Meeting Abstract
Fish use their visual systems for a variety of tasks (capturing prey, detecting predators, schooling, and courtship) that require them to resolve an image; however, spatial acuity (the ability to resolve detail) is highly variable across fish species. Eye size, ecology, and habitat (in particular depth) may potentially drive variation in spatial acuity. While prior studies have explored the effects of ontogeny, morphology, or environment within a single species or several related species, broad comparative analyses of the relationships between visual acuity, eye and body size, ecology, and depth in fish are currently lacking. We conducted a literature review of spatial acuity (measured behaviorally, morphologically, and electrophysiologically) in fish and elasmobranchs, and used phylogenetic comparative methods to explore these relationships in species from different families, ecologies, and environments. Fish are an excellent system for such a study, because fish eyes vary in size between species and across lifespan, in shape from spherical to oblong, and in various morphological specializations such as multiple lenses or lack of lenses altogether. Additionally, fish differ in ecology (i.e. diurnal/nocturnal, herbivore/predator) and habitat, occupying a variety of depth ranges. Such cross-species analyses help elucidate how visual capabilities may be adapted to an animal’s visual needs; overall, identifying the factors that influence visual acuity will increase our understanding of sensory ecology in fishes as well as other organisms with camera type eyes.
