Sexing your iguana can be difficult, especially if you don't know what to look for. Below we have outlined some of the most common attributes associated with sexing an iguana.
If you encounter any physical attributes listed below that you are not familiar with, visit our Iguana Anatomy page as a reference.
Sexing Male Iguanas
There are certain characteristics that male iguanas have that help distinguish them from female iguanas. Many of these characteristics are not visible or trustworthy until the iguana has reached sexual maturity, or 8" svl. It is safer and more reliable however to wait until your iguanas is 1.5 - 2 years old to positively sex it.
Males have very noticeable femoral pores on the inside of their bottom thigh area. Each of the pores will be clearly visible and may contain waxy plugs during breeding season that are believed to be used to mark their territory.
Males tend to have larger heads which are defined by the large jowls they have. Males tend to have "brain bumps", which are fatty deposits behind the eye ridge and before the nuchal crest. Males also have a hemipenal bulge at the base of their tail. This is where their hemipenes are stored. The hemipenal bulge is typically noticeable between 1 and 1.5 years of age. Males also tend to be generally bigger than females in size with a heavier body mass.
Females are easier to sex because they lack all of the items that define a male. Females do not have a hemipenal bulge. They tend to have undefined jowls and lack "brain bumps". They are typically slimmer and have smaller heads than males do. The femoral pores of a female are much less defined than a male. Most of the pores on a female will be barely noticeable, the exception being the first few which may be pronounced.