Calling activity and calls' temporal features inform about fish reproductive condition and spawning in three cultured Sciaenidae species.

Although many fish species are vocal, the use of fish sounds for aquaculture management and wild population protection has not received much attention. In this study, sound production of three members of the Sciaenidae family was monitored before and during spawning in aquaculture facilities. The species examined include the meagre Argyrosomus regius, the shi dum Umbrina cirrosa and red drum Sciaenops ocellatus. Red drum reproduces spontaneously in captivity, whereas shi drum and meagre often require hormonal stimulation using gonadotropin releasing hormone agonist (GnRHa) for the induction of oocyte maturation, ovulation and spawning. In all three species, a clear increase in calling activity was detected during spawning nights, when longer sounds with a higher number of faster repeated
pulses were emitted. Changes of call temporal features could be related to histological changes in the sonic muscles. After GnRHa treatment and during spawning,
meagre sonic fibres were wider and the ratio of sarcoplasmic reticulum to myofibril cross-sectional area was higher. The correlation of calling activity with spawning events opens up the possibility of using the monitoring of calling activity and of call temporal features as tools for evaluating the reproductive state of different sciaenid species, both in the wild and captivity.