title: Agonistic sounds signal male quality in the Lusitanian toadfish.
abstract: Acoustic communication during agonistic behaviour is widespread in fishes. Yet, compared to other taxa, little is known on the information content of fish agonistic calls and their effect on territorial defence. Lusitanian toadfish males (Halobatrachus didactylus) are highly territorial during the breeding season and use sounds (boatwhistles, BW) to defend nests from intruders. BW present most energy in either the fundamental frequency, set by the contraction rate of the sonic muscles attached to the swimbladder, or in the harmonics, which are multiples of the fundamental frequency. Here we investigated if temporal and spectral features of BW produced during territorial defence reflect aspects of male quality that may be important in resolving disputes. We found that higher mean pulse period (i.e. lower fundamental frequency) reflected higher levels of 11-ketotestosterone (11KT), the main teleost androgen which, in turn, was significantly related with male condition (relative body mass and glycogen content). BW dominant harmonic mean and variability decreased with sonic muscle lipid content. We found no association between BW duration and male quality. Taken together, these results suggest that the spectral content of fish agonistic sounds may signal male features that are key in fight outcome.
authors.affiliation: MARE - Marine and Environmental Sciences Centre, ISPA - Instituto Universitário, Lisbon, Portugal. Electronic address: amorim@ispa.pt.
authors.forename: M Clara P
authors.initials: MC
authors.lastname: Amorim
authors.affiliation: MARE - Marine and Environmental Sciences Centre, ISPA - Instituto Universitário, Lisbon, Portugal. Electronic address: conticarlotta@hotmail.it.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Conti
authors.affiliation: Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8000-810 Faro, Portugal. Electronic address: tmodesto@ualg.pt.
authors.forename: Teresa
authors.initials: T
authors.lastname: Modesto
authors.affiliation: Division of Aquaculture and Upgrading, Portuguese Institute for the Sea and Atmosphere, I.P. (IPMA, I.P.), Lisbon, Portugal. Electronic address: amparo@ipma.pt.
authors.forename: Amparo
authors.initials: A
authors.lastname: Gonçalves
authors.affiliation: Departamento de Biologia Animal and cE3c - Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal. Electronic address: pjfonseca@fc.ul.pt.
authors.forename: Paulo J
authors.initials: PJ
authors.lastname: Fonseca
mesh_terms: D000162:Acoustics; D000305:Adrenal Cortex Hormones / Q000097:blood; D000378:Agonistic Behavior / Q000502:physiology*; D000818:Animals; D005399:Fishes / Q000502:physiology*; D006003:Glycogen / Q000378:metabolism; D006854:Hydrocortisone / Q000097:blood; D008055:Lipids / Q000032:analysis; D008297:Male; D011863:Radioimmunoassay; D013057:Spectrum Analysis; D013731:Territoriality; D013739:Testosterone / Q000097:blood; D014828:Vocalization, Animal / Q000502:physiology*
chemical_list: D000305:Adrenal Cortex Hormones; D008055:Lipids; D013739:Testosterone; D006003:Glycogen; D006854:Hydrocortisone
keywords: Acoustic communication; Fish; Spectral cues; Steroid hormones; Temporal cues; Territorial defence