The cognitive abilities of fish have long been underestimated, often studied in sterile laboratory conditions far removed from the natural habitats of rivers, lakes and seas. Now, researchers at Wageningen University & Research have developed a simple and cost-effective method to assess the learning capacity of fish directly in the wild — with striking results.
Testing cognitive skills in natural settings
Fish possess remarkable cognitive abilities, yet for a long time these have mostly been studied under artificial conditions. Laboratory studies provide controlled environments to investigate cognitive mechanisms and have yielded valuable insights. However, such artificial settings can distort our understanding of fish cognition, as captivity may influence cognitive and behavioural performance.
Determined to address this, Catarina Vila-Pouca and Alexander Kotrschal, together with their team, devised a practical tool: a feeding board enabling fish to push aside discs to access a food reward - without the need for capture or confinement.
Autonomous learning observed
"We sought a solution that could be deployed anywhere, from shallow ponds to fast-flowing rivers," Catarina Vila-Pouca explained. "By enabling fish to make independent choices, we gain a far more accurate understanding of their learning processes."
Explorers and opportunists among fish
The apparatus was tested on guppies (Poecilia reticulata) in Trinidad and ninespine sticklebacks (Pungitius pungitius) in the Netherlands. The fish demonstrated progressive improvements in selecting the correct discs - a performance consistent with results previously observed in laboratory conditions. The study also revealed intriguing social strategies: while some individuals actively discovered food sources ('explorers'), others benefited from their efforts ('opportunists').
Advancing understanding of fish intelligence
According to Alexander Kotrschal, the new methodology offers a valuable window into fish cognition: "By studying animals within their natural habitats, we are better able to observe authentic behaviour. This not only enhances our understanding of cognitive evolution but also has implications for conservation and animal welfare."
Versatile and accessible
The device is inexpensive, easy to modify for different fish species, and suitable for studying social learning and memory. The researchers hope this simple innovation will significantly advance the field of fish cognition research.
