KIDNEY STRUCTURE AND RENAL INDEXES OF DASYURID MARSUPIALS

Examination of kidney structure for 25 dasyurid marsupials showed that kidneys of species from arid habitats tend to have a relatively thicker medulla and higher renal indices than those of species from semi-arid, mesic and tropical areas. Arid-dwelling species such as Ningaui ridei and Pseudantechinus macdonnellensis had the highest renal indices while Antechinus swainsonii, collected from alpine environments, had the lowest renal index values. Renal indices were significantly correlated also with body weight, average daily maximum temperature and average annual rainfall of the habitat. The renal indices for xeric species differed significantly by discriminant analysis from the indices for other species. There was no obvious phylogenetic conservatism in renal indices; for example, renal indices varied almost as much within the genus Sminthopsis as between all of the other genera of Dasyuridae examined.