Sound Production in Two Divergent Madtom Species

Abstract

Acoustic signaling is well-documented in most North American catfish species, however, in madtoms (genus Noturus) it remains largely understudied, with research limited to a single species. In this study, we describe vocalizations of N. leptacanthus and N. phaeus in a laboratory setting during social interactions and investigate their behavioral context in N. leptacanthus. Size-matched pairs in both species were recorded with simultaneous audio and video for two hours per pair. Single-pulse signals were the most common call type in both species and were most commonly associated with male agonistic behavior. Females of both species produced longer, more complex vocalizations than males. Larger madtoms typically established themselves as the dominant, more aggressive individual. These findings reveal that both sexes engage in competitive acoustic interactions. This highlights the role of sound production in competitive success and also establishes females in an active role in this species’ vocalizing scheme.