It aa an Important article In their diet and have considered It a favored niah. Evidence that the black tana was eaten by the ancient people has been unearthed during excavations of shell mounds in the East and Tohoku regions. Bones which are Identifiable as those of the black tana were uncovered from these mounds. little exlstsi however to indicate the first fishing techniques used to capture these giant fish. Aathorltlee believe that huge traps placed in shallow waters were the most primitive method by which they were caught. When the fish entered these traps they were either clubbed to death or speared and drawn up on shore. Until comparatively recent times the black tuna was taken almost solely In coastal waters by set nets which were a natural development from single traps. With the introduction of motor-driven vessels It was possible to use other gear for taking klaus tunas in the deeper offshore waters. Today the species is caught for the most part by set nets located close to shore and by long lines in the deeper sea regions. Z. Diagnostic Characteristics The black tuna (Figure 7) can be recognized by the short tapering pectoral fin, which scarcely reaches the origin of the second dorsal fin. and by the sharp upward bend of the lateral line at a point above the origin of the pectorals. The lateral line then bends gradually downward and posteriorly. The back is nearly black, changing to a grayish blue with metallic reflections in the posterior part. The belly is grayish with many colorless dots. In mature specimens these markings tend to disappear. The first dorsal and the ventrals are grayleht the second dorsal is grayish with a yellow tip, the dorsal fillets are yellow the anal and the anal finlets are silvery> and the pectorals are nearly black. Several differences between the Japanese species and the California blue In tuna, such as color of the fins and ramification of the cutaneous blood vessels, were noted by Kishinouye (1923, p 440). However, detailed comparisons between these forms and the Hawaiian and Australian common tunas have not been made, and the exact relationships of the various geographically separated Pacific units are as yet undetermined. The mature black tunas taken In Japanese waters generally weigh between 125 and 200 kilograms, but the species attains even more gigantic sizes. Kishinouye (1923, p 439) reported specimens welding about 375 kilograms taken near Odawara in 1913, and more recently (date unknown) a specimen weighing 450 kilograms was taken in Toyama Bay on the Sea of Japan coast of Honshu. 3. Distribution and Migration The distribution of the black tana Is known only from the areas In which commercial operations take place. Therefore, Its known distribution is more indieatlte of areas where the fish tend to shoal or congregate, thus mekong eomoeroial operations feasible, rather than of true range. The fishing grounds in the northwestern Pacific Ocean extend from Sakhalin and and the southern Kuril Islands south along both coasts of Japan and the Korean coast, through the uncus and the Bonins to the area between southern Formosa and northern Luzon (Figure 6). Records show that in recent years black tunas have been obtained in offshore waters east of Japan by long line vessels fishing primarily for albacore or swordfish (Kimara, MS). The known distribution of the species has thus been extended, but its true range will not be ascertained until research workers begin critical compilation of all records obtained throughout the western Paolfie. Data of value concerning the migratory routes followed by the black tuna in Japanese waters are based solely on reports given by vessels as to seasonal changes In major fishing grounds. Dr K. Kimara, of the Tokyo Central Fisheries Ibqerlmental Station, Is now preparing this material for publication. For Philippine waters, information has been supplied by Ir H. Hakasnra, formerly of the Formosa Fisheries Experimental Station. As the black tuna Is found in the southern ryukyu daring Jane and In the Tohoku coastal region (northeastern Honshu) at the same time, several races within the species are postulated by Japanese scientific workers. Morphological analysis to support this belief has not been attempted, but a division Into Japanese and Philippine units appears to be valid from the evidence at hand. The information presented indicates the complexity of the life 19 p-6307