Dehydration Hardly Slows Hopping Toads (Rhinella granulosa) from Xeric and Mesic Environments

Author(s)

Prates, Ivan ^{[1, 2, 3]} ; Angilleta, Jr., Michael J. ^[4] ; Wilson, Robbie S. ^[5] ; Niehaus, Amanda C. ^[5] ; Navas, Carlos A. ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Biociencias, Dept Fisiol, BR-05508900 Sao Paulo - Brazil

^[2] CUNY, City Coll, Dept Biol, New York, NY 10031 - USA

^[3] CUNY, Grad Ctr, New York, NY 10031 - USA

^[4] Arizona State Univ, Sch Life Sci, Tempe, AZ 85287 - USA

^[5] Univ Queensland, Sch Biol Sci, St Lucia, Qld 4072 - Australia

• Document type: Journal article
• Source: PHYSIOLOGICAL AND BIOCHEMICAL ZOOLOGY; v. 86, n. 4, p. 451-457, JUL-AUG 2013.
• Web of Science Citations: 8

Abstract

The locomotor capacity of amphibians depends strongly on temperature and hydration. Understanding the potential interactions between these variables remains an important challenge because temperature and water availability covary strongly in natural environments. We explored the effects of temperature and hydration on the hopping speeds of Rhinella granulosa, a small toad from the semiarid Caatinga and the Atlantic Rain Forest in Brazil. We asked whether thermal and hydric states interact to determine performance and whether toads from the Caatinga differ from their conspecifics from the Atlantic Forest. Both dehydration and cooling impaired hopping speed, but effects were independent of one another. In comparison to performances of other anurans, the performance of R. granulosa was far less sensitive to dehydration. Consequently, dehydrated members of this species may be able to sustain performance through high body temperatures, which agrees with the exceptional heat tolerance of this species. Surprisingly, toads from both the Caatinga and the Atlantic Forest were relatively insensitive to dehydration. This observation suggests that migration or gene flow between toads from the forest and those from a drier region occurred or that toads from a dry region colonized the forest secondarily. (AU)

• FAPESP's process: 06/52491-4 - Hydroregulation in Bufo (Anura: Bufonidae): physiological and behavioral aspects of Caatinga and Mata Atlantica species
• Grantee: Ivan Prates
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 03/01577-8 - Causes and correlations of physiological variation: role of environmental and behavioral gradients at different levels of organization
• Grantee: Carlos Arturo Navas Iannini
• Support Opportunities: Research Projects - Thematic Grants