Geographic variation and sexual size dimorphism of Emys orbicularis in Italy and Slovenia: results of the monitoring task within the LIFE URCA PROEMYS project

The task was necessary to estimate presence and density in the light of the following tasks.We show preliminary data on biometry and dimorphism. We have considered 40 ZSCareas of 2000 Natura network, between April and September 2023. We followed guidelinesof ISPRA (2016) manual: 10 fishing nets/area, with three sampling sessions and threenight/traps/area; all presence data have been recorded on GIS. Individuals have beenmeasured and marked with standard procedures. Biometric data (carapace and plastronlength and width, scute height and bmass) analysed with parametric statistics (IBM SPSS20). We captured 1395 Emys in Italy and 345 in Slovenia, 846 and 155 were first capture,respectively. Adult sexual differences (428 ♂♂, 324 ♀♀ Italy; 85 ♂♂, 36 ♀♀ Slovenia) arehighly significant, with ♀♀ being larger and heavier. We ran a multivariate analysis ofvariance (MANOVA) on all linear vars and on two ratios (carapace width/length; carapacelength/bmass), with sex and area code as factors and their interaction. We found i) strongsexual dimorphism (with exception of both ratios, P>0.3) and ii) strong differences amongareas (♂♂ and ♀♀ data pooled), with no interaction, with the exception of carapace width/length ratio (F=1.641; df: 19; P=0.042). Main differences relate to Emys orbicularis fromLiguria (Lerrone-Valloni), Latium (Macchia Grande) and Slovenia (Draga Pri Igu),characterised by a higher rounded carapace shape, with respect to other areas (and regions),which show a more elongated shape. Our data confirm the known variability of the speciesin Italy, and increase significantly the Italian sample, to date limited to a small number of studied areas.