Characterizing dual-pulse calls in five Sciaenid species

Many fish species use acoustic signals for various purposes, with sciaenids being among the best-known vocal teleosts. Although advertisement and disturbance calls have been well studied, the dual-pulse call (or dual-knock) has been reported infrequently. Here, we recorded dual-pulse sounds in five South Atlantic sciaenid species and analyzed their acoustic features from four species in captivity and one in the wild. These stereotyped calls are emitted by both free-swimming and stationary individuals, often without apparent social interactions, although they are routinely elicited by a human feeder. The occurrence of this call type across geographically distant species in South America, North America, and Asia suggests it may represent a basal trait within the family, potentially serving important but yet undetermined functions.