Unexpected morphometric differentiation of the Algerian mouse, Mus spretus (Rodentia: Muridae) from Kabylie of Djurdjura (Algeria)

Abstract

Abstract A preliminary morphometric study of the Algerian mouse, Mus spretus in Algeria based on populations collected in the Kabylie of Djurdjura revealed an unexpected strong differentiation when compared with samples from Morocco, Tunisia, Spain, and France. Skull, mandible, and teeth have been measured on an original sample of Algerian animals and on foreign specimens from private collections. A first principal component analysis revealed a noticeable morphometric differentiation within populations of Kabylie of Djurdjura based on several variables including palatal breadth, palatal foramina length, and first lower molar breadth. At the scale of the species range the results of a second principal component analysis were even more distinctive with two clearly separated groups, mice from Algeria vs. mice from all other parts of the range. Mice from Algeria are characterized by a finer nose, a broader palate, and smaller teeth. The evolutionary history of this species cannot explain such a differentiation which is more likely a local adaptation.