Larval period and molting in the Japanese spiny lobster Panulirus japonicus under laboratory conditions

A total of 325 pueruli of the spiny lobster Panulirus japonicus was success fully reared in the laboratory at Minami-Iku Station of Japan Sea-Farming A ssociation, Shizuoka, Japan, during 1989-1997. Of these pueruli, 136 indivi duals metamorphosed into the first juvenile stage. The duration of the phyl losoma stage ranged from 231 to 417 days (mean 319.4 days), and it has a te ndency to extend as the increase of water volume in the rearing tanks. The number of molting in the phyllosoma stage was 20-31. The body length of the last-stage phyllosoma ranged from 27.9 to 34.2 mm and the duration of the last stage was 11-26 days. The carapace length of the puerulus stage was 6. 0-8.0 mm and the duration was 9-26 days. The present data and those of prev ious studies suggest that the body size and the duration of phyllosoma stag e in captivity are affected by environment as in the field. The duration of the puerulus stage is considered to be controlled basically by water tempe rature and nutritional conditions in the phyllosoma.