Detection of Blood Parasites in Fish

Abstract

Fish are often infected with different blood protozoa of the genera Babesiosoma, Trypanosoma, and Hemogrigarina. These blood parasites match the genera which infect the blood of mammals. A total of 120 samples from five different fish species (Barbus grypus, Barbus sharpyi, Liza abu, Carasobarbus luteus, and Aspius vorax) were collected from the Khazar River in Ninevah Governorate, Iraq at weekly intervals during the period from April 2022 to October 2022 for the detection of blood parasites and hematological analysis. Thin and thick Giemsa stained blood smears revealed significant infection with Trypanosoma, Babes iosoma, and Haemogregarina which were recorded in 32%, 16%, and 8% of Carasobarbus luteus samples, respectively; 30%, 15%, and 10% of B. sharpyi samples, respectively; and 23.3%, 16.7%, and 6.7% of B. grypus samples, respectively. No infection with Trypanosoma or Babesiosoma were recorded in L. Abu, and no infection with Babesiosoma or Haemogregarina were recorded in A. vorax. Hematological parameters of blood samples from infected fish showed a significant decrease in hemoglobin concentration, total red blood cells, and stacked cell size along with a significant increase in the number of inflammatory cells including lymphocytes, eosinophils, and basophils. This is the first study to identify blood parasites in fishes and to monitor the changes of hematological parameters in blood samples of infected fishes from the waters of Mosul, Iraq.