New research shows fish are smarter than we thought

For years, scientists underestimated the intelligence of fish, often relying on laboratory studies that did not accurately reflect their behavior in the wild. However, a team from Wageningen University in the Netherlands recently developed a simple, low-cost tool that allows them to observe fish learning directly in rivers, lakes and streams. The results were surprising.

Testing the cognitive abilities of fish in the wild

Fish are much smarter than we once thought, but most previous research has taken place in artificial environments. While labs allow for controlled conditions and exploration of fish thinking, unnatural environments can alter their behavior and learning abilities.

To get a more realistic look, researchers Catarina Vila-Pouca and Alexander Kotrschal built a field tool: a simple feeding board that allows fish to push plates aside to get food without having to capture or confine them.

'We are looking for solutions that can be deployed anywhere, from shallow ponds to fast-flowing rivers ,' explains Dr Catarina Vila-Pouca. 'By letting fish make independent choices, we get a much more precise understanding of their learning process . '

The device was tested on guppies (Poecilia reticulata) in Trinidad, and nine-spined sticklebacks (Pungitius pungitius) in the Netherlands. The individuals gradually improved their accuracy in selecting the food dish – improvements that matched lab results.

The study also revealed an interesting social strategy: while some individuals actively discover food sources ( "explorers" ), others take advantage of these findings ( "opportunists" ).

Promoting understanding of fish intelligence

According to Alexander Kotrschal, the new method opens an important door to studying cognition in fish: "Observing animals in their natural habitat allows us to record authentic behavior. This not only improves our understanding of cognitive evolution, but also has implications for conservation and animal welfare . "

The device is low-cost, easily adapted to different fish species, and is suitable for studying both social learning and memory. Scientists hope that this simple invention will significantly advance the field of fish cognition research.

Lesley Montoya

Update 30 June 2025