EVALUATION OF COPPER, IRON AND LEAD SUBSTITUTION TECHNIQUES IN ELASMOBRANCH AGE-DETERMINATION

Copper and lead substitution reactions were found to be useful in demo nstrating growth patterns in vertebrae from several elasmobranch speci es. In contrast, iron substitution was ineffective in detecting variat ions in vertebral mineralization. The present study provides two alter native methods for elasmobranch age determination that may prove usefu l when traditional methods are deemed ineffective. However, species-sp ecific variations in the efficiency of these methods re-emphasize the observation that different types of vertebrae often require different methods of staining. (C) 1998 The Fisheries Society of the British Isl es.