Summary of the major fish groups from Speciation through the lens of biomechanics: locomotion, prey capture, and reproductive isolation

Speciation is a multifaceted process that involves numerous aspects of the biological sciences and occurs for multiple reasons. Ecology plays a major role, including both abiotic and biotic factors. Whether populations experience similar or divergent ecological environments, they often adapt to local conditions through divergence in biomechanical traits. We investigate the role of biomechanics in speciation using fish predator-prey interactions, a primary driver of fitness for both predators and prey. We highlight specific groups of fishes, or specific species, that have been particularly valuable for understanding these dynamic interactions and offer the best opportunities for future studies that link genetic architecture to biomechanics and reproductive isolation. In addition to emphasizing the key biomechanical techniques that will be instrumental, we also propose that the movement towards linking biomechanics and speciation will include 1) establishing the genetic basis of biomechanical traits, 2) testing whether similar and divergent selection lead to biomechanical divergence, and 3) testing whether/how biomechanical traits affect reproductive isolation. Future investigations that examine speciation through the lens of biomechanics will propel our understanding of this key process.