Octopuses have long fascinated scientists with their remarkable intelligence, but new research suggests their cognitive abilities may be even more advanced than previously thought. A study published in the journal Current Biology has demonstrated that octopuses can use mirrors to locate food hidden from their direct line of sight, a skill previously documented only in vertebrates.
Researchers at Dartmouth College trained three California two-spot octopuses to interpret reflected information and use it to identify the location of a reward. Rather than reacting directly to an image seen in a mirror, the animals learned to determine where the stimulus was actually located and move toward it.
The experiment involved projecting a virtual crab image behind the octopuses while a mirror was positioned in front of them. To obtain a real crab reward, the animals had to understand that the reflected image was not physically located in the mirror and instead navigate toward the correct position behind them. The octopuses successfully chose the correct location in approximately 73 percent of trials.
According to lead researcher Mary Kieseler, the findings provide the first evidence that an invertebrate can use a mirror to gather spatial information about its surroundings. The discovery expands scientific understanding of animal cognition and suggests that sophisticated problem-solving abilities may have evolved independently in very different branches of the animal kingdom.
The study also highlights the unique evolutionary position of octopuses. Humans and octopuses share a common ancestor that lived hundreds of millions of years ago, making them among the most distant intelligent organisms on Earth. Despite this separation, both have developed advanced ways of processing information about the world around them.
Researchers believe the findings could support the idea that octopuses possess internal representations of space, allowing them to navigate complex environments such as coral reefs and the ocean floor. While further studies are needed to confirm the existence of detailed mental maps, the results offer new insight into how these marine animals perceive and interact with their surroundings.
The research adds to a growing body of evidence showing that octopuses are among the most intelligent invertebrates known to science. From solving puzzles and escaping enclosures to using mirrors as navigational tools, these animals continue to challenge traditional assumptions about the limits of cognition in the natural world.
