Dimensions and settings of the preference chamber.

<p>Dimensions and settings of the preference chamber.</p

Results of the second order polynomial regression for specific growth rate (SGR), total feed intake (TFI) and feed conversion ratio (FCR).

<p>Results of the second order polynomial regression for specific growth rate (SGR), total feed intake (TFI) and feed conversion ratio (FCR).</p

Water temperatures in the preference chamber during the preference tests for the three acclimation temperatures.

<p>Mean (SD, n = 6) water temperatures in the five temperature zones during the non-gradient observation, installation of the temperature gradients and acute preference observations are presented for the tests conducted with fish acclimated to 18°C (A), 22°C (B) and 28°C (C). Water temperatures during the 24 h preference observation equalled the water temperatures during the acute preference observations (not shown).</p

Water temperatures during the growth experiment.

<p>For each temperature treatment the mean (SD, n = 2) water temperature during the acclimation, installation of temperatures and the experiment is presented. Overall mean temperature per treatment during the experiment (n = 26) differed significantly among all treatments (ANOVA, p<0.0001).</p

Fish distribution over the preference chamber.

<p>Fish distributions during non-gradient, acute preference and 24 h preference observations are expressed as odds ratios (proportion of temperature zones used dived by the proportion of temperature zones available) and are presented for fish acclimated to 18°C (A), 22°C (B) and 28°C (C). Fish distribution was non-random during all non-gradient observations (MANOVA, p = 0.002) without differences among temperature acclimation treatments (MANOVA, p = 0.42). Fish distribution observed during acute preference observations differed significantly from the non-gradient observations (MANOVA, p<0.001). Fish distribution during 24 h preference observations differed significantly from the non-gradient (MANOVA, p<0.0001) as well as the acute preference observations (MANOVA, p<0.002). Among acclimation temperature treatments fish distribution differed during acute preference observations (MANOVA, p = 0.01) but not during the 24 h preference observations (MANOVA, p = 0.21).</p

Schematic presentation of the preference chamber.

<p>Top view (A) presents schematically the water flows (arrows) and the main elements: 1) water inflow, 2) mixing channel, 3) swimming channel, 4) effluent channel, 5) central section with water drain. Top view (B) presents schematically the temperature gradient in the preference chamber.</p

Ranking of the use of the temperature zones in the preference chamber (PC) by Dover sole acclimated to 18, 22 and 28°C, directly after installation of the temperature gradient (acute preference) and 24 h thereafter (24 h preference).

<p>Ranks with different superscripts are significantly different (t-test, p<0.05). 4 = most used, 0 = least used.</p