Seasonal distribution of protozoan parasite infections in rainbow trout (Oncorhynchus mykiss) farms in the Eastern Black Sea of Turkey

Abstract

In the present study a total of 8850 rainbow trout (Oncorhynchus mykiss) fry (0.2-10 g) and juveniles (30-80 g) were sampled monthly from 15 farms in the Eastern Black Sea region of Turkey during a one-year period. the parasites Trichodina sp., Chilodonella sp., khthyobodo sp., Ichthyophthirius multifiliis and Spironucleus salmonicida were recorded from all trout farms. Infections with these protozoa are responsible for the high mortality (30% to 50%) rates found in rainbow trout farms in this region. Infested trout displayed exophthalmia, skin discoloration and abdominal distension. the seasonal prevalence of the infections varied between 5.77 +/- 1.46 and 37.72 +/- 4.41% for Trichodina sp., 5.63 +/- 1.36 and 38.25 +/- 12.27% for Chilodonella sp., 5.77 +/- 1.46 and 37.72 +/- 4.41% for khthyobodo sp., 5.34 +/- 1.37 and 49.96 +/- 7.91% for I. multifiliis and 8.02 +/- 4.30 and 38.52 +/- 12.27% for S. salmonicida, respectively. This is the first study to provide seasonal data on the presence and intensity of five protozoan parasites in cultured rainbow trout in Turkey.