Search results for "kalataudit"
showing 10 items of 30 documents
Genetic and environmental factors associated with the virulence of fish pathogen Flavobacterium columnare
2016
Diplostomiasis ( Diplostomum spathaceum and related species).
2020
This book chapter describes various aspects of diplostomiasis caused by Diplostomum spathaceum: diagnosis, epidemiology, life cycle, transmission, developmental stages, population dynamics, effects of climate change on parasite distribution, and disease control and prevention. peerReviewed
Opposing health effects of hybridization for conservation
2021
The continuing decline of many natural plant and animal populations emphasizes the importance of conservation strategies. Hybridization as a management tool has proven successful in introducing gene flow to small, inbred populations, but can be also associated with health risks. For example, hybridization can change susceptibility to infection in either direction due to heterosis (hybrid vigor) and outbreeding depression, but such health effects have rarely been considered in the genetic management of populations. Here, we investigated the effects of experimental outcrossing between the critically endangered Saimaa landlocked salmon (Salmo salar m. sebago) and the genetically more diverse A…
Hydraulic Habitat Structure Impacts Risk of Trematode Infection
2022
Abstract— Variability in infection rates of trematodes Diplostomum pseudospathaceum in 0+ rainbow trout Oncorhynchus mykiss under different hydraulic regimes was studied in the experimental setup with regulated flow rates and environmental heterogeneity. The average infection rate in the conditions of the current was 1.5 times less than that in the stagnant water. An increase of the flow rate from 3.2 to 11.3 cm/s did not result in lower infection rates, while the interindividual variability in the infection rate (coefficient of variation) tended to increase along with changing the still-water conditions (20%) to the high flow rate environments (40%) within the experiment. A decrease in th…
Atypical Aeromonas salmonicida -infection as a threat to farming of Arctic charr (Salvelinus alpinus L.) and European grayling (Thymallus thymallus L…
2004
Päivi Pylkön väitöskirjatutkimus osoittaa harjuksen ja nieriän olevan lohikaloista herkimpiä epätyyppisen Aeromonas salmonicida (aAS)–bakteerin aiheuttamalle tulehdukselle. Tautia esiintyy vuosittain useimmilla harjusta ja nieriää viljelevillä laitoksilla. Laitoskasvatus on ensiarvoista vaarantuneiden harjus- ja erittäin uhanalaisten nieriäkantojen säilymiselle. This review summarizes the results of studies on atypical Aeromonas salmonicida (aAS) -infection among farmed Arctic charr (Salvelinus alpinus) and European grayling (Thymallus thymallus) (later referred as charr and grayling, respectively). Specifically, I aimed to characterize the causative agent of aAS -infection, to describe put…
Alkuperäinen aineisto julkaisulle: Differences in parasite community composition support ecological differentiation in a freshwater gadoid fish
2022
The data file contains original data from burbot (Lota lota), captured from two sampling depths, littoral and profundal, in Lake Konnevesi during the breeding season of the fish in 2019-2020. The other variables indicate total body length of the fish (mm), gender, and abundance of 9 metazoan parasite taxa observed in the fish. Column F indicates the mean coverage of cataracts caused by Diplostomum parasites found in the eye lenses (column E).
Bacteriophage Adherence to Mucus Mediates Preventive Protection against Pathogenic Bacteria
2019
The mucosal surfaces of animals are habitat for microbes, including viruses. Bacteriophages—viruses that infect bacteria—were shown to be able to bind to mucus. This may result in a symbiotic relationship in which phages find bacterial hosts to infect, protecting the mucus-producing animal from bacterial infections in the process. Here, we studied phage binding on mucus and the effect of mucin on phage-bacterium interactions. The significance of our research is in showing that phage adhesion to mucus results in preventive protection against bacterial infections, which will serve as basis for the development of prophylactic phage therapy approaches. Besides, we also reveal that exposure to m…
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…
Exploring phage-bacterium interactions : new ways to combat a fish pathogen
2014
Rearing background and exposure environment together explain higher survival of aquaculture fish during a bacterial outbreak
2019
1.Parasitic diseases represent one of the greatest challenges for aquaculture worldwide and there is an increasing emphasis on ecological solutions to prevent infections. One proposed solution is enriched rearing, where traditional stimulus‐poor rearing tanks are equipped with different types of structures to increase habitat complexity. Such spatial enrichment is known to increase survival of fish during parasite epidemics, but the underlying mechanisms are still unclear. 2.We studied whether enriched rearing affected infection of an important fish pathogen Flavobacterium columnare in young Atlantic salmon (Salmo salar) and sea‐migrating brown trout (Salmo trutta). First, we used natural b…