Skin Structure and Wiping Behavior of Phyllomedusine Frogs
Four species of the genus Phyllomedusa (sauvagei, iherengi, pailona and hypochondrialis) were found to have previously undescribed integumental alveolar glands which contain lipid material. No lipid glands were observed in Agalychnis annae and very few in Pachymedusa dacnicolor, two other members of the subfamily Phyllomedusinae. The four species of Phyllomedusa demonstrate a complex and stereotyped wiping of the body surface immediately after the secretion of lipid. These frogs demonstrate very low evaporative water loss through the skin. The low water loss is associated with a constellation of behavioral and physiological characters: the selection of a permanent perch where the frogs remain during the day, the secretion of lipid by skin glands, wiping behavior and the assumption of torpor. Light and electron microscopy of the integument of these frogs demonstrated a typical anuran skin, with the exception of the presence of lipid glands. The impermeability of the skin is attributed to the formation of a lipid layer on the skin surface.