Características histológicas de la tumefacción frontal de Melanophryniscus (Amphibia: Anura: Bufonidae)

Abstract

We analyzed the histology of skin from the head region of six species of Melanophryniscus, belonging to the stelzneri (4) and tumifrons (2) groups, to understand the frontal tumefaction structure and function. The histological features of the skin in the stelzneri group are in agreement with the current description for the genus Melanophryniscus. However, the features of the skin on the anterior head region of M. tumifrons shows several changes associated with the frontal tumefaction. This structure consists of a macrogland of similar organization to that of other dermic glands (e.g., parotoid, paracnemid) of amphibians. We propose the name frontal macrogland for this structure. Our results suggest a possible defense role for this macrogland.