MOESM2 of Calcium ions in the aquatic environment drive planarians to food

Additional file 2: Figure S1. Feeding behavior assays in tap water with or without EGTA. a. The food-localization assay in tap water containing 10 mM EGTA. Planarians in tap water (Ctrl) showed a preference for moving to and staying in the region with the food, whereas planarians in tap water containing 10 mM EGTA did not show such food-localization behavior. This result is consistent with the results obtained using Kanatani water. t = 300 s. b. Time spent in the target quadrant during assay of planarians in tap water containing EGTA is shown as a box-and-whisker plot with mean (circles). c. Speed of movement of planarians during the assay. The absence of calcium ions in the environmental water impaired the motor activity. d. The food-localization index is the adjusted value of the spent time in the target quadrant calculated by assuming all individuals had the same speed of movement. The adjustment was performed using the median value of the speed (0.60 mm/sec) of the planarians in tap water containing EGTA. e. The feeding index of planarians in tap water containing EGTA is shown as a box-and-whisker plot with means (circles). Chelation of calcium ions by EGTA in tap water reduced food intake. **, p < 0.01; ***, p < 0.005 (Wilcoxon test).