Full Description

"Conversely, maximum nightly sound pressure levels (SPL) ranged from a low of 89·5 dB in April to a high of 131·9 dB (re: 1 _Pa) in February. The temporal centre of sound production was relatively stable among all nights sampled but spawning occurred earlier in the day as the season progressed and exhibited a strong, positive association with increased water temperature. The negative relationship between the levels of sound production and egg production was unexpected given the usefulness of sound production as a proxy for reproduction on a seasonal basis and may possibly be explained by differences in the spawning potential of the female population in the study area on nights sampled."

"The temporal centre of sound production was relatively stable among all nights sampled and occurred between 2120 and 2240 hours (Table II)."

". Contrary to trends in earlier spawning and relatively consistent timing of the centre of sound production, chorus start times became gradually later and chorus duration shorter as the spawning season waned (Table II and Fig. 3)."

"The stereotypical loud drum call described by Mok & Gilmore (1983) was the dominant call type recorded. An unusually longer, (nearly _2) (Locascio & Mann, 2011a) and uncommon variant of this call (mean ± s.d., 1·1 ± 0·1 s, n = 8) was recorded six times on January 29 between 1815 and 2200 hours; once on 15 February at 2233 hours, c. 17 min prior to the collection of blastodiscs; once on 4 March at 1922 hours, 30 min after blastodiscs were collected. The specific context of this call variant remains unknown. What appears possibly to have been the staccato, a disturbance call (Mok & Gilmore, 1983; Tellechea et al., 2010), was recorded four times on 20 March between 1735 and 1817 hours. This call type has only previously been observed and recorded when the species was handled."

Observation Environment Quotes

"This study was conducted in a dead-end basin of the canal system c. 250 m _ 235 m in area and 7 m deep. To investigate the temporal and quantitative relationships between egg production and sound production of P. cromis, surface plankton samples were collected hourly from 1800 to 0400 hours on two consecutive nights while acoustic recordings were made simultaneously at five separate locations in the canal basin."

Behaviour Description Quotes

"The stereotypical loud drum call described by Mok & Gilmore (1983) was the dominant call type recorded. An unusually longer, (nearly _2) (Locascio & Mann, 2011a) and uncommon variant of this call (mean ± s.d., 1·1 ± 0·1 s, n = 8) was recorded six times on January 29 between 1815 and 2200 hours; once on 15 February at 2233 hours, c. 17 min prior to the collection of blastodiscs; once on 4 March at 1922 hours, 30 min after blastodiscs were collected. The specific context of this call variant remains unknown. What appears possibly to have been the staccato, a disturbance call (Mok & Gilmore, 1983; Tellechea et al., 2010), was recorded four times on 20 March between 1735 and 1817 hours. This call type has only previously been observed and recorded when the species was handled."

"Aalbers & Drawbridge (2008) found increased calling (rates and intensity) and specific vocalization types associated with gamete release but Connaughton & Taylor (1996) reported the cessation of calling during gamete release by sciaenids. Sciaenid sound production has been reported to occur before, during and after spawning (Mok & Gilmore, 1983; Connaughton & Taylor, 1995) and extended periods of sound production were recorded in this study prior to spawning earlier in the season and well after spawning occurred later in the season. Because P. cromis are indeterminate, group-synchronous spawners, patterns in calling prior to and following spawning may serve a physiological purpose by helping females come into or maintain spawning condition."

Sound Name Quotes

"Maximum SPL is highly correlated with measures of total acoustic energy of a night-chorus event (r ≥ 0·95) and can be used quantitatively to represent nightly P. cromis sound production (Locascio & Mann, 2011a)."

". Contrary to trends in earlier spawning and relatively consistent timing of the centre of sound production, chorus start times became gradually later and chorus duration shorter as the spawning season waned (Table II and Fig. 3)."

"The stereotypical loud drum call described by Mok & Gilmore (1983) was the dominant call type recorded. An unusually longer, (nearly _2) (Locascio & Mann, 2011a) and uncommon variant of this call (mean ± s.d., 1·1 ± 0·1 s, n = 8) was recorded six times on January 29 between 1815 and 2200 hours; once on 15 February at 2233 hours, c. 17 min prior to the collection of blastodiscs; once on 4 March at 1922 hours, 30 min after blastodiscs were collected. The specific context of this call variant remains unknown. What appears possibly to have been the staccato, a disturbance call (Mok & Gilmore, 1983; Tellechea et al., 2010), was recorded four times on 20 March between 1735 and 1817 hours. This call type has only previously been observed and recorded when the species was handled."