6533b7d7fe1ef96bd1268455
RESEARCH PRODUCT
Seasonality of two gill monogeneans from two freshwater fish from an oligotrophic lake in northeast Finland.
M. ProstR. RahkonenE. T. Valtonensubject
GillbiologyEcologyFishesZoologyAquatic animalFresh WaterTrematode Infectionsbiology.organism_classificationPopulation densityFish DiseasesInfectious DiseasesFreshwater fishPrevalenceHelminthsAnimalsParasitologySeasonsCoregonusGymnocephalusOverwinteringFinlanddescription
The seasonal occurrence of Dactylogyrus amphibothrium and Discocotyle sagittata from the gills of ruffe (Gymnocephalus cernuus) and whitefish (Coregonus acronius), respectively was studied in Lake Yli-Kitka, a large oligotrophic lake in Northeast Finland. The lake, located near the Arctic Circle, is ice-covered for 7-8 months of the year. The prevalence of D. amphibothrium infection was 70.7% and remained high throughout all size-classes of fish. The length distribution and developmental stages of the worms indicated two generations per year. The overwintering generation produces a summer generation which lives for only a few weeks and matures in July. Discocotyle sagittata has only one generation yearly. Its worms mature and produce eggs in July-August and recruitment of the new generation starts in the autumn. The prevalence of D. sagittata infection varied between 40% (in January) and 6.7% (in September); smaller fish were more heavily infected than larger fish.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1990-02-01 | International journal for parasitology |