A video of two goldfish from Hokkaido, Japan, broke this common belief and shocked its viewers and scientists. The video shows an orange goldfish helping its sick companion to float to the surface so it can have a meal. This kind of empathetic behaviors of fish have never been documented before.
According to the Hokkaido Shimbun Press, the owner of the two goldfish, Hitoshi Takeda, noticed the black one began to have a difficulty swimming and spent most of its time lying at the bottom of the tank. He expected the black one to die soon but somehow it kept on living. Takeda got curious so he started filming the duo to find out how the sickly goldfish was surviving.
Takeda was amazed with his findings and shared with the local media. Since then, the video went viral.
Jonathan Balcombe, the director of animal sentience with the Humane Society Institute for Science and Policy, wrote in New York Times, "As a biologist who specializes in animal behavior and emotions, I've spent the past four years exploring the science on the inner lives of fishes. What I've uncovered indicates that we grossly underestimate these fabulously diverse marine vertebrates. The accumulating evidence leads to an inescapable conclusion: Fishes think and feel."