1. Research Institute for Aquaculture No. 3, 33 Dang Tat St., Nha Trang, Vietnam.
2. Department of Veterinary Pathobiology, Faculty of Life Sciences, University of Copenhagen, Frederiksberg C 1870, Denmark.
3. Institute for Biology, University of Bergen, Allegaten 41, Bergen N-5007, Norway.
4. Department of Aquaculture, Nha Trang University, 2 Nguyen Dinh Chieu, Nha Trang, Vietnam.
5. Research Institute for Aquaculture No. 1, Dinh Bang, Tu Son, Bac Ninh, Vietnam.