Perennibranchiate, in zoology, is the condition of an organism retaining branchae, or gills, through life; This condition is generally said of certain amphibia, such as the mudpuppy; the term is opposed to caducibranchiate. In some cases only a small proportion of a given amphibian population is perennibranchiate, but in other instances a preponderance of the individuals have an adult gill retention. For example, in the case of the Rough-skinned Newt in the Cascade Mountains populations, approximately ninety percent of the adult population is perennibranchiate.