At Face Value Analyzing Species and Sex Differences in Facial Colorations of Two Co-occurring Species of jumping Spiders Using Microspectrophotometry

Abstract

Record ID: 248

Award(s): Excellence in Research Mentoring

Student Major: Biology, Environmental Studies

Project Advisor: Nathan Morehouse

Abstract: In nature, visual signals may convey important information such as species identity. Studies have found that organisms from diverse lineages sometimes signal such information through facial color, pattern, and ornamentations. Many of these studies have focused on primates, but little is known about the role of faces in non-primates, especially invertebrates. The Habronattus genus of jumping spiders acts as an ideal model for gaining a better understanding of this concept due to their color vision capability, high visual acuity, and diversity of facial colors exhibited by male spiders. We hypothesized that Habronattus spider faces may communicate species- and sex- specific information. In this study, we analyzed the facial colorations of two co-occurring species of jumping spiders: Habronattus orbus and Habronattus decorus. We used a microspectrophotometer to measure the color reflection at 6 specific focal points on the faces of both male and female individuals from each species. We used the R package ‘pavo’ to visualize and model this data into how Habronattus might distinguish between these colors. Our results indicated both sex- and species-specific differences in facial coloration. These findings shed light on how an invertebrate system may utilize similar regions important to many primates, likely to select potential mates or for species discrimination. These insights further serve as the building blocks to future research to test potential differences in visual communication across different species in these jumping spiders.