title: Unusual sound production mechanism in the triggerfish Rhinecanthus aculeatus (Balistidae).
abstract: The ability to produce sound has been known for decades in Balistidae. Sounds of many species have been recorded and a variety of sound-producing mechanisms have been proposed, including teeth stridulation, collision of the buccal teeth and movements of the fins. The best-supported hypothesis involves movements of the pectoral fin against the lateral part of the swimbladder, called a drumming membrane. In this study, we describe for the first time the sounds made by the blackbar triggerfish Rhinecanthus aculeatus, which are like short drum rolls with an average duration of 85 ms, 193 Hz dominant frequency and 136 dB SPL level at 3 cm distance. The sounds are a series of pulses that result from alternate sweeping movements of the right and left pectoral fins, which push a system of three scutes that are forced against the swimbladder wall. Pulses from each fin occur in consecutive pairs. High-speed videos indicate that each pulse consists of two cycles. The first part of each cycle corresponds to the inward buckling of the scutes, whereas the second part of the cycle corresponds to an apparent passive recoil of the scutes and swimbladder wall. This novel sound production mechanism is probably found in many members of Balistidae because these peculiar scutes occur in other species in the family. Comparison of sound characteristics from fishes of different sizes shows that dominant frequency decreases with size in juveniles but not in adults.
authors: Université de Liège, Laboratoire de Morphologie Fonctionnelle et Evolutive, AFFISH-RC, Institut de Chimie - B6C, Sart Tilman, Liège 4000, Belgium E.Parmentier@ulg.ac.be.
authors: Eric
authors: 0000-0002-0391-7530
authors: E
authors: Parmentier
authors: Université de Liège, Laboratoire de Morphologie Fonctionnelle et Evolutive, AFFISH-RC, Institut de Chimie - B6C, Sart Tilman, Liège 4000, Belgium.
authors: Xavier
authors: X
authors: Raick
authors: USR 3278 CNRS-EPHE-UPVD, CRIOBE, Paris Sciences Lettres (PSL), Moorea, French Polynesia.|Laboratoire d'Excellence "CORAIL", Moorea 98728, French Polynesia.
authors: David
authors: D
authors: Lecchini
authors: Département d'Ecologie et de Gestion de la Biodiversité, Muséum National d'Histoire Naturelle, 57 rue Cuvier, Case postale 55, Paris Cedex 5 75231, France.
authors: Kelly
authors: K
authors: Boyle
authors: Département d'Ecologie et de Gestion de la Biodiversité, Muséum National d'Histoire Naturelle, 57 rue Cuvier, Case postale 55, Paris Cedex 5 75231, France.|Department of Biology, Universiteit Antwerpen, Universiteitsplein 1, Antwerpen B-2610, Belgium.
authors: Sam
authors: S
authors: Van Wassenbergh
authors: Université de Liège, Laboratoire de Morphologie Fonctionnelle et Evolutive, AFFISH-RC, Institut de Chimie - B6C, Sart Tilman, Liège 4000, Belgium.
authors: Frédéric
authors: F
authors: Bertucci
authors: Université de Liège, Laboratoire de Morphologie Fonctionnelle et Evolutive, AFFISH-RC, Institut de Chimie - B6C, Sart Tilman, Liège 4000, Belgium.
authors: Loïc
authors: L
authors: Kéver
mesh_terms: D000400:Air Sacs / Q000502:physiology; D000819:Animal Communication; D058500:Animal Fins / Q000502:physiology; D000818:Animals; D009068:Movement; D011114:Polynesia; D013016:Sound; D013018:Sound Spectrography / Q000662:veterinary; D023721:Tetraodontiformes / Q000502:physiology*; D014741:Video Recording
keywords: Acoustic; Communication; Swimbladder