Ergasilus luteusi Al-Sahlany, Adday et Ali, 2024 (CYCLOPOIDA: ERGASILIDAE) parasite of two fishes and effect of length groups, gender and season in Al-Gharraf River, Southern Iraq

The copepod Ergasilus Nordman, 1832 common ectoparasite of both freshwater and marine fishes; however the present work aim to study ecological aspect of new parasite Ergasilus sp. parasite on two freshwater cyprinid (Planiliza abu and Carasobarbus lutues) occurred in Al-Gharraf River, Thi Qar Province, Southern Iraq. The seasonal prevalence by Ergasilus sp. with C. luteus differ little from that from P. abu; while the higher prevalence with the crustacean is found in the median group length of both fish species. The results are discussed according to the variation in environmental factor between seasons, physiological aspect between males and females and the correspondence between second antenna of the parasite and size of gill fillaments.