Growth, Daily Age, and Hatching Phenology of Red Mullet, Mullus barbatus in the Shallow Nursery Grounds of Gökçeada Island (Northern Aegean Sea)

Understanding early life history, growth dynamics and hatching phenology of the red mullet, Mullus barbatus in nursery habitats is essential for effective fisheries management. Using otolith daily age readings of 60 juveniles collected between July and November 2013 from Gökçeada Island (Northern Aegean Sea), daily age structure, individual growth rates, and hatching pattern have been determined. Otolith increment analysis revealed ages ranging from 71 to 200 days, with body lengths from 4.7 to 13.2 cm. Growth was best described by linear model (mean daily growth rate: 0.64 mm·day⁻¹, R² = 0.87). Estimated hatching dates, showed a clear spring concentration (March–April), indicating synchronized spawning and rapid juvenile growth in nursery habitats. The age–length key developed here enables estimation of age structure from simple length measurements in the field. These findings align with published phenology and growth rates for M. barbatus in the Mediterranean and provide a robust baseline for future monitoring and management of local stocks.