Summary
The stomach contents of 49 specimens of Coleo-dactylus amazonicus (Sauna, Gekkonldae) were analised. The taxa numerically most predominant were Collembola and Acari, respectivelly. After establishing that these animals feed exclusively on the soil fauna, a sampling program of the soil was carried out, v/hich showed that the Acari was by far the most abundant group, followed by Collembola. This indicates that there is a feeding preference for a taxon which is not the most common in the soil. The items found in the stomach contents and in the soil fauna were measured and counted, and their distributions compared by the X2 test. In the range of the small items (0.1 mm to 0,5 mm) it was noted that the animals were selecting the bigger ones (0,4 mm to 0,5 mm) as food, even when these bigger items are comparativelly at lesser densities in the soil. Also, tests of regression of the size of the prey on the size of the lizard showed a positive correlation. However, parallel to this tendency it was observed that the bigger lizards feed on a wider range of prey sizes, ex-ploting more efficiently their alimentary niche.