Blood parasite infections in the Carniolan Lizard, Zootoca carniolica (Mayer et al., 2000)

Abstract

Blood parasites play a crucial role in shaping host ecology and fitness in reptiles, yet their occurrence in many lacertid species remains poorly documented. We here report the first evidence of blood parasites in Zootoca carniolica, a recently recognized oviparous species, from Slovenia. Fifty adult lizards (25 males, 25 females) were sampled from a population at an elevation of 1300 m in Pokljuka, Slovenia, during the summer of 2021. Blood smears were analysed to determine parasite prevalence and intensity, and the relationships of parasite data with host body size, sex, and seasonality. Overall, 52% of individuals were infected. A distinct sex-specific pattern in parasite infection was found: in males, body size was positively correlated with parasite prevalence, likely reflecting increased exposure to potential parasite vectors through enhanced social interactions and movement in bigger males. In females, larger individuals exhibited higher parasite intensity, possibly due to trade-offs between reproductive investment and immune function, or cumulative parasite exposure with age. Additionally, females showed a significant seasonal decline in parasite intensity from July to August, which is potentially linked to reproductive cycles, environmental factors, or physiological condition. On the other hand, it might also reflect a body size effect since larger females were found in July. These findings highlight the complex interactions between host traits, seasonality, and parasite dynamics in a high-elevation lizard population, contributing to our understanding of host-parasite interactions in European lacertids.