Trypanosoma Infection in Freshwater Fish and Its Corellation with Water Quality.

The Nile tilapia (Oreochromis niloticus) and the African sharptooth catfish (Clarias gariepinus) are the most widely cultivated fish species in Egypt. The production cycle runs from spring to autumn, during which water temperatures are conducive to fish growth and the propagation of leeches, which transmit fish hemoflagellates (Trypanosoma spp.). A total of 710 Nile tilapia and 385 catfish were randomly collected from three different sites--two private farms and Burullus Lake--throughout the year. Fish blood samples were examined for Trypanosoma infection. Regardless of fish species or collection site, the highest infection rate of T. mukasai was observed during summer. The catfish samples showed a higher infection rate than the Nile tilapia, and fish farms had higher infection rates compared to Burullus Lake. A positive correlation was found between Trypanosoma infection and water temperature, nitrogenous compounds (unionized ammonia, nitrite, and nitrate), total bacterial count (TBC), and total coliform count (TCC). Based on these findings, Trypanosoma infection can be expected during the production cycle (spring to autumn), and it is recommended to maintain optimal water parameters to prevent conditions favorable to infectious agents. [ABSTRACT FROM AUTHOR]

Copyright of Egyptian Journal of Aquatic Biology & Fisheries is the property of Egyptian Society for Fisheries Development & Human Health and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)