Parasite Diversity of Freshwater Fishes from Al-Gharraf River, Dhi-Qar Province and Remarks on such Helminth Parasites in Tigris River, Iraq

The Al-Gharraf River is a major distributary of the Tigris River, branching from its right bank at the Kut Dam and flowing into the Euphrates basin. It traverses the provinces of Wasit and Dhi-Qar before ending in the Al-Hammar marsh. This river is ecologically significant due to its diverse fish populations; however, the parasites inhabiting these fish remain understudied. The parasite diversity in the Al-Gharraf River comprises 28 species belonging to five major taxa: 12 species of Monogenoidea, 6 Trematoda species, 6 Cestoda species, 2 Nematoda species, and 2 Acanthocephala species, which have been isolated from nine different fish hosts. A comparison between current parasite assemblages and historical records indicates that most identified parasites show considerable colonization from the Tigris River. This pattern reflects either the specificity of intermediate hosts for internal parasites present in this region or the ecological conditions in the river that favor external parasites.