Quantifying pigment cover to assess variation in animal colouration

Siegenthaler, A; Mondal, D; Benvenuto, C

Abstract

The study of animal colouration addresses fundamental and applied aspects relevant to a wide range
of fields, including behavioural ecology, environmental adaptation and visual ecology. Although a
variety of methods are available to measure animal colours, only few focus on chromatophores
(specialized cells containing pigments) and pigment migration. Here, we illustrate a freely available
and user friendly method to quantify pigment cover (PiC) with high precision and low effort using
digital images, where the foreground (i.e., pigments in chromatophores) can be detected and
separated from the background. Images of the brown shrimp, Crangon crangon were used to
compare PiC with the traditional Chromatophore Index (CI). Results indicate that PiC outcompetes CI
for pigment detection and transparency measures in terms of speed, accuracy and precision. The
proposed methodology provides researchers with a useful tool to answer essential physiological,
behavioural and evolutionary questions on animal colouration in a wide range of species.

Citation

Siegenthaler, A., Mondal, D., & Benvenuto, C. (2017). Quantifying pigment cover to assess variation in animal colouration. Biology Methods and Protocols, 2(1), bpx003. https://doi.org/10.1093/biomethods/bpx003

• Journal Article Type: Article
• Acceptance Date: Feb 17, 2017
• Online Publication Date: Mar 27, 2017
• Publication Date: Mar 27, 2017
• Deposit Date: Mar 8, 2017
• Publicly Available Date: Mar 31, 2017
• Journal: Biology Methods & Protocols
• Electronic ISSN: 2396-8923
• Publisher: Oxford University Press
• Volume: 2
• Issue: 1
• Pages: bpx003
• DOI: https://doi.org/10.1093/biomethods/bpx003
• Publisher URL: http://dx.doi.org/10.1093/biomethods/bpx003
• Related Public URLs: http://biomethods.oxfordjournals.org/
• Additional Information: Projects : Effects of contaminants in the brown shrimp Crangon crangon: a field-based approach