The hidden language of cephalopod skin

Photo: Andrea Izzotti/Adobe Stock

A camouflaged squid

Cephalopods, including cuttlefish, octopuses, and squids, are known for their complex behaviors, particularly their dynamic skin displays. These behaviors include camouflage, inking, visual communication through skin patterns, and displaying patterns during sleep. Cephalopods’ skin is directly controlled by neurons from their brains, making their skin patterns a direct reflection of neural activity. This connection allows scientists to study how cephalopods perceive and interact with their environment.

Camouflage is the most notable cephalopod behavior. They can quickly change the color, pattern, and texture of their skin to blend into their surroundings, avoid predators, or hunt prey. Cephalopods do this by expanding and contracting pigment-filled sacs called chromatophores in their skin. They also have iridophores and leucophores, nonpigmented cell types, that contribute to their ability to change colors and create complex patterns. Despite being colorblind, cephalopods are highly adaptable when it comes to matching their surroundings, likely using a combination of visual textures and feature detection to create an effective camouflage.

Cephalopods also use their skin patterns for communication. During social interactions, such as courtship or conflict, they display distinct patterns that convey their internal states. For example, male cephalopods often display high-contrast patterns to attract females or intimidate rivals. Some species even show different patterns on each side of their body, demonstrating a form of divided attention. These social displays are usually innate and become more prominent as the animals mature.

Cephalopods' nervous systems are highly developed and centralized, with large brains relative to their body size. Their brains are divided into multiple lobes, each with specific functions related to sensory processing, motor control, and cognition. The optic lobes, which process visual information from the eyes, are particularly important for their dynamic skin behaviors. The neurons in these lobes send signals to motor neurons which control the chromatophores, enabling the rapid and complex changes in skin patterns.

Recent advancements in machine learning, optical imaging, and electrophysiological tools are helping scientists explore the neural bases of cephalopod behaviors in greater detail. For example, by tracking the expansion and contraction of individual chromatophores, investigators can see how cephalopods develop and control their skin patterns.

Understanding these processes not only provides insight into cephalopod biology but also has broader implications for the study of neural computation and behavior in other animals. With ongoing advancements in research tools, scientists are looking forward to uncovering even more about cephalopod behavior and neurobiology.

Ava Landry is a 2026 PharmD candidate studying veterinary pharmacy at the University of Connecticut in Storrs.

Reference

Shook EN, Barlow GT, Garcia-Rosales D, Gibbons CJ, Montague TG. Dynamic skin behaviors in cephalopods. Current Opinion in Neurobiology. April 22, 2024. Accessed July 2, 2024. https://doi.org/10.1016/j.conb.2024.102876