Morphological and molecular evidence for Paradiplozoon vorax sp. nov. (Polyopisthocotyla: Diplozoidae) from Leuciscus vorax in southern Iraq

Freshwater streams in Iraq harbour a remarkable diversity of the fish species.Similarly high diversity is also recorded for diplozoid parasites, which are commonly associated with the cyprinoid fish.A new species Paradiplozoon vorax sp.nov. is described from Leuciscus vorax from Al-Gharraf River.This is the 21 st Paradiplozoon species recorded from Iraq and presumably the eleventh species from this fish host.Phylogenetic analyses based on ITS2 rDNA region revealed a close relationship between Paradiplozoon vorax sp.nov.and P. pavlovskii, which exhibits wide geographical range spanning Europe and the Middle East.Although these two species are morphologically similar, they differ in important characters such as number of folds in the hindbody, shape of postovarian caecum, or shape of anterior joining sclerite of clamps.It is hypothesized that these two species originated by vicariant speciation from a common ancestor associated with ancestral Aspius-like leuciscids.