New Jersey Institute of Technology Jersey City, New Jersey
Visual systems in animals often reflect the demands of their ecological interactions. Ants occupy a wide range of terrestrial microhabitats and ecological roles within them. Additionally, ant eye morphology is highly variable; species range from eyeless subterranean-dwellers to highly visual predators or desert navigators. Through a comparative approach spanning 64 species, we evaluated the relationship between ecology and eye morphology on a wide taxonomic scale. Using worker caste specimens, we developed two- and three-dimensional measurements to quantify eye morphology, corresponding to investment in visual acuity. While accounting for shared ancestry, we find that three-dimensional eye area and eye length is correlated with foraging niche. Additionally, ommatidia density is correlated with trophic level. We find that ommatidia density has a negative correlation with antennal scape length and that there is a significant relationship between eye position and antennal scape length. We also report a positive correlation between antennal scape length and eye height, which may be related to the shared developmental origin of these structures. Along with previously known relationships between two-dimensional eye size and ecology, these results suggest a greater investment in visual acuity in predatory species and taxa that forage above-ground or arboreally.
