Zebrafish yawn upon seeing other zebrafish yawn: Study
A new study has found that Zebrafish yawn and their yawn is contagious, which means they yawn upon seeing other Zebrafish yawn. While yawning, these fishes open their mouths slowly, stretch them widely, and then snap them closed. The study stated that a Zebrafish also stretches its body while yawning for about 50% of the time.