Note on size variation of body and statoliths in the oval squid Sepioteuthis lessoniana hatchlings

Oval squid Sepioteuthis lessoniana hatchlings originated from maternally identical egg strings were incubated under constant temperature and examined with special reference to statolith formation. Statoliths of a hatchling already had an adult-like shape, and some increments were observed. In spite of the maternally identical origin and constant incubation temperature (25°C), dorsal mantle length and statolith length of the hatchlings varied from 4.70 to 6.26 mm and 320 to 410 μm, respectively (N=14). These variations had a positive correlation with the embryonic duration ranging from 22 to 27 d, which means that the size of body and statolith becomes larger in hatchlings hatching later