That Sounds Fishy: Fish Choirs and How They Make Their Music

There are many astonishing sounds in the natural world. Here, I will give an example of how sound plays a role in nature, through looking at how fish come together to create some unusual, diverse noises.

It is commonly known that birds sing together in unison, daily at dawn and dusk. These are the organisms that surround us humans, and we often hear them in our gardens or surrounding areas. It is less known that fish participate in the same phenomenon at dawn and dusk around reefs in the ocean. This is what it sounds like…

This audio was recorded by a research team from Perth, Australia who collected many recordings of Aquatic choirs over 18 months.

You can hear that there are a few different sounds going on. Each individual sound is a different species of fish. Take a listen and decide what you think each noise sounds like. Then read ahead to find out what species are making these sounds and what the sounds have been compared to in the past.

The first species of fish in this audio is the Blackspotted Croaker (Protonibea diacanthus) which is making the low foghorn-like noise. It is known in Australia as the black jewfish and is native to the Indo-Pacific region. Second is a species of Terapontid, which is making the sound which has been compared by the researcher Miles Parsons to the buzz from the game of Operation. The Terapontidae are a large family of small to medium-sized perciform fishes, which are also found in the Indo-Pacific region. Lastly is the Batfish, which is making the quieter “ba-ba-ba” call. These fish are elongated and laterally flattened which allows them to move through narrow crevices. This helps them escape predation.

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So how do fish produce sound? The first biological mechanism is stridulation which involves rubbing body parts together to create a sound. It also occurs in other organisms such as crickets. When fish feed, their teeth rub together and this stridulatory noise is created. This sound lies within the frequency range of <100 to >8000 hertz.  Another way that fish create sound, and one that often works in combination with stridulation, is using the swim bladder.

The swim bladder is the machinery that fish also use to create sound. It is an air-filled chamber that lies within the abdominal cavity of most bony fish. Sound is created from the drumming of this swim bladder with the sonic muscle. It serves many functions, one of which is regulating buoyancy.

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The last way fish produce sound is through hydrodynamics, which is sound as a result of fish quickly changing direction and/ or velocity. This produces a low humming sound and may play a role in predator-prey communication. It may have a negative effect as sharks are known to detect schools of fish through these low sounds.

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To summarise, fish can create many interesting sounds, which may serve a variety of functions. Here, a few species which make these sounds have been identified, and are shown to be characteristically different. To understand how these sounds are made, fish physiology has been explored. In my previous articles. I touched upon music’s role in biology; the evolution of music, how music interacts with emotions, the development of music taste and music therapy. These topics have mostly related to humans and so by providing you with this article, you have seen how sound plays a role in biology in an organism other than humans. There are so many ways which connect music with biology.  I would encourage you continue your exploration into this wide and fascinating topic.

Where to find out more:

• 11 Strange and Mysterious Sounds on Earth & Beyond: What’s That Noise? 11 Strange and Mysterious Sounds on Earth & Beyond | Live Science
• Fish recorded singing dawn chorus on reefs just like birds: Fish recorded singing dawn chorus on reefs just like birds | New Scientist
• Fishes of Australia – Blackspotted Croaker: Protonibea diacanthus (fishesofaustralia.net.au)
• How do fish produce sounds?: How do fish produce sounds? – Discovery of Sound in the Sea (dosits.org)