Fig. 2: The impact of background visual patterns on estimates of distance made by Rhinecanthus aculeatus.
From: Visual odometry of Rhinecanthus aculeatus depends on the visual density of the environment
a Overall distance estimates across visual treatments. b Distance estimates across visual treatments, split across fish identity. Fish were trained to a target distance of 0.80 m (horizontal dashed line), and tested across four visual backgrounds. Population averages across treatments were as follows: test 1 mean = 0.759 m; test 2 mean = 0.397 m; test 3 mean = 0.710 m; test 4 mean = 0.935 m. Test 2 produced significant underestimates of distance travelled compared to all visual treatments, and test 4 produced significant overestimates compared to all visual treatments. Box plots indicate the median, interquartile range, and notches compare medians between groups. Grey points indicate individual distance estimates in figure (a) and outliers in figure (b). Sample sizes across fish and treatments were as follows. Test 1: n = 268 (By fish: A, n = 43; B, n = 45; C, n = 45; D, n = 45; E, n = 45; F, n = 45), Test 2: n = 265 (By fish: A, n = 44; B, n = 45; C, n = 44; D, n = 44; E, n = 43; F, n = 45), Test 3: n = 176 (By fish: A, n = 45; B, n = 44; D, n = 43; E, n = 44), Test 4: n = 216 (By fish: A, n = 45; B, n = 44; D, n = 44; E, n = 41; F, n = 42).
