Validation of the periodicity of opaque zone formation in the otoliths of four temperate reef fish from South Africa

Abstract

An oxytetracycline (OTC) marker was used to validate the periodicity of opaque zone deposition in the otoliths of Chrysoblephus laticeps, Cheimerius nufar, Cymatoceps nasutus (Sparidae) and Dichistius capensis (Dichistiidae) in the wild. Fish were injected with OTC and tagged with external dart tags within a research fishing area of the Tsitsikamma National Park marine reserve on the southern Cape coast of South Africa. Recaptured fish, injected with OTC, were at liberty for between 711 and 2 102 days. Examination of their otoliths revealed that all deposited one opaque zone each year. The study confirmed the age estimates from previous studies that made use of marginal zone analysis as a validation method.

Keywords:

• AGE VALIDATION
• LINEFISH
• OXYTETRACYCLINE MARKER
• SOUTH AFRICA