It is most often found in the vicinity of rivers and streams. Male iguanas tend to be larger and have brighter overall coloration than females. The distinct color of males is especially pronounced during the breeding season.
Males tend to have larger heads than females, in part because of swollen jowls.
Both sexes have 12-13 prominent pores arranged in a row on the underside of both thighs. These glandular structures secrete a waxy substance with which iguanas mark their territory and identify each other. This developmental modification probably enables the male to better grasp the female during copulation. An iguana's skin is entirely covered with very tiny scales. Young iguanas are pale green with black-ringed tails.