0000000000449099
AUTHOR
Hanna Ahonen
showing 3 related works from this author
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…
Myosporidium ladogensis n. comb. in burbot Lota lota from Finland: fine structure and microsporidian taxonomy.
2020
Infections with microsporidian parasites are described in skeletal muscle of burbot Lota lota from Lake Haukivesi, Finland. Infected myocytes contained spores within sporophorous vesicles (SPVs) in contact with host cell cytoplasm, similar to Pleistophora ladogensis in L. lota and smelt Osmerus eperlanus in western Russia and northern Germany. Analysis of small subunit ribosomal RNA (SSU rRNA) gene sequences indicated identity with Myosporidium spraguei in burbot and pike-perch from this lake. The latter is considered a junior synonym of P. ladogensis. Phylogenetic analysis of SSU rRNA sequences resolved the burbot parasite apart from a clade containing the type species P. typicalis, but to…