The current study included the isolation and diagnosis of fungi from different places of the watercourse of Baghdad University in AL-Jadryia. The samples were collected twice a week for a period of three months, starting from October to December of the year 2022. The results showed average ranges of the air and water temperature with values of 20.6- 34 and 15.5- 24.5^ºC, respectively, while pH ranged from 7.4- 7.7; electrical conductivity ranges were 710- 714μS/ cm, and salinity ranged from 4.4- 4.5mg/ L. The highest percentage of genus identified from water samples was Aspergillus niger, comprising 18.9%.  The isolation of adherent fungi on Limnaea stagnalis revealed a variety of fungal species, with the highest percentage being Aspergillus sp., accounting for 20.2%. The isolation of adherent fungi on the invertebrate Spongilla lacustris showed that Aspergillus sp. had the highest percentage, accounting for 27.1%. Furthermore, isolating fungi from inside the tissues of Limnaea stagnalis, after treating it with a chlorine solution diluted with water to remove all external microorganisms, revealed that Achlya sp. was the most prevalent genus, comprising 27.2%. The fungi obtained from inside Spongilla lacustris tissues showed that Saprolegnia sp. had the highest percentage, accounting for 17.5%. The current study aimed to identify the biological diversity of fungi that were isolated from the stream located in the Jadriyah area, which derives its water from the Tigris River from some types of invertebrates, as well as the possibility of using these types of invertebrates as traps and a natural alternative to cultural media.