Fitness of control and aposymbiotic D. fasciatus on an artificial diet with and without B vitamins, respectively. (a,b) Survivorship and developmental time from egg hatching to adulthood, respectively. Shading of boxes signifies the experimental treatments. Lines represent medians, boxes comprise the 25–75 percentiles and whiskers denote the range. Significant differences (Friedman test with Wilcoxon–Wilcox post hoc measures, p < 0.05) are marked by an asterisk.