Evolutionary Patterns in Sound Production across Fishes

Abstract

Sound production by fishes has been recognized for millennia, but is typically regarded as comparatively rare and thus yet to be integrated into broader concepts of vertebrate evolution. We map the most comprehensive dataset of sound production yet assembled onto a family-level phylogeny of ray-finned fishes (Actinopterygii), a clade containing more than 34,000 extant species. Family-, rather than species-, level analyses allowed broad investigation of sound production mostly based on illustrations of acoustic recordings and morphological specializations (82%) strongly indicative of sound production along with qualitative descriptions (18%), and a conservative estimate of the distribution and ancestry of a character that is likely more widespread than currently known. Compilation of sonic-related morphological characters shows 60 families exhibiting muscles coupled to swim bladder vibration and 39 families that employ movement of skeletal parts against each other, i.e., stridulation. Eighteen of these families, mostly catfishes (13), include individual species exhibiting both mechanisms. The results show that families with soniferous species contain nearly two-thirds of actinopterygian species, including a clade originating circa 155 Ma, and that sound production has independently evolved approximately 33 times within Actinopterygii. Despite the uncertainties of presence-only data records and incomplete evidence of absence, under-sampling species, and assuming family-level conservation of sound production, sensitivity analyses show that these patterns of shared ancestry are robust. In aggregate, these findings offer a new perspective on the ancestry and convergent evolution of sound production among actinopterygians, a clade representing more than half of extant vertebrate species.