These freshwater fish communicate in a very similar way to humans, using electrical impulses. Now we've been able to "listen" to them.
Species in the animal kingdom with incredible abilities are aplenty. Think of the fascinating immortal jellyfish, microorganisms able to resurrect after a long sleep in the ice, or even some molluscs with very special teeth. Now, to the list of faunal oddities, join also these fish that can communicate almost as if they were human beings.
They are certain aquatic specimens belonging to the species of Mormyridae, freshwater fish commonly known as "elephant fish". And that apparently can "talk" to each other in a method that closely resembles that of our species.
To fully understand it, let's take a step back. When we talk to each other, even without being fully aware of it, we use certain techniques to focus or emphasize a particular speech: sometimes we use pauses, others we prefer to scan the words with greater emphasis. Well, the Mormyridae do exactly the same, but using electrical impulses, naturally sent in a very precise way. For a behavior that, in fact, also occurs in human speech, in which short silences and sighs exist to capture the attention or to make the concept that is being expressed more solemn.
The researchers have therefore observed that placing two Mormyrids in the same body of water, it can be verified with certainty that the pair of fish go to exchange messages "electrical", also marking the precise pauses during their dialogue in apnea. A behavior that instead does not seem to occur when they are completely isolated.
To hear the chief researcher Tsunehiko Kohashi of the Department of Biology at Washington University, in Missouri, this curious way of "talking" allows these animals to not get too accustomed to the hum of the electrical signal: without these particular pauses, the fish would run the risk of losing focus on what is being said, confusing the signal received for a simple noise. Exactly as it happens among us in front of a not very attentive interlocutor. A pause of about one second - this is the value recorded and published in the research - can instead prepare him to receive further messages without getting distracted:
Our discovery highlights not only that these phenomena occur to better scan the 'words', but also highlights a strong analogy with human speech, which tends to set a pause between words.
Human or fish, it seems that it is silence, and the intelligent use we can make of it, that makes communication more effective.
Andrea Guerriero