camouflage in colour-changing animals: Trade-offs and constraints

Abstract

Colour change is widespread in ectotherm animals including crustaceans, insects, cephalopods, amphibians, reptiles and fish (Bagnara & Hadley 1973). There are two types of colour change, morphological and physiological, which differ in their mechanism and speed. Morphological colour change occurs due to changes in the density and quality of pigment-containing cells (chromatophores) in the dermis (a layer of the skin) and usually takes place over a timescale of days or months. For instance, a common form of morphological colour change is long-term background or chromatic adaptation, in which the animal's colour changes to more closely resemble that of the background. Long-term background adap..