Relation between Water Balance and Climatic Variables Associated with the Geographical Distribution of Anurans

Author(s)

Titon Junior, Braz ^[1] ; Gomes, Fernando Ribeiro ^[1]

Affiliation

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

• Document type: Journal article
• Source: PLoS One; v. 10, n. 10 OCT 15 2015.
• Web of Science Citations: 8

Abstract

Amphibian species richness increases toward the equator, particularly in humid tropical forests. This relation between amphibian species richness and environmental water availability has been proposed to be a consequence of their high rates of evaporative water loss. In this way, traits that estimate water balance are expected to covary with climate and constrain a species' geographic distribution. Furthermore, we predicted that coexisting species of anurans would have traits that are adapted to local hydric conditions. We compared the traits that describe water balance in 17 species of anurans that occur in the mesic Atlantic Forest and xeric Cerrado (savannah) habitats of Brazil. We predicted that species found in the warmer and dryer areas would show a lower sensitivity of locomotor performance to dehydration (SLPD), increased resistance to evaporative water loss (REWL) and higher rates of water uptake (RWU) than species restricted to the more mesic areas. We estimated the allometric relations between the hydric traits and body mass using phylogenetic generalized least squares. These regressions showed that REWL scaled negatively with body mass, whereas RWU scaled positively with body mass. Additionally, species inhabiting areas characterized by higher and more seasonally uniform temperatures, and lower and more seasonally concentrated precipitation, such as the Cerrado, had higher RWU and SLPD than species with geographical distributions more restricted to mesic environments, such as the Atlantic Forest. These results support the hypothesis that the interspecific variation of physiological traits shows an adaptation pattern to abiotic environmental traits. (AU)

• FAPESP's process: 10/16804-3 - Water balance and locomotor performance in Bufonids inhabiting thermal and hygric contrasting biomes
• Grantee: Braz Titon Junior
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 08/01917-7 - Water balance and locomotor performance in anuran species from the Atlantic Forest and Cerrado
• Grantee: Braz Titon Junior
• Support Opportunities: Scholarships in Brazil - Master