A comparison of staining techniques to improve precision of age estimation from fish otoliths

Abstract

A total of 30 pairs of sagitta otoliths of horse mackerel Trachurus trachurus were sampled from three length‐classes, and five staining methods were applied to each pair. Ten age estimates were obtained per fish, method and length‐class. Significant differences in age estimates were found between methods, due to the variable enhancement in the otolith pattern produced by each method. A method using amido‐schwartz as the staining reagent produced the best results in terms of precision of the age estimates.