Statolith growth of juvenile oval squid Sepioteuthis lessoniana (Cephalopoda: Loliginidae) with special reference to ambient thermal condition

Abstract

Growth of the statolith of the oval squid, Sepioteuthis lessoniana, was observed in captive juveniles up to 45 days post-hatching. Juveniles were raised at different water temperatures (20°C, 25°C, 30°C, including switching from 20 to 25°C regimes). Statolith size was strongly correlated with squid body size regardless of age, and these relationships were positively correlated with ambient thermal condition. At 30 days post-hatch, mantle length and total length of statolith were 8.70±0.15 mm and 636.4±12.5 µm, respectively, in the 20°C group and 12.48±0.78 mm and 730.4±8.8 µm in the 30°C group. It was revealed that oval squid statoliths grew in a circular manner from the centre and were affected by ambient temperature.