Spatial, Temporal, and Host-Specificity Patterns of Three Genera of Blood Coccidian Parasites in Two Syntopic Mediterranean Lizards

Abstract

We investigated the phenological variation of three genera of blood parasites of lizards (Schellackia, Karyolysus, and Lankesterella)using samples of 275 adult Psammodromus algirus and 138 Acanthodactylus erythrurus collected from April to September in 2021and 2022. Both years experienced heatwaves, and 2022 had the warmest summer on historical record for the region. We capturedlizards in two close areas that differed in vegetation quality due to differential human pressure. We found that Schellackia andKaryolysus more frequently infected P. algirus, whereas Lankesterella infected A. erythrurus. We fitted generalized additive modelsto explain parasite intensity, including the non-linear effect of phenology sorted by sex and the linear effects of body length, bodycondition, host sex, heterophil–lymphocyte ratio, distance to a road, and microclimate. We found a positive effect of body length onparasite intensity across parasite genera. The intensity of Schellackia was higher in female hosts, contradicting the dogma of highermale susceptibility to infections. The intensity of Lankesterella was lower closer to the road, indicating that parasite transmissionsuccess can vary at the microgeographic scale. We found a non-linear significant increase of Karyolysus across the activity period,suggesting a relaxation of the antiparasitic control upon this genus toward the end of the activity period. For Lankesterella, weobserved a phenological increase only in female lizards, suggesting sexual differences in immunocompetence. We found higherintensity of Karyolysus and Lankesterella in 2022, conforming to the idea that heat waves may impair lizards’ immunocompetence.