Complex sentence: Most amphibians, however, are able to exchange gases with the water or air via their ski air, where oxygen is more concentrated, some small species can rely solely on cutaneous gas exchange, most famously the plethodontid salamanders, which have neither lungs nor gills.
Split into simpler sentences: Most amphibians, however, are able to exchange gases with the water or air via their skin. In air, where oxygen is more concentrated, some small species can rely solely on cutaneous gas exchange, most famously the plethodontid salamanders, which have neither lungs nor gills.