Dynamic Mimicry

The common octopus (Octopus vulgaris) is found in tropical and temperate waters throughout the worlds oceans. Selection pressures are high for the common octopus, with almost every known marine carnivore as a predator, it's no wonder they have developed such an effective defense mechanism (Hanlon, 2007).

WATCH: Octopus vulgaris Camouflage Change

You've all seen the footage of this amazing camouflage, but how does it work?

Cephalopods (octopus, cuttlefish and squid) have the ability to rapidly alter their body pattern, both colour and apparent texture depending on their surroundings. When threatened, the common octopus uses a complex visual system to rapidly produce neurally controlled body patterns to mimic their surroundings. Coordinated optical malleability within the skin combines pigmentary and structural colouration to successfully and almost instantly, blend in to coral reefs, sea grass, kelp forest and even sand. Iridiphores (directional structural reflectors) produce polarized signals to overlying pigmented chromatophores (pigment containing, light reflecting cells)(Hanlon, 2007). 

With this adaptive and dynamic mimicry it's no wonder the octopus is considered by many to be the most intelligent invertebrate. 

References:

Hanlon, R. 2007, "Cephalopod dynamic camouflage", Current Biology, vol. 17, no. 11, pp. R400-R404.

Video - https://www.youtube.com/watch?v=JSq8nghQZqA 

Mimicry in Hawk-moth Species for Offspring Survival

 

In the larval stage of the Hawk-moths life cycle, individuals exhibit cunningly deceptive markings resembling reptilian facial features (shown below in Figure 1). 

Figure 1. A threatened Hawk-moth (Deilephila elpenor) caterpillar displaying impressive markings, mimicking a snake head, to ward off predators.

This type of mimicry, known as Batesian mimicry, is used by a harmless species in order to avoid predation (Mappes & Alatalo, 1997). By mimicking the features of a snake, Hawk-moths larvae send a signal to potential predators that they are not palatable (containing toxic bodily fluids), or that they themselves are harmful predators. Deceiving predators, even for just a brief moment, enables the larvae an opportunity to escape mealtime. This physical adaptation allows a greater chance of offspring survival, and ultimately impacts on the survival of the entire population  (Rothschild, 1989). 

Figure 2. Spurge Hawk-moth (Hyles euphorbia) and it's eggs, disguised on a spurge plant as unripe seeds.

 

Spurge Hawk-moths (Hyles euphorbia), pictured in Figure 2, provide another example of mimicry used to aid offspring survival. Spurge Hawk-moths lay their eggs on the apex of spurge plants, within full sight of predators. The eggs, however, strongly resemble the unripe seeds of spurge plants and therefore disguise themselves as an unpleasant meal (Rothschild, 1989).  

References:

Mappes, J. & Alatalo, R.V. 1997, "Batesian Mimicry and Signal Accuracy", Evolution, vol. 51, no. 6, pp. 2050-2053.

Rothschild, M. 1989, "Moths and memory", Endeavour, vol. 13, no. 1, pp. 15-19.

Figures:  

www.telegraph.co.uk

 Rothschild, M. 1989, "Moths and memory", Endeavour, vol. 13, no. 1, pp. 15-19.