The Effects of Short Freshwater Bath Treatments on the Susceptibility to Different Stages of Neobenedenia girellae Infecting Barramundi (Lates calcarifer)

Truong Dinh Hoai 1 , Trinh Thi Trang 2 and Nguyen Thi Huong Giang 3

1Faculty of Fisheries, Vietnam National University of Agriculture, Hanoi
2Faculty of Fisheries, Vietnam National University of Agriculture, Hanoi 131000, Vietnam
3Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 131000, Vietnam
Received: Jun 9, 2019 /
Revised: Dec 24, 2019 /
Published: Dec 24, 2019

Main Article Content

Full-Text | pdf


Neobenedenia girellae is one of the most pathogenic parasites affecting marine fish in captivity conditions. The use of chemicals for parasite prevention and treatment have several benefits; however, they can cause various negative side-effects. In an effort to discover cost-effective and sustainable practices, our current study was aimed at investigating the efficiency of freshwater treatments on N. girellae. A challenge test was conducted to produce infected fish which became materials for the freshwater immersion experiments. The duration and reaction of the parasites at different development stages from eggs to adult parasites were examined. Our findings revealed that 100% of the adults and oncomiracidia of N. girellae were killed quickly in freshwater. The eggs of N. girellae, however, were highly resistant to freshwater with a hatching success rate of more than 95% in all the freshwater immersion treatments (2, 5, 10 and 30min). The eggs hatched mainly on day 7 and finished hatching on day 8. Thus, the freshwater immersion method can be applied to treat N. girellae at most stages excepted for the egg stage. The best practical treatment for this parasite is to perform a replicated immersion recommended 8 days following the first treatment.

Keywords: N. girellae, freshwater, treatment, parasites, marine fish

Article Details

How to Cite
Hoai, T., Trang, T., & Giang, N. (2019). The Effects of Short Freshwater Bath Treatments on the Susceptibility to Different Stages of Neobenedenia girellae Infecting Barramundi (Lates calcarifer). Vietnam Journal of Agricultural Sciences, 2(3), 409-417.


    Brazenor A. K. & Hutson K. S. (2015). Effects of temperature and salinity on the life cycle of Neobenedenia sp. (Monogenea: Capsalidae) infecting farmed barramundi (Lates calcarifer). Parasitology Research. 114(5): 1875-1886.
    Buchmann K., Roepstorff A. & Waller P. (1992). Experimental selection of mebendazole‐resistant gill monogeneans from the European eel, Anguilla anguilla L. Journal of Fish Diseases. 15(5): 393-408.
    Bullard S. A., Goldstein R. J., Hocking R. & Jewell J. (2003). A new geographic locality and three new host records for Neobenedenia melleni (MacCallum) (Monogenea: Capsalidae). Gulf and Caribbean Research. 15(1): 1-4.
    Deveney M. R., Chisholm L. A. & Whittington I. D. (2001). First published record of the pathogenic monogenean parasite Neobenedenia melleni (Capsalidae) from Australia. Diseases of Aquatic Organisms. 46(1): 79-82.
    Diggles B., Roubal F. & Lester R. (1993). The influence of formalin, benzocaine and hyposalinity on the fecundity and viability of Polylabroides multispinosus (Monogenea: Microcotylidae) parasitic on the gills of Acanthopagrus australis (Pisces: Sparidae). International Journal for Parasitology. 23(7): 877-884.
    Ellis E. P. & Watanabe W. O. (1993). The effects of hyposalinity on eggs, juveniles and adults of the marine monogenean, Neobenedenia melleni Treatment of ecto-parasitosis in seawater-cultured tilapia. Aquaculture. 117: 15-27.
    Fajer-Ávila E. J., Martínez-Rodríguez I., de la Parra M. I. A., Álvarez-Lajonchere L. & Betancourt-Lozano M. (2008). Effectiveness of freshwater treatment against Lepeophtheirus simplex (Copepoda: Caligidae) and Neobenedenia sp. (Monogenea: Capsalidae), skin parasites of bullseye puffer fish, Sphoeroides annulatus reared in tanks. Aquaculture. 284(1): 277-280.
    Hirazawa N., Mitsuboshi T., Hirata T. & Shirasu K. (2004). Susceptibility of spotted halibut Verasper variegatus (Pleuronectidae) to infection by the monogenean Neobenedenia girellae (Capsalidae) and oral therapy trials using praziquantel. Aquaculture. 238(1-4): 83-95.
    Hirazawa N., Takano R., Hagiwara H., Noguchi M. & Narita M. (2010). The influence of different water temperatures on Neobenedenia girellae (Monogenea) infection, parasite growth, egg production and emerging second generation on amberjack Seriola dumerili (Carangidae) and the histopathological effect of this parasite on fish skin. Aquaculture. 299(1-4): 2-7.
    Hoai T. D. & Hutson K. S. (2014). Reproductive strategies of the insidious fish ectoparasite, Neobenedenia sp. (Capsalidae: Monogenea). PLoS One. 9(9): e108801. DOI: 10.1371/journal.pone.0108801.
    IBM C. (2016). IBM SPSS statistics for Windows, version 24.0. Armonk: IBM Corp.
    Kaneko J., Yamada R., Brock J. & Nakamura R. (1988). Infection of tilapia, Oreochromis mossambicus (Trewavas), by a marine monogenean, Neobenedenia melleni (MacCallum, 1927) Yamaguti, 1963 in Kaneohe Bay, Hawaii, USA, and its treatment. Journal of Fish Diseases. 11(4): 295-300.
    Liao I. C., Huang T. S., Tsai W. S., Hsueh C. M., Chang S. L. & Leaño E. M. (2004). Cobia culture in Taiwan: current status and problems. Aquaculture. 237(1-4): 155-165.
    Ohashi H., Umeda N., Hirazawa N., Ozaki Y., Miura Y. C. & Miura T. (2007). Purification and identification of a glycoprotein that induces the attachment of oncomiracidia of Neobenedenia girellae (Monogenea, Capsalidae). International Journal for Parasitology. 37(13): 1483-1490.
    Ohno Y., Kawano F. & Hirazawa N. (2009). The effect of oral antibiotic treatment and freshwater bath treatment on susceptibility to Neobenedenia girellae (Monogenea) infection of amberjack (Seriola dumerili) and yellowtail (S. quinqueradiata) hosts. Aquaculture. 292(3-4): 248-251.
    Ogawa K., Miyamoto J., Wang H. C., Lo C. F. & Kou G. H. (2006). Neobenedenia girellae (Monogenea) infection of cultured cobia Rachycentron canadum in Taiwan. Fish Pathology. 41(2): 51-56.
    Thoney D. (1990). The effects of trichlorfon, praziquantel and copper sulphate on various stages of the monogenean Benedeniella posterocolpa, a skin parasite of the cownose ray, Rhinoptera bonasus (Mitchill). Journal of Fish Diseases. 13(5): 385-389.
    Thoney D. A. & Hargis W. J. (1991). Monogenea (Platyhelminthes) as hazards for fish in confinement. Annual Review of Fish Diseases. 1(1): 133-153.
    Whittington I. D. (2011). Benedenia seriolae and Neobenedenia Species. In: Woo P. T. K. & Buchmann K. (Eds.). Fish Parasites: pathobiology and protection. CABI International. 225-244.
    Whittington I. D. & Chisholm L. A. (2008). Diseases caused by Monogenea. In: Eiras J. C., Segner H., Wahlii T. & Kapoor B. G. (Eds.). Fish Diseases (2 Vols.). Science Publishers, Inc., New Hampshire, USA. 683-816.
    Whittington I. D. & Horton M. A. (1996). A revision of Neobenedenia Yamaguti, 1963 (Monogenea: Capsalidae) including a redescription of N. melleni (MacCallum, 1927) Yamaguti, 1963. Journal of Natural History. 30(8): 1113-1156.
    Yoshinaga T., Segawa I., Kamaishi T. & Sorimachi M. (2000). Effects of temperature, salinity and chlorine treatment on egg hatching of the monogenean Neoheterobothrium hirame infecting Japanese flounder. Fish Pathology. 35(2): 85-88.