Search results for "Vieraslaji"
showing 10 items of 39 documents
Invasion of Finnish inland waters by the alien moss animal Pectinatella magnifica Leidy, 1851 and associated potential risks
2018
Introduced alien species bring potential adverse impacts on biodiversity and ecosystem functions. International shipping is an important vector for such unintentional introductions in aquatic environments. Therefore, in addition to climate change and eutrophication, increasing international shipping may enhance the spread of alien species into areas which have not previously been considered prone to alien invasions. One example of such development might be the recent invasion of the moss animal Pectinatella magnifica into Finnish inland waters, which are generally considered to be hostile to alien species. We took advantage of observations made by the general public and recorded by environm…
Täpläravun (Pacifastacus leniusculus) vaikutus särjen (Rutilus rutilus) loisiin Päijänteellä
2013
Täplärapu (Pacifastacus leniusculus) on Suomen vesistöissä verrattain uusi vieraslaji, joka leviää sekä suunnitelluin istutuksin että suunnittelematta uusille alueille. Täplärapu on alun perin tuotu Suomeen korvaamaan rapuruton turmelemia jokirapukantoja, mutta sitä on istutettu myös alueille, joissa ei alkuperäistä rapukantaa ole aiemmin ollut. Kotoperäiseen jokirapuun verrattuna täplärapu on paitsi vastustuskykyisempi rapurutolle, myös nopeampi kasvamaan ja lisääntymään. Täplärapu kasvaa jokirapua suuremmaksi ja on luonteeltaan aggressiivisempi. Vieraslajina täplärapu voi muuttaa uuden elinympäristön rakennetta ja toimintaa. Täplärapu käyttää ravintonaan muun muassa selkärangattomia pohja…
The Diapause Lipidomes of Three Closely Related Beetle Species Reveal Mechanisms for Tolerating Energetic and Cold Stress in High-Latitude Seasonal E…
2020
During winter insects face energetic stress driven by lack of food, and thermal stress due to sub-optimal and even lethal temperatures. To survive, most insects living in seasonal environments such as high latitudes, enter diapause, a deep resting stage characterized by a cessation of development, metabolic suppression and increased stress tolerance. The current study explores physiological adaptations related to diapause in three beetle species at high latitudes in Europe. From an ecological perspective, the comparison is interesting since one species (Leptinotarsa decemlineata) is an invasive pest that has recently expanded its range into northern Europe, where a retardation in range expa…
Sequencing, De Novo Assembly and Annotation of the Colorado Potato Beetle, Leptinotarsa decemlineata, Transcriptome
2012
Background. The Colorado potato beetle (Leptinotarsa decemlineata) is a major pest and a serious threat to potato cultivation throughout the northern hemisphere. Despite its high importance for invasion biology, phenology and pest management, little is known about L. decemlineata from a genomic perspective. We subjected European L. decemlineata adult and larval transcriptome samples to 454-FLX massively-parallel DNA sequencing to characterize a basal set of genes from this species. We created a combined assembly of the adult and larval datasets including the publicly available midgut larval Roche 454 reads and provided basic annotation. We were particularly interested in diapause-specific g…
Parasites in sympatric populations of native and invasive freshwater bivalves
2021
An increasing threat to local, native freshwater mussels (Unionida)—an ecologically important but globally alarmingly declining group— is the invasion by exotic bivalves. The Enemy Release Hypothesis predicts that introduced species should benefit from enemy-mediated competition because they are less likely to be harmed by natural enemies, such as parasites, than their native competitors. We investigated within-site differences in parasitism between sympatric native (tot. five spp.) and invasive (tot. three spp.) bivalves in eight northern European waterbodies, which harboured totally 15 parasite taxa. In paired comparisons using within-site averages, the mean number of parasite species in …
Impacts of piscicide-induced fish removal on resource use and trophic diversity of lake invertebrates
2022
Chemical eradication of non-native species has become a widely used method to mitigate the potential negative im- pacts of altered competitive or predatory dynamics on biodiversity and natural ecosystem processes. However, the re- sponses of non-target species can vary from rapid full recovery to delayed or absent recolonization, and little is known about the potential shifts in resource use and trophic diversity of native species following chemical treatments. We used a before-after-control-impact approach to study the effects of rotenone piscicide treatment on abundance and tro- phic niche of benthic invertebrates in three untreated and three treated lakes in central Norway, the latter gr…
The effect of environmental fluctuations on the invasion success of bacterial invader Serratia marcescens
2017
Ilmastonmuutoksen on odotettu lisäävän ympäristöolosuhteissa tapahtuvien vaihteluiden määrää. Teorian mukaan nämä vaihtelut voisivat lisätä vieraslajien levittäytymistä uusille alueille, mikäli ne vaikuttavat ekologisiin ja evolutiivisiin prosesseihin, jotka tekevät lajeista menestyksekkäitä vieraslajeja sekä paikallisista eliöyhteisöistä ja ympäristöistä alttiimpia levittäytymiselle. Häiriöherkkien alueiden on oletettu olevan otollisia levittäytymiselle, minkä lisäksi vieraslajit ovat voineet valmiiksi sopeutua sietämään vaihtelevia olosuhteita alkuperäisalueellaan. Nopeasti vaihtelevissa ympäristöolosuhteissa luonnonvalinta voi suosia ominaisuuksia, kuten generalismia, joka auttaa eliöitä…
Sublethal Pyrethroid Insecticide Exposure Carries Positive Fitness Effects Over Generations in a Pest Insect
2019
AbstractStress tolerance and adaptation to stress are known to facilitate species invasions. Many invasive species are also pests and insecticides are used to control them, which could shape their overall tolerance to stress. It is well-known that heavy insecticide usage leads to selection of resistant genotypes but less is known about potential effects of mild sublethal insecticide usage. We studied whether stressful, sublethal pyrethroid insecticide exposure has within-generational and/or maternal transgenerational effects on fitness-related traits in the Colorado potato beetle (Leptinotarsa decemlineata) and whether maternal insecticide exposure affects insecticide tolerance of offspring…
Täpläravun (Pacifastacus leniusculus) vaikutus Säkylän Pyhäjärven siian poikastuotantoon
2015
Täplärapu (Pacifastacus leniusculus) on vieraslaji, mutta sitä on istutettu paljon suomalaisiin vesistöihin etenkin rapuruton hävittämien jokirapukantojen tilalle. Kalataloudellisesti täpläravun merkitys on nykyään huomattava. Täpläravun vaikutusta kalalajeihin on tutkittu vähän. Säkylän Pyhäjärvellä täplärapukanta on kasvanut nopeasti 2000-luvulla, mutta samalla myös siikapopulaatio on heikentynyt huomattavasti. Tässä tutkimuksessa selvitettiin täpläravun vaikutusta siikapopulaatioon vuosina 1998–2010. Täpläravut voivat käyttää kalojen mätiä ravinnokseen, ja suurissa tiheyksissä ravut saattavatkin saalistuksellaan vaikuttaa negatiivisesti siikojen mädin säilyvyyteen. Kohorttianalyysin avul…
The role of salmonid fishes in conservation of the endangered freshwater pearl mussel (Margaritifera margaritifera)
2016
The abundance of freshwater pearl mussels (Margaritifera margaritifera) has declined widely during the past century, and new conservation initiatives are needed. This thesis focused on the relationship between M. margaritifera and its salmonid host required for reproduction of this species. First, by exposing fish experimentally to glochidium larvae of M. margaritifera, different M. margaritifera populations were shown to demonstrate strong differences in their ability to parasitize different salmonid species. Atlantic salmon was clearly a better host for mussels in large river channels, whereas in small headwater tributaries brown trout was the best, or the only suitable, host. These findi…