Double cones are used for colour discrimination in the reef fish, Rhinecanthus aculeatus

Biol Lett. 2010 Aug 23;6(4):537-9. doi: 10.1098/rsbl.2009.1010. Epub 2010 Feb 3.


Double cones (DCs) are the most common cone types in fish, reptiles and birds. It has been suggested that DCs are used for achromatic tasks such as luminance, motion and polarization vision. Here we show that a reef fish Rhinecanthus aculeatus can discriminate colours on the basis of the difference between the signals of individual members of DCs. This is the first direct evidence that individual members of DCs are used in colour vision as independent spectral channels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Color Vision / physiology*
  • Discrimination Learning / physiology
  • Models, Biological
  • Retinal Cone Photoreceptor Cells / cytology*
  • Retinal Cone Photoreceptor Cells / physiology*
  • Tetraodontiformes / anatomy & histology
  • Tetraodontiformes / physiology*