When one fish species gathers to mate, the machine-gun-like sound of its mating “song” can get so loud it actually can be heard above the waves. Scientists now use sound to count some of the fish in the sea. More than 800 species of fish can produce sound and will use sound in everyday behaviour

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When one fish species gathers to mate, the machine-gun-like sound of its mating “song” can get so loud it actually can be heard above the waves. Scientists now use sound to count some of the fish in the sea. More than 800 species of fish can produce sound and will use sound in everyday behaviour