Copied!
Mok, Hin-Kiu
Gilmore, R. Grant
Bulletin of the Institute of Zoology, Academia Sinica
1983
22
2
157–186
0001-3943
English
Select Fish:
Detection
Species Identified
Sound Detected
Examination Types
Morphophysiological
Auditory
Visual
Sound Types Detected
Active
Passive Feeding
Other Passive
Full Description
"Pogonias cromis produced two principal sound types characterized as a"loud drum'' and a"short grunt", while B. chrysoura produced a series of sound combinations all based on a sequence of"knocks". Cynoscion nebulosus produced a complex series of sounds characterized as"grunts","knocks"and"staccato". Diel and seasonal changes in sound production associated with specific recording locations were also determined. Maximum daily sound production for all three species occurred between 1700 and 2200 hr and was coincidental with the appearance of eggs and larvae in the water column at the recording sites. Seasonal peaks in sound production occurred during the winter for P. cromis, spring for B. chrysoura and spring to summer for C. nebulosus. Peak sound production in all species occurred at specific locations and time periods coincidentally with the known principal spawning period for the species. All three species were found to produce sounds of maximum intensity in the deeper portions of the estuary along the Intracoastal Waterway."
"When a black drum was hand-held or disturbed in captivity, it produced a"staccato"sound. This sound type was composed of a series of units (Fig. 3A) with energy mainly limited below 400 Hz; repetition rate of the unit reached 14 units/sec. Besides this"staccato"sound, P. cromis produced at least two other sound types in natural conditions. One was the"loud drum"sound (Fig. 3B-D) and the other was the"short grunt"sound (Fig. 4). Each sound type was emitted repeatedly. The occurrence of"short grunt"sound varied with seasons (see below). When they occurred, one or two"loud drum"sounds was frequently mingled with a long series of"short grunt"sounds (Fig. 4). For the"loud drum"sound, the order of harmonics, fundamental frequency, and the energy content at each order of harmonics were variable. In a sample of 194"loud drum"sounds, the number of harmonics recognizable from the sonograms ranged from 3 to 13 (Table 1). At one extreme, order of harmonics reached 19. Only the high harmonic bands were missing in those sounds with a lower number of harmonics. Frequency of the"loud drum"sound ranged from 100 to 1850 Hz. Frequency ranges of the first five orders of harmonics are listed in Table 2."
"The"loud drum"sound can be divided into two subgroups. The first group sounds like the word"boon"and the second one sounds like the word"bound"(Fig. 3C) . The"bound"sound which is usually louder than the"boon"sound has energy spreading to higher frequency range."
"The"loud drum"sound can be put into two subgroups differing in their duration as shown in two normal distributions which peaked in 216 msec and 280 msec, respectively, with an overlapping area at approximately 250 msec (Fig. 6)."
"In a two-sound series the interval (duration between the beginnings of two immediately adjacent sounds) was 960 msec. In a threesound series the intervals were 4850 and 1000 msec, respectively (listed from the beginning interval to the last interval). In a five-sound series the intervals were 1750, 2280, 610, 2700 msec, respectively."
"In the"short grunt"sounds most sound energy were restricted to a band at about 200 Hz (Fig. 4A, B), although some energy was contentrated near 140 Hz (Fig. 4B). Very little energy was found at higher frequencies. This sound lasted about 300 msec."
Observation Environment Quotes
"From December 1979 to June 1980 hydrophone recordings were made of sounds produced by the black drum, Pogonias cromis, silver perch, Bairdiella chrysoura and spotted seatrout, Cynoscion nebulosus in the Indian River lagoon, east-central Florida, U.S. A."
Behaviour Description Quotes
"The present data set documents sounds produced by P. cromis, B. chrysoura, and C. nebulosus within the Indian River lagoon illustrated in oscillograms, sonograms, and spectrograms which were used to characterize both individual and aggregate sounds of these species."
"When a black drum was hand-held or disturbed in captivity, it produced a 'staccato' sound."
Sound Name Quotes
"Pogonias cromis produced two principal sound types characterized as a 'loud drum"
" and a 'short grunt', while B. chrysoura produced a series of sound combinations all based on a sequence of 'knocks'. Cynoscion nebulosus produced a complex series of sounds characterized as 'grunts', 'knocks' and 'staccato'. Diel and seasonal changes in sound production associated with specific recording locations were also determined. Maximum daily sound production for all three species occurred between 1700 and 2200 hr and was coincidental with the appearance of eggs and larvae in the water column at the recording sites. Seasonal peaks in sound production occurred during the winter for P. cromis, spring for B. chrysoura and spring to summer for C. nebulosus. Peak sound production in all species occurred at specific locations and time periods coincidentally with the known principal spawning period for the species. All three species were found to produce sounds of maximum intensity in the deeper portions of the estuary along the Intracoastal Waterway."
"For the 'loud drum' sound, the order of harmonics, fundamental frequency, and the energy content at each order of harmonics were variable."
Observation Environments
Wild
Behaviour Descriptions
Aggregations
Disturbance
Sound Names
Drum
Grunt Thump
Staccato
Aggregation
Tonal Harmonic
Included Diagrams
Spectrogram
"Four types of C. nebulosus sounds were recorded in the lagoon. They are designated as ( 1) a"grunt"followed by a series of"knocks", (2)"aggregated grunts", (3)"long grunt", and (4)"staccato". The first sound type was recorded in the Link Port Study Area (slightly north of Station 7; Fig. 17) and was composed of a train of calls each of which was led by a single"grunt"followed by a series of"knocks"(Figs. 17, 18A; long arrow indicates this leading grunt). The duration of the leading grunt ranged from 70 to 140 msec with a mean of 114 msec (N =69). The"knocks"were shorter than the leading grunts, ranging from 51 to 97 msec with a mean of 75 msec (N=l20). In 71 calls analysed durations of all"knocks"within the same call were similar. Most calls contained two"knocks". The occurrence of various numbers of"knocks"(k) per call are listed in an increasing order as follows: lk=20, 2k=34, 3k=8, 4k=2, 5k= 1 and"rapid staccato"=6. The last category represents a series of closely placed"knocks"(k:26; Fig. 18A; short arrow indicates these knocks). The intervals between two closest"knocks"in a"rapid staccato"were shorter than other calls with 2k (or two knocks) to 5k. As a result, individual"knocks"could not be easily distinguished by examining the sonogram (e. g., Fig. 18A). Durations of a sample of"rapid staccatos"were measured and found to have a mean of 365 msec. (185 to 1180 msec). Interval between two adjacent calls as measured from the end of one call to the beginning of the leading"grunt"of the following call peaked at a mean value of 335 msec (305 to 380 msec; Fig. 19). This interval was subjected to rather high variation."
"Frequency composition of the leading"grunt"and the following"knocks"were quite similar (Fig. 17). The frequency ranged from 300 to 1350 Hz and there was a discontinuous frequency band or low energy band around 500 to 900 Hz (Fig. 17). Most of the calls examined had the lower and upper frequencies located at 300 and 1000 Hz, respectively (Fig. 17). For the discontinuous frequency band, the lower and upper frequencies were 600 and 700 Hz, respectively (Fig. 17). Fr.qu~cy range and amplitude of adjacent calls were similar in most cases. However, changes in these characters were noted in some instances (Fig. 17). The calls recorded earlier in the series were higher in frequency range but lower in amplitude, whereas those appeared later in the series were lower in frequency range but higher in amplitude (Fig. 17). Oscillograms of a single leading"grunt"showed three to four wave groups, each similar in temporal amplitude change (Fig. 20). In the early part of a wave group sound intensity changed rapidly and significantly (Fig. 20;"a"represents this part of the wave group). Rate and degree of intensity change reduced toward the end of a wave group (Fig. 20;"b"represented this part of the wave group). Among other sound types of C. nebulosus,"aggregated grunts"occurred most frequently, whereas the"staccato"and"long gn.:nt"were occasionally mixed in a chain of"aggregated grunts". The"long grunt"appeared more often than the"staccato". These sounds can best be distinguished by their time-amplitude wave forms (see below)."Aggregated grunts"were composed of several closely placed grunts (2 to 7, mostly 2 grunts; Fig. 18C). Individual grunts lasted a mean of 110 msec (Fig. 21 ). Duration of the"aggregation grunts"was variable; it ranged from 206 to 845 msec (mean 440 msec; Fig. 22). Most sound energy was distributed from 220 to 600 Hz with some energy dispersed to the higher frequencies (Fig. 18B, C; Fig. 23AC). The loud group-sound of"aggregated grunts"is characterized by an energy band from 150 to 650 Hz (Fig. 23D, E). No consistent time-amplitude waveform of the"aggregated grunts"was noted except that the middle wave group consistently showed three peaks of amplitude change (Figs. 24B, 25; dotted line in the later figure indicates these peaks). In the"long grunt"peak wave amplitudes did not vary significantly throughout the sound (Fig. 24A, C). Two wave groups appeared alternatively at the mid portion of the"long grunt". The first wave group consists of one to two peaks followed by a much longer peak (Fig. 26B, C, F; section"a"). The second wave group is composed of t.vo (rarely three) long peaks (Fig. 26B, C; section"b"). No predictable waveform was seen at the beginning and end of the sound (Fig. 26A, D, and E). Durations of the"long grunts"ranged from 400 to 500 msec. Sound energy was spread to several narrow bands (harmonic sound) from 200 to 1400 Hz (Fig. 18B, D, E). The frequencies of the"long grunt"were higher than those of the"staccato"and"aggregated grunts"(Fig. 18B). The"staccato"consisted of a chain of similar components, each representing a series of rapid amplitude change (Figs. 24D, E, 27A; arrows in the latter figure point to three ofthe wave groups composing a"staccato"). Peak amplitude increased and reached its maximum value in the mid section of the component wave group and then decreased (Figs. 24D. E, 27 A). Duration of these wave groups ranged around 30 msec. Intervals between two adjacent wave groups were variable but were usually less than 10 msec (Fig. 27A). Maximum amplitudes of these wave groups in the same"staccato"sound did not vary much (Fig. 27A). No specific pattern of intensity change at any particular part of the"staccato"was observed (Fig. 27B-D). Energy in the"staccato"was distributed from 200 to 600 Hz; most of this energy was limited to a broad band ranging from 200 to 350 Hz and a narrow band at a higher frequency of 500 to 600 Hz (Fig. 188, F). Reduction in energy content was observed in the frequencies between these bands and also above the upper narrow band (between 500 and 600 Hz). The energy distribution pattern of the"staccato"differed from that of the first sound type of C. nebulosus, i.e., the leading grunt plus a succeeding series of"knocks", by having two recognizable broad bands with no energy between them."
"Four types of C. nebulosus sounds were recorded in the lagoon. They are designated as ( 1) a 'grunt' followed by a series of 'knocks', (2) 'aggregated grunts', (3) 'long grunt', and (4) 'staccato'. The first sound type was recorded in the Link Port Study Area (slightly north of Station 7; Fig. 17) and was composed of a train of calls each of which was led by a single 'grunt' followed by a series of 'knocks' (Figs. 17, 18A; long arrow indicates this leading grunt). The duration of the leading grunt ranged from 70 to 140 msec with a mean of 114 msec (N =69)."
Knock
Complex Call
"The calls of B. chrysoura were composed of various numbers of"knocks"(Figs. 9A, lOA, B). For a majodty of calls, the number of"knocks"ranged from 2 to 26 (mode=8, N =60)."Knocks"belonging to the same call were usually equal 10 duration (Fig. 9A). The duration of each"knock"ranged from 34 to 70 msec, with a frequency peak near 53 to 56 msec (Fig. llA). No clear association between the number of"knocks"per call and the duration of the"knock"was noted (Fig. 11 A). In terva Is between the two nearest"knocks"(measured from the end of one"knock"to the beginning of the following"knock") within the same call were usually similar. However, in many cases this interval was shorter between those"knocks"in the early part of the call (Fig. 9A). The mean duration of this interval was estimated to be 80 to 90 msec with the lower and upper ranges to be 42 and 204 msec, respectively (Fig. 12). No obvious association was observed between the number of"knocks"per call and the duration of the interval (Fig. 118). Frequency compositioo of the calls was variable. On the basis of sound energy distribution within treir frequency range, the calls were classified into three types: Type 1. Sound energy is spread almost continously from about 330 to 2900Hz (Fig. 13A). Tyre 2. Most sound energy is limited to a particular frequency and can be sorted into two sub-types: (A) Sound energy is limited between 200 and 1900 Hz (Fig. 13B). (B) Most energy is distributed in a narrower and lower frequency range in comparison to (A), i.e., from 500 to 1200 Hz (Figs. 13C, D and 9A, B). Type 3. Sound energy is reduced in some frequency ranges such that distinguishable narrow high energy bands appear at particular frequencies (e. g., at 700, 1000, 2000 Hz or at 400 and 700 Hz; Fig. 13E, F)."
"It can be concluded that the width of this band and its lower and upper frequency ranges were variable and for B. chrysoura, it may best be defined from 550 to 1800 Hz."