Fish lack eyebrows. This may not matter to you, but to the animators of the 2003 Pixar film “Finding Nemo,” it posed a problem. That’s because their biggest challenge was to create fish that communicate like people but still look like fish, said the film’s writer and director Andrew Stanton, speaking at the Clark Center last week.

Our eyebrow and eye movements allow our faces to speak volumes. But with absent eyebrows and unblinking eyes, fish faces fall short when it comes to expression. So to make the faces more communicative, the animators took liberties with fish anatomy: moving eyes from the sides to the front, transforming flat eyes into blinking eyeballs and adding eyebrowesque bulges. Stanton, joined by animators Dylan Brown and Mark Walsh, talked about anatomy from an animator’s perspective at a lecture for the interdisciplinary medical school class “Anatomy of Movement.” Roughly 50 people, including course director Amy Ladd’s two older children, attended.

All of the course’s lectures are open to the public. Visit http://move.stanford.edu for a schedule or contact Ladd at 723-6796 or alad@stanford.edu. The lectures take place at 3 p.m. on Mondays, Wednesdays and Friday at the Clark Center (check the Web site for the room number).