Abstract
Lagocephalus lunaris spadiceus (RICHARDSON) is a common puffer in Japan and the only harmless one having no tetradotoxin, widely distributed from the waters around. Japan to the East China Sea and Indo-Australian regions.
The author carried out the artificial insemination at Nomozaki Machi neighbouring districts of Nagasaki City on June 22, 1965, and reared hatched larvae feeding with the boiled egg yolk and brine shrimp nauplii.
The spawning season seems to extend from the middle of May to the latter of June in the east part of Gotto Nada, Kyushu.
The egg is colorless and transparent, demersal and faintly adhensive in nature, . spherical in shape measuring 0.61-0.70 mm in diameter with a claster of small oil-globules each measuring 0.009-0.09 mm.
The incubation period was about 76 hours at the water temperature 21.7-24.5°C. In the course of development, the small oil-globules united in two or three larger ones accompanied by one or two small ones, but did not unite in the only one.
The newly hatched larva was slender in form and 1.91 mm in total length. It had 21 (8+13) myomers. The yolk was elongated elliptical, 0.82 mm in long axis, with three or five oil-globules. The abdominal surface of the trunck was covered with melanophores and xanthophores, but other part of the body except the yolk was free from any chromatophores. It swam freely in the tank.
The four day old larva began to bite the boiled egg yolk. In five days after being hatched, the larva consumed its yolk and attained 2.4 mm in total length. The nine day old larva began to bite the brine shrimp nauplii. In 18 days the rudiments.. of the dosal, anal and caudal fins were formed. In 26-31 days the larva 6.6 mm in total length reached early juvenile stage.
