Morphological Characteristics of Adult Male Weasel "Mustela Subpalmata, Hemprich and Ehrenberg, 1833" From Different Regions in Egypt

Abstract

Most of the characteristics explaining the variability between populations or species were those directly connected with their morphological measurements. Many studies have dealt with morphological measurements among mammalian skulls, but few have dealt in detail with morphological measurements of cranial and dental characters. Forty one adult male specimens of the weasel, Mustela subpalmata, were collected from four different regions in Egypt; Alexandria, Giza, Beni Suif, and Sharquiya. Twenty-eight absolute morphometric characters (body mass + 4 external + 23 cranial and dental) and 23 selected morphological ratios were undertaken. All of these measurements showed no significant difference, except the upper molar M 1 breadth/maxillary tooth row length (MuB/MxtL) ratio which showed a significant difference between these four studied regions. The complete external description and coloration of the Egyptian weasel pelage were analyzed in detail. The dental characters showed highly correlation with each other and were highly correlated with the cranial characters, which are also highly correlated with each other. Standing on 28 morphological and 23 selected ratio characters, the Egyptian weasels collected from Beni Suif region differ from those of Alexandria, Giza, and Sharquiya regions. The similarity index between the Egyptian weasels collected from Alexandria and Sharquiya regions is very high. The cluster of each of Alexandria and Sharquiya is somewhat close to Giza cluster.Palearctic species of Mustela depending on cytogenetic and biochemical characteristics [5] .The common weasel, M. nivalis, is distributed in temperate and arctic regions. It is distributed also in Morocco, Algeria, Egypt, and Lebanon [6] . The separation between its distribution in Lebanon and its presence in the Nile Delta of Egypt is unexpected and has taken zoologists to believe that this weasel was introduced into Egypt [6] .Dayan and Tchernov [7] documented that during a cooler phase of the region in the Pleistocene, M. nivalis is one of the little species that shifted southwards into Egypt through the Mediterranean coast. Today M. nivalis remains a glacial relict in Egypt; the high productivity of the Nile Delta and M. nivalis commensalism may allow it to resist climate change in the region. The size variation is very significant in M. nivalis. Large-sized weasels are found in the Levant southwest and reaching the maximum size forms in Egypt [8] .Several previous studies considered the Egyptian weasel as a subspecies of M. nivalis. Whereas, the Egyptian weasel differs morphometrically and concerning sexual dimorphism of size from all the other taxa of M. nivalis. Van Zyll de Jong [2] used skull morphometric analysis of M. nivalis then he deduced that the large Egyptian weasel is a separate species as M. subpalmata, Hemprich and Ehrenberg 1833. Reig [9] followed the opinion of van Zyll de Jong [2] and considered the Egyptian weasel as a separate species.Abramov and Baryshnikov [10] assume the following logic scheme of the origin and ...