Octopuses are preyed upon by a range of animals, including fish and mammals, and they also try to hide from a variety of potential prey, each having its own particular visual system. Yet an octopus needs to present a body-pattern that will conform to its predator's view of the surroundings. An octopus's visual cues, which trigger its pattern matching, are fairly different from those perceived by its predators. Octopuses possess a single, mid-wavelength visual pigment, making them essentially colorblind (, ,, and reviewed in ). These studies also described a response to size-specific cues rather than to aspect ratios or shapes in the visual background, the effects of mean substrate intensity on the disruptive response, and the organism's sensitivity to spatial phase and localized visual edges. In those studies, the effects of contrast, aspect ratio, shape, and pattern size were investigated, and some of the cues that trigger the camouflage reaction were revealed. Recent studies, , –, , – used artificial substrates, such as checkerboards, to investigate specific visual cues that elicit the various body patterns in cuttlefish. These structures confer on octopuses the ability to instantaneously change their body patterns to produce a range of patterns, often described as uniform, mottled, and disruptive, to achieve deceptive and general resemblance (, ,, , patterns for different species described by Borreli and references within). To create such a wide variety of body patterns (described in detail by Borreli for various cephalopod species), an octopus uses its sophisticated skin, which contains pigmented chromatophore organs, reflecting iridophores, and light scattering leucophores (reviewed in ). In cephalopods, background matching is a dynamic, visually driven process, in which the animal assesses a range of background variables such as contrast, brightness, edge, orientation, and size of objects when deciding what camouflage pattern to display, –. Background matching is one strategy to achieve crypsis, the principle of which has long been acknowledged (Darwin ).

Taking a different approach, crypsis has been described as a range of strategies that prevent detection. Cephalopods, particularly octopuses, possess the remarkable ability to change their body patterns to match changes in their visual background (termed crypsis by Endler ), categorized and described in detail for Octopus cyanea by Hanlon and Messenger. However, several empirical studies revealed that cryptic animals do not necessarily match their backgrounds precisely. As such, the better the animal matches its background, the less likely it is to be detected by either predator or prey –. Predation is a strong evolutionary driving force selecting for the development of various defensive mechanisms and behaviors, including cryptic coloration and camouflage.

Coral reef animals octopus home screen