As I reported in the March issue of the SDFSA newsletter, “According to a Facebook post by ASFB (@AustSocFishBiol), “Report your observations of fish tool use! A new citizen science project by @TarielJuliette and @CulumBrown is inviting divers, snorkellers and aquarium-goers to submit their observations of tool use behaviour, in which fish use anvils to crack open prey.

According to the web page at, “Have you seen fish using tools? Let us know!

What to look for?

A fish uses a hard surface to help it open a hard-shelled prey item (such as a sea urchin or shell).

After grabbing the prey in its mouth, the fish slams it quickly and repeatedly on the hard surface until it breaks.

(Source: Have you seen fish using tools? · iNaturalist Australia (

If you have seen this (kind of) striking behaviour, try to remember the species/genus/family of the fish… And then fill this participation form or send … an email (to) . Any information is helpful, so don’t hesitate, even if you have no idea about the fish species.

If you have never seen this behaviour, open your eyes. You might see a fish using a rock as a tool very soon.

The use of tools allows fish to access food resources that would otherwise be inaccessible to it. It would not have been able to break open these prey items using only its mouth and teeth. Given the high advantages of tool use, why did not all fish … evolve it?

In the research project, your participation would help determining all fish species that use anvils so we can (1) find out whether this behaviour evolved once or several times in the evolutionary history of fish, and (2) test hypotheses about the factors driving the evolution of tool use, such as that tool use only evolves in species with large brains.

Please feel free to contact us if you have any comments or would like to get more involved.”

Juliette Tariel-Adam says that fish use a rock as a tool to help them to break open hard-shelled prey (molluscs) and that 15 wrasse species have been observed using such tools to date.

UPDATES: Juliette Tariel-Adam reports that Susan Prior has observed a new species of fish using a rock as a tool to break up its prey at Norfolk Island. Details can be found at

A recent Twitter post at shows some video footage by Wolf Rock Dive Centre of a wrasse using a rock to smash open an urchin.

(Meanwhile, scientists filmed AROUND 10 gloomy octopus (Octopus tetricus) in Jervis Bay, NSW tossing material such as silt & shells at each other by using their siphons.)

(This topic has also been published online via iNaturalist

Have you seen fish using tools?)

By Steve Reynolds

Steve Reynolds is the current President of MLSSA and is a long-standing member of the Society. Steve was a keen diver, underwater explorer & photographer before illness struck. He is chief author of the Society's extensive back catalogue of newsletters and journals.

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