From an evolutionary perspective, parasites and their hosts co-evolved. As a result, parasites have developed various morphological traits, including those associated with attachment organs, enabling them to append successfully to different hosts. Monogeneans, as ectoparasites with a monoxenous life cycle, exhibit extraordinary morphological diversity. They also express various levels of host specificity ranging from strict host specialist (i.e., a single parasite species infects a single host species) to generalist (i.e., a single parasite species infects phylogenetically distant host species). This host-specificity is partially associated with morphological adaptation, which is also evident at the intraspecific level.
Various patterns of morphological adaptation in host-parasite systems have been previously neglected. Therefore, this thesis aims to summarize the literature on the application of morphological methods in parasitology with a focus on analyzing the morphological intraspecific variability and the potential of these methods to detect differences between parasite specimens of the same species on various hosts. For the practical part, the student will analyze the effects of geographical distribution and host population/species on the morphological intraspecific variability of Dactylogyrus lenkorani, a generalist representative of the genus Dactylogyrus parasitizing various host populations or host species across the Middle East (different geographically distant basins). All the parasitological material originated from the Middle East field study.