Two species of monogenetic trematodes of the genus Dactylogyrus were recorded in the present paper for the first time in Iraq from two freshwater fishes from Diyala river, Diyala province. The first species,  D. bocageii Alvarez Pellitero, Vicente et Gonzalez Lanza, 1981 was recorded from gills of Aspius vorax, the second species, D. lenkorani Mikailov, 1967 was recorded from gills of Barbus sharpeyi. The descriptions and measurements of these parasites as well as their illustrations were given.

A total of 72 individuals of genus Pristina were sorted from aquatic plant, Ceratophyllum demersum L., and filamentous algae collected from three sites on Tigris River at Baghdad including: Al-Sarafiya area (S1), Al- Jadiriyah area (S2), and Al- Za´afaraniya area (S3). Four species were identified including P. longiseta, P. aequiseta, P. proboscidea and P. foreli, with percentags of 51.7 , 36.4, 1.1, and 10.5 % respectively. The first two species found in all sites , while , P. proboscidea found only in S1 and P. foreli only in S2.

This study was performed on the Tigris River (Baghdad city section) during the period between December 2016 and December 2018 to assess seasonal variation in water quality using the Overall Index of Pollution (OIP). The OIP is one of the reliable tools for the assessment of surface water quality. To calculate OIP-values, eight parameters were measured ( pH, Dissolved Oxygen "DO", Biological Oxygen Demand "BOD", Total Dissolved Solid "TDS", Total Hardness "TH", calcium "Ca", Sulphate "SO4" and Alkalinity). The results showed the anthropogenic activities impact of Baghdad population that directly discharge of "inadequate treated" waste water to the river.  OIP values were acceptable (1˃OIP˃ 1.7) in 2011, 2012, 2013 and 2018. However, in

Sheikh Hanafi was born in one of the popular shops of Baghdad with interlocking social relations, and had a profound impact this camp where his talents in the first Venco loving to Mahalah and Baghdad and was born with this development since his days looked forward to the folklore and folk. In the middle of his youth, including authoring loves the heritage of folk legacies began in motion, from Baghdad, books, articles, research has brought him wide acclaim were not possible without the seriousness and diligence, independence and self-Asamath that mushroom on them
The trip was one of his tools in the scientific fame has gone to many Eastern and Asian countries and visited religious and literary institutes and delivered the lectures an

      Three monogeneans: Dactylogyrus folkmanovae from gills of Chondrostoma regium, D. reinii from gills of Mesopotamichthys sharpeyi and D. robustus from gills of Leuciscus vorax were collected from Diyala River in Diyala Province. The description, measurements and illustrations of these parasites were given.

Seasonal variations of the species composition and abundance of Cladocera were studied in two stations at the end of the Tigris River and one station at the confluence of the Tigris with Euphrates area, at the beginning of the Shatt Al-Arab River in Al-Qurnah North of Basrah Province, from October 2015 to August 2016. Samples of zooplankton were collected by plankton net 100-µm. mesh size. The population density of Cladocera ranged between 1 Ind /m³ during summer and 211 Ind./m³ during winter at station 1 (Al-Jewaber Bridge). A total of 16 species of Cladocera belonging to 12 genera were recorded in the study. The average density of Cladocera ranged from 23.2 ind./m³ at Station 2 (Hamayon Bridge) to 53.7 Ind./m³