Introduction

Human and animal expressions and postures reveal and communicate basic emotional states such as fear, aggression, contentment, disgust and sexual arousal. Body patterns of cephalopod molluscs such as cuttlefish, octopus and squid give a comparable but richer medium of expression (Hanlon & Messenger 1988). The cuttlefish, Sepia, varies its body coloration with unsurpassed versatility. Some patterns blend cryptically with the textures of the seafloor, while others are conspicuous displays used for communication with members of its own and with other species. Sepia's use of shapes and textures to create patterns that communicate or conceal is a rich and exotic mode of expression. Sometimes changes are so rapid and dramatic it is as if one can see the animals thinking.

Sepia's coloration patterns provide unique access to the perception and expression of a non-human animal, but hitherto have been difficult to analyse (Hanlon & Messenger 1988). Now using advanced image processing and statistical techniques, warping and independent component analysis, we find that cuttlefish flexibly express a small number of relatively simple motifs at different weights to produce a rich array of coloration patterns. This is not surprising; mixing simple elements to create complexity and meaning is fundamental both to the expression of emotion in man and animals? (Darwin 1872), and to artistic expression.

References

 

Darwin C (1872) The expression of emotion in man and animals. John Murray, London

Hanlon RT & Messenger JB (1988) Adaptive coloration in young cuttlefish (Sepia officinalis L.): the morphology and development of body patterns and their relation to behaviour. Phil. Trans. R. Soc. Lond. (B) 320,437-487