Full Description

"THE oyster toadfish Opsanus tau produces two sounds, an agonistic grunt and a courtship boatwhistle [7,16], by contracting a specialized pair of sonic muscles [10,15] intrinsic to the swimbladder [3]."

"The first case comes from electric stimulation of the brain. The following grunt [4] is a short or long series of pulses with a stereotyped pattern occurring after cessation of the electric stimulus. A similar natural sound is occasionally heard (personal observation), but its function is unknown. Some of the pulses in a following grunt can have greater amplitude and higher frequency components than others (Fig. 1A)."

"Secondly, the toadfish does not typically produce sounds of different amplitudes. One can listen to an individual calling male for long periods and, depending on variations in the background noise, boatwhistles will not vary more than a few dB on the VU meter of a tape recorder. Thirdly, a calling fish demonstrates increased motivation by calling faster rather than louder [7, 9,17, 18]."

"On rare occasions, grunts in the field (Fig. 1B) are emitted with pulses of two different amplitudes."

"(B) Excerpt from a sequence of grunts recorded in the Broadkil River, Lewes, Delaware, 29 July 1968. (C, D and E) Boatwhistles recorded in Narrow River, Rhode Island, 6 June 1974: (C) typical call; (D) boatwhistle with a grunt in the middle; (E) oscillogram of selection D. All sonograms made with a 1500 Hz scale and a wide band filter except selection A which used a narrow band filter."

"A normal field-recorded boatwhistle begins and ends with an asynchronous gruntlike portion and consists of a fundamental frequency, generated at the muscle contraction rate, and higher order harmonics (Fig. 1C). Occasional boatwhistles have a grunt interposed between the rise-fall portion of the call (Fig. 1D, E). Repetition of this same call pattern eliminates the possibility that the grunt is produced by a nearby fish."

"A toadfish sonic muscle would be similarly restricted, yet Fig. 1D demonstrates that the tonal portion of the boatwhistle continues during the grunt."

Observation Environment Quotes

"The first case comes from electric stimulation of the brain."

"On rare occasions, grunts in the field (Fig. 1B) are emitted with pulses of two different amplitudes."

"(B) Excerpt from a sequence of grunts recorded in the Broadkil River, Lewes, Delaware, 29 July 1968. (C, D and E) Boatwhistles recorded in Narrow River, Rhode Island, 6 June 1974: (C) typical call; (D) boatwhistle with a grunt in the middle; (E) oscillogram of selection D."

Behaviour Description Quotes

"THE oyster toadfish Opsanus tau produces two sounds, an agonistic grunt and a courtship boatwhistle [7,16], by contracting a specialized pair of sonic muscles [10,15] intrinsic to the swimbladder [3]. "

"The first case comes from electric stimulation of the brain."

"The following grunt [4] is a short or long series of pulses with a stereotyped pattern occurring after cessation of the electric stimulus. A similar natural sound is occasionally heard (personal observation), but its function is unknown."

Sound Name Quotes

"THE oyster toadfish Opsanus tau produces two sounds, an agonistic grunt and a courtship boatwhistle [7,16], by contracting a specialized pair of sonic muscles [10,15] intrinsic to the swimbladder [3]. "

"The first case comes from electric stimulation of the brain. The following grunt [4] is a short or long series of pulses with a stereotyped pattern occurring after cessation of the electric stimulus. A similar natural sound is occasionally heard (personal observation), but its function is unknown. Some of the pulses in a following grunt can have greater amplitude and higher frequency components than others (Fig. 1A). "

"One can listen to an individual calling male for long periods and, depending on variations in the background noise, boatwhistles will not vary more than a few dB on the VU meter of a tape recorder. "

"A normal field-recorded boatwhistle begins and ends with an asynchronous gruntlike portion and consists of a fundamental frequency, generated at the muscle contraction rate, and higher order harmonics (Fig. 1C)."