DISTRIBUTION AND ABUNDANCE OF 2 MALARIAL PARASITES OF THE ENDEMIC ANOLIS LIZARD OF SABA ISLAND, NETHERLANDS-ANTILLES

The ecology of 2 parasites, Plasmodium floridense and Plasmodium azuro philum, was studied in the endemic lizard, Anolis sabanus, on Saba isl and in the eastern Caribbean. Prevalence of the two parasite species w as similar, but prevalence varied among sites. Lowest prevalence occur red at dry, windy sites or cool, wet mountain peaks (0-20%); the paras ites were more common at most other locations on the island (40-80% in fected; overall prevalence = 47%). High and low prevalence sites somet imes were only a few hundred meters apart. Prevalence was similar for males and females but increased with body size except for a decline in the largest (= oldest) lizards. A surplus of mixed infections (P. flo ridense and P. azurophilum together in the same host) existed compared with chance proportions. Parasitemia generally was low; 70% of P. flo ridense infections were less than or equal to 100 parasites/10,000 ery throcytes, and 70% of P. azurophilum infections were less than or equa l to 50/10,000. Parasitemia in solitary infections averaged more than twice that seen in mixed infections for both species.