Fig. 4: Relationships between the probability of non-native fish occurrence and nonnative-native phylogenetic distance in six biogeographical realms of the world.

a The relationship in the Palearctic realm. b The relationship in the Afrotropic realm. c The relationship in the Neotropic realm. d The relationship in the Australasia realm. e The relationship in the Indo-Malay realm. f The relationship in the Nearctic realm. For each biogeographical realm, (i) the variation in the occurrence probability of exotic fish species with the MPD between exotic and native fish species, (ii) the variation in the occurrence probability of exotic fish species with the MNTD between exotic and native fish species, (iii) the variation in the occurrence probability of translocated fish species with the MPD between translocated and native fish species, and (iv) the variation in the occurrence probability of translocated fish species with the MNTD between translocated and native fish species. Statistical tests and predictive curves were obtained using generalized linear mixed models (GLMMs) while assuming a binomial error distribution, with solid lines representing significant effects (p < 0.05). Statistical significance (p values) and sample size (n) are displayed in the figure. Different colors are used to highlight the relationships observed in different biogeographical realms. For each realm, a chord diagram illustrates the network relationship between countries and exotic fish species, showing which exotic fishes have been introduced into specific countries and which countries have introduced specific exotic fish species. The most frequently introduced exotic fish species and the country that introduced the largest number of exotic fish species are noted below the chord diagrams for clarity.