Signal complexity in apteronotids

These data were used to partially examine the social complexity hypothesis for communicative complexity in the electric modality. South American electric knifefishes produce signals called chirps, or brief modulations of the baseline electric organ discharge frequency used during social interaction. Variation in chirp parameters and complexity were calculated from recordings collected in response to artificial playback for six species of apteronotid electric knifefishes that vary in social behavior - territorial Parapteronotus hasemani, semi-social Apteronotus leptorhynchus, territorial Apteronotus albifrons, territorial 'Apteronotus' bonapartii, gregarious Adontosternarchus devenanzii, and gregarious Adontosternarchus balaenops. Animal care and experimental protocols were approved by the Indiana University Bloomington Institutional Animal Care and Use Committee.