Study reveals tool use in tropical fish species

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 colorful reef fish.

The study logs fish deliberately picking up hard-shelled prey like crabs and mollusks, smashing them against hard surfaces like rocks to access the meal inside.

“Tool use is typically associated with humans, but this behavior is proof that fish are far cleverer than they get credit for,” says Dr. Tariel-Adam.

Researchers from Australia, Brazil and Caicos Islands have provided the first evidence of anvil use in several species of Halichoeres wrasses, suggest the behavior is far more common than previously thought.

Wrasses use hard surfaces, also called ‘anvils,’ to crack open hard-shelled prey such as crabs and mollusks. 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.

Professor Culum Brown, head of the Fish Lab at Macquarie University and senior author of the study says the study adds to research into fish intelligence. “They demonstrate flexible and dexterous tool use, expanding our understanding of tool use evolution in the animal kingdom.”

View more video footage: https://www.youtube.com/playlist?list=PLEGR7FN3Lr-54JaQ3gURVCkGsvQ_mXwkH.