Full Description

"Lusitanian toadfish males that provide parental care rely on acoustic signals (the boatwhistle) to attract females to their nest. We test the hypothesis that male quality, namely male size and condition that are relevant for parental success, is reflected in vocal activity and boatwhistle characteristics and thus advertised to females."

"The Lusitanian toadfish Halobatrachus didactylus (Bloch and Schneider 1801) produces a long (about 1s) tonal low-frequency advertisement sound, the boatwhistle, which is highly stereotyped and shows considerable inter-individual differences during short periods of time (<10min) (Amorim and Vasconcelos, 2008)."

"Breeding males of the Lusitanian toadfish, H. didactylus, form conspicuous choruses from May to July (in Portugal) and defend nests in estuarine shallow waters that can contain clutches from different females (Amorim et al., 2006)."

"All males produced boatwhistles (BW) during the study period but calling rate varied markedly among males and within males. The average calling rate varied from 0.1 to 361.7BWh–1 per male (overall mean calling rate=39.9BWh–1; Table2). Only seven out of the 22 recorded males exhibited average calling rates higher than 10BWh–1 during the study period, and the maximum calling rate observed for each male varied between 2 and 1071BWh–1 (mean=244.5BWh–1). Males vocalised for a different number of days [mean (range)=5 (2–8)] and for a different number of hours (calling effort, Table2) but remained in silence most of the time."

"Here, we have shown that calling rate, calling effort, pulse period and amplitude modulation may honestly signal male quality, namely male condition, spawning readiness and sonic muscle hypertrophy in a batrachoidid."

Observation Environment Quotes

"Sixty artificial hemicylinder-shaped concrete shelters capped at one end were deployed 1.5_m apart in an intertidal area of the Tagus estuary (Portugal, Montijo, Air-Force Base 6; 38°42N, 8°58W) that was only exposed to air during spring low tides. Water level varied between 0_m and 2.8_m in the study area. The shelters were large enough (internal dimensions: 50_cm long 30_cm wide 20_cm high) to house a large male and several females and were readily used as nests during the breeding season (Amorim et al., 2010). Three groups of 6–8 males (N_22) that spontaneously occupied these artificial concrete shelters were recorded over a period of eight days in June and July in 2006 and 2007, during the peak of the reproductive season (May to July in Portugal) (Modesto and Canário, 2003a). Shelters (6–8) containing subject males were placed 1.5_m apart in two rows and were at least 15_m apart from the remaining shelters. The entrance of the subject males’ shelters were closed with a plastic mesh preventing fish from abandoning the nest during recordings but allowing prey items to enter and possible visual interactions with conspecifics."

Behaviour Description Quotes

"Lusitanian toadfish males that provide parental care rely on acoustic signals (the boatwhistle) to attract females to their nest. We test the hypothesis that male quality, namely male size and condition that are relevant for parental success, is reflected in vocal activity and boatwhistle characteristics and thus advertised to females."

" Vasconcelos et al. (Vasconcelos et al., 2010) have shown that the Lusitanian toadfish also emits boatwhistles during territorial intrusions by other males but these lack amplitude modulation, which seems characteristic of a mating context."

Sound Name Quotes

"Lusitanian toadfish males that provide parental care rely on acoustic signals (the boatwhistle) to attract females to their nest. We test the hypothesis that male quality, namely male size and condition that are relevant for parental success, is reflected in vocal activity and boatwhistle characteristics and thus advertised to females."

". Because pulse period had low variability, consistent with the existence of a vocal central pattern generator, we suggest that males that sustain sonic muscles contraction at a very fast rate close to their physiological limit may be honestly advertising their quality (condition)."

"The Lusitanian toadfish Halobatrachus didactylus (Bloch and Schneider 1801) produces a long (about 1s) tonal low-frequency advertisement sound, the boatwhistle, which is highly stereotyped and shows considerable inter-individual differences during short periods of time (<10min) (Amorim and Vasconcelos, 2008)."

"Breeding males of the Lusitanian toadfish, H. didactylus, form conspicuous choruses from May to July (in Portugal) and defend nests in estuarine shallow waters that can contain clutches from different females (Amorim et al., 2006)."