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KA3IAKICHI KISHINOÜYE: 



mass like a rod with the plexus of aiierioles from the dorsal aoiia to the 

 vertical of the ninth vertebra ; bub anterior to the vertebra the plexus is 

 discontinued and is divided only into small bundles of venules. 



Kidneys are much elongated posteriorly. In the haemal canal, below the 

 vertebral column, there is also a renal body. 



The back is dark bluish violet, with some transverse light coloured 

 markings, the sides are silvery with four or more dark coloured longitudinal 

 bands on each side. Dorsals, dorsal unlets, pectorals, and the anal are dusky. 

 Ii'is silvery, with a greenish shade. 



The bonito lives in the clejir blue water of the Kuroshiwo, 20-30° ia 

 temperatm-e, and 1.024-1.026 in specific gravity. On the Japan ^a, this fish 

 is caught in small numbers, late in autumn or in winter only, there being no 

 special fishing for this fish. On the northeastern coast of Hondo, the bonitD 

 is generally caught in grounds very far from the land, 100-200 miles ofi". In 

 spring bouitos begin to migrate northward, and reach the ground oiF the 

 southeastern coast of Hokkaido in summer. Sometimes the fish makes big 

 shoals of several hundreds to thousands, and when they attack a school 

 of small fishes, such as sardines and anchovies, they surroimd the latter 

 till the victims form a dense si^herical mass. Then the bonitos feed gi'aduaUy 

 on the stragglers from the school, swimming around outside the mass. 

 Generally they feed on the medium sized plankton : — amphi}X)ds, SqiiiUa's 

 larvae and other crustaceans, pteropjds, heteropods (chiefl}- Atlanta), 

 calamnries, and immattn*e or small fishes, etc. According tj experienced 

 fishermen, bonitos are said to contain plenty of food in their stomach, when 

 they are caught in large quantities with rods and lines ; but «almost no trace 

 of food is found in their stomachs, when refuse to bite a hook. This 

 is true also of the tunny fishery by means of long lines. Though bonitos and 

 tunnies are very voracious and bite a hook easily and eagerly, especially when 

 they are in a h'enzy of competition to get as much food as possible, yet they 

 are coal and cautious when there is only a little food. .\nd in midsummer 

 when the reproductive elements become ripe, bonitos seem to fast. In the 

 water round Ryukyu and the adjacent islands we find small bonitos about 20 cm 

 in length in August, and in Jjuiuary I have obtained small bonitos ca. 30 cm 

 (without caudal) from the stomach of tunnies, caught near the Ogasawara 



