Cephalopods are renowned for their ability to adaptively camouflage on diverse backgrounds. Sepia officinalis camouflage body patterns have been characterized spectrally in the laboratory but not in the field due to the challenges of dynamic natural light fields and the difficulty of using spectrophotometric instruments underwater. To assess cuttlefish color match in their natural habitats, we studied the spectral properties of S. officinalis and their backgrounds on the Aegean coast of Turkey using point-by-point in situ spectrometry. Fifteen spectrometry datasets were collected from seven cuttlefish; radiance spectra from animal body components and surrounding substrates were measured at depths shallower than 5 m. We quantified luminance and color contrast of cuttlefish components and background substrates in the eyes of hypothetical di- and trichromatic fish predators. Additionally, we converted radiance spectra to sRGB color space to simulate their in situ appearance to a human observer. Within the range of natural colors at our study site, cuttlefish closely matched the substrate spectra in a variety of body patterns. Theoretical calculations showed that this effect might be more pronounced at greater depths. We also showed that a non-biological method ("Spectral Angle Mapper"), commonly used for spectral shape similarity assessment in the field of remote sensing, shows moderate correlation to biological measures of color contrast. This performance is comparable to that of a traditional measure of spectral shape similarity, hue and chroma. This study is among the first to quantify color matching of camouflaged cuttlefish in the wild.
|Number of pages
|Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology
|Published - Mar 2013
Bibliographical noteFunding Information:
Acknowledgments We thank Elron Yellin, Sinan Akkaynak and C¸es¸mealtı Güzelles¸tirme Derneg˘i for their help with data collection. We are grateful to Dr. Felice Frankel for helping with data presentation and to four anonymous reviewers for their constructive comments. JJA is grateful for support from a National Defense Science and Engineering Graduate Fellowship. This study was funded by ONR grant N000140610202 to RTH.
- Animal coloration
- Body pattern
- Color match
- Fish predator
- Spectral angle
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Animal Science and Zoology
- Behavioral Neuroscience