Parasite load, throat colors, and cellular immune response in Quedenfeldtia trachyblepharus, a high-altitude gecko endemic to Morocco

Abstract

Color polymorphisms in lizards are maintained by complex interactions between environmental factors, genetics, and physiological traits (e.g., immunity) that can differ among morphs. Here, we investigated the relationship between mite load, throat coloration (orange, yellow, and white), and cell-mediated immune responsiveness (CMI) in the Atlas day gecko, Quedenfeldtia trachyblepharus (Boettger, 1874) during its post-mating period. We also evaluated the relationship between the patterns of infestation by ectoparasites and sex, throat color, and host size. The prevalence and intensity of infestation by mites did not differ by sex, host body length, or throat color. Furthermore, there was no significant relationship with host body condition. The CMI was related to sex and lizard body size (SVL). Additionally, there was a positive correlation between the intensity of infestation and the CMI response of the gecko hosts. Likewise, there was a significant positive correlation between CMI and the scaled mass index (SMi) of the lizards. In addition, geckos with broken tails had a significantly higher CMI than those with regenerated or intact tails. Moreover, CMI differed significantly among morphs; orange morphs had a higher immune response than yellow one, while the white individuals presented the lowest response. Thus, CMI is morph-specific in this gecko, suggesting that this immunological trait could play a determinant role in maintaining throat color polymorphism in this species.