Bm. Mcallan et al., THE KIDNEY STRUCTURE OF THE COMMON WOMBAT (VOMBATUS-URSINUS) AND THE HAIRY-NOSED WOMBAT (LASIORHINUS-LATIFRONS), Australian journal of zoology, 43(2), 1995, pp. 181-191
The common wombat (Vombatus ursinus) lives in a mesic habitat whereas
the hairy-nosed wombat (Lasiorhinus latifrons) inhabits a xeric habita
t. The kidney structure of these two wombats was studied and it was fo
und that kidney size, kidney weight, and kidney weight as a percentage
of body weight, were larger in V. ursinus. However, relative medullar
y thickness, percentage medullary volume, and medullary thickness as a
percentage of total thickness, were significantly greater in L. latif
rons, suggesting that L. latifrons has a greater capacity to conserve
water than does V. ursinus. The number of glomeruli and mean glomerula
r area were the same in both species whereas the mean diameter of the
proximal and distal tubules was larger in V. ursinus. There were more
proximal tubules per square millimetre in L. latifrons. The larger num
ber of collecting ducts per square millimetre in the medullary region
in L. latifrons indicates that the nephrons join the collecting ducts
deep in the medulla, a feature that has been associated with increased
urinary concentrating ability. Urinary pH was significantly lower, an
d urinary ammonia, creatinine and sodium levels were higher, in L. lat
ifrons, as were plasma sodium and chloride levels. These data suggest
that L. latifrons has a greater capacity to conserve water.