Molecular Phylogenies of Leeches and Haemoparasites Infecting Freshwater Turtles in Aquatic Ecosystems of Northern Africa Suggest Phylogenetic Congruence between Placobdella costata Sensu Lato and Haemogregarina stepanowi Sensu Lato.

Haemogregarines are blood parasites with a life-cycle involving a vertebrate as the intermediate host and an invertebrate as the definitive host and vector. Extensive phylogenetic investigations based on 18S-rRNA gene sequences have shown that (Apicomplexa: Haemogregarinidae) is able to infest a large diversity of freshwater turtle species, including the European pond turtle , the Sicilian pond turtle , the Caspian turtle , the Mediterranean pond turtle , and the Western Caspian turtle , among others. From the same molecular markers, is further considered to be a complex of cryptic species predisposed to infect the same host species. While is known to be the unique vector of , it is only recently that independent lineages within have been illustrated-suggesting the presence of at least five unique leech species across Western Europe. The aims of our study were therefore to investigate from mitochondrial markers (COI) the genetic diversity within haemogregarines and leeches infecting freshwater turtles of the Maghreb, in order to identify processes of parasite speciation. We showed that consists of at least five cryptic species in the Maghreb, while two species were identified in the same area. Although an Eastern-Western speciation pattern was apparent for both leeches and haemogregarines, we cannot make definitive conclusions regarding co-speciation patterns between parasites and vectors. However, we cannot reject the hypothesis of a very strict host-parasite specificity within leeches.