Mean swimming time (%) of fish during experimental testing period.

<p>Mean swimming time (%) of fish during experimental testing period.</p

Allocation preference of fish in the spectral range between 825 and 890 nm (Spectrum S1).

<p>(A). Sector diagrams show mean allocation time [%] with regard to mean head position of fish in 24 sectors of the swimming vessel, representing 15° each. Each left and right sector diagram shows mean data for 15 fish of each species. (B). Bar graphs show mean allocation time of individuals of each fish species [s] ± standard deviation (n = 30) for NIR (black) and control halves (white) of the swimming vessel, respectively.</p

Mean angle (°) of the preferred fish head alignment with regard to direction of the NIR-light source (± mean angular deviation).

<p>Direction to NIR-light source = 0°.</p

Spectral characteristics of applied light.

<p>Spectral characteristics of applied light.</p

Spectra used.

<p>The range of each spectrum was measured by spectroradiometer ILT950 at a distance of 10 cm between swimming vessel and light source. S1: 825–890 nm; S2: 845–950 nm; S3: 910–1020 nm; S4: 930–1020 nm. For wavelengths above 1020 nm only noise of the detecting device was observed.</p

Allocation preference of fish in the spectral range between 845 and 950 nm (Spectrum S2).

<p>(A). Sector diagrams show mean allocation time [%] with regard to mean head position of fish in 24 sectors of the swimming vessel, representing 15° each. Each left and right sector diagram shows mean data for 15 fish of each species. (B). Bar graphs show mean allocation time of individuals of each fish species [s] ± standard deviation (n = 30) for NIR (black) and control halves (white) of the swimming vessel, respectively.</p

Comparison of allocation preference of tested species in different NIR spectra.

<p>(A–E) Lines represent mean allocation time [s] ± standard deviation in NIR (line with circles) and control (line with squares) halves of the swimming vessel for each tested spectrum and species.</p

Allocation preference of fish in the spectral range between 910 and 1020 nm (Spectrum S3).

<p>(A). Sector diagrams show mean allocation time [%] with regard to mean head position of fish in 24 sectors of the swimming vessel, representing 15° each. Each left and right sector diagram shows mean data for 15 fish of each species. (B). Bar graphs show mean allocation time of individuals of each fish species [s] ± standard deviation (n = 30) for NIR (black) and control halves (white) of the swimming vessel, respectively.</p

Length of the mean directional vector <i>R</i>.

<p>Length of the mean directional vector <i>R</i>.</p

Penetration depths of light at spectral ranges of 0.7–1.2 µm.

<p>Curves represent wavelength-dependent penetration of fractions of 10% (gray line), 1% (black line) and 0.1% (black dashed line) of initial light intensities. Graph is based on data from Palmer and Williams <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064429#pone.0064429-Palmer1" target="_blank">[37]</a>.</p