Octopuses, along with their cephalopod relatives—cuttlefish and squids—are nature’s masters of disguise. These ocean dwellers possess an incredible ability not only to change the color and patterns of their skin but also to alter their body shape and texture in ways that defy belief.
Some Reasons Octopuses Change Shape and Color
Cephalopods’ Shapeshifting Abilities
Cephalopods can transform their appearance faster than the blink of an eye—a feat unmatched in the animal kingdom. This rapid change allows them to blend seamlessly into their surroundings or stand out in moments of need. According to Michael Vecchione, curator of Cephalopoda at the Smithsonian National Museum of Natural History, they are the best at this transformative skill, despite most of them being color-blind. The mystery of how they perceive and replicate colors remains unsolved, yet it is clear that this ability has been crucial for their survival.
How Do They Do It?
These soft-bodied mollusks have skin embedded with millions of pigment-filled sacs called chromatophores, each surrounded by tiny muscles. By contracting or expanding these muscles, cephalopods can create an array of complex patterns and colors. In addition, octopuses and cuttlefish are equipped with papillae—small bumps, flaps, and ridges that can be ruffled or smoothed out to change skin texture, adding another layer to their already impressive camouflage abilities.
For instance, the common day octopus (Octopus cyanea) can shift from almost transparent beige to dark, rugged tones in an instant, depending on its environment. Meanwhile, cuttlefish can mimic the appearance of algae by clumping and shriveling, allowing them to blend into their surroundings effortlessly. These shapeshifting skills serve multiple purposes, from camouflage to communication, and even to intimidate or hypnotize prey.
Why Do Octopuses Change Their Appearance?
To Intimidate Predators
When blending in isn’t enough to escape predators, cephalopods have another trick up their sleeve—they can make themselves appear more formidable. An octopus caught in camouflage might suddenly darken its body, stretch out its arms, and assume a larger posture to intimidate a would-be attacker. Cuttlefish have been known to create eye-like shapes on their mantles, effectively staring down their predators.
Some species, like the venomous blue-ringed octopus, take intimidation to another level by flashing vivid rings of color as a warning signal. On the other hand, the mimic octopus (Thaumoctopus mimicus) takes a different approach, impersonating more dangerous creatures like lionfish to ward off threats.
To Hypnotize Prey
Cephalopods don’t just use their color-changing abilities for defense; they also employ them to catch prey. Pharaoh cuttlefish, for example, can mimic the appearance of harmless hermit crabs, allowing them to get close to their prey without raising suspicion. Similarly, Caribbean reef squid (Sepioteuthis sepioide) can disguise themselves as herbivorous parrotfish to approach their targets stealthily.
Broadclub cuttlefish (Sepia latimanus) have been observed using moving patterns of color to mesmerize prey, creating an illusion that confuses and disorients their target. The tropical octopus (Octopus laqueus) also uses pulsating dark patterns to trick prey into revealing themselves.
To Communicate with Each Other
Even in the darkest depths of the ocean, where sunlight is scarce, cephalopods have found ways to communicate. The Humboldt squid (Dosidicus gigas) uses bioluminescent cells called photophores to create a glowing backdrop against which they can display color changes. These signals help them coordinate movements within their schools and assert dominance during encounters with rivals.
Male cephalopods, especially during mating season, use their skin to send signals that are hard to miss. Male day octopuses (Octopus cyanea) turn pale and flash black stripes, while Caribbean reef squids display a rich, dark red to attract mates. Some species of cuttlefish even split their mantle patterns, showing one side to attract a mate and the other to deceive rivals.
A Glimpse Into Their Minds?
While cephalopods’ color and shape-changing abilities are well-documented, the question of whether these actions are conscious remains. Tessa Montague, a cephalopod neuroscientist at Columbia University, suggests that these changes might reflect involuntary reactions tied to brain activity, such as fear or aggression. Interestingly, footage of octopuses changing colors during sleep has led researchers to speculate that they might even dream.
Montague’s research aims to decode the mental processes behind these physical changes, offering a glimpse into the inner workings of these fascinating creatures. Whether intentional or not, the fact remains that cephalopods have mastered the art of communication, camouflage, and survival, all through the incredible display of their ever-changing skin.
