Data from: Plasticity contributes to a fine-scale depth gradient in sticklebacks’ visual system

The light environment influences an animal’s ability to forage, evade
predators, and find mates, and consequently is known to drive local
adaptation of visual systems. However, the light environment may also vary
over fine spatial scales at which genetic adaptation is difficult. For
instance, in aquatic systems the available wavelengths of light change
over a few meters depth. Do animals plastically adjust their visual system
to such small-scale environmental light variation? Here, we show that in
threespine stickleback (Gasterosteus aculeatus), opsin gene expression (an
important determinant of colour vision) changes over a 2-meter vertical
gradient in nest depth. By experimentally altering the light environment
using light filters to cover enclosures in a lake, we found that opsin
expression can be adjusted on a short time frame (weeks) in response to
the local light environment. This is to our knowledge the smallest spatial
scale on which visual adjustments through opsin expression have been
recorded in a natural setting along a continuously changing light
environment.