They are often said to have a three-second memory, but the brain power of fish has been considerably underestimated, according to scientists who found some fish can recognise themselves in the mirror. The fish live in mutually beneficial partnerships with larger client fish from whom they feed on dead skin and parasites. During the mirror test, the researchers placed a mark on the fish in a location that could only be seen in a mirror reflection. These activities were not seen when the fish were given marks without a mirror present or when they interacted with marked fish across a clear divider. Prof Gordon Gallup, a psychologist at the University at Albany in New York, who pioneered the mirror test in 1970, disputed whether the fish really recognised themselves.

Source: The Guardian February 07, 2019 19:00 UTC