Molecular identification of water molds (oomycetes) associated with chum salmon eggs from hatcheries in Japan and possible sources of their infection
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Oomycete infection of various freshwater animals, including salmonid eggs, causes significant economic damage to aquaculture worldwide. In this study, we detected oomycetes in infected chum salmon Oncorhynchus keta eggs at two hatcheries in northern Japan, in the source water used for egg incubation, and in the air at the hatcheries to clarify the source(s) of oomycete transmission using a DNA molecular marker. Seven oomycete taxa, belonging to Saprolegniaceae and Pythiaceae, were detected from the infected eggs. From the source water used for egg incubation and the air at the hatcheries, nine oomycete taxa, including those found on infected eggs, were detected, suggesting that both water and air are potential sources of oomycete transmission. There is no report of airborne transmission of these oomycetes detected in this study so far. Regarding protection and sterilization against oomycete infection in aquaculture hatcheries, not only water used at hatcheries but also the air in hatcheries may need to be considered hereafter.
KeywordsOomycetes Chum salmon eggs Saprolegniaceae Pythiaceae Internal transcribed spacer 2
We thank the staffs of the two salmon hatcheries for their help with sample collection and Ms. Midori Hagio for DNA analyses.
This study was supported by the research project Tohoku Ecosystem-Associated Marine Sciences from the Ministry of Education, Culture, Sports, Science, and Technology.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All applicable international, national, and/or institutional guidelines for the care and use of animals were followed by the authors.
- Ali SE, Evensen Ø, Skaar I (2015) Recent advances in the mitigation of Saprolegnia infections in freshwater fish and their eggs. In: Méndez-Vilas A (ed) The battle against microbial pathogens: basic science, technological advances and educational programs. Formatex Research Center, Badajoz, pp 691–697Google Scholar
- Braidwood JC (2000) Use of bronopol for the treatment of diseases in fish. Vericore Limited, BasingstokeGoogle Scholar
- Bruno DW, van West P, Beakes GW (2011) Saprolegnia and other oomycetes. In: Woo PTK, Bruno DW (eds) Fish diseases and disorders. Volume 3: viral, bacterial and fungal infections. CABI Publishing, Wallingford, pp 669–720Google Scholar
- Czeczuga B, Bartel R, Kiziewicz B, Godlewska A, Muszyńska E (2005) Zoosporic fungi growing on the eggs of sea trout (Salmo trutta m. trutta L.) in river water of varied trophicity. Pol J Environ Stud 14:295–303Google Scholar
- Diéguez-Uribeondo J, Fregeneda-Grandes JM, Cerenius L, Pérez-Iniesta E, Aller-Gancedo JM, Tellería MT, Söderhäll K, Martín MP (2007) Re-evaluation of the enigmatic species complex Saprolegnia diclina-Saprolegnia parasitica based on morphological, physiological and molecular data. Fungal Genet Biol 44:585–601CrossRefGoogle Scholar
- Kimura T, Yoshimizu M, Tajima K (1980) Disinfection of hatchery water supply by ultraviolet (U.V.) irradiation-II. U.V. susceptibility of some fish pathogenic fungi. Fish Pathol 14:133–137 [in Japanese with English abstract]Google Scholar
- Liu Y, de Bruijn I, Jack AL, Drynan K, van den Berg AH, Thoen E, Sandoval-Sierra V, Skaar I, van West P, Diéguez-Uribeondo J, van der Voort M, Mendes R, Mazzola M, Raaijmakers JM (2014) Deciphering microbial landscapes of fish eggs to mitigate emerging diseases. ISME J 8:2002–2014CrossRefGoogle Scholar
- Ogawa G (2014) Fluctuations in the stock size and return rate, and the damage and recovery from the great East Japan earthquake in hatchery for the chum salmon Oncorhynchus keta in Iwate Prefecture. J North Japan Fish Econ 42:20–23 [in Japanese]Google Scholar
- Vlasenko ML (1969) Ultraviolet rays as a method for the control of diseases of fish eggs and young fishes. Probl Ichthyol 9:697–705Google Scholar
- Yanong RPE, Erlacher-Reid C (2012) Biosecurity in aquaculture, part 1: an overview. South Reg Aquac Cent 4707:1–16Google Scholar