COMPARATIVE RENAL MORPHOLOGY OF SOME SOUTHERN AFRICAN OTOMYINE RODENTS

The kidney structure of 21 individual otomyine rodents representing si x southern African taxa from localities with differing climatic profil es was studied by means of light microscopy. Variation in the data was accounted for primarily by relative cortex and medulla proportions. T he kidneys of Otomys angoniensis Wroughton, 1906, O. irroratus (Brants , 1827) and O. sloggetti robertsi Hewitt, 1927 displayed mesic adaptat ion, and those of O. unisulcatus F. Cuvier, 1829, Parotomys brantsii ( A. Smith, 1834) and P. littledalei Thomas, 1918 xeric adaptation, refl ecting species-specific patterns of geographic distribution across sou thern African rainfall gradients. Neither mesic nor xeric renal charac ters appear optimally expressed in the species considered, and it is p ostulated that feeding habits and behavioural adaptations play a signi ficant role in the water economy of otomyine rodents.