Research has shown that many animal species can recognize their own image in a mirror, and fish are no exception.
Many people believe that goldfish have a memory span of only three seconds. However, we may be underestimating their cognitive abilities.
A new study has revealed that certain fish species can recognize themselves in a photograph. This indicates that fish are among the animals capable of self-awareness. The research was published in the journal PNAS.
Fish recognize facial features rather than bodies.
This may seem like a basic skill for us. However, self-awareness is a sign that an animal can perform higher mental processes. This ability is most commonly tested using mirrors.
Many animals, including dogs, will react to their reflection as if it were another individual. However, some species are capable of recognizing that the reflected image in the mirror is themselves.
Great apes, dolphins, elephants, and some bird species have passed this test. In contrast, children take about 18 months to recognize this.
Years ago, scientists investigated whether a marine fish known as the cleaner wrasse could pass the mirror test. They marked the fish with something resembling a parasite on their throat and placed a mirror in the tank.
The results showed that many of the fish noticed the mark in their reflection. Subsequently, they attempted to rub the mark off their throat, indicating they recognized themselves in the mirror.
In the new study, scientists aimed to test whether the fish could recognize themselves in a photograph. The research team showed each fish more than four images.
One image of itself, one image of a strange fish, one image featuring its face on the body of another fish, and one image with a strange face on its own body.
Cleaner wrasse tend to attack territorial intruders. In this case, they attacked the photos of strange fish rather than their own images.
They also did not attack the photos showing their face on the body of another fish. However, they did attack the images with a strange fish’s face on their own body. This suggests that this fish species recognizes facial features more than body shapes.
Masanori Kohda, the lead researcher from Osaka Metropolitan University (Japan), stated: “This is the first study to demonstrate that fish possess self-awareness. Since the target animal was a fish, this finding indicates that nearly all vertebrate species have a higher degree of self-awareness.”
