title: Interspecific variation of warning calls in piranhas: a comparative analysis.
abstract: Fish sounds are known to be species-specific, possessing unique temporal and spectral features. We have recorded and compared sounds in eight piranha species to evaluate the potential role of acoustic communication as a driving force in clade diversification. All piranha species showed the same kind of sound-producing mechanism: sonic muscles originate on vertebrae and attach to a tendon surrounding the bladder ventrally. Contractions of the sound-producing muscles force swimbladder vibration and dictate the fundamental frequency. It results the calling features of the eight piranha species logically share many common characteristics. In all the species, the calls are harmonic sounds composed of multiple continuous cycles. However, the sounds of Serrasalmus elongatus (higher number of cycles and high fundamental frequency) and S. manueli (long cycle periods and low fundamental frequency) are clearly distinguishable from the other species. The sonic mechanism being largely conserved throughout piranha evolution, acoustic communication can hardly be considered as the main driving force in the diversification process. However, sounds of some species are clearly distinguishable despite the short space for variations supporting the need for specific communication. Behavioural studies are needed to clearly understand the eventual role of the calls during spawning events.
authors: Laboratoire de Morphologie Fonctionnelle et Evolutive, Institut de Chimie, Bât. B6c, Université de Liège, B-4000 Liège, Belgium.
authors: Geoffrey
authors: G
authors: Mélotte
authors: HYDRECO Guyane, Laboratoire Environnement de Petit Saut, B.P. 823-97388 Kourou Cedex, French Guiana.
authors: Régis
authors: R
authors: Vigouroux
authors: Département de Biologie, Ecologie et Evolution, AFFISH Research Center, Université de Liège, Institut de Zoologie, 22 quai Van Beneden, B-4020 Liège, Belgium.
authors: Christian
authors: C
authors: Michel
authors: Laboratoire de Morphologie Fonctionnelle et Evolutive, Institut de Chimie, Bât. B6c, Université de Liège, B-4000 Liège, Belgium.
authors: Eric
authors: E
authors: Parmentier
mesh_terms: D000400:Air Sacs / Q000502:physiology; D000818:Animals; D060125:Characiformes / Q000145:classification / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D010802:Phylogeny; D013045:Species Specificity; D014732:Vibration; D014828:Vocalization, Animal