Fig. 4

Metazoan parasite abundance, prevalence and species richness in Barbus spp. populations. Mean values (+ standard errors) of log-transformed total abundance and averaged prevalence, and species richness (Chao1 index) of metazoan parasites in B. barbus (BB), B. meridionalis (BM) and their hybrids (H) corrected for fish body length, water temperature and sampling year