Niigata Prefectural Kaiyo high school, Nou, Niigata 949-1352, Japan
The age and growth of the devil stinger, Inimicus japonicus, collected from the coastal waters of Joetsu City, Niigata Prefecture, were examined by way of the metapterygoid of 292 individuals. Observation of the outer margin of the metapterygoid showed that hyaline and opaque zones composed the ring mark which was formed once a year. The relationship between the metapterygoid radius and the total length of the fish was estimated to be 
R=0.0382TL−0.1341, 
R=0.0381TL+0.0709. The Bertalanffy's growth equations calculated from the total length, estimated from metapterygoid ring radii, were as follows: Lt=283.315 (1−e−0.2406(t+0.5104)), Lt=324.400 (1−e−0.2094(t+0.6058)), Lt: total length at age, t: age. The growth of females was remarkably superior to that of males. The spawning season was estimated to occur from June to August according to monthly changes of the gonad somatic index in each sex.