ABSTRACT
Parrotfishes are a group of fishes which exhibit highly diverse colours and colour patterns. This chapter provides a comprehensive summary of current knowledge on parrotfish coloration as well as on the visual system of this group of fish. In order to understand the functions of the colours, it is important to evaluate the colours not from the perspective of humans but rather from that of the intended receiver, e.g. other parrotfish. This chapter therefore includes information about the various parameters necessary to evaluate how a parrotfish might see another parrotfish. The physical properties of fish colours, the mechanisms of different modes of colour changes and the functions of fish colours are discussed, as well as the properties of the underwater light spectrum and the different components of the visual system required for the detection of fish colour patterns. This general review then forms the context within which to better interpret parrotfish colour diversity and vision.
