What is mimicry?

Mimicry is a mechanism used by many organisms to disguise and camouflage themselves. Organisms sometimes mimic inanimate objects, such as rocks or differently patterned backgrounds. But more dynamic mimicry behaviors are also observed, wherein an organism will mimic another model organism, in coloration and behavior, to better blend in with its environment. Cephalopods have been found to mimic their background environments with body coloration and patterning. But several observations have also found that species will mimic other organisms found in their environments [4][9].

Types of Mimicry: Mullerian and Batesian
Mullerian mimicry occurs when two poisonous species share similar physiological or behavioral traits. This similarity reinforces the message to predators that individuals with these traits are poisonous, thus aiding both species in their deterrence of predators. Batesian mimics exhibit coloration, patterning or behavior similar to a species that is poisonous, but they are not actually poisonous themselves. This similarity will deter potential predators from taking the chance on potentially deadly prey. It seems most likely that mimcry in cephalopods is Batesian. The diversity of mimic patterns and general polymorphism in cephalopods who exhibit these behaviors suggests that these behaviors are likely Batesian. Mullerian mimics are expected to exhibit less variance, as their success depends upon similar appearance. The fact that cephalopods mimic so many different models, and that these behaviors are not continuously exhibited, suggests a Batesian mimicry model [9]

Why Mimic?

Cephalopods display dynamic mimicry behavior both as a disguise in foraging and as a primary defense to attacks by other species [9] (Conroy). The Indo-Malayan octopus has been found to mimic a swimming flatfish when foraging among worm mounds. This allows the octopus to disguise itself from predators when moving faster along the foraging area. The same species has also taken on the posture of a sea-snake upon attack by territorial damselfishes [9]. These examples, reported by Norman, Finn and Tregenza [9], are the first published observations of cephalopod mimicry of another animal in the absence of the model organism. Previously, the squid Drpioteuthis sepioidea has been observed exhibiting body patterning and behavior to mimic the parrotfish common in its habitat [3][8]. This behavior is exhibited to hide among foraging parrotfish schools, rather than to mimic an individual organism independent of the model organism’s presence [9].

Behavior Characteristics
Such behaviors as these have great adaptive value for the cephalopods that exhibit them. The color changes and body morphs required for such exhibitions are enabled by the mechanisms of chromatophores and high shape flexibility. Developing these high levels of morphological plasticity are an important part of cephalopod ontogeny, and can be explained to a great degree by their phylogeny.