Patterns of skull variation in relation to some geoclimatic conditions in the greater jerboa Jaculus orientalis (Rodentia, Dipodidae) from Tunisia

Authors: ABDERRAOUF BEN FALEH, HASSEN ALLAYA, JEAN PIERRE QUIGNARD, ADEL ABDEL ALEEM BASYOUNY SHAHIN, MONIA TRABELSI

Abstract: The greater Egyptian jerboa Jaculus orientalis is a member of the subfamily Dipodinae and widely distributed in Tunisia. Previous allozymic and karyotypic studies showed high gene flow and absence of genetic structuration. This study aimed to analyze the geographic patterns of cranial morphometric variation among populations of this species in Tunisia. The extent of morphometric patterns was addressed in a survey of 13 craniodental characters among 162 adult specimens collected from 12 localities within its distribution range by using univariate and multivariate statistics. Our results supported the existence of three morphotypes of this species comparable to three climatic zones, the northern, central, and southern regions of Tunisia. The probability of the correct classification of specimens was 99.38%, indicating significant degrees of variation in craniodental characteristics among these three morphotypes. In addition, we tested the effects of age, sex, geography, and some habitat variables (such as precipitation) on the size of the skull. The results showed that latitude and precipitation had significant effects on skull size. Hence, the pattern of morphometric variation is probably correlated with local environmental factors.

Keywords: Classical morphometrics, Jaculus orientalis, geographic variation, Tunisia

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