Meeting Abstract
The evolution of eye size has been studied across multiple vertebrate and invertebrate taxa. Most research has focused on species with high visual acuity or the adaptive loss of eyes in no light environments. In scorpions, the eyes have been studied to assess their sensitivity and function. However, little attention has been given to the evolution of eye size in scorpions, with the exception of troglobite species. Scorpions are nocturnal predators that rely primarily on specialized setae to detect substrate and air vibrations of their prey. However, the persistence of the eyes in most scorpion species suggests the eyes are functional, albeit not for prey capture. Research has shown the eyes of scorpions are sensitive to changes in ambient light and may assist with celestial navigation and circadian rhythms. Although many scorpions are desert inhabitants, others occupy a variety of habitats, including environments with significant canopy cover. We previously found that relative median eye size, was significantly larger in a species from Florida (high canopy cover), than in a species from the western US (low canopy cover). This research tested the relative size of the median eyes, in multiple species of scorpion, across multiple families and environments. It was predicted that species from greater canopy cover would exhibit larger relative eye size, and differences would be greater among families than within. Controlling for carapace length (measure of body size), eye size was larger in the scorpion species that occupies a forested environment compared to the desert species. These data coupled with phylogenetic analysis could give great insight into our understanding of the evolution of eye size.
