When attacked, an octopus changes its color to a darker one to scare away lighter colored animals, while it also tries to increase its body size by standing higher above the ground to scare away smaller animals. This behavior is meant to intimidate threats and scare other animals to preserve life. For a naive shark, grouper, or eel that swims across a coral reef, an octopus seems like an easy meal. Unfortunately for the would-be predator, octopuses are protected by a variety of defensive adaptations.
When trying to escape, the octopus can cross the water, imitate another animal, or change its color to blend with the substrate. If none of these tactics work, the octopus will eject a thick cloud of black ink into the water and disappear amidst the distraction. Godfrey-Smith said the researchers observed that debris hitting another octopus tended to be thrown from under the aggressor's arms differently, slightly sideways than forward. A study reveals that the shady octopus, its real name, belongs to the small club of animals that throw things at other members of their own species.
For example, an octopus may try to flee from an attacker by fleeing by plane and then try to camouflage itself in the sandy bottom. In addition, the material released varied depending on the context; when apparently trying to hit another octopus, sediment was the weapon of choice. While some cephalopods, such as nautils, live long lives, octopuses are ephemeral creatures that rarely exceed 3 years of age. As a final tactic, some octopuses may lose one of their arms to distract a predator, just as some lizards lose their tails.
Octopuses have eight long arms, covered with small saplings; they use them to grab their prey and carry it to their mouths in the shape of a beak. Animals have been known to attack humans before, such as when a woman in the United States put an octopus on her face to take a picture of her. They opened the tank every other day for two weeks and touched the octopuses with a test tube brush before offering them crabs to eat. A study published Wednesday in the journal PLOS ONE shows that octopuses of at least one species shed sediments and shells, sometimes at each other.
This behavior is rare in the animal kingdom, and the study is the first time it has been documented in octopuses. When threatened, many octopus species, as well as most cephalopods, discharge a cloud of dark ink. Some of the clearest evidence of octopus-to-octopus attacks comes from two observations of recidivism by a single individual. He described how an octopus from the New England Aquarium sprayed water to a volunteer every time he had the chance.