German researchers found that cichlids and stingrays can calculate small quantities without really counting them.. like change on a table.
One researcher explains “We trained the animals to perform simple additions and subtractions. In doing so, they had to increase or decrease an initial value by one.”
More research is being done to see what other pieces of intelligence fish are hiding. They’re often joked about as the dunces of the world because a fish’s memory span can be as short as three seconds.