Related Experiment Video
Updated: Jul 8, 2026
Alternative Method of Removing Otoliths from Sturgeon
Published on: June 27, 2016
Otolith-based age determination in Anguilla anguilla (Linnaeus 1758) from Lake Vistonida, NE Greece: A modified Crack
Paraskevi Papadopoulou1,2, Argyriοs Sapounidis1, Manos Koutrakis1
1Hellenic Agricultural Organization-DIMITRA, Fisheries Research Institute, Kavala, Greece.
Abstract:
This study presents a modified otolith preparation protocol to estimate the age of Anguilla from Lake Vistonida (NE Greece). In experimental attempts, 300 otoliths were processed using standard and modified eel ageing methods, producing low success rates (0%-20%) due to poor annuli visibility and structural damage. To overcome these limitations, a ten-step Fisheries Research Institute (FRI) modified Crack and Burn protocol, representing a species-specific adaptation of existing Crack & Burn methodologies, was developed, combining thermal treatment, polishing, acid bath and glycerin application. This method achieved 90% success in age determination and provided a reliable method for age reading (CV = 1.97).
