Growth process of grass puffer Takifugu niphobles was analysed by sagittal otolith size measurements. The growth of otolith was monitored using otolith height (OH). The OH increaaed rapidly from hatching to 60 days after hatching. The growth rates somewhat varied yearly. The growth rate decreased later, and growth stopped from December to next April. The otolith growed slowly（0.220mm/214days）and stably with small yearly variation after age one. Otolith did not grow from December to April. The von Bertalanffy growth model, TL_t=31.2{1-e^{-1.12(t+1.35)}} was derived. Otolith daily growth rings were observed by dorso-ventral sections. Winter no growing marks were observed in otolith sections of age-2 T. niphobles. Above mentioned growth of otolith was confirmed by measurements of otolith daily growth ring widths.
sagittal otolith
otolith daily growth ring
Takifugu niphobles
von Bertalanffy growth model