title: Sound production in Onuxodon fowleri (Carapidae) and its amplification by the host shell.
abstract: Onuxodon species are well known for living inside pearl oysters. As in other carapids, their anatomy highlights their ability to make sounds but sound production has never been documented in Onuxodon. This paper describes sound production in Onuxodon fowleri as well as the anatomy of the sound production apparatus. Single-pulsed sounds and multiple-pulsed sounds that sometimes last more than 3 s were recorded in the field and in captivity (Makemo Island, French Polynesia). These pulses are characterized by a broadband frequency spectrum from 100 to 1000 Hz. Onuxodon fowleri is mainly characterized by its ability to modulate the pulse period, meaning that this species can produce pulsed sounds and tonal-like sounds using the same mechanism. In addition, the sound can be remarkably amplified by the shell cavity (peak gain can exceed 10 dB for some frequencies). The sonic apparatus of O. fowleri is characterized by a rocker bone in front of the swimbladder, modified vertebrae and epineurals, and two pairs of sonic muscles, one of which (primary sonic muscle) inserts on the rocker bone. The latter structure, which is absent in other carapid genera, appears to be sexually dimorphic suggesting differences in sound production in males and females. Sound production in O. fowleri could be an example of adaptation where an animal exploits features of its environment to enhance communication.
authors.affiliation: Laboratoire de Morphologie Fonctionnelle et Evolutive Liège, Institut de Chimie, B6c, 4000 Liège, Belgium. Loic.Kever@ulg.ac.be.
authors.forename: Loïc
authors.initials: L
authors.lastname: Kéver
authors.affiliation: Laboratoire de Morphologie Fonctionnelle et Evolutive Liège, Institut de Chimie, B6c, 4000 Liège, Belgium.
authors.forename: Orphal
authors.initials: O
authors.lastname: Colleye
authors.affiliation: Dipartimento di Neuroscienze, Universitá di Parma, 43100 Parma, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Lugli
authors.affiliation: USR 3278 CNRS-EPHE-UPVD, CRIOBE, BP1013 Papetoai, 98729 Moorea, French Polynesia. Laboratoire d'Excellence 'CORAIL', BP1013 Papetoai, 98729 Moorea, French Polynesia.
authors.forename: David
authors.initials: D
authors.lastname: Lecchini
authors.affiliation: USR 3278 CNRS-EPHE-UPVD, CRIOBE, BP1013 Papetoai, 98729 Moorea, French Polynesia.
authors.forename: Franck
authors.initials: F
authors.lastname: Lerouvreur
authors.affiliation: UMR 7179 CNRS/MNHN, Département d'Ecologie et de Gestion de la Biodiversité, 57 rue Cuvier, Case Postale 55, 75231, Paris Cedex 5, France. Ghent University, Evolutionary Morphology of Vertebrates, K.L. Ledeganckstraat 35, B-9000 Ghent, Belgium.
authors.forename: Anthony
authors.initials: A
authors.lastname: Herrel
authors.affiliation: Laboratoire de Morphologie Fonctionnelle et Evolutive Liège, Institut de Chimie, B6c, 4000 Liège, Belgium.
authors.forename: Eric
authors.initials: E
authors.lastname: Parmentier
mesh_terms: D000400:Air Sacs / Q000033:anatomy & histology; D000819:Animal Communication; D060105:Animal Shells; D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology; D017753:Ecosystem; D005260:Female; D005399:Fishes / Q000033:anatomy & histology* / Q000502:physiology*; D008297:Male; D009132:Muscles / Q000033:anatomy & histology; D049911:Pinctada; D011114:Polynesia; D013016:Sound; D014828:Vocalization, Animal
keywords: Carapidae; Morphology; Pearl Oyster; Rocker bone; Sound