Meeting Abstract

P1.137  Tuesday, Jan. 4  Seat patch water potentials of two anuran species, Lithobates pipiens and Pseudacris cadaverina. LEMENAGER, L.A. *; TRACY , C.R. ; University of Nevada lemen22@hotmail.com

The water potentials of the seat patches of anuran amphibians (Northern leopard frog, Lithobates pipiens; and California Treefrog, Pseudacris cadaverina) were inferred from experiments of water exchange between frogs and environments in which the water potential was controlled. Water exchanges of frogs were inferred from changes in their body mass when they were allowed to exchange water with sucrose solutions differeing in water potential. Rates of water exchange by frogs were plotted against the osmotic potentials of experimental solutions, and the x-intercept of this graph was taken to be the water potential of the seat patch of the frogs (the point at which the water potential of the environment is equal to the water potential of the seat patch). Seat patch water potentials for L. pipiens were different from the water potential of their blood, and this implies that individuals of this species have some control of water uptake. Seat patch water potentials for P. cadaverina were similar to the water potentials of blood implying that they have no control of water uptake.