Carson Lavanway
Research Mentor: Alison Davis Rabosky
Mentor Department: Ecology and Evolutionary Biology, LSA
Author(s): Carson LaVanway, Andressa Viol, Natasha Stepanova, Michael Hogan, Alison Davis Rabosky
Session: Session 3 (11:00 AM – 11:50 AM)
Presentation Type: Poster 138
Abstract
The Harderian gland occurs near the orbit of many tetrapods. In squamate reptiles, several functions have been proposed, including aiding in eye lubrication, supplementary salivation, and facilitating vomeronasal olfaction, the last of which has been determined to be most likely. Little is known about how ecology affects Harderian gland morphology, or if its size can be predicted from the size of other related cephalic organs. In the present study, we use diceCT scans of specimens from the University of Michigan Museum of Zoology to analyze the anatomy of the Harderian gland, the venom gland, and the vomeronasal organ (VNO) across the snake subfamily Dipsadinae. All morphological variables were normalized using cranial distances to account for differences in overall snake size. We found a positive correlation between relative Harderian gland and VNO volume, while there was no significant correlation between Harderian gland size and habitat. We also saw no significant positive correlation between Harderian and venom gland volumes, contrary to our original predictions. We believe that this could be a result of head size confounding the relationship between these gland volumes, and potential accommodation of these larger glands within the cranium. In dipsadine snakes, our results support the Harderian gland’s functional coupling with vomeronasal olfaction, and we observed no tradeoffs between the size of the Harderian and venom glands. Ultimately, we found that these glands are dynamic and require additional research to better understand their evolution.
