New research led by Macquarie University has documented tool use in five species of wrasse fish across the western Atlantic, revealing these colourful reef dwellers can select and use rocks as tools to crack open hard-shelled prey.
26 Mar 2025
Fish use tools too: Discovery of new tool-using fishes in the western Atlantic
Scientists have debunked the belief that using tools is unique to mammals and birds, after documenting tropical fish that smash shellfish against rocks to open and eat the meat, in a fascinating new study published in the journal Coral Reefs on 26 March 2025.
Dr Juliette Tariel-Adam from the School of Natural Sciences at Macquarie University led a project tracking tool use in multiple species of wrasses — a colourful reef fish.
The study logs fish deliberately picking up hard-shelled prey like crabs and molluscs, smashing them against hard surfaces like rocks to access the meal inside.
“Tool use is typically associated with humans, but this behaviour is proof that fish are far cleverer than they get credit for,” says Dr Tariel-Adam.
The researchers from Australia, Brazil and Caicos Islands have provided the first evidence of anvil use in several species of Halichoeres wrasses, suggest the behaviour is far more common than previously thought.
Citizen science insights
Wrasses use hard surfaces, also called ‘anvils,’ to crack open hard-shelled prey such as crabs and molluscs. Until now, this behaviour had been observed in a limited number of fish species all belonging to the same family of fish - wrasse.
However, through a citizen science initiative Fish Tool Use, researchers gathered 16 new observations across five species of Halichoeres wrasses.
These findings mark the first evidence of anvil use for three species and the first video evidence for the other two, and extend the known range of anvil use to the western Atlantic.
“With these newly discovered tool-using species, it becomes clear that many species of wrasses use tools that we previously didn't know about,” said Dr Tariel-Adam.
“If we truly want to understand this behaviour, we need the help of divers, snorkelers, and marine enthusiasts to report their observations.
“There are over 600 species of wrasses all around the world, and we are still far from knowing how many of them use tools. It’s only through collective efforts that we can uncover these hidden behaviours in marine life.”
Flexible and adaptable intelligence
The study found that wrasses show flexibility in their tool use, selecting different types of anvils to crack open a vast diversity of prey, and may even switch anvils while attempting to open a single prey item.
“For a long time, tool use was thought to be exclusive to primates and birds,” said Professor Culum Brown, head the Fish Lab at Macquarie University and senior author of the study.
“Our findings add to a growing body of research showing that fish are just as intelligent. They demonstrate flexible and dexterous tool use, expanding our understanding of tool use evolution in the animal kingdom.”
View video footage: https://www.youtube.com/playlist?list=PLEGR7FN3Lr-54JaQ3gURVCkGsvQ_mXwkH.
Read more, or contribute observations at https://fishtooluse.com.
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