Two chromosomal races of the house moue occur in central Tunisia: a standard type (2n = 40) and a Robertsonian race (2n = 22). Although contact between races is not restricted, hybrid populations are rare. Patterns of mate preference between wild mice of the two races suggest that, although incipient, this premating divergence could limit the number of crosses between races in nature. In this paper we compare sexual preference of laboratory-born mice and their parents caught as adults in the wild with the aim to assess whether the social context of development to adulthood could influence expression of preference. We predict that in the absence of such influence, parents and laboratory-born offspring should show a comparable pattern of preference. Results show that offspring preference is always lower than and not related to that of their parents. However, a significant pair effect exist leading us to group parents and offspring into three categories according to the parents' preference: homokaryotypic, heterokaryotypic, or dissimilar. Offspring exhibit a preference, which is consistent with that of their parents, only in two cases: male offspring of the standard race when both parents show a heterokaryotypic preference; all offspring when the homokaryotypic preference of fathers is high. Discrepancy between preferences of wild-caught mice and their laboratory-born progeny suggests that, here, preference may be partly influenced by social conditions experienced before and during adulthood.
Type populations of four fossil species of voles belonging to the genus Mimomys are redescribed. Mimomys ostramosensis is a large-sized, hypsodont Mimomys with enamel islet, Mimomys-ridge and relatively abundant cement. Mimomys tornensis, a medium-sized vole, is characterized by lack of typical Mimomys-ridge and islet present only in M3/, with very abundant cement accumulation. Mimomys pitymyoides, a medium-sized Mimomys, with broadly confluent triangles, is distinguished by the presence of islets and Mimomys-ridge in most specimens relatively low tracts and differentiation of enamel thickness not so distinct as in other Mimomys species. Mimomys pusillus is a small-sized vole with islet present only in younger wear stages, relatively frequent Mimomys-ridge and relatively low tracts.