When a Japanese pygmy squid gets attacked, it will use its ink as a decoy so that the predator attacks the ink instead. It's not just a visual decoy — ink will also throw the predator of the squid's scent, literally. However, distracting a predator is not as easy as just releasing a single cloud of ink. In a recent , researchers showed that the Japanese pygmy squid use elaborate methods to mislead their predators.
When the squid are followed by a predator or, in this case, a scuba diver pretending to be a predator, they will often first change their color to be pale, which is less obvious in the water. They then swim away in a straight line, releasing little puffs of ink behind them. After releasing a few puffs, they will do one of two things: either they suddenly stop, or they suddenly change direction.
If they suddenly stop in what's called an they will often also darken their color, so that they seem like one of the ink clouds, and the predator is unable to find them. If they change direction, called a , they will remain pale, thus being as inconspicuous as possible. In both cases, the goal is for the predator to be distracted by the ink clouds and attack the decoys instead. The researchers showed that if the squid released more ink clouds during their escape, predators were more likely to attack those instead of the squid.
The question remains whether all squid have similar behaviors, or whether each species has evolved its own behavior to avoid predation. This might have to do with the specific species predating on the squid and their surroundings. In any case, judging from the, it looks like its methods work pretty well for the Japanese Pygmy squid.