Sounds Fishy: Clownfish Make Calls to Show Status in Social Groups

Clownfish make sounds to defend their breeding and social status in their group, reveals a new study.

Clownfish are more popularly known from the film "Finding Nemo." The brightly colored species belongs to the family Pomacentridae. These fishes are commonly found in warm waters and live among the tentacles of the sea anemone.

They live in unique groups with six members in each group living around a single anemone, having a symbiotic relationship with the anemone. The stinging tentacles of the anemone protects the clownfish from predators.

The largest fish in the group develop as a female and the second largest will be a mating male. The rest of the fishes in the group remain gender neutral.

If the largest female fish dies, the second largest male becomes the alpha male and the next largest male becomes the mating partner. Other gender neutral fishes in the group will also be able to change gender when the mating pairs die.

A team of researchers led by Orphal Colleye from the University of Liege, Belgium, have found that the clownfish make sounds to defend and emphasize their social status. They noticed that the fishes make two different kinds of sounds - aggressive calls made by charging and chasing fish and calls made by submissive fish.

Clownfish use a pop sound towards smaller fish and a click sound towards a larger fish. The smaller fish produce sounds that are shorter, and at a higher frequency than that produced by larger fish. Although researchers theorized that each clownfish of the same size make slightly different sounds (differing in frequency and duration) to show their individuality, they noticed that the signals made by all submissive clownfish sounded similar, reported Live Science.

"It's unclear to me what aspect of the signal distinguishes two individuals of the same size (though I note that in natural groups there are rarely two individuals of similar size)," Paul Buston, a biology professor at Boston University who was not involved in the study, wrote in an email to Live Science.

Experts are further planning to study the factors that differentiate the sounds between individual fish. They will also be examining the factors that trigger the clownfish to change its gender.

The findings of the study, "Overview on the Diversity ofSounds Produced by Clownfishes (Pomacentridae): Importance of Acoustic Signalsin Their Peculiar Way of Life," are published in the journal PLOS ONE.