1. Department of Poultry and Fish Diseases, Faculty of Veterinary Medicine, Alexandria University, Edfina, Egypt;
2. Department of Fish Biology and Ecology, Central Laboratory for Aquaculture Research, Agriculture Research Center, Abo-Hammad, Sharqia, Egypt;
3. School of Freshwater Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA;
4. Department of Animal Production, Faculty of Agriculture, Kafrelsheikh University, Kafrelsheikh, Egypt;
5. Clinical Division of Fish Medicine, University of Veterinary Medicine, Vienna, Austria