Parasitic infections in pond-reared rainbow trout Oncorhynchus mykiss in Denmark

Abstract

From October 1993 to December 1995, 5 Danish freshwater rainbow trout Oncorhynchus myklss farms were surveyed for parasites, the most comprehens~ve survey to date in Denmark. A total of 805 f~s h , aged 0+ and l+, were examined, and the parasites were identified by light microscopy, scanning electron microscopy and histochemistry. Prevalence (protozoans and metazoans) and abundance (metazoans) were recorded. The 12 protozoans iound were: an intestinal diplomonadid flagellate, the ectoparasitic kinetoplastid Ichthyohodo necator, and the clhates Ichthyophthlnus multifiliis, Chilodonella piscicola, Capriniana (Tr~chophrya) sp., Tr~chodina nigra, 7. mutabills, 7 fultoni, Trichodinella epizootlca, Apiosoma sp., Amblphrya sp and Epistylis sp The 10 metazoan species found were: the inyxosporean organism PKX, the monogeneans Gyrodactylus derlavinl and G. salaris, the digeneans Diplostomum spathaceum and Tylodelphys clavata, the cestodes PI-oteocephalus exlguus. P. long~coll~s, Eubothnum crassum, and Triaenophorus nodulosus, and the crustacean Argulus fohaceus. The diplomonad occurred predominantly in anorectic undersized fish, and was associated with mortality. I necator produced discoloration a n d epidermal hyperplasia and I. niultlflllls infections were associated with mortalities. G. salai-IS and G. derjavini produced alterations (lesions and hyperplasia) of the host epidermis visible in the scanning electron microscope. Soine D spathaceum infections caused cataract. Prevalence of I. mult~filiis increased with temperatul-e (maximum at 16 to 20°C), whereas the diplomonad had h~g h e s t prevalence at l to 5°C Likewise, the gyrodactylids occurred more abundantly at lower temperatures KEY WORDS R a~n b o w trout Oncorhynchus mykiss Parasites Protozoa hletazoa Fish farming Aquaculture Ep~demiology

Prevalence of Argulus foliaceus in ornamental fishes [goldfish (Carassius auratus) and Koi (Cyprinus carpio)] in Kerman, southeast of Iran

“…A few parasites species like protozoa are seemingly non-host specific species and have been found in a large-scale of fresh or brackish water fish species throughout the world. A. foliaceus were reported from different fish's species worldwide and reported with some of the goldfish in Turkey Sarieyyupoglu and Saglam (Buchmann and Bresciani 1997). In the present study, A. foliaceus was reported on goldfish and Koi which this was first recorded in Kerman, southeast of Iran.…”

“…Besides the damage and stress caused by A. foliaceus itself, one of the main worries for fish Producers is the associated secondary infestation that can result from infestations with this ectoparasite (Noaman et al 2010). Many researches have been done on prevalence of A. foliaceus but the reseaches on prevalence of this ectoparasite in Iran are scanty (Al-Dulaimi 2010; Buchmann and Bresciani 1997;Ebrahimzadeh Mousavi et al 2011;Harrison et al 2006;Noaman et al 2010;Pazooki et al 2007;Thilakaratne et al 2003;Yildiz and Kumantas 2002). Therefore, this study was aimed to determine the prevalence A. foliaceus of ornamental fishes (Goldfish and Koi) of Kerman, southeast of Iran.…”

The first report of Gyrodactylus salaris Malmberg, 1957 (Platyhelminthes, Monogenea) on Italian cultured stocks of rainbow trout (Oncorhynchus mykiss Walbaum)

“…Throughout Europe, G. salaris has also been reported from Norway (Johnsen and Jensen, 1991;Johnsen et al, 1999), from rivers on the Swedish west coast Alenä s, 1998), Denmark (e.g. Buchmann and Bresciani, 1997;Buchmann et al, 2000), Finland (Rimaila-Pä rnä nen and Wiklund, 1987;Kerä nen et al, 1992;Koski Malmberg, 1995;Koski, 1996;Rintamä ki-Kinnunen and Valtonen, 1996), Russia (Ergens, 1983;Ieshko et al, 1996Ieshko et al, , 1997Meinilä et al, 2004), Germany (Lux, 1990;Dzika et al, 2009), Spain (Malmberg, 1993), France (Johnston et al, 1996) and, most recently, from Poland (Rokicka et al, 2007). While the presence of G. salaris has been confirmed by molecular methods for many of these, the reports from certain countries, i.e.…”

Caligus Elongatus and Photobacterium Damselae Subsp Piscicida Concomitant Infections Affecting Broodstock European Seabass, Dicentrarchus Labrax, with Special Reference to Histopathological Responses

“…Strong evidence links potentiated bacterial infections to copepods infestations in fish [19,29,30], either providing portals of entry by damaging fish skin [31,32], or acting as a mechanical vector for numerous bacterial pathogens [19].…”