Gyobyo Kenkyu 28:131-134. Parasitic Diseases of Trout An
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3rd International Symposium on Sustainable Development, May 31 - June 01 2012, Sarajevo Santer R.M. & Greer-Walker M. (1980) Morphological studies on the ventricle of teleost and elasmobranch hearts. Journal of Zoology (London) 190, 259–272. Smith J.W. (1997) The blood flukes (Digenea: Sanguinicolidae and Spirorchidae) of cold- blooded vertebrates: Part 2. Helminthological Abstracts 66, 329–344. Watts, M. (1995) The development of a fluorescent antibody stain to identify a Uronenla sp. (Ciliophora: Scuticociliatida) implicated in fatal encephalitis in farmed tuna (Thunnus maccoyii). Honours thesis, University of Tasmania, Launceston. Williams E.H. & Bunkley-Williams L. (1996) Parasites of Offshore Big Game Fishes of Puerto Rico and the Western Atlantic. Puerto Rico Department of Natural Environmental Resources and the University of Puerto Rico, Mayaguez. Yoshinaga T, Nakazoe J (1993) Isolation and in vitro cultivation of an unidentified ciliate causing scuticociliosis in Japanese flounder (Paralichthys olivaceus). Gyobyo Kenkyu 28:131-134. Parasitic Diseases of Trout and Their Controls in Sustainable Development of Aquculture: Platyhelminthes Erol Tokşen1, Erkin Koyuncu2 1Ege University, Fisheries Faculty, Department of Fish Diseases, Bornova 35100 İzmir, Turkey 2Mersin University, Fisheries Faculty, Department of Fish Diseases,Yenişehir 33169 Mersin, Turkey E-mails: [email protected], [email protected] Abstract Aquaculture is an important food-producing sector. It provides much needed protein, employment, income and livelihoods support to many people in the world and this is especially true in most developing countries. A significant challenge to the expansion of aquaculture production is the outbreak of disease. Potential economic losses from disease outbreaks are significant, and can affect the survival of the industry. Fish diseases were caused by enfectious agents as parasite, bacteria, virus and fungus. Gyrodactylus spp., Tetraonchus spp., Discootyle spp., Cyathocephalsus spp., Proteocephalus spp., Eubothrium spp., Diphyllobothrium spp., Trianophorus spp., Crepidostomum spp., Phyllodistomum spp., Sanguinicola spp., Diplostomum spp., Tylodelphys spp., Apatemon spp. are observed in rainbow trout. Gyrodactylus salaris caused the mortality up to 95 % in salmon population in some rivers in Norvay. So, G. salaris is a disease between compulsory notifiable diseases in EU. However, such a pathogen monogenean enfestations have not been appeared in Turkey, First record of Crepidostomum farionis was carried out in rainbow trout in Elazığ from Turkey. The present work aim to the parasitic diseases of freshwater trout caused by phylum 50 3rd International Symposium on Sustainable Development, May 31 - June 01 2012, Sarajevo Plathyhelmintes, how they are transmitted, which effects they have on trouts, how they could be diagnosed, and how they could be controlled and treated. Keywords: Trout, disease, parasite, platyhelminthes, diagnosis, treatment 1.INTRODUCTION Turkey has rich inland water sources, about 200 natural lakes, about 750 artificial lakes or ponds, about 193 reservoirs, 33 rivers and streams of 177.714 km length and 8.333 km of coastal strips. Aquaculture sector in Turkey is new when compared with European countries. The first fish farm was established as a rainbow trout farm in 1970s. The following years, new fish farms have been established year by year. The main fish species cultured in Turkey are Carp (Cyprinus carpio), Rainbow trout (Oncorhynchus mykiss), Atlantic salmon (Salmo salar), Gilthead sea bream (Sparus aurata), European sea bass (Dicentrarchus labrax), Bluefin tuna (Thunnus thynnus), Black sea turbot (Psetta maxima), Mediterranean mussel (Mytilus galloprovincialis) and Shrimp (Penaeidae spp). Aquaculture production of Turkey has grown steadily over the years from 5782 tonnes in 1990 to 63 000 tonnes in 1999 and to 152 186 tonnes in 2008. Recently, it is shown in Table.1 that trout pruducts have reached to 68,649 tons in Turkey (TUIK 2012). Type of fish 2006 2007 2008 2009 2010 Inland water Trout 56 026 58 433 65 928 75 657 78 165 Marine Trout 1 633 2 740 2 721 5 229 7 079 Total 57 659 61 173 68 649 80 886 85 244 Table.1. Aquaculture production of Turkey (Ton) (TUIK 2012) The intensification of aquaculture and globalization of the seafood trade have led to remarkable development in the aqauculture industry. The industry has been plagued with disease problems caused by viral, bacterial, fungal and parasitic pathogens. In recent years, disease outbreaks are becoming more frequent in he aquaculture and associated morbidity and mortality have caused substantial economic losses. Health problems have two fiscal consequences on the industry: loss of productivity due to animal mortality and morbidity, and loss of trade due to food safety issues. Thus, disease is undoubtedly one of the major constraints to production, profitability and sustainability of the aquaculture industry. Parasites 51 3rd International Symposium on Sustainable Development, May 31 - June 01 2012, Sarajevo in fish have become increasingly visible during the latest decades in connection with the development of aquacultural industries in the world. Thus, focus has been placed on parasitic infections in these enterprises and their economic and ecological impact. Diseases problem caused by parasitic organisms are the main threat to further increase of the industry. There are various parasites caused the diseases on the trout. This study consist of crustaceans parasites. This research presents the individual parasites types producing problems in sea bream and sea bass. Each section is presented with 1. aetiyology, the parasitic organism responsible for the disease, 2. epizootiology, the transmission of the diseases and life cycle of the parasite, 3. pathogenicity, how the parasite produces diseases in the fish, 4. symptoms, clinical signs of the diseases, 5. diagnose, how the infection can be identificated, 6. treatment, how the infection can be controlled. The Plathelminthes typically are slightly dorso-ventrally flatted, witth a few exceptions hermophroditic worms without an anus and some of them without a mouth and intestine. Their surface layer is a tegument which is made of a syncytium. This Phylum comprise monogeneans, digeneans and cestodes Monogeneans are flatworms with representatives in freshwater, brackish and marine habitatts. The most of species are ectoparasitic and they all have a direct life cycle. A few species have adopted an endoparasitic life. They have a characteristic posterior attachment organ called an opisthaptor. This organ is equipped with sclerotiinized structures as large hooks, clamps and marginal hooklets. Also the fore part of the parasite has adhesive pads. Using these adhesive structures he flatworm can move in a leech-like manner on the host. 2. Tetraonchosis: 2.1. Aetiology: Tetraonchus alaskensis, T. awakurai. T. oncorhynchi The lenght of the T. awakurai is 650-1080 µm and width is 250-415 µm (Ogawa and Egusa 1978). 2.2. Epizootiology: Tha adult parasite attaches to the gill epithelium with its two pairs of anchors and their associated marginal hooklets, then produce eggs. These are liberated to the aquatic enviroment where they develop and hatch. The ciliated larva called oncomiracidium seeks the its host, attaches, sheds the ciliated cells and moves to the gill filaments. Depending on the ambient temperature the post larva develops to the adult stage on the gills (Buchmann and Bresciani 2001). Oncomiracidia hatch from embryonated eggs and transmission occurs when the temperature is above 10 °C (Ogawa and Egusa 1985). 2.3.Pathogenicity: Heavy infections mat elicit inflamatorry reactions in the gills, hyperplasia of epithelial and mucous cella and haemorrhages. 2.4. Symtomps: Parasite cause hyperventilation, lethargy and mortality. 2.5. Diagnosis: Detection of the parasite on the gills of the host. The parasite has four eye spots, four large hooks in the opisthahaptor. 2.6. Prophylaxis: Quarantine measures, mechanical filtration of fish tank water to remove oncomiracidia. 2.7. Treatment: Formalin, mebendazole and praziquantel may have effect (Buchmann and Bresciani 2001). 52 3rd International Symposium on Sustainable Development, May 31 - June 01 2012, Sarajevo 3. Gyrodactylosis: 3.1. Aetiology: Gyrodactylus salmonis, G. salaris, G. derjavini, G. truttae, G. colemanensis, Gyrodactylus elegans, G. cobitis. G. salmonis measures 0.5 mm in length and 0.15 mm in width. The hamuli are stout and 53-65 um long. 3.2. Epizotiyology: They are vivipourus hermophroditic parasites. The female parasite give birth to an almost fully developed daughter which already has a growing embryo in its uterus. The parasites attcches to thebody surface, fins, buccal cavity. At a farm nets and buckets are potential vehicles of transmission. Water-borne transmission occurs in spring when melting ice frequently causes flooding between holding units. Shipment of fish from other facilities are also potential sources of infeciton and so is the water supply of the farm. 3.3. Pathogenicity: Due to penetration of the epithelium by the marginal hooklets and the feeding activitiy the fish may suffer from osmoregulatory distress. Opportunistic infections may arise in the injured epidermis. 3.4. Symtomps: Heavily infected fish with parasite are cachexic, lethargic and overall dark in clour (Cone and Cusack 1988). 3.5. Diagnosis: Microscopic examination of slides with the parasite shows the approximately 0.5 mm platyhelminth without eyespot