Acoustic Variation in Ictalurid Catfishes

Abstract

More than 35,000 ray-finned fish (Actinopterygii) species are potentially using acoustic communication. However, of the approximately 1200 known soniferous fish species, few include North American freshwater fish. To help fill this knowledge gap in fish acoustic communication, which holds great promise for conservation monitoring, I document acoustic measurements (duration 90%, bandwidth 90%, number of pulses, center frequency, and peak time) across 4 species (Ameiurus nebulosus, Ameiurus natalis, Noturus flavus, Ictalurus punctatus) from 3 genera of the North American catfish family, Ictaluridae. This was done by recording 10 trials of disturbance calls from 28 individuals and analyzing 1294 sounds using Raven Pro 1.6 software. I hypothesized that: 1) more phylogenetically/morphologically related species would have more similar acoustic features, 2) acoustic features would correlate with one another, and 3) acoustic features would correlate with standard length (cm). For hypothesis 1, I instead found that Ameriurus nebulosus was the most acoustically dissimilar, despite having the highest level of phylogenetic/morphological similarity with Ameirus natalis. However, only Ameriurus nebulosus' number of pulses were significantly different from other species. For hypothesis 2, it was found that many acoustic measurements were correlated with one another as predicted. For hypothesis 3, only the number of pulses was found to be significantly correlated with standard length, but minimally so. These findings further support that pulsation measurements may contain a high level of phylogenetic signal, given that it is the most crucial characteristic to differentiate species.