COMPARATIVE STUDY OF SCOMBROID FISHES. 
405 
saba. Moreover in tlie former variety the dark coloured bauds in the back run 
down beyond the lateral median line. In that variety the caudal fin is yellowish. 
The fish lives near the coast, but in deeper layers of water. Its flesh is more 
oily and palatable. In the other variety which is also called “ gomasaba ” the 
dark coloured bands in the back are found, only above the lateral median line. 
On that line there is a row of round spots, and below the line there are 
numerous greyish spots. It is chiefly found in off-shore grounds and in shallower 
strata of water, making larger shoals than the former variety. 
This species inhabits rather littoral waters, and its range of distribution 
in our country is very wide, from Karafuto to Taiwan. On our coast this 
species is rarely found in layers of water deeper than about a hundred metres. 
We observe more or less the bathybial as well as latitudinal migration of the 
mackerel. In spring the mackerel enters the Inland Sea, and in summer it is 
caught off Notasan, west coast of Karafuto. In winter it is caught near Ta- 
negashima, Kagoshima-ken. In Hondo it is caught all the year round, but 
large catches are expected in summer and autumn. It is also caught abun¬ 
dantly on the east coast of Chosen, especially near the Channel of Chosen. At 
the Channel of Chosen, i. e. at the southern entrance of the Japan Sea, ma¬ 
ckerels make thick shoals in spring and autumn. Two hundred and sixty thou¬ 
sand mackerel with a part of saurel were caught in a haul with a purse seine. 
Sometimes two millions of mackerel are landed in the port of Högyoshin near 
Fusan in one day. Mackerel are caught in twilight when they come to shal¬ 
lower layers of water. In cloudy weather they often rise to the surface. 
Adult mackerel approach the twenty metre line shoreward, and are dis¬ 
tributed a little beyond the two hundred metre line. They are never found 
in the Kuroshiwo, being found in waters of 10-20° C. On a cold day and during 
the cold season mackerel are foimd near the bottom of the sea. The optimum 
density for the mackerel is 1.025. 
Mackerel spawn in May. Fry and the immature fish are found among those 
of the sardine, anchovy, and the saurel. They grow very rapidly, feeding on 
fries of other fishes. When they are about 36 cm in length and \ kg in weight, 
they are ripe for the first time. The age of these fishes is not exactly known. 
They may be two or three yearn old. Fish of about 60 cm long and 1 2 kg 
in weight are very large and rare. 
