrate in summer to shallow waters, ca 20 m deep in a bay, 
but retire in autumn to deeper waters of 40-100 m, and in winter to off-shore 
banks, ca 200 m in depth. Generally mackerels are not found in deeper strata 
of water than ca 100 m. In waters within the 100 m line of depth, mackerels 
are found 1-4 m above the bottom. They come near the surface in the even¬ 
ing, and may be attracted to shallow strata within 40 m below the surface. 
Bastrelliger is confined to the Ryukyu Islands in our country, but it is 
widely distributed in the tropical seas. 
In the Cybiidae, Grammatorcynus is found only in Ryukyu Islands in our 
country, but is widely distributed in the tropical region of the Indo-Pacific. 
Gybium niphonium is found in the littoral waters of Japan, Korea, and China. 
Gybium koreanum is restricted to the west coast of Korea. It is remarkable 
that this species ascends the brackish part of rivers. Cybium commerson is 
regularly caught, though in small numbers, near Senzaki, Yamaguclii-ken, in 
autumn and winter. This species is caught in abundance in Formosa in spring. 
Gybium guttatum is found in our waters only in Formosa. Gybium chineuse 
is found in Japan and China, frequently near the Korean Channel ; but they 
are rather rare in other regions. Acanthyocybimn solandri is a pelagic species, 
nomadic in habit, and inhabiting warm seas. It is found at the mouth of Tokyo 
Bay, in the east, and in the south western part of the Japan Sea. Sarcla 
orientalis is abundant in Kyushyu, but it may be fouud in Aomori-ken in the 
north, both off the Pacific and the Japan Sea coasts. None have been found in 
Formosan waters. I do not know whether the Indian species of Sarcla is identical 
