Alizarin Red S Marking in Otoliths: A Study on the Growth Dynamics of Diplodus vulgaris Juveniles

This study investigates the age and growth rates of juvenile Diplodus vulgaris in the Çanakkale Strait, utilizing Alizarin Red S (ARS) marking to analyze otoliths for daily growth increments. The research aimed to validate the daily deposition of growth rings in otoliths as a reliable method for age determination in young fish. A total of 65 specimens were subjected to ARS immersion at varying concentrations to identify the optimal marking conditions that would not adversely affect the survival rates of the juveniles. Post-treatment, the fish were released into controlled environments and monitored over a period to assess the incorporation and visibility of ARS marks in the otoliths. The results demonstrated a clear correlation between fish size and age, with a consistent daily growth rate that supports the hypothesis of daily increment formation in otoliths. The mortality rate associated with ARS treatment was within acceptable limits, confirming the method's viability for non-lethal age and growth studies. This research not only underscores the effectiveness of ARS marking in studying juvenile fish growth patterns but also contributes to a better understanding of the life history of D. vulgaris in the Çanakkale Strait, offering valuable insights for fisheries management and conservation efforts.