title: Behaviours associated with acoustic communication in Nile tilapia (Oreochromis niloticus).
abstract: BACKGROUND
  Sound production is widespread among fishes and accompanies many social interactions. The literature reports twenty-nine cichlid species known to produce sounds during aggressive and courtship displays, but the precise range in behavioural contexts is unclear. This study aims to describe the various Oreochromis niloticus behaviours that are associated with sound production in order to delimit the role of sound during different activities, including agonistic behaviours, pit activities, and reproduction and parental care by males and females of the species.
  
  
  RESULTS
  Sounds mostly occur during the day. The sounds recorded during this study accompany previously known behaviours, and no particular behaviour is systematically associated with sound production. Males and females make sounds during territorial defence but not during courtship and mating. Sounds support visual behaviours but are not used alone. During agonistic interactions, a calling Oreochromis niloticus does not bite after producing sounds, and more sounds are produced in defence of territory than for dominating individuals. Females produce sounds to defend eggs but not larvae.
  
  
  CONCLUSIONS
  Sounds are produced to reinforce visual behaviours. Moreover, comparisons with O. mossambicus indicate two sister species can differ in their use of sound, their acoustic characteristics, and the function of sound production. These findings support the role of sounds in differentiating species and promoting speciation. They also make clear that the association of sounds with specific life-cycle roles cannot be generalized to the entire taxa.
authors.affiliation: Laboratory of Functional and Evolutionary Morphology, University of Liège, Liège, Belgium.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Longrie
authors.forename: Pascal
authors.initials: P
authors.lastname: Poncin
authors.forename: Mathieu
authors.initials: M
authors.lastname: Denoël
authors.forename: Vincent
authors.initials: V
authors.lastname: Gennotte
authors.forename: Johann
authors.initials: J
authors.lastname: Delcourt
authors.forename: Eric
authors.initials: E
authors.lastname: Parmentier
mesh_terms: D000162:Acoustics; D000818:Animals; D023681:Cichlids / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D008297:Male; D013018:Sound Spectrography; D013731:Territoriality; D014828:Vocalization, Animal / Q000502:physiology*