Full Description

"Seasonal variation of sound production, which includes boatwhistles, grunts, croaks and double croaks, was studied in the Lusitanian toadfish Halobatrachus didactylus. Boatwhistles were emitted during the mating season in contrast with the other sound types, which were emitted all year round."

"Boatwhistles emitted by the Lusitanian toadfish are tonal sounds, c. 800 ms long, which start and end with a grunt-like portion. The fundamental frequency is c. 60 Hz and dominant frequencies are typically either the second or the fourth harmonic (pers. obs.) (Fig. 1). Grunts are short drumming sounds emitted in trains (typically eight grunts per grunt train) with dominant frequencies around 300 Hz (Fig. 1). Croaks are low frequency pulsed sounds emitted in isolation; they are longer and present higher dominant frequencies (around 650 Hz) than individual grunts and, unlike double croaks, do not show amplitude or frequency modulation (dos Santos et al., 2000). In contrast, double croaks are made up of two croak-like elements that present both amplitude and frequency modulation, with typical durations of c. 90 ms (each) and dominant frequencies around 500 Hz (Fig. 1)."

"Total boatwhistle duration (n = 100, rs = 0.46, P < 0.001) and tonal phase (TP) duration (n = 100, rs = 0.37, P < 0.001) significantly increased with temperature."

Observation Environment Quotes

"Recordings of the Lusitanian toadfish sounds were made from piers in two areas within the Tagus estuary, Portugal: Montijo (38°429 N; 8°589 W) and Barreiro (38°399 N; 9°049 W)."

Behaviour Description Quotes

"Dos Santos et al. (2000) have suggested, in analogy to other batrachoidids, that boatwhistles are mating signals whereas the other sound types are probably agonistic. "

"Grunts and double croaks were emitted all year round and showed a pronounced emission peak at the start of the breeding season. It is likely that these sound types are agonistic signals and may play a role in territorial establishment by nesting males."

Sound Name Quotes

"Seasonal variation of sound production, which includes boatwhistles, grunts, croaks and double croaks, was studied in the Lusitanian toadfish Halobatrachus didactylus. Boatwhistles were emitted during the mating season in contrast with the other sound types, which were emitted all year round."

" Boatwhistles emitted by the Lusitanian toadfish are tonal sounds, c. 800 ms long, which start and end with a grunt-like portion. The fundamental frequency is c. 60 Hz and dominant frequencies are typically either the second or the fourth harmonic (pers. obs.) (Fig. 1). Grunts are short drumming sounds emitted in trains (typically eight grunts per grunt train) with dominant frequencies around 300 Hz (Fig. 1). Croaks are low frequency pulsed sounds emitted in isolation; they are longer and present higher dominant frequencies (around 650 Hz) than individual grunts and, unlike double croaks, do not show amplitude or frequency modulation (dos Santos et al., 2000). In contrast, double croaks are made up of two croak-like elements that present both amplitude and frequency modulation, with typical durations of c. 90 ms (each) and dominant frequencies around 500 Hz (Fig. 1)."