Full Description

"Because of apparent reproductive isolation between Northern and Southern hemisphere populations of the black drum Pogonius cromis, we tested the hypothesis that advertisement calls from a southern population would differ from known calls of North American populations. Additionally, we quantified disturbance and advertisement calls, their changes with fish size and sex, not previously examined in this species. Unlike most sciaenids, both sexes of P. cromis possess robust sonic muscles, and both produce disturbance calls when handled. However, only males produce an advertisement call used in courtship. The disturbance call consists of a variable train of short-duration pulses (average 23 ms). The duration, interpulse interval, and dominant frequency of pulses are similar in males and females and change developmentally: pulse duration and interpulse interval increase and dominant frequency decreases with fish size. Advertisement calls, recorded in the field and in captivity, are long-duration (average 184 ms) and tonal. Based on variation in fundamental frequency, which decreases with fish size, field choruses are composed of differentsized individuals."

"During the reproductive season, black drum, P. cromis and most other male sciaenids produce drumming sounds, which is used as an advertisement call (Tower, 1908; Burkenroad, ’31; Fish and Mowbray, ’70; Tavolga, ’71; Mok and Gilmore, ’83; Saucier and Baltz, ’93; Locascio and Mann, 2009)."

". Disturbance calls were recorded from individual fish held in a hand net 1 m from the hydrophone underwater, after which LT was measured."

"We analyzed sounds from field choruses and from 18 captive individuals. Both sexes emitted a disturbance call (n = 18), but advertisement calls were emitted only by males (n = 6), the same animals were used in the recording of these two calls."

"Disturbance calls were recorded individually (n = 18) in a canvas tank when fish were handled. Calls consisted of trains of 3–12 pulses emitted in 1–3 bursts (Fig. 2). The duration, interpulse interval, and dominant frequency of pulses averaged 24 ms, 22 ms, 131 Hz for males, and 23 ms, 23 ms, 139 Hz for females, respectively (Table 1). These differences were not significant for pulse duration (P = 0.351), interpulse interval (P = 0.756), and dominant frequency (P = 0.199). Train durations were similar in both sexes (P = 0.78) and averaged 0.44+-0.22 and 0.52+-0.25 s for males and females, respectively. Pulse duration and interpulse interval increased significantly with LT for males and females (Table 2, Fig. 3) and dominant frequency decreased significantly in both sexes (Table 2, Fig. 3)."

"Each captive male produced a series of three advertisement calls. Additional males were captured in the spawning area were also spermiating, and many briefly emitted an advertisement call in the net, but females in spawning condition with hydrated oocytes never produced the advertisement call. Field-recorded advertisement calls were long-duration and tonal with various amplitude envelopes. Maximum amplitude typically occurred abruptly near call onset and exhibited various patterns of attenuation. Expanded waveforms indicate a near constant period between cycles (i.e. muscle contraction rate) over time. The waveform period in a 59-cm LT male was 7.7 ms for both the disturbance and advertisement call indicating that the muscle is contracting at the same rate in both, and this value agrees with the fundamental frequency found on the power spectrum. Advertisement calls had durations, inter-call intervals, and dominant frequencies of 184 ms, 82 ms, and 128 Hz, respectively (Table 3). In general size, effects on call parameters mirrored those found for disturbance calls."

"Dominant frequency of calls recorded in the field varied from 120 to 250 Hz, therefore suggesting choruses of different-sized males."

"Advertisement calls were recorded between 16:00 and 22:00 hr in Piriapolis Harbor, and between 20:00 and 23:00 hr in Pando Stream and Santa Lucia River during the summer spawning season (December, January, 2007–2009) (Fig. 1). Water temperatures varied between 18 and 24C, and salinity between 20 and 27/oo. Advertisement calls were absent during the autumn, winter, and spring cold period (April–September; 11–14C, 2–10/oo) in all study areas."

"We recorded two different sounds produced by black drum, a disturbance call—the ‘‘staccato’’ of Mok and Gilmore (’83)— produced by both sexes and an advertisement or courtship call produced exclusively by males."

"Although similar in fundamental frequency and waveform, the advertisement calls of the black drum in Uruguay have shorter call durations (between 120 and 200ms than calls from the same species in the Northern hemisphere). Florida population has durations that are over three-fold longer (600+-22 ms) (Mok and Gilmore, ’83; Locasico and Mann, 2009). In addition, the analysis of the duration of 48 calls recorded off the coast of Georgia, shows a mean call duration of 0.396+-0.009 s (Aaron Rice, personal communication). This difference suggests that the Northern and Southern hemisphere populations have diverged genetically since fish sounds appear to be genetically controlled (Johnston, 2006; Longrie et al., 2008)."

Observation Environment Quotes

"Black drum were recorded between October and March of 2008 and 2009. A hydrophone was placed above a big group of black drum in the Santa Lucia River, Pando stream, Piriapolis Harbor during the peak spawning season between October and December (Macchi et al., 2002). Hydrophone depth was 1–2 m below the surface, and recordings were made at several positions at each site (Fig. 1). Eighteen individuals were recorded (eight in February 2008 and ten in December 2009) in 3000-l canvas tanks (3 1.5 0.60 m) on board the research vessel or in a fish pen in shallow water. These captive recordings verify the sound producer explicitly."

Behaviour Description Quotes

"Because of apparent reproductive isolation between Northern and Southern hemisphere populations of the black drum Pogonius cromis, we tested the hypothesis that advertisement calls from a southern population would differ from known calls of North American populations. Additionally, we quantified disturbance and advertisement calls, their changes with fish size and sex, not previously examined in this species. Unlike most sciaenids, both sexes of P. cromis possess robust sonic muscles, and both produce disturbance calls when handled. However, only males produce an advertisement call used in courtship. The disturbance call consists of a variable train of short-duration pulses (average 23 ms). The duration, interpulse interval, and dominant frequency of pulses are similar in males and females and change developmentally: pulse duration and interpulse interval increase and dominant frequency decreases with fish size. Advertisement calls, recorded in the field and in captivity, are long-duration (average 184 ms) and tonal. Based on variation in fundamental frequency, which decreases with fish size, field choruses are composed of differentsized individuals. "

". Disturbance calls were recorded from individual fish held in a hand net 1 m from the hydrophone underwater, after which LT was measured."

Sound Name Quotes

"Because of apparent reproductive isolation between Northern and Southern hemisphere populations of the black drum Pogonius cromis, we tested the hypothesis that advertisement calls from a southern population would differ from known calls of North American populations. Additionally, we quantified disturbance and advertisement calls, their changes with fish size and sex, not previously examined in this species. Unlike most sciaenids, both sexes of P. cromis possess robust sonic muscles, and both produce disturbance calls when handled. However, only males produce an advertisement call used in courtship. The disturbance call consists of a variable train of short-duration pulses (average 23 ms). The duration, interpulse interval, and dominant frequency of pulses are similar in males and females and change developmentally: pulse duration and interpulse interval increase and dominant frequency decreases with fish size. Advertisement calls, recorded in the field and in captivity, are long-duration (average 184 ms) and tonal. Based on variation in fundamental frequency, which decreases with fish size, field choruses are composed of differentsized individuals. "

"During the reproductive season, black drum, P. cromis and most other male sciaenids produce drumming sounds, which is used as an advertisement call (Tower, 1908; Burkenroad, ’31; Fish and Mowbray, ’70; Tavolga, ’71; Mok and Gilmore, ’83; Saucier and Baltz, ’93; Locascio and Mann, 2009).' 'Disturbance calls were recorded individually (n = 18) in a canvas tank when fish were handled. Calls consisted of trains of 3–12 pulses emitted in 1–3 bursts (Fig. 2). "

"We recorded two different sounds produced by black drum, a disturbance call—the ‘‘staccato’’ of Mok and Gilmore (’83)— produced by both sexes and an advertisement or courtship call produced exclusively by males."