Meeting Abstract

P3-65   -   Is evolutionary loss of a color signal linked to changes in vomeronasal organ morphology? Erudaitius, AP*; Pruett, JA; Campos, SM; Ossip-Drahos, AG; Lannoo, SJ; Zúñiga-Vega, JJ; Vital-García, C; Hews, DK; Martins, EP; Romero-Diaz, C; School of Life Sciences, Arizona State University, Tempe AZ, USA; Department of Biological Sciences, Southeastern Oklahoma State University, Durant OK, USA; Biology Department, Swarthmore College, Swarthmore PA, USA; Department of Chemistry and Physical Sciences, Marian University, Indianapolis IN, USA; Indiana University School of Medicine - Terre Haute, Terre Haute IN, USA; Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico; Departamento de Ciencias Veterinarias, Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Mexico; Department of Biology, Indiana State University, Terre Haute IN, USA; School of Life Sciences, Arizona State University, Tempe AZ, USA; School of Life Sciences, Arizona State University, Tempe AZ, USA aerudait@asu.edu

Recent behavioral studies suggest that male lizards of Sceloporus species that have evolutionarily lost a signaling blue belly patch may also rely more on chemical scent marks than do those that retain the blue sexual signal. In reptiles, the vomeronasal organ (VNO) plays an important role in olfaction of chemicals, including the scent marks that Sceloporus lizards use to defend territories. Here, we asked whether evolutionary loss of the abdominal patch is associated with size of the vomeronasal organ, using histological methods to measure the area of VNO epithelium of male lizards from 10 different species (6 that retain the colorful belly patch and 4 that do not). Preliminary results suggest that the area of VNO sensory epithelium is strongly and positively correlated (r > 0.9) with the total area of the VNO. We found substantial interspecific variation in the relative area of VNO sensory tissue, but did not find strong evidence that this corresponds to differences in the presence of the ventral color patch. We also compare and discuss links between the relative amount of VNO tissue and field measures of chemical and visual signaling behavior. Further studies on how VNO volume impacts chemical sensitivity, chemosensory behavior, and on possible importance of olfaction are needed.