Harvestmen, colloquially known as daddy longlegs, comprise the third most diverse order within the arachnid species, yet very little research has been devoted to them (Pinto-da-Rocha 2007). Harvestmen nervous systems and their external leg sensors may provide investigators with an amenable system for analysis and modeling of the internal sensors of other organisms. The proposed investigation will examine specific harvestmen leg tactile receptors using scanning electron microscopy. Specifically, the experiment would focus on the tactile receptors on their second legs which seem to act as environmental surface detectors, since harvestmen reach forward with these legs to feel the ground as they move. This leg contains tiny sensory projections referred to as sensilla that may accumulate static charges and are the likely mediators of touch sensitivity. (Sackett, 2012). This subject is important to study because of its potential as a model for touch sensors in humans and other mammals.
