Skin and Aestivational Cocoon of the Aquatic Amphibian, Siren intermedia Le Conte
The skin of Siren intermedia is fully metamorphosed, amphibian-like, and specialized in its cocoon-producing function. During aestivation in burrows in the bottoms of dry ponds, epidermal and dermal skin glands secrete a cocoon which covers the entire body except the mouth. This structure, remarkably like the cocoons of African lungfishes, retards desiccation and permits sirens to remain in periodically dry, aquatic environments. This adaptive strategy may be alternative to that of avoiding drought by overland movement to nearby water.