Abstract
Cnemidophorus arubensis, an edemic teiid lizard of Aruba island, Netherlands Antilles, is parasitized by a haemogregarine protozoan. The proportion of animals infected (prevalence) was greater for males than females and for adults compared to juveniles. Brightly colored males were more likely to be infected than blandly colored males of the same body size. Percent of erythrocytes infected with parasite gametocytes, and parasite prevalence, were similar in both wet and dry seasons. Infected and noninfected lizards were similar for several hematological, physiological, anatomical, and behavioral measures of parasite virulence. The Aruban haemogregarine appears to have an avirulent effect on Cnemidophorus arubensis.