Fish prove intelligence: test results reveal surprising abilities

Fish prove intelligence: test results reveal surprising abilities

Scientists have developed a groundbreaking method to test the intelligence of fish in their natural environment. Led by researcher Kotrschal from Wageningen University in the Netherlands, the new apparatus shows that fish removed from their habitat have elevated levels of stress hormones, which can negatively impact their ability to learn. This could indicate that the results of laboratory studies distort the cognitive performance of fish, as Kotrschal explains in a scientific article.

Innovative tests in water

The test consists of an innovative “feeding board” on which plastic discs are mounted that obscure access to food. The fish have to learn to push these discs aside to get to the rewards. This device can be used both on the bottom of the water and in different water depths, which makes it very versatile. Researchers have already had positive results with nine-spined sticklebacks and guppies. The sticklebacks were observed to be able to distinguish colors, while the guppies were able to distinguish independent fish from exploitative “scroungers”.

The results are astonishing: around one in five guppys was able to solve the tasks competently by opening the colored discs to access food. The exercise not only showed that fish are capable of learning and differentiating, but also that social behaviors can be recognized among the species. These research findings have the potential to fundamentally change how we view fish intelligence by considering their cognitive abilities in their natural habitat rather than simply testing them in a laboratory. Further information can be found in the detailed study by besjournals.onlinelibrary.wiley.com to read.