Interpretability and precision of annulus counts for calcified structures in carp, Cyprinus carpio L.

Abstract

Scales, opercular bones and whole otoliths of carp from the River Murray, Australia, were analysed for interpretability and reproducibility of annulus counts by three interpreters of disparate experience. Interpretability was least for scales and highest for opercular bones, and annulus counts from scales and opercular bones were more precise than those from otoliths. However, these differences were not statistically significant. Relatively high values of the index of average percent error (IAPE) and of the mean coefficient of variation (V) confirmed that age interpretation in carp is difficult and requires extensive training and experience.