COMPARATIVE STUDY OF SCOMBROID FISHES. 
295 
Introduction. 
Japanese naturalists of olden times, such as Ekiken Kaibara (38), Jyubei 
Kuroda (50), and Shyusaku Takei (73), arranged the scombroid fishes in four 
groups :—mackerels, seerfishes, tunnies, and bonitos. Though these authors did 
not mention the general characters of these groups, I do not hesitate to say 
that their observations were keen and accurate. 
In the occident, Linnaeus and his followers grouped the scombroid fishes 
in a single genus Scomber without order ; but in 1829 Cd vier founded a new 
classification, and arranged the scombroid fishes (les Scombres) in eight genera :— 
Scomber, Thynnus, Orcynus, Auxis, Sarcla, Cybium, Thrystes, and Gerapyles. 
This system has been followed by succeeding authors, though more or less 
altered by them. Thus at present tunnies and bonitos are classified with 
seerfishes and mackerels together in one and the same family, Scombridæ, and 
even many recent investigators who have the tendency of dividing old families 
into many new ones have not yet touched this family. Regan (62) observed 
that the definition of the family Scombridæ is not satisfactory, and the natural 
affinities of different genera are little explained. Recently Starks (69) tiled 
to solve the mutual relationship of scombroid fishes from the study of the 
skeleton, and published valuable results. 
The scombroid fishes are of great consequence in the economy of our 
country, ranking next in importance to the clupeoid fishes. Their annual catch 
amounts to ca. 150,000,000 kg. in weight, and 25,000,000 yen in value. These 
figures are based on statistical reports from the government, and I believe that 
they are much underestimated. Of course the amount of catch fluctuates 
yearly ; but there is a tendency to gradual increase, as the fishing grounds are 
more and more extended. Though these fshes are caught nearly in every 
part of our empire, and the whole year round, they are more abundant in 
southern parts, and more on the Pacific coasts than on the Japan Sea 
coasts. Recently Japanese fishermen have begun to catch tunnies and bonitos 
in great abundance in the Hawaiian waters and in South California. 
The scombroid fishes are mostly migratory, swim near the surface of the sea, 
and are very widely distributed. They form large schools, grow very rapidly, 
mostly attaining a gigantic size, and furnish a rich, palatable, nutricious food. 
