Characterization of visually-guided behaviors by the nudibranch, Berghia stephanieae


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


82-5  Sat Jan 2  Characterization of visually-guided behaviors by the nudibranch, Berghia stephanieae Quinlan, PD*; Cho, AK; Katz, PS; University of Massachusetts, Amherst, MA; University of Massachusetts, Amherst, MA; University of Massachusetts, Amherst, MA pquinlan@umass.edu

Although it was previously thought that nudibranchs use their eyes for just detecting light, we found that they exhibit visually-guided behaviors that are distinct from light-dark preference. To examine how nudibranch behavior is guided by light, we tracked the paths of locomotion of the nudibranch Berghia stephanieae in response to different visual stimuli using DeepLabCut. In a light-dark preference test, Berghia spent a majority of time in the dark. This occurred for both hungry and sated animals. Berghia crawled more slowly in the dark portion of the arena. When presented with a black stripe on a white background outside of the arena, Berghia reliably navigated to the stripe. This behavior was hunger state- and context-dependent; animals did not approach a stripe when hungry or in the presence of a food odor. Berghia also approached a stripe that was isoluminant with the background. These results suggest that visual information guides Berghia’s behavior with two distinct mechanisms. While the level of ambient light modulates speed to cause Berghia to spend more time in the dark, Berghia may be making spatial comparisons of light to navigate to a stripe.

the Society for
Integrative &
Comparative
Biology