Convergence to the tiniest detail: vocal sac structure in torrent-dwelling frogs

Author(s)

Elias-Costa, Agustin J. ^{[1, 2]} ; Faivovich, Julian ^{[1, 2]}

Affiliation

^[1] Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Biodiversidad & Biol Expt, Buenos Aires, DF - Argentina

^[2] Consejo Nacl Invest Cient & Tecn, Museo Argentino Ciencias Nat Bernardino Rivadavia, Div Herpetol, Av Angel Gallardo 470, C1405DJR, Buenos Aires, DF - Argentina

• Document type: Journal article
• Source: Biological Journal of the Linnean Society; v. 128, n. 2, p. 390-402, OCT 2019.
• Web of Science Citations: 0

Abstract

Cascades and fast-flowing streams impose severe restrictions on acoustic communication, with loud broadband background noise hampering signal detection and recognition. In this context, diverse behavioural features, such as ultrasound production and visual displays, have arisen in the evolutionary history of torrent-dwelling amphibians. The importance of the vocal sac in multimodal communication is being increasingly recognized, and recently a new vocal sac visual display has been discovered: unilateral inflation of paired vocal sacs. In the diurnal stream-breeding Hylodidae from the Atlantic forest, where it was first described, this behaviour is likely to be enabled by a unique anatomical configuration of the vocal sacs. To assess whether other taxa share this exceptional structure, we surveyed torrent-dwelling species with paired vocal sacs across the anuran tree of life and examined the vocal sac anatomy of exemplar species across 18 families. We found striking anatomical convergence among hylodids and species of the distantly related basal ranid genera Staurois, Huia, Meristogenys and Amolops. Ancestral character state reconstruction identified three new synapomorphies for Ranidae. Furthermore, we surveyed the vocal sac configuration of other anuran species that perform visual displays and report observations on what appears to be unilateral inflation of paired vocal sacs, in Staurois guttatus - an extremely rare behaviour in anurans. (AU)

• FAPESP's process: 12/10000-5 - A multi-disciplinary approach to the study of amphibian diversification
• Grantee: Taran Grant
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 13/50741-7 - Diversity and conservation of Brazilian amphibians
• Grantee: Célio Fernando Baptista Haddad
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants