Meeting Abstract
From flattened flounder, to elongate eels, and leg-wielding frogfishes, benthic fishes exhibit a remarkable diversity of body shapes, many of which deviate strongly from the generic streamlined fish profile. Living on or within the benthos may relax the selective pressures incurred by constant midwater movement and promote complex interactions between the body and substrate, resulting in adaptations and body shapes not favored in midwater fishes. Though fishes have radiated into benthic and fossorial habitats numerous times, the phenotypic diversity of benthic fishes has never been systematically explored and compared to midwater taxa. We ask whether a benthic lifestyle results in novel body shapes and if this habitat transition leads to increased rates of morphological diversification. Using the collections at the Smithsonian Museum, we have amassed an unprecedented morphological dataset of linear measurements capturing body shape across roughly 6,000 teleost species. Applying phylogenetically-informed analyses, we show that bottom-dwelling fishes are far more dispersed in morphospace than midwater fishes. We find that benthic living both facilitates the evolution of novel body shapes and dramatically intensifies the rate of body shape evolution. This study highlights a prime example of the potential for habitat colonization to generate widespread morphological innovation and diversification.
