A method for ageing the abalone Haliotis rubra (Mollusca : Gastropoda)

Abstract

A technique for ageing Haliotis rubra is described. The spire of the shell is ground to create a polished disc of nacre in which rings are visible. The number of rings present in each shell is related to the size of the shell. The age at which each ring is deposited has been determined using an age-length key derived from length-frequency histograms and tag return data. For the population studied, three minor rings are deposited in the first 16 months of life and a major ring at an age of approximately 20 months. Subsequent rings are deposited at approximately annual intervals.