With our natural attention focused on ourselves, we often forget that other creatures have different ways of accomplishing the processes of life. Mention breathing, for example, and not surprisingly we think of lungs. Indeed, many of us would be hard put to think of another way of breathing. Yet, numerous other ways exist. Our desert fish, as with fish elsewhere, use gills to extract dissolved oxygen from the surrounding water. Many amphibians use their skin for at least part of their respiratory needs, using their large area of external coverings much as fish use gills. Although most amphibians also use lungs, a group of salamanders living in the cool coniferous forests of Southwestern mountains manage to do quite nicely without them; the skin, kept moist by the animals inhabiting damp microhabitats, is quite sufficient for these small creatures.
All of the animals mentioned, you might note, are cold-blooded. The
relatively slow pace of their lives require much less oxygen than does our hectic
existence. A life of just laying around passively absorbing oxygen is not for us!
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.