Host repertoire
Most species of Cichlidogyrus had a higher structural specificity than expected at random as their di’ estimates often significantly exceeded the respective null distributions (Appendix S5). For the phylogenetic specificity, differences to the null models were less often significant but in case of significant differences, host meta-communities were clustered at the level of mean pairwise distance (MPD) or MPD and mean nearest taxon distance (MNTD) (Appendix S5).
Functional-phylogenetic distances (FPDist) were calculated for all species of Cichlidogyrus with more than one host species (Appendix S6) with the weighting parameter a between 0 and 1. Plots for some species are shown in Fig. 4 to illustrate the main patterns observed across all species. Generally, FPDist decreased with increasing phylogenetic weight (MPD or MNTD) as indicated by the falling trend of FPDist estimates (Fig. 4). Observed MPD and MNTD showed a significant pattern of underdispersion compared to 1000 random simulations in some cases. Specifically, MPD metrics of FPDist became mostly significant if the weight of phylogenetic distances (PDist) increased (i.e. a → 1) (Fig. 4). In contrast, MNTD estimates were largely non-informative regardless of a . One exception to these observation is Cichlidogyrus sp. ‘nyanza’ (Gobbin et al.2021) with MNTD estimates being lowest for a → 0 (Fig. 4).