A Second Collection of Monogeneans and Trematodes (Phylum Platyhelminthes) Parasitic on Some Fishes from Tigris River at Baghdad Province, Iraq

Aims: This works aims to report on the monogeneans and trematodes that infect some species of fishes from Tigris River in Baghdad Province, Iraq.
Place and Duration of Study: Tigris River in Baghdad Province at three sites in Baghdad province: Al-Taji in the north of Baghdad city, Al-Shawaka in the center of Baghdad city and Al-Zaafaraniya in the south of Baghdad city during the period from January to December 2011.
Methodology: Monthly samples were collected from three stations from Tigris River in Baghdad province with the aid of gill and cast nets. Fishes were examined for external and internal parasites. For each parasite species, prevalence of infection was calculated.
Statistical Analysis: A comparison of parasitic infections of fishes from the three stations was investigated.
Results and Discussion: Result of inspection showed that five (out of eight) fish species were infected with 13 species of monogeneans and four species of trematodes. The monogeneans included one species each of Paradiplozoon and Thaparocleidus, two species of Gyrodactylus and nine species of Dactylogyrus, while the trematodes included one species each of Ascocotyle and Clinostomum and two species of Diplostomum. Among all these parasites, A. coleostoma infected the highest number of hosts (five host species), while 13 parasite species infected only one host each.
Among these fishes, Carassius carassius was infected with the highest number of parasite species (nine species), followed by Carasobarbus luteus (eight species) and Chondrostoma regium (four species) while no infection was detected from three fish species (Alburnus caeruleus, Cyprinus carpio and Leuciscus vorax).
In addition, a total of seven new host records in Iraq were reported for seven species of these parasites.
Conclusion: Host specificity is clear in monogeneans as 12 out of the 11 monogenean species infected one fish species each. All the trematodes were as metacercariae which later infect piscivorous aquatic birds.