ブリ

From the 14th of April to the 19th of May, 1954, the authors expect Uchida stayed at the fishing-ground of the "Otosi-ami", a kind of trap-nets, on the coast of Mesima Island, one of the Danjyo Islands, some 90 nautical miles southwest of Nagasaki City with the main purpose of researching for the spawning and early life history of "Buri", or Japanese yellow tail, Seriola quingeradiate Temminck et Schlegel, together with other fishes. The ripe "Buri" caught there during that period ranged from 4 to 12 kg in body-weight. No difference was found in external features between female and male of the ripe "Buri". From the examination of the ripe gonads of both sexes, the ripe "Buri" seems to spawn several times in one spawning-season (Fig. 2). The weight of the ripe gonad exceeds 10 % of the body-weight. The number of ovarian eggs was enumerated as. from 550,000 to 1,600,000. The artifical insemination was executed. The fertilized egg is buoyant and spherical in shape, measuring 1.19 to 1.27 mm in diameter, with an oil-globule. Faint alveolar structure appears in the yolk. The development of the egg is figured in Plate 18. The incubation period was about 50 hours at the temperature changing from 18.0 to 24.0℃. During the staying period, 408 eggs of " Buri" were collected from the vicinity of the Danjyo Islands with the surface tow-net. The water temperature there ranged from 19.0 to 22.0℃, and the specific gravity of sea water was 23.5=δ15. The newly hatched larvae ranged from 3.42 to 3.48 mm in total length (Pl. 18, P). The larvae were kept in a glass-jar for three days, and grew to 3.85 mm in total length and nearly consumed the yolk (Pl. 18, R). Later growing stages up to 34.0 mm in total length, are figured in Plate 19.