Some animals, such as primates, have mathematical abilities. Even insects, specifically bees, can do math. But what about water-dwelling animals like fish? The answer to that is a wild yes!
Like how humans can tell the quantity of a small number of coins on a table at a glance, fish can similarly detect small amounts (presumably) without counting. With this ability, they can be trained to distinguish varying quantities, such as three from four correctly.
However, a recent study from April 2022 from the University of Bonn in Germany revealed more about their ability to do basic math calculations. The study, published in the Scientific Reports journal, states that cichlids (a colorful aquarium fish) and stingrays (flat-bodied rays related to sharks) can perform basic addition and subtraction of 1 to a number range of five.
“We trained the animals to perform simple additions and subtractions,” states Professor Dr. Vera Schluessel from the University of Bonn Institute of Zoology. “In doing so, they had to increase or decrease an initial value by one.”
How do you get a fish to solve math problems?
How do you get a stingray to solve the sum of 3+1? The answer lies in color-coded geometric shapes. Schluessel and her team of researchers used a method that successfully tested the math skills of bees in a past study.
The fish were shown cards containing a geometric shape (circle, triangle, square) in corresponding colors. When the shapes are blue, it means to “add one,” while yellow means to “subtract one.” Afterward, they’re presented with two gates, each with a different number of shapes displayed, one containing the correct mathematical answer.
Here’s an example. If the researchers show the fish three blue shapes, it means they are to add one to the quantity of three and swim through the gate that shows four shapes. They’re rewarded with a treat each time they choose the correct answer. Over time, the fish began associating the colors with adding and subtracting one value.
How complex is basic math for fish?
Although the test may appear simple in nature, it may not be the case for our fish friends. Fish do not have a neocortex, or what is commonly known as the cerebral cortex — the part of the brain that is in charge of complex cognitive tasks in mammals.
Even when the fish were shown a combination of different shapes in varying sizes, the fish recognized the objects and shapes, and figured out the calculation based on color.
“They had to keep both in working memory when exchanging the original picture for the two result pictures. And they had to decide on the correct result afterward. Overall, it’s a feat that requires complex thinking skills” Schluessel explains.
What do fish benefit from knowing math?
Neither cichlid nor stingray species is found to require numerical skills in the wild, which is why researchers are amazed to discover that they can perform basic math. Despite the astonishing discovery of their math skills, researchers still do not know what the two species would need them for.
“Both are opportunistic feeders, not hunters, that show no mating- or reproduction-related behaviors relying on numbers (e.g., counting stripes or eggs),” the study claims. However, cognitive skills could be an advantage for survival in specific situations, as both the cichlid and stingray live in complex habitats. However, they can still live without it and not be disadvantaged.
The study included six cichlids and three stingrays in total. Both species found learning addition easier than subtraction. Meanwhile, cichlids were faster learners than the stingrays, but the latter excelled in individual performance.
