Changes in absolute and proportional water content during growth and metamorphosis of Rana sylvatica

Abstract

1. 1. Wet and dry weights were determined for Rana sylvatica larvae (Taylor-Kollros stages II-XXV). 2. 2. Wet weight and absolute water content increase steadily through stages XVII–XVIII and then rapidly decrease. 3. 3. Proportional water content (water:dry weight) decreases from a high level of 20:1 to a low level of 6.3:1. 4. 4. Although 50% of the absolute water content is lost between stages XVII and XXV, the apparent drop is only 2.2% when water is expressed as a percent of total body weight. 5. 5. These data demonstrate that the comparison of water in percent-of-body-weight terms can potentially lead to erroneou conclusions.