David L. Clark, Ph.D.
Directed Student Presentations and Achievements
Ms. Meghan Rector, Reflectance Measurements of the Dimorphic Male Jumping Spider, Maevia inclemens (Salticidae)
Received award from the American Arachnological Society for Best Student Poster Presentation.
Abstract: Males of the dimorphic jumping spider, Maevia inclemens, differ in both morphology and courtship behavior. To help understand the differences between these males, we measured reflectance patterns of several body regions using spectrographic techniques. Thirteen grey morphs, 11 tufted morphs, and 18 females were measured for reflectance in predetermined locations the body. As expected, reflectance patterns of males differed considerably. Notably, the black pedipalps of the tufted male have very low reflectance intensities compared to the grey morph and the pedipalps of the grey morph peak in the orange wavelengths. An interesting discovery was that tufted males have a highly reflective area posterior to the tufts on the dorsal prosoma. The location of this bright spot suggests a unique means of illuminating or backlighting the tufts when males position themselves in a courtship stance and are facing females, perhaps silhouetting the tufts for contrast against backgrounds. Such differences in reflectance patterns further support the hypothesis of divergent courtship strategies, which evolved for long distance vs., close displays relative to the female.