RESUMO
Loma salmonae, an obligate intracellular microsporidian parasite, is the causal agent of microsporidial gill disease of salmon (MGDS), characterized by the production, growth and eventual rupture of spore-filled xenomas. MGDS in farmed chinook salmon remains occult until xenoma rupture, at which time the infected fish respond with intense branchitis and high rates of mortality. The present study showed that in experimentally infected fish the rate of change of xenoma diameter could be modelled through regression analysis, particularly through the period of 4-9 weeks post-infection, yielding the predictive equation: xenoma diameter=-42.9 microns +15.3 microns x (number of weeks post-infection). This provides a tool for diagnosticians to predict the time to xenoma rupture and hence to the initiation of the clinical phase of MGDS.
Assuntos
Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Microsporídios/crescimento & desenvolvimento , Microsporidiose/veterinária , Oncorhynchus/parasitologia , Infecções Protozoárias em Animais/parasitologia , Animais , Doenças dos Peixes/patologia , Doenças dos Peixes/transmissão , Brânquias/patologia , Microsporidiose/parasitologia , Microsporidiose/patologia , Infecções Protozoárias em Animais/patologia , Organismos Livres de Patógenos EspecíficosRESUMO
During 1991, in one of three specimens of Oncorhynchus mykiss cultured in Puyehue Lake (40 degrees 36'S, 72 degrees 26'W) was registered for first time the infection by Camallanus corderoi. Comments on the morphological and geographic distribution of the three species of Camallanus described in South America are also given.