A guide to scale interpretation and age estimation for the East-Atlantic and West-Mediterranean shads (Alosa spp.).

The general objective of this guide is to provide a practical manual for in terpreting scales and the estimation of age of Alosa from the East Atlantic and West-Mediterranean (Allis shad, Atlantic and mediterranean shad). Foll owing a brief presentation of the species, populations and rivers studied, the scales, sampling methods and their preparation for reading are describe d in detail, Definitions and a standard system of notating age are given. T he majority of the difficulties encountered in the interpretation of scales are analysed, solutions proposed and some recommendations given. The whole guide is largely illustrative using examples of typical and atypical scale s from the various taxons of the different populations studied.