The physical and chemical parameters of Tigris River water in AL- Kut City have been studied. Three stations have been chosen. . The sampling of study was made monthly and for six months from September 2014 until February 2015.The result of turbidity values showed height mean in summer 84 NTU, The decrease of turbidity was one of the positive results to the effect of AL-Kut Dam on the Tigris River after the Dam and on the total suspended solids. The electrical conductivity was 1340 µs/cm in winter that may be due to the existence of the polluted elements. The river water was fresh (0.48‰ semiebrachish) with a good aerated water and the height of the dissolved oxygen mean value has been noticed 13.1mg/L at many times. Over satura

    Literature reviews of reports concerning the parasitic fauna of fishes of Al-Diwaniyah province, Iraq till the end of December 2018 showed that a total of 43 parasite species are so far known from 13 valid fish species investigated for parasitic infections. The parasitic fauna included one euglenozoan, two myzozoans, six ciliophorans, three myxozoans, three trematodes, nine monogeneans, four cestodes, six nematodes, three acanthocephalans and six crustaceans. The infection with the trematodes, one monogenean, two cestodes and one nematode occurred with larval stages, while the remaining infections were either with trophozoites or adult parasites. Among the inspected fishes, Carasobarbus luteus was infected wit

 A total of 1453 freshwater fishes, belonging to 14 species of the
family Cyprinidae was collected from Lesser Zab and Greater Zab
rivers in north of Iraq during the period from November 2000 to the
end of November 2001. The inspection of skin, gills and different
internal organs revealed the infection of these fishes with a total of 14
species of Myxobolus which included seven species that represented
their first record in Iraq. These species included M. bulbocordis from
both Barbus sharpeyi and Chondrostoma regium; M. karuni from B
grypus; M. mesopotamiae from B. luteus; M. molnári from B
esocinus; M. pcrsicus from both B. grypus and Cyprinion macrostomum;
M.  Shaagani from both B. b

For the first time in Iraq, two species of monogenetic tretamtodes of the genus Dactylogyrus were recorded from gills of Alburnus caeruleus from Tigris river at Al-Zaafaraniya, south of Baghdad during June 1995. The first species, Dactylogyrus sphyrna is characterized by having the seventh pair of marginal hooklets almost twice as large as other marginal hooklets, powerful inner and outer processes of median hooks especially the inner one which is expanded terminally, one connecting bar and long spirally twisted copulatory organ. The second species, Daclytogyrus phoxini differs from the first one by having marginal hooklets of the same size, inner and outer processes of median hooks are not powerful, two connecting bars

The foreguts of a total of 515 fish of Chondrostoma regium (Heckel, 1843) (locally: Bala’aot Malloky) were studied. These fish were collected from Tigris River at Salah Al-Deen Province (between Al-Hagag & Yathrib) for 20 months between March and October of the next year. Detritus, plant in origin materials (19.6%, 23.0% & 24.9%); green and blue green algae, mostly Cladophora, Cosmarium and Merismpedia sp. (17.1%, 12.9% & 12.2%) and diatoms, mostly Diatoma, Chanathes, Amphora and Cyulbella sp. (16.9%, 8.8% & 8.2%) were the main food categories taken by these fishes according to occurrence (O%), volumetric methods (V%) and ranking index (R%). Debris (not part of the diet) took 45.3% of the studied fish foreguts by volume. Detritus was also

    A total of 54 abu mullet Planiliza abu (Heckel, 1843) were collected from two stations (north and south stations) along the Euphrates River near Samawa City, Al-Muthanna province and were examined during the period from October 2016 till September 2017 for parasites. Six out of 35 examined fishes from the north station (17.1%) and one out of 19 examined fishes (5.3%) from south station were infected with the microcotylid Solostamenides paucitesticulatus Kritsky & Öktener, 2015. The parasite was illustrated and described, and it is considered as a new record for the parasitic fauna of fishes of Iraq.

Sludge worm samples were collected from the Tigers River sediment during the period from November 2018 to June 2019 in Al Sarafiya District/ Baghdad- Iraq. Biometric morphological measurements focusing on the form of penis sheath and chaetal morphology were used for species identification, in addition to molecular analysis by amplification of conserved 18s rRNA encoding gene using ITS1 and ITS4 universal primers.According to the morphological measurement records, the results revealed the existence of Limnodrilus hoffmeisteri Claparede 1862, L. claparedeianus Ratzel, 1868 and L. cervix Brinkhurst 1963. Other two groups of specimens, with short penis sheath, were identified by molecular technology as L

The study was conducted to measure diatom species diversity in the lotic ecosystem across the Wasit Province for 12 months. The quantitative study of diatoms (phytoplankton) was investigated in the Tigris river. The density of algae was ranged from 60989 cell×103/l to 112780.82 cell×103/l in the five sites. These algae were belonging to 39 genera. The richness index values ranged from 1.53 at site 5 in January 2016 to 6.34 at site 1 and June2015. Shannon-Weiner diversity index (H´) was 2.33 in February 2016 and 3.72 in June 2015 both values at site 3, whereas Evenness index was 0.54 at site 5 in March2016 and 0.98 at site 1 in both August2015 and May2016. The lack of homogeneity of the appearance of species indicates the dominance of a