Search results for "Henneguya zschokkei"
showing 5 items of 5 documents
Henneguya zschokkei (Myxozoa) infection in cultured whitefish: Age-dependence, seasonality and distribution within host
2017
Abstract Whitefish ( Coregonus lavaretus ) is an important species for European fisheries and aquaculture. Recently, the myxosporean Henneguya zschokkei has been observed to infect the muscles of whitefish in fish farms. Plasmodia of H. zschokkei prevent marketing of the fillet and cause economic losses. The factors associated with occurrence of the parasite in fish farms have not been investigated previously. We studied age-dependence, seasonality, and within-host distribution of H. zschokkei plasmodia in farmed whitefish by examining a total of 1599 fish. Distribution of plasmodia within the fish was not uniform. When the fillet was divided into parts, the number of plasmodia was positive…
Henneguya zschokkei (Myxozoa) infection in cultured whitefish : Age-dependence, seasonality and distribution within host
2017
Whitefish (Coregonus lavaretus) is an important species for European fisheries and aquaculture. Recently, the myxosporean Henneguya zschokkei has been observed to infect the muscles of whitefish in fish farms. Plasmodia of H. zschokkei prevent marketing of the fillet and cause economic losses. The factors associated with occurrence of the parasite in fish farms have not been investigated previously. We studied age-dependence, seasonality, and within-host distribution of H. zschokkei plasmodia in farmed whitefish by examining a total of 1599 fish. Distribution of plasmodia within the fish was not uniform. When the fillet was divided into parts, the number of plasmodia was positively correlat…
Spore-forming parasites infecting muscles of freshwater fishes : ecology and epidemiology
2017
Fish parasites may potentially harm fisheries and aquaculture. Infected fish are unusable, even though they would not pose a direct risk to human health. The aim of this thesis was to investigate the ecology and epidemiology of three previously unknown or poorly known spore-forming parasites infecting muscles of economically important fish species. The first novel microsporidian species, here described as Microsporidium luciopercae, was found from pike-perch (Sander lucioperca) and European perch (Perca fluviatilis) and formed opaque-looking patches in the muscles. The second novel microsporidian species, Myosporidium spraguei, was found from pike-perch and burbot (Lota lota) and occurred w…
Development of Henneguya zschokkei (Myxozoa: Myxosporea) actinospores in oligochaetes and plasmodia in whitefish Coregonous lavaretus
2013
The aim of this study was to describe the life cycle of H. zschokkei by observing the development of actinospores in oligochaete and the morphological development of H. zschokkei cysts in whitefish. Laboratory observation of seasonal occurrence of actinospores sampled from oligochaetes from RTKL Tervo Fish Farm revealed 6 types of actinospores from collective groups of Triactinomyxon, Raabeia and Aurantiactinomyxon in 2010, and 3 types of actinospores in 2011. Both years showed similar patterns with the release of actinospores peaking in both summer (June and July) and winter (January and February) times. The infection experiment was not successful in infecting Coregonus lavaretus with myxo…
Siian rakkoloision (Henneguya zschokkei) elämänkierto sekä esiintyminen kalassa ja harvasukamadossa
2010
Siian rakkoloisio (Henneguya zschokkei) on Myxozoa-pääjaksoon kuuluva itiöloinen. Myxozoa-loisilla on monimutkainen elämänkierto, joka pitää sisällään sekä selkärangattoman että selkärankaisen isäntäeliön. Siian rakkoloision pääisäntä on harvasukamato (Oligochaeta) ja väli-isäntä on siika (Coregonus lavaretus). Rakkoloisiota on tavattu mahdollisesti myös muikulla (C. albula). Loisitun kalan lihaksessa on valkoisia ellipsin muotoisia kystejä, joiden sisällä on maitomaista nestettä. Neste sisältää suuren määrän mikroskooppisia kaksihäntäisiä myksospoori-itiöitä. Kalan lihaksessa voi olla useita, jopa satoja erikokoisia kystejä. Loinen aiheuttaa ongelmia niin kalanviljelyssä kuin vapaa-ajankal…