Long‐term monitoring of captive red drum Sciaenops ocellatus reveals that calling incidence and structure correlate with egg deposition

Abstract

In the present study, quantitative data were collected to clarify the relationship between calling, call structure and eggs produced in a captive population of red drum Sciaenops ocellatus. Sciaenops ocellatus were held in four tanks equipped with long-term acoustic loggers to record underwater sound throughout a simulated reproductive season. Maximal sound production of captive S. ocellatus occurred when the photoperiod shifted from 13·0 to 12·5 h of light, and the water temperature decreased to c. 25° C. These captive settings are similar to the amount of daylight and water temperatures observed during the autumn, which is the primary spawning period for S. ocellatus. Sciaenops ocellatus exhibited daily patterns of calling with peak sound production occurring in the evenings between 0·50 h before dark and 1·08 h after dark. Spawning occurred only on evenings in which S. ocellatus were calling, and spawning was more productive when S. ocellatus produced more calls with longer durations and more pulses. This study provides ample evidence that sound production equates to spawning in captive S. ocellatus when calls are longer than 0·8 s and contain more than seven pulses. The fact that more calling, longer calls and higher sound pressure levels are associated with spawns that are more productive indicates that acoustic metrics can provide quantitative information on spawning in the wild.

Long-term acoustic monitoring of fish calling provides baseline estimates of reproductive timelines in the May River estuary, southeastern USA

“…Positive temperature anomalies increased calling, while negative temperature anomalies decreased sound production. These findings are similar to reports from captive studies with spotted seatrout, weakfish, oyster toadfish, and red drum, where higher temperatures increased the amount of calling and the number of pulses in a call (Fine 1978, Connaughton et al 2000, Maruska & Mensinger 2009, Montie et al 2016, 2017.The lunar phase significantly influenced calling intensity of oyster toadfish and spotted seatrout. We detected pronounced cyclic patterns in the amount of calling and chorus duration for spotted seatrout.…”

“…For example, the timing and amount of calling in wild weakfish were positively correlated with the timing and numbers of sciaenid eggs collected (Luczkovich et al 1999). Similar findings have been observed in captive studies (Guest & Lasswell 1978, Connaughton & Taylor 1996, Lowerre-Barbieri et al 2008, Montie et al 2016, 2017. In weakfish held in laboratory tanks, courtship behavior, male calling, and spawning were correlated (Connaughton & Taylor 1996).…”

“…In weakfish held in laboratory tanks, courtship behavior, male calling, and spawning were correlated (Connaughton & Taylor 1996). In a quantitative study with captive red drum, findings revealed that spawning was more productive when the amount of calling increased; more eggs were collected when calls were longer in duration and contained more pulses (Montie et al 2016). In a similar study with captive spotted seatrout, spawning was more likely to occur when male fish called more frequently; a positive relationship was found between sound pressure levels in tanks and the number of eggs collected (Montie et al 2017).…”

“…Saucier & Baltz 1993, Mann & Lobel 1995, Luczkovich et al 2008, Walters et al 2009, Mann et al 2010, Montie et al 2016, 2017. Studies have recorded underwater sounds during spawning seasons and have shown that patterns of peak calling coincide with patterns of reproductive senescence (i.e.…”

“…chilipepper rockfish Sebastes goodie, California halibut Paralichthys californicus) (Asch 2015). As shown in captive experiments for spotted seatrout, red drum, and weakfish, spawning is strongly associated with the production of courtship sounds (Connaughton & Taylor 1996, Montie et al 2016, 2017. Therefore, listening to the estuarine soundscape may provide an easier, more efficient alternative to plankton sampling to track interannual variability in spawning.…”