オニオコゼ

Inimicus japonicus (Cuvier et Valenciennes) is a common scorpaenid fish with poisonous spines of southern Japan. The spawning season seems to extend from late June to middle of July in the vicinity of Fukuoka City, Kyushu. The authors carried out artificial insemination of this fish on July 6, 1954, at Shikanoshima near Fukuoka City, and reared the hatched larvae for about 4.5 days in a glass jar. The egg is buoyant, colorless and spherical in shape, measuring 1.31～1.43 mm. in diameter, with no oil-globule. The fundamental process of development is much the same with the ordinary teleostean(Fig. A-L). Hatching took place in about 41 hours at the water temperature 20～24℃. The newly hatched larva (Fig. M) is 3.18～3.27 mm. in total length with the myotomes 11/17～18=28～29. The yolk is oval, measuring 1.32～1.41 mm. in long axis. The rudiment of pectoral fin already appeared. Melanophores and numerous xanthophores are distributed on the body and the yolk surface as well as on the larval fin. The larva one day old (Fig.N) has large round pectoral fins, on which three big black blotches appeared. 2 big black blotches of similar size appeared on the ventral side of tail. The large round pectral fin and these black clotches may be taken as the charactaristics of this larva. In 2 days after hatching (Fig. O) the mouth opened and the eyes became black. In 3 days (Fig.P), the larva absorbed almost all the yolk.