Fish produce sounds with the aim of communicating. Two principal mechanisms govern the production of their sound messages, and our growing awareness of the voices of the ocean. Two of them are relatively well known: one involves the rubbing of the body’s harder parts against each other (pharyngeal teeth, pectoral fins against the pectoral girdle), whilst the other involves the swimbladder. A new mechanism has just been discovered in the clownfish by a team working in the University of Liège’s Functional and Evolutive Morphology Lab (Prof. P. Vandewalle). This work, the results of which were published in the journal Science in May, 2007, was led by Eric Parmentier (an FNRS (Belgian National Fund for Research and Science) research collaborator) and carried out in association with American researchers and the University of Antwerp’s Laboratory of Functional Morphology.

Researchers have just discovered, for the very first time, the existence of sound communication through oral channels amongst fish, in this case the clownfish. This means that, to push the analogy, we can put forward the idea that fish in the Pomacentridae family (around 350 species) ‘speak’.

Since the 1930s, the ability of the clownfish to produce sounds has been recorded in scientific literature. That's an established fact, but how is it done? Whilst numerous hypotheses have been formulated, none has been tested, and thus none has been verified. The originality of Éric Parmentier and his teams' work lies precisely in the fact that they have succeeded in demonstrating the mechanism by which sound is produced in one of the 27 species of clownfish: Clark’s anemonefish (Amphiprion clarkii).