The Using of Skeletochronology as a Screening Method for Age Determination of Alpine Newts (Mesotriton Alpestris): a Technical Report

Abstract

Skeletochronology is a widely used method for age determination in amphibians. This method is based mainly on the histological examination of the fi nger bones. However, the lengths of utilized severed fi ngers have not been specifi ed in previous studies. The objective of this study was to analyse the structure of line arrested growth (LAGs) involving taking only the last two phalanges of a fi nger, and using the entire fi nger of Alpine newts (Mesotriton alpestris). Altogether 432 fi ngers were taken from four localities in the Czech Republic during the newt breeding period. The fi rst group (group A) contained fi ngers that consisted of the last two phalanges (330 samples), and the second (group B) contained complete fi ngers with all phalanges (102 samples). All fi ngers were processed using standard histological methods and stained with hematoxylin-eosin. Phalange cross-section slides were made, and the ages of the individuals were determined by the number of LAGs. From two phalanges it is determine the age of 17.87% of newts; however, age determination was successful in 49.01% of newts when using whole fi ngers. Age determination success rate diff erences between groups were signifi cant (P < 0.001). This is a histological study and it is recommended utilizing whole fi ngers in future Caudata amphibian screening age studies.