Effects of Changing Water Volume on the Tadpoles of Two Anuran Species (Pseudacris triseriata and Rana blairi)

ABSTRACT

Organisms living in temporary freshwater habitats need to respond to changes in hydroperiod to be successful. We investigated responses of tadpoles of two frogs (Pseudacris triseriata and Rana blairi) to changes in water volume. Tadpoles experienced one of three treatments: 1) constant water volume, 2) a gradual decrease in water volume, and 3) a gradual decrease in water volume available for swimming. Pseudacris triseriata tadpoles in the swimming volume treatment tended to metamorphose smaller than and after the tadpoles in the other two treatments. Rana blairi tadpoles in the control treatment attained larger size than they did in the experimental treatments, but there was no apparent difference in development rate. These results suggest that the success of these two species will differ based upon the hydroperiod of the pond.