Molecular identification and characterization of waterborne protozoa among stranded Dugong dugon

The Persian Gulf hosts the second-largest population of Dugongs. The International Union for the Conservation of Nature (IUCN) lists them as Vulnerable to Extinction species. Incidental fishing, vessel strikes, environmental pollution, habitat degradation, and infectious diseases currently threaten these sirenians. While research focused on the abovementioned threats, little is known about pathogen infections, particularly waterborne parasites. The current study aimed to investigate the prevalence of the waterborne parasites, namely Blastocystis , Cryptosporidium , Dientamoeba fragilis , Giardia duodenalis , and Toxoplasma gondii in the Qatar Dugongs population. Hence, twenty-three tissues from stranded Dugongs' carcasses were collected postmortem and subjected to DNA extraction and parasite qPCR screening. Only Blastocystis and Cryptosporidium species were detected in different tissues across the tested animals harboring genotypes ST1 and Cryptosporidium hominis IbA9G3, respectively, with the first-time report of Blastocystis sp. within sirenian hosts. Continuous monitoring should be provided to shed lights about the contamination sources of these endangered species and clarify the zoonotic potential transmission routes between wildlife and humans. • The widespread of parasites and their environmental resistance may lead to their transmission to wild endangered marine fauna. • Only Blastocystis and Cryptospordium have been identified within stranded Dugongs • First time report on Blastocystis sp. from sirenians extending the host range of this protozoan • The Cryptosporidium “Human” genotype, renamed C. hominis harboring IbA9G3 genotype was identified.