Effect of Temperature on the Early Development of Paralichthys olivaceus Otoliths.

Abstract

This study aimed to investigate the influence of temperature on the early otolith growth and development in P. olivaceus by examining natural (15-19.5 °C) and constant (20 ± 0.5 °C) temperature regimes. The findings indicated that the initial daily ring appeared on the fifth day after hatching, with the regular formation of daily increments observed under both temperature regimes. Throughout the incubation period (0-30 days), no significant difference in growth rate was observed between the two temperature regimes. However, from days 35 to 50, the growth rate was significantly higher under the natural temperature regime than under the constant temperature regime. Morphological changes in otoliths differed between the two temperature regimes, with more distinct daily rings observed under the natural temperature regime than under the constant temperature regime. Furthermore, otolith growth strongly correlated with fish growth, with otolith size positively correlated with total length. This study demonstrated that the temperature regime significantly affected the early growth of otoliths and the formation of daily increments, offering essential data for reconstructing early life history and assessing stocking and release success.