Quantifying pitviper depth-perception through molecules and preserved museum specimens
Hogan, Michael P.
Rabosky, Alison R. Davis
Department of Ecology and Evolutionary Biology
Museum of Zoology
University of Michigan
Ann Arbor, Michigan USA
Hunt, Tyler C.
Erickson, Gregory M.
Rokyta, Darin. R.
Department of Biological Sciences
Florida State University
Tallahassee, Florida USA
Predatory species which hunt for their food rely heavily on their ability receive and process prey-based stimuli. Sensory cues can be perceived through multiple, often unrelated channels simultaneously, therefore requiring precise anatomical coordination. Pitvipers, the venomous snake clade which includes rattlesnakes, have evolved specialized prey seeking sensory traits integrated within their cranial anatomy. Pitvipers employ sit-and-wait hunting tactics leading up to a precisely aimed and timed envenomating strike. This predatory strike presumably requires a high-level of depth-perception by their keen vision and thermal-sensing pit organs. To determine the relative contributions of the eyes and pits in pitviper depth-perception ability, we utilized micro-CT reconstructions of pitviper head morphology and artificially reanimated the visual fields perceived through the eyes and the bifocal thermal-sensing fields perceived through the pits. We report the ground-truthing and preliminary findings of this exciting novel approach which elevates preserved museum specimens as profound tools for investigating pitviper sensory evolution. To virtually appreciate the color vision ability of pitvipers, we utilized quantitative mass spectrometry (qMS) to evaluate the proteomic photoreceptor composition of 8 Crotalus adamanteus whole eyes. We report one instance of color blindness from our genome animal, and further display short wavelength sensing as the least abundant photoreceptor in the rattlesnake eye.