Renal Structure and Body Size in Heteromyid Rodents

Abstract

The relationship between body size (i.e., body mass, surface area, and relative surface area) and urine concentrating ability (via renal morphology) was determined using six sympatric species of heteromyids. These rodents share similar feeding habits and life histories but differ in adult body size. When variables such as ecological distribution, dietary habits, and other aspects of an animal's life history are reduced, renal morphology is highly and negatively correlated with body size; small heteromyids have relatively thicker medullae and presumably greater urine concentrating abilities than large ones. Renal medullary thickness is as strongly correlated with body mass as with measurements of surface area and mass-specific surface area.