Subordinates exhibit submissive postures (lateral quivering) while producing submissive sounds.
(Photo Credit: Citation: Colleye O, Parmentier E (2012) Overview on the Diversity of Sounds Produced by Clownfishes (Pomacentridae): Importance of Acoustic Signals in Their Peculiar Way of Life. PLoS ONE 7(11): e49179. doi:10.1371/journal.pone.0049179)
An aggressive clownfish chases a smaller fish while producing a series of aggressive sounds.
(Photo Credit: Citation: Colleye O, Parmentier E (2012) Overview on the Diversity of Sounds Produced by Clownfishes (Pomacentridae): Importance of Acoustic Signals in Their Peculiar Way of Life. PLoS ONE 7(11): e49179. doi:10.1371/journal.pone.0049179)
This is a clownfish.
(Photo Credit: Orphal Colleye)
Source: Public Library of Science