Seasonal Changes in the Renal Morphometry of Antechinus Stuartii (Marsupialia: Dasyuridae)

Abstract

The renal morphology of Antechinus stuartii was examined in males and females in February, May, July and August. Kidney mass was higher in males than females, although the reverse was true when adjusted for body mass. The predicted kidney mass and kidney size calculated from allometric equations were significantly larger than the actual values in males from August, although at other times and for females these values were not different. Relative medullary thickness, percentage medullary thickness and medullary thickness were not different between seasons or sexes. Both superficial and juxtamedullary glomerular volumes increased in July and August in males and this coincided with a reduction in glomerular number per mm(2) of cortex. In general, tubular diameters increased in males in July and August, but not in females. The same was true of cellular volumes from the same sections of the nephron. The renal morphological changes in the males correlate with the life history and endocrine changes of A. stuartii.