Scientists have found one of many world's smallest fish is able to making sounds registering greater than 140 decibels - which is louder than a pneumatic drill.

The translucent Danionella cerebrum is simply 12mm-long and has the smallest identified mind of any vertebrae.

The sound was first seen by scientists finding out the species in Berlin, Germany, who might hear sounds as they walked previous the fish tanks.

Researchers then arrange high-speed cameras on a tank containing the fish to work out precisely what was happening.

"The fish are so loud that, even when just walking past their tanks, you can hear audible pulsing sounds," Verity Cook, the research's lead creator, informed New Scientist.

The sound is produced when one of many fish's ribs is pulled into its swim bladder, making a "drumming sound".

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It is simply the males who make the noise and the explanation they do is unclear - however Ms Cook thinks it could be to assist them talk and find one another in murky waters.

"The fact that it's only males that make sound suggests that it's to do with aggressive behaviour towards other males or mating behaviour with females," she mentioned.

The research has been revealed within the journal, Proceedings of the National Academy of Sciences.