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  • 1. Abalaka, J. L.
    et al.
    Ottosson, Ulf
    Tende, Talatu
    Larson, Keith W.
    Rock Firefinch Lagonosticta sanguinodorsalis in the Mandara Mountains, north-east Nigeria: a new subspecies?2010In: African Bird Club Bulletin, ISSN 1352-481X, Vol. 17, no 2, p. 210-211Article in journal (Refereed)
    Abstract [fr]

    L’Amarante des rochers Lagonosticta sanguinodorsalis dans les Monts Mandara, Nigeria du sud-est: une nouvelle sous-espèce ? Nous fournissons une description d’un mâle et d’une femelle, ainsi que desphotos d’un mâle, d’un amarante capturé dans les Monts Mandara, au nord-est du Nigeria. Le plumage et le cri de cet amarante sont identiques à ceux de l’Amarante des rochers Lagonosticta sanguinodorsalis, une espèce précédemment rapportée de la zone, excepté que le mâle n’a pas la couronne grise typique de l’espèce. Des travaux supplémentaires sur le terrain sont nécessaires pour déterminer s’il agit d’un individu aberrant ou d’une population de l’Amarante des rochers morphologiquement distincte.

  • 2.
    Alfredsson, Jessica
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    INNOVATIVE TOOL-MODIFICATIONS AND TOOL SELECTIVITY IN NEW CALEDONIAN CROWS (CORVUS MONEDULOIDES)2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Tool-use and tool-manufacture are thought to require high cognitive skills and have been considered as an exclusive attribute to primates. Recent observations of New Caledonian crows (NCCs) challenge this assumption. In this study 13 NCCs were tested with two different tool production tasks. The NCC either had to straighten a hook or bend a stick to retrieve food from two different kinds of tree trunks. The result showed that 3/5 birds bent sticks and used them to retrieve food and 1/5 birds straightened hooks to retrieve food. The birds managed to solve both tasks but not the birds in the control group. This indicates that NCC's tool making is a flexible innovative act and not just an innate predisposition to bend flexible material. This finding is interesting given that recent studies on human children show that below 8 years of age children fail in similar innovative tool making tasks.

  • 3.
    Arnqvist, Göran
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Sexual selection and intersexual conflicts in water striders1992Doctoral thesis, comprehensive summary (Other academic)
  • 4.
    Bartels, Pia
    et al.
    Department of Ecology and Genetics, Limnology, Uppsala University, Uppsala, Sweden.
    Hirsch, Philipp E.
    Svanbäck, Richard
    Eklöv, Peter
    Water Transparency Drives Intra-Population Divergence in Eurasian Perch (Perca fluviatilis)2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 8, p. e43641-Article in journal (Refereed)
    Abstract [en]

    Trait combinations that lead to a higher efficiency in resource utilization are important drivers of divergent natural selection and adaptive radiation. However, variation in environmental features might constrain foraging in complex ways and therefore impede the exploitation of critical resources. We tested the effect of water transparency on intra-population divergence in morphology of Eurasian perch (Perca fluviatilis) across seven lakes in central Sweden. Morphological divergence between near-shore littoral and open-water pelagic perch substantially increased with increasing water transparency. Reliance on littoral resources increased strongly with increasing water transparency in littoral populations, whereas littoral reliance was not affected by water transparency in pelagic populations. Despite the similar reliance on pelagic resources in pelagic populations along the water transparency gradient, the utilization of particular pelagic prey items differed with variation in water transparency in pelagic populations. Pelagic perch utilized cladocerans in lakes with high water transparency and copepods in lakes with low water transparency. We suggest that under impaired visual conditions low utilization of littoral resources by littoral perch and utilization of evasive copepods by pelagic perch may lead to changes in morphology. Our findings indicate that visual conditions can affect population divergence in predator populations through their effects on resource utilization.

  • 5.
    Berg, Håkan
    Umeå University, Faculty of Medicine, Molecular Biology.
    Teleost reproduction: Aspects of Arctic char (Salvelinus alpinus) oocyte growth and maturation.2003Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In all vertebrate species, reproduction is a hormonally controlled process, important for growth and maturation of gonads and germ cells. Production of functional germ cells is of outmost importance to secure the survival of a species. Fish comprises 50% of the known vertebrates and are found in aquatic habitats all over the world. Even though fish have evolved a wide variety of morphological and physiological characteristics, due to large differences in the living environment, the growth an maturation of germ cells follows the same pattern in all species. In this thesis the focus has been directed on oocyte growth and development in Arctic char (Salvelinus alpinus), and if stress might inflict disturbances on the reproductive systems.

    All sexually mature female egg laying vertebrates produces yolky eggs surrounded by an eggshell. Production of yolk and egg shell is under estrogenic control and it is known that production of egg components can be induced in male and juvenile fish by estrogenic substances. Many manmade chemicals have been found to interfere with hormonally controlled processes. Therefore production of the egg yolk precursor, vitellogenin (VTG), and the egg shell components, vitelline envelope proteins (VEP), have been used as biomarkers for estrogenic effect. Exposure to endocrine disrupting substances (EDS) does not only give rise to hormonal effects on the organism, but in addition it also gives rise to an increase in stress hormone, cortisol (F), levels.

    It is evident that a wide variety of substances may affect Arctic char oocyte growth and maturation. VTG and VEP production is found to be under dose dependent estrogenic control, but the production was directly affected by F. Under natural condition it has been found that F increases towards ovulation. Even though both VTG and VTG is under estrogenic control, these studies showed that stress lead to a decrease of VTG while the VEP production increased. These effects was only observed on protein levels indicating that a post transcriptional down regulation of VTG production is mediated by F in Arctic char.

    In order for an egg to become fertilizatible, it must undergo a maturation phase. This maturation phase is primarily induced by gonadotropins, which in turn induce the production of species specific maturation inducing substances (MIS). To investigate oocyte development in Arctic char a characterization of its MIS receptor was made. The MIS receptor is localized on the oocyte surface and displays a single class of high affinity and low capacity binding sites. The binding moieties displays association and dissociation kinetics typical of steroid membrane receptors.

    Even though high specificity for Arctic char MIS was observed, it was found that some EDS bind to the Arctic char oocyte membrane receptor. This suggest that certain EDS might affect oocyte maturation and thereby might alter the reproductive success. Furthermore, it was found that F did not bind to the MIS receptor in Arctic char. It is therefore suggested that oocytes are more sensitive to stress during the growth phase than during maturation

  • 6. Bolnick, Daniel I
    et al.
    Svanbäck, Richard
    Araújo, Márcio S.
    Persson, Lennart
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Comparative support for the niche variation hypothesis that more generalized populations also are more heterogeneous2007In: Proceedings of the National Academy of Sciences, Vol. 104, no 24, p. 10075-10079Article in journal (Refereed)
    Abstract [en]

    There is extensive evidence that some species of ecological generalists, which use a wide diversity of resources, are in fact heterogeneous collections of relatively specialized individuals. This within-population variation, or "individual specialization," is a key requirement for frequency-dependent interactions that may drive a variety of types of evolutionary diversification and may influence the population dynamics and ecological interactions of species. Consequently, it is important to understand when individual specialization is likely to be strong or weak. The niche variation hypothesis (NVH) suggests that populations tend to become more generalized when they are released from interspecific competition. This niche expansion was proposed to arise via increased variation among individuals rather than increased individual niche breadth. Consequently, we expect ecological generalists to exhibit stronger individual specialization, but this correlation has been repeatedly rejected by empiricists. The drawback with previous empirical tests of the NVH is that they use morphological variation as a proxy for niche variation, ignoring the role of behavior and complex phenotype–function relationships. Here, we used diet data to directly estimate niche variation among individuals. Consistent with the NVH, we show that more generalized populations also exhibit more niche variation. This trend is quite general, appearing in all five case studies examined: three-spine stickleback, Eurasian perch, Anolis lizards, intertidal gastropods, and a community of neotropical frogs. Our results suggest that generalist populations may tend to be more ecologically variable. Whether this translates into greater genetic variation, evolvability, or ecological stability remains to be determined.

  • 7.
    Breitling, Rainer
    et al.
    Faculty of Life Sciences, University of Manchester, UK.
    Buckland, Philip I.
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies, Environmental Archaeology Lab.
    Epigean spiders at Abisko Scientific Research Station in Swedish Lapland (Arachnida:Araneae)2015In: Arachnology, ISSN 2050-9928, E-ISSN 2050-9936, Vol. 16, no 8, p. 287-293Article in journal (Refereed)
    Abstract [en]

    The Torneträsk area, including the Abisko National Park, Sweden, is arachnologically one of the best explored sites of Fennoscandia. Here we report the results of pitfall trapping at Abisko Scientific Research Station during the summers of 2004 and 2005, recording 791 individuals of 62 species of spiders. As expected, at the species level, samples were dominated by members of the Linyphiidae, while at the level of individuals Pardosa hyperborea and other lycosids were dominant. Two subsites, on heath and bog, differed substantially in their species profile: 7 species were statistically overrepresented on the drier heath site, while 2 species showed a strong preference for the wetter bog site. The samples also contained the first reported lateral gynadromorph of Archaeodictyna consecuta (Dictynidae). This study, from 195 km north of the Arctic Circle, provides important reference data for continued studies on the long-term effects of climate change on arctic ecosystems.

  • 8.
    Brånin, Bertil
    Umeå University, Faculty of Science and Technology.
    Vattenfysikalisk-kemiska och bottenfaunaförhållanden i ett norrländskt vattendrag påverkat av utsläpp från sulfidmalmbrytning och anrikning1979Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The raining and milling of complex zinc and copper pyrite ore is the cause of water pollution in some districts of the county of Västerbotten. To determine the effects of the wastewater from the mining process in the stream Vorm-bäcken 1971 - 1975, physical, chemical and biological investigations have been performed and evaluated.The character of the stream is changed principally by the inflow of sulphur, calcium and heavy metals. In addition to higher concentrations of a number of substances an acidification occurs, which is most distinct in the lower reaches of the stream. The pH decrease is greatest during summer and autumn, when the metal concentrations also peak. Several of the physicochemical parameters are closely correlated. Most evident is the correlation between conductivity and sulphate. But turbidity, iron, colour and pH are also related to each other in different ways. This means that for a continuous survey of the physical and chemical conditions there is redundancy of data in this comprehensive material. Within the framework of the present control program, a more careful selection of parameters and sampling times should therefore provide a considerably better overall picture of the physicochemical effects.The bottom fauna in the riffles, sampled by a simple netting technique, are qualitatively changed. The effects are most accentuated on mussels, mayflies and stoneflies. The number of taxa for the total fauna and for the combined orders mayflies, stoneflies and caddisflies is the most reliable parameter compared to the total abundance and the number of specimens of each taxon. The number of taxa also follows the changing physicochemical conditions better than the commonly used diversity index (the Shannon-Weaver index). The number of riffle fauna taxa are lowest in summer and autumn.The changes in number of taxa and diversity indices are best related to colour, conductivity, pH and turbidity. The decrease in number of taxa is also associated with the decrease in primary production, such as perifyton and mosses. Based upon these results, some alterations of the existing physical and chemical control program are proposed. As an indicator of the changed biological conditions, it is suggested that bottom fauna investigations should be performed annually each autumn.

  • 9.
    Buckland, Philip I.
    et al.
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies, Environmental Archaeology Lab. Umeå University, Faculty of Arts, Humlab.
    Buckland, Paul C.
    BugsCEP, an entomological database twenty-five years on2014In: Antenna (Journal of the Royal Entomological Society), ISSN 0140-1890, Vol. 38, no 1, p. 21-28Article in journal (Refereed)
  • 10.
    Buckland, Philip I.
    et al.
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies, Environmental Archaeology Lab.
    Buckland, Paul C.
    Species found as fossils in Quaternary sediments2018In: Checklist of Beetles of the British Isles: with a chapter on Fossil Beetles / [ed] Duff, A. G., United Kingdon: Pemberley Books , 2018, 3, p. 171-174Chapter in book (Other academic)
    Abstract [en]

    The latest (third) edition of Andrew Duff's Checklist of Beetles of the British Isles is now available (published May 2018), providing a comprehensive listing of subfamilies, genera and species. This is the most up-to-date and comprehensive checklist of the beetle fauna of the British Isles (covering Great Britain and Ireland, including the Isle of Man, but not the Channel Islands), and represents many person-years of effort by leading British coleopterists. The main checklist is fully annotated with detailed endnotes.

  • 11.
    Buckland, Philip I.
    et al.
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies, Environmental Archaeology Lab.
    Buckland, Paul C.
    Olsson, Fredrik
    Paleoentomology: Insects and Other Arthropods in Environmental Archaeology2018In: Encyclopedia of Global Archaeology / [ed] Smith C., Cham: Encyclopedia of Global Archaeology/Springer Verlag, 2018, p. 1-22Chapter in book (Other academic)
    Abstract [en]

    Insects are the most diverse group of animals on the planet and as such are present in a wider variety of habitats than most other complex organisms. This diversity, in addition to a long evolutionary history (Grimaldi and Engel 2005), and together with a propensity to be preserved in both desiccating and anaerobic environments, has provided an excellent tool for the reconstruction of both Quaternary and more immediate archaeological environments. Insect remains often provide proxy environmental information on the immediate context from which the fossils are derived, and as such may be either complementary to the more regional picture provided by palynology or indicate site conditions, such as levels of hygiene and evidence of trading connections, which are rarely available from any other palaeoecological source. They therefore provide information on a broad range of habitats and conditions, on- and off-site, and in addition, in appropriate contexts, also climate. Processing of samples is essentially simple, requiring readily available materials, yet is time consuming, and identification of the usually disarticulated fragments (sclerites) requires diligence and patience and access to well-curated reference collections. Fortunately, abundant literature, computer software, and database tools now exist to aid in their interpretation.

  • 12.
    Buckland, Philip I.
    et al.
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies, Environmental Archaeology Lab.
    Eriksson, Erik J.
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies, Environmental Archaeology Lab.
    Palm, Fredrik
    Umeå University, Faculty of Arts, Humlab.
    SEAD - The Strategic Environmental Archaeology Database: Progress Report Spring 20142014Report (Other academic)
    Abstract [en]

    This report provides an overview of the progress and results of the VR:KFI infrastructure projects 2007-7494 and (825-)2010-5976. It should be considered as a status report in an on-going long-term research infrastructure development project.

  • 13.
    Byström, Pär
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Huss, Magnus
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Persson, Lennart
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Ontogenetic constraints and diet shifts in Perch (Perca fluviatilis): mechanisms and consequences for intra-cohort cannibalism2012In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 57, no 4, p. 847-857Article in journal (Refereed)
    Abstract [en]

    1. In many populations, sufficient size variation to allow for cannibalism may develop not only among age cohorts but also within them. Here, we used data on resource dynamics, consumer body size distribution and gape size limitation to unravel mechanisms promoting cannibalism within cohorts of young-of-the-year (YOY) perch (Perca fluviatilis). 2. Perch are strongly gape limited when feeding on large zooplankton during early ontogeny. As a consequence, only initially large fish were able to shift to feeding on abundant large invertebrates, necessary to sustain fast growth. 3. We suggest that a combination of high initial size variation and exclusive access to resources for individuals with an initial size advantage is a prerequisite for the development of a size distribution sufficient for intra-cohort cannibalism to occur. 4. During the time when cannibalism was observed, growth of the largest individuals in YOY perch cohorts was faster than that of smaller individuals. However, the energy gain from cannibalism did not increase growth rate enough to reach a size necessary to feed on more abundant size classes of victims, and therefore, the effect of cannibalism on overall cohort density was minor. 5. In addition to a high energy gain from cannibalism allowing for fast growth, strong resource limitation and slow growth rates of small individuals (i.e. potential victims) are a prerequisite not only for the development of intra-cohort cannibalism but also for its persistence.

  • 14.
    Båmstedt, Ulf
    et al.
    Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Wikner, Johan
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Mixing depth and allochthonous dissolved organic carbon: controlling factors of coastal trophic balance2016In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 561, p. 17-29Article in journal (Refereed)
    Abstract [en]

    ABSTRACT: The interacting effects of different mixing depths and increased allochthonous dissolved organic carbon (DOC) on the ratio of heterotrophic to autotrophic production (i.e. trophic balance) was evaluated in a mesocosm study with a stratified water column. An autumn plankton community from the northern Bothnian Sea showed significantly decreased phytoplankton production and somewhat increased bacterial production with added DOC. In addition, increased mixing depth further reduced phytoplankton production. With a deep pycnocline and added DOC, the system became net-heterotrophic, with an average bacteria-to-phytoplankton production ratio of 1.24. With a deep pycnocline without added DOC, the trophic balance was changed to 0.44 (i.e. autotrophic). With a shallow pycnocline, the system remained net-autotrophic irrespective of DOC addition. We propose that increased precipitation in northern Europe due to climate change may result in changed density stratification and increased allochthonous DOC transport to the sea, leading to more heterotrophic coastal aquatic ecosystems. Such a scenario may entail reduced biological production at higher trophic levels and enhanced CO2 emission to the atmosphere.

  • 15. Cote, Julien
    et al.
    Brodin, Tomas
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Fogarty, Sean
    Sih, Andrew
    Non-random dispersal mediates invader impacts on the invertebrate community2017In: Journal of Animal Ecology, ISSN 0021-8790, E-ISSN 1365-2656, Vol. 86, no 6, p. 1298-1307Article in journal (Refereed)
    Abstract [en]

    Dispersers are often not a random draw from a population, dispersal propensity being conditional on individual phenotypic traits and local contexts. This non-randomness consequently results in phenotypic differences between dispersers and non-dispersers and, in the context of biological invasions, in an invasion front made of individuals with a biased phenotype. This bias of phenotypes at the front may subsequently modulate the strength of ecological effects of an invasive species on invaded communities. We recently demonstrated that more asocial mosquitofish (Gambusia affinis), one of the 100 worst invasive species, disperse further, suggesting a sociability-biased invasion front. As behavioural types are related to the strength of interspecific interactions, an invasion by a biased subset of individuals should have important ecological implications for native communities. Here, we tested the impact of phenotypic biases in dispersing individuals (relative to non-dispersers) on prey communities in experimental mesocosms. We show that dispersers reduce prey abundance more than do non-dispersers during the first 4 weeks after introduction, and that the disperser's social types are likely drivers of these differences. These differences in prey communities disappeared after 8 weeks suggesting prey community resilience against predation in these mesocosm ecosystems. Consequently, we call for the integration of non-random dispersal, dispersal syndromes and more generally intraspecific variation into studies predicting the impacts of invasions.

  • 16. Dessborn, Lisa
    et al.
    Elmberg, Johan
    Englund, Göran
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Pike predation affects breeding success and habitat selection of ducks2011In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 56, no 3, p. 579-589Article in journal (Refereed)
    Abstract [en]

    1. Fish and ducks often belong to the same local food web, and several studies indicate that there is a general negative effect of fish on breeding ducks. This pattern has so far been addressed mainly within the framework of competition for common invertebrate prey, while predation by large fish as a force behind settlement and abundance patterns in ducks remains largely unknown. This is the first study to address the effect of fish predation on breeding ducks, isolated from that of competition, and the first experiment to explore the ability of ducks to identify and avoid lakes with high risk of fish predation.

    2. We used a before–after control–impact design and 11 naturally fishless lakes. Waterfowl on the lakes were surveyed during the breeding season of 2005. Large adult pike (Esox lucius) were added to two lakes in early spring 2008, and waterfowl surveys were repeated on all 11 lakes.

    3. Pike introduction did not affect the number of pairs on lakes during the nesting season in any of three focal duck species (mallard Anas platyrhynchos, teal Anas crecca, and goldeneye Bucephala clangula). During the brood-rearing season, however, there was a decrease in duck days in teal and goldeneye in lakes with pike, with similar trends observed in mallard. The number of goldeneye ducklings was also significantly lower in lakes with pike. We were unable to determine whether the response was attributable to direct pike predation or to broods leaving experimental lakes, but in either case, our study demonstrates high fitness costs for ducks breeding on lakes with pike.

    4. The apparent inability of nesting ducks to detect pike and the clear fitness implications may influence the annual recruitment of ducks on a larger scale as pike are both common and widespread. Vegetation complexity and food abundance are likely to be of overriding importance when breeding ducks are choosing a nesting site. As pike have a strong influence on breeding birds, relying on vegetation and cues of food abundance, while ignoring indicators of predation risk from fish, could lead to lakes with pike acting as an ecological trap.

  • 17. Dessborn, Lisa
    et al.
    Englund, Goran
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Elmberg, Johan
    Arzel, Celine
    Innate responses of mallard ducklings towards aerial, aquatic and terrestrial predators2012In: Behaviour, ISSN 0005-7959, E-ISSN 1568-539X, Vol. 149, no 13-14, p. 1299-1317Article in journal (Refereed)
    Abstract [en]

    Reproductive success in ducks is strongly influenced by predation on the breeding grounds. Ducklings are targeted by a range of terrestrial, aerial and aquatic predators, giving a strong selective advantage to individuals and broods that have effective ways to avoid predation. In experiments on naive mallard (Anas platyrhynchos) ducklings without an accompanying adult female we investigated the innate ability to identify and avoid threats at varying intensity from aerial, aquatic and terrestrial predators. Ducklings displayed increased vigilance in response to pre-recorded calls of predatory birds, representing a low level of threat. They did not react to visual and olfactory stimuli generated by motionless northern pike (Esox lucius). Neither did they show a strong response to caged American mink (Neovison vison) (visual and olfactory stimuli), although they avoided the area with the mink, indicating a certain level of recognition. High intensity threats were simulated by staging attacks from aerial (goshawk, Accipiter gentilis) and aquatic predators (northern pike). The aerial attack made ducklings dive and scatter under water, whereas the response to attack by pike was to run on the water and scatter in different directions. The lack of response to a 'passive' pike and the rather weak avoidance of mink indicate that olfactory cues are not as important in identifying a potential predatory threat by ducklings as are auditory cues. Visual cues appear to be of little importance unless they are combined with movement, and a clear response is only triggered when the intensity of predator threat is high. Mallard ducklings, thus, show an innate capacity to adjust anti-predator behaviour to different predator types and to threat intensity. Our study highlights the general trade-off between foraging needs and predator avoidance, but also second-order trade-offs in which innate avoidance behaviour towards one type of predator may increase predation risk from another.

  • 18. Eeva, Tapio
    et al.
    Andersson, Tommi
    Berglund, Åsa M M
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Brommer, Jon E
    Hyvönen, Raimo
    Klemola, Tero
    Laaksonen, Toni
    Loukola, Olli
    Morosinotto, Chiara
    Rainio, Kalle
    Sirkiä, Päivi M
    Vesterinen, Eero J
    Species and abundance of ectoparasitic flies (Diptera) in pied flycatcher nests in Fennoscandia2015In: Parasites & Vectors, ISSN 1756-3305, E-ISSN 1756-3305, Vol. 8, article id 648Article in journal (Refereed)
    Abstract [en]

    Background: Birds host several ectoparasitic fly species with negative effects on nestling health and reproductive output, and with the capability of transmitting avian blood parasites. Information on the abundance and distribution of the ectoparasitic fly genera Ornithomya (Hippoboscidae) and Protocalliphora (Calliphoridae) in northern Europe is still generally poor, and we thus explored their geographic range and occurrence of these flies in the nests of a common avian model species, the pied flycatcher Ficedula hypoleuca. Methods: Nests of F. hypoleuca were collected from 21 locations across Fennoscandia in summer 2013, across a latitudinal gradient (between 56 degrees N - 70 degrees N) and examined for the presence of fly puparia. Adult specimens of Ornithomya spp. were also collected for species identification. Fly species were identified morphologically and identifications confirmed with DNA barcoding. Results: We found three species: two louse-flies - Ornithomya chloropus and O. avicularia - and one blow-fly, Protocalliphora azurea. The prevalence of O. avicularia was higher in southern latitudes and this species was not encountered beyond 62 degrees N whereas O. chloropus and P. azurea occurred across the whole range of latitudes. The prevalence of O. chloropus further increased with increasing distance from the coast - a pattern not documented before. The three fly species showed no interspecific associations in their prevalence. Conclusions: Our study revealed relatively high prevalence for all the species (O. chloropus 59 %, O. avicularia 20 %, P. azurea 32 %), and an interesting spatial pattern in the prevalence of the two louse fly species. Our sample did not indicate any major range shifts towards the north for the southern species as compared to the information from the past. Morphological identification of O. chloropus did not match with the corresponding sequences published in the GenBank and taxonomy of this group calls for further studies.

  • 19. Eklöv, Peter
    et al.
    Svanbäck, Richard
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Predation favors adaptive morphological variation in perch populationsManuscript (Other academic)
  • 20.
    Englund, Göran
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Competition in caddis larvae1992Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis deals with behavioural strategies used by caddis larvae in pairwise contests and when selecting microhabitats. Effects of caddis larvae on survival and habitat selection of other insect taxa have also been studied.

    The behaviours used by Arctopsyche ladogensis larvae fighting for nets, and Agrypnia pagetana larvae fighting for cases, agreed well with predictions from the sequential assessment game, which is an ESS model of animal fighting behaviour.

    Establishment by net-spinning Hydropsyche siltalai larvae on artificial substrates was highest at intermediate densities of residents. Emigration/mortality was density independent, and it was higher at a poor site (low food availability) than at a rich site. Establishment was unaffected by site quality. Growth was density dependent because larvae in upstream positions reduced both current velocity and concentration of food particles for larvae in downstream positions.

    A field experiment involved manipulations of the density of H. siltalai larvae and their nets in a lake outlet stream. H. siltalai larvae affected all abundant taxa, but the mechanism involved varied between taxa. Rhyacophila nubila (Trichoptera) and chironomid larvae benefited from the presence of H. siltalai nets. Negative effects on nymphs of the mayfly Ephemerella ignita were due to predation by H. siltalai larvae, while a combination of predation and increased emigration in response to nets depressed densities of Simulium truncatum blackfly larvae.

  • 21. Fors, Lisa
    et al.
    Markus, Robert
    Theopold, Ulrich
    Ericson, Lars
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Hambäck, Peter A.
    Geographic variation and trade-offs in parasitoid virulence2016In: Journal of Animal Ecology, ISSN 0021-8790, E-ISSN 1365-2656, Vol. 85, no 6, p. 1595-1604Article in journal (Refereed)
    Abstract [en]

    1. Host-parasitoid systems are characterized by a continuous development of new defence strategies in hosts and counter-defence mechanisms in parasitoids. This co-evolutionary arms race makes host-parasitoid systems excellent for understanding trade-offs in host use caused by evolutionary changes in host immune responses and parasitoid virulence. However, knowledge obtained from natural host-parasitoid systems on such trade-offs is still limited.

    2. In this study, the aim was to examine trade-offs in parasitoid virulence in Asecodes parviclava (Hymenoptera: Eulophidae) when attacking three closely related beetles: Galerucella pusilla, Galerucella calmariensis and Galerucella tenella (Coleoptera: Chrysomelidae). A second aim was to examine whether geographic variation in parasitoid infectivity or host immune response could explain differences in parasitism rate between northern and southern sites.

    3. More specifically, we wanted to examine whether the capacity to infect host larvae differed depending on the previous host species of the parasitoids and if such differences were connected to differences in the induction of host immune systems. This was achieved by combining controlled parasitism experiments with cytological studies of infected larvae.

    4. Our results reveal that parasitism success in A. parviclava differs both depending on previous and current host species, with a higher virulence when attacking larvae of the same species as the previous host. Virulence was in general high for parasitoids from G. pusilla and low for parasitoids from G. calmariensis. At the same time, G. pusilla larvae had the strongest immune response and G. calmariensis the weakest. These observations were linked to changes in the larval hemocyte composition, showing changes in cell types important for the encapsulation process in individuals infected by more or less virulent parasitoids.

    5. These findings suggest ongoing evolution in parasitoid virulence and host immune response, making the system a strong candidate for further studies on host race formation and speciation.

  • 22. Fossen, Erlend I.
    et al.
    Ekrem, Torbjørn
    Nilsson, Anders N
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Bergsten, Johannes
    Species delimitation in northern European water scavenger beetles of the genus Hydrobius (Coleoptera, Hydrophilidae)2016In: ZooKeys, ISSN 1313-2989, E-ISSN 1313-2970, no 564, p. 71-120Article in journal (Refereed)
    Abstract [en]

    The chiefly Holarctic Hydrobius species complex (Coleoptera, Hydrophilidae) currently consists of H. arcticus Kuwert, 1890, and three morphological variants of H. fuscipes (Linnaeus, 1758): var. fuscipes, var. rottenbergii and var. subrotundus in northern Europe. Here molecular and morphological data are used to test the species boundaries in this species complex. Three gene segments (COI, H3 and ITS2) were sequenced and analyzed with Bayesian methods to infer phylogenetic relationships. The Generalized Mixed Yule Coalescent (GMYC) model and two versions of the Bayesian species delimitation method BPP, with or without an a priori defined guide tree (v2.2 & v3.0), were used to evaluate species limits. External and male genital characters of primarily Fennoscandian specimens were measured and statistically analyzed to test for significant differences in quantitative morphological characters. The four morphotypes formed separate genetic clusters on gene trees and were delimited as separate species by GMYC and by both versions of BPP, despite specimens of H. f. var. fuscipes and H. f. var. subrotundus being sympatric. H. arcticus and H. f. var. rottenbergii could only be separated genetically with ITS2, and were delimited statistically with GMYC on ITS2 and with BPP on the combined data. In addition, six or seven potentially cryptic species of the H. fuscipes complex from regions outside northern Europe were delimited genetically. Although some overlap was found, the mean values of six male genital characters were significantly different between the morphotypes (p < 0.001). Morphological characters previously presumed to be diagnostic were less reliable to separate H. f. var. fuscipes from H. f. var. subrotundus, but characters in the literature for H. arcticus and H. f. var. rottenbergii were diagnostic. Overall, morphological and molecular evidence strongly suggest that H. arcticus and the three morphological variants of H. fuscipes are separate species and Hydrobius rottenbergii Gerhardt, 1872, stat. n. and Hydrobius subrotundus Stephens, 1829, stat. n. are elevated to valid species. An identification key to northern European species of Hydrobius is provided.

  • 23.
    Hellström, Gustav
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Heynen, Martina
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Borcherding, Jost
    Magnhagen, Carin
    Individual consistency and context dependence in group-size preference of Eurasian perch2016In: Behavioural Processes, ISSN 0376-6357, E-ISSN 1872-8308, Vol. 133, p. 6-11Article in journal (Refereed)
    Abstract [en]

    Many fish spend a large part of their life in groups. The size of the group influences potential costs and benefits of group living, and depending on context a fish may prefer different group sizes. Group-size preference may also depend on personality, with social individuals expected to prefer larger groups than asocial fish. This study investigates context-dependent group size preference in two populations of a highly social fish, young of the year Eurasian perch. The perch were given a choice between a group of two and a group of eight conspecifics under three different situations: the small group was feeding, the small group had access to shelter, and a control treatment with no extra stimuli. In general, the perch associated more with the large group, but significantly less so during the food treatment. Perceived access to shelter did not affect group size preference compared to the control treatment. Consistent individual differences in social attraction were found within each context, but not among all contexts. Also, an individual's sociability did not correlate with its degree of boldness, indicating a lack of a behavioural syndrome between the two personality traits in the studied populations. The results highlight the importance of considering environmental context when studying social behaviour in obligate social fish, and show the complexity of the concept of sociability as a personality trait by demonstrating context dependence in individual consistency in social behaviour.

  • 24.
    Hellström, Gustav
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Magnhagen, Carin
    Balancing past and present: how experience influences boldness over time in Eurasian perch2017In: Current Zoology, ISSN 1674-5507, Vol. 63, no 2, p. 159-164Article in journal (Refereed)
    Abstract [en]

    Adapting to fluctuating predation conditions is a challenge for prey. By learning through experience, animals may adjust their anti-predator behavior to better reflect current predation risk. Although many studies show experience of predation to alter prey behavior, little is known about how prey rely on such experience over time. By comparing boldness over different temporal scales between individuals of Eurasian perch, either experienced or naive of predators, we examine how risk is traded based on past and present experience. Differences in predator exposure during the first year of life were found to lead to differences in risk-taking behavior, even after the perch been kept in a predator-free environment for 9 months. However, the response to a potential predator was quickly readjusted after increased experience of current conditions. The results highlight how prey have to balance past experiences of predators against current threat levels.

  • 25.
    Heynen, Martina
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Institute of Zoology of the University of Cologne, Department of General Ecology & Limnology, Ecological Field Station Grietherbusch, Rees, Germany.
    Borcherding, J.
    Bunnefeld, N.
    Magnhagen, C.
    Plasticity and consistency of behavioural responses to predation risk in laboratory environments2016In: Journal of Zoology, ISSN 0952-8369, E-ISSN 1469-7998, Vol. 300, no 3, p. 228-235Article in journal (Refereed)
    Abstract [en]

    The individual animal is currently a major focus of behavioural research and an increasing number of studies raise the question of how between-individual behavioural consistency and behavioural plasticity interact. Applying the reaction norm concept on groups, our study addresses both of these aspects in one framework and within an animal's natural social environment. Risk-taking behaviour in 1-year-old perch Perca fluviatilis was assayed in aquarium experiments before and after the fish were subjected to the presence or absence of a piscivorous predator for 3weeks. To analyse the inter-individual behavioural variation across the repeated measurements, we dissected the behavioural change across the predator treatment into individual constant and plastic components using hierarchical mixed-effects models. During the predator treatment, juvenile perch increased in boldness and decreased in vigilance, the magnitude of these behavioural changes was influenced by group composition. However, the behavioural changes were not influenced by the presence of a predator, indicating the difficulties in generating realistic long-term predation pressure in the laboratory. Individuals differed in the relative increase in boldness across the predator treatment and, thus, varied in the shape of their reaction norms. In accordance, the best linear unbiased predictors, extracted from the random effects of separate linear mixed-effects models for the data before and after the predator treatment were only weakly correlated. Hence, between-individual variation seems to change under laboratory conditions and therewith not necessarily represents the initially present natural' variation, giving important implications for the conduction and interpretation of behavioural experiments.

  • 26.
    Heynen, Martina
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Bunnefeld, Nils
    Borcherding, Jost
    Facing different predators: adaptiveness of behavioral and morphological traits under predation2017In: Current Zoology, ISSN 1674-5507, Vol. 63, no 3, p. 249-257Article in journal (Refereed)
    Abstract [en]

    Predation is thought to be one of the main structuring forces in animal communities. However, selective predation is often measured on isolated traits in response to a single predatory species, but only rarely are selective forces on several traits quantified or even compared between different predators naturally occurring in the same system. In the present study, we therefore measured behavioral and morphological traits in young-of-the-year Eurasian perch Perca fluviatilis and compared their selective values in response to the 2 most common predators, adult perch and pike Esox lucius. Using mixed effects models and model averaging to analyze our data, we quantified and compared the selectivity of the 2 predators on the different morphological and behavioral traits. We found that selection on the behavioral traits was higher than on morphological traits and perch predators preyed overall more selectively than pike predators. Pike tended to positively select shallow bodied and nonvigilant individuals (i.e. individuals not performing predator inspection). In contrast, perch predators selected mainly for bolder juvenile perch (i.e. individuals spending more time in the open, more active), which was most important. Our results are to the best of our knowledge the first that analyzed behavioral and morphological adaptations of juvenile perch facing 2 different predation strategies. We found that relative specific predation intensity for the divergent traits differed between the predators, providing some additional ideas why juvenile perch display such a high degree of phenotypic plasticity.

  • 27. Hruska, Kimberly A.
    et al.
    Hinch, Scott G.
    Healey, Michael C.
    Patterson, David A.
    Larsson, Stefan
    Umeå University, Faculty of Science and Technology, Umeå Marine Sciences Centre (UMF).
    Farrell, Anthony P.
    Influences of Sex and Activity Level on Physiological Changes in Individual Adult Sockeye Salmon during Rapid Senescence2010In: Physiological and Biochemical Zoology, ISSN 1522-2152, E-ISSN 1537-5293, Vol. 83, no 4, p. 663-676Article in journal (Refereed)
    Abstract [en]

    A noninvasive biopsy protocol was used to sample plasma and gill tissue in individual sockeye salmon (Oncorhynchus nerka) during the critical life stage associated with spawning-arrival at a spawning channel through senescence to death several days later. Our main objective was to characterize the physiological changes associated with rapid senescence in terms of the physiological stress/cortisol hypersecretion model and the energy exhaustion model. Salmon lived an average of 5 d in the spawning channel, during which time there were three major physiological trends that were independent of sexual status: a large increase in plasma indicators of stress and exercise (i.e., lactate and cortisol), a decrease in the major plasma ions (i.e., Cl(-) and Na(+)) and osmolality, and a decrease in gross somatic energy reserves. Contrary to a generalized stress response, plasma glucose decreased in approximately 2/3 of the fish after arrival, as opposed to increasing. Furthermore, plasma cortisol levels at spawning-ground arrival were not correlated with the degree of ionoregulatory changes during rapid senescence. One mechanism of mortality in some fish may involve the exhaustion of energy reserves, resulting in the inability to mobilize plasma glucose. Sex had a significant modulating effect on the degree of physiological change. Females exhibited a greater magnitude of change for gross somatic energy, osmolality, and plasma concentrations of Cl(-), Na(+), cortisol, testosterone, 11-ketotestosterone, 17,20 beta-progesterone, and estradiol. The activity level of an individual on the spawning grounds appeared to influence the degree of some physiological changes during senescence. For example, males that received a greater frequency of attacks exhibited larger net decreases in plasma 11-ketotestosterone while on the spawning grounds. These results suggest that rapid senescence on spawning grounds is influenced by multiple physiological processes and perhaps behavior. This study provides some of the first data to look at sex differences in senescence in Pacific salmon.

  • 28.
    Hudson, Alan G.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. Division of Aquatic Ecology & Macroevolution, Institute of Ecology & Evolution, University of Bern, Bern, Switzerland and Department of Fish Ecology & Evolution, EAWAG Centre of Ecology, Evolution and Biogeochemistry, Kastanienbaum, Switzerland.
    Vonlanthen, Pascal
    Division of Aquatic Ecology & Macroevolution, Institute of Ecology & Evolution, University of Bern, Bern, Switzerland and Department of Fish Ecology & Evolution, EAWAG Centre of Ecology, Evolution and Biogeochemistry, Kastanienbaum, Switzerland.
    Bezault, Etienne
    Department of Biology, Reed College, Portland, USA, Division of Aquatic Ecology & Macroevolution, Institute of Ecology & Evolution, University of Bern, Bern, Switzerland and Department of Fish Ecology & Evolution, EAWAG Centre of Ecology, Evolution and Biogeochemistry, Kastanienbaum, Switzerland.
    Seehausen, Ole
    Division of Aquatic Ecology & Macroevolution, Institute of Ecology & Evolution, University of Bern, Bern, Switzerland and Department of Fish Ecology & Evolution, EAWAG Centre of Ecology, Evolution and Biogeochemistry, Kastanienbaum, Switzerland.
    Genomic signatures of relaxed disruptive selection associated with speciation reversal in whitefish2013In: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 13, p. 108-Article in journal (Refereed)
    Abstract [en]

    Background: Speciation reversal: the erosion of species differentiation via an increase in introgressive hybridization due to the weakening of previously divergent selection regimes, is thought to be an important, yet poorly understood, driver of biodiversity loss. Our study system, the Alpine whitefish (Coregonus spp.) species complex is a classic example of a recent postglacial adaptive radiation: forming an array of endemic lake flocks, with the independent origination of similar ecotypes among flocks. However, many of the lakes of the Alpine radiation have been seriously impacted by anthropogenic nutrient enrichment, resulting in a collapse in neutral genetic and phenotypic differentiation within the most polluted lakes. Here we investigate the effects of eutrophication on the selective forces that have shaped this radiation, using population genomics. We studied eight sympatric species assemblages belonging to five independent parallel adaptive radiations, and one species pair in secondary contact. We used AFLP markers, and applied F-ST outlier (BAYESCAN, DFDIST) and logistic regression analyses (MATSAM), to identify candidate regions for disruptive selection in the genome and their associations with adaptive traits within each lake flock. The number of outlier and adaptive trait associated loci identified per lake were then regressed against two variables (historical phosphorus concentration and contemporary oxygen concentration) representing the strength of eutrophication. Results: Whilst we identify disruptive selection candidate regions in all lake flocks, we find similar trends, across analysis methods, towards fewer disruptive selection candidate regions and fewer adaptive trait/candidate loci associations in the more polluted lakes. Conclusions: Weakened disruptive selection and a concomitant breakdown in reproductive isolating mechanisms in more polluted lakes has lead to increased gene flow between coexisting Alpine whitefish species. We hypothesize that the resulting higher rates of interspecific recombination reduce either the number or extent of genomic islands of divergence surrounding loci evolving under disruptive natural selection. This produces the negative trend seen in the number of selection candidate loci recovered during genome scans of whitefish species flocks, with increasing levels of anthropogenic eutrophication: as the likelihood decreases that AFLP restriction sites will fall within regions of heightened genomic divergence and therefore be classified as F-ST outlier loci. This study explores for the first time the potential effects of human-mediated relaxation of disruptive selection on heterogeneous genomic divergence between coexisting species.

  • 29. Huser, Brian
    et al.
    Bartels, Pia
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    The feeding ecology of carp2015In: Biology and ecology of carp / [ed] C. Pietsch and P.E. Hirsch, CRC Press, 2015, p. 217-243Chapter in book (Refereed)
  • 30.
    Hörnfeldt, Birger
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Cycles of voles, predators, and alternative prey in boreal Sweden1991Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Bank voles, grey-sided voles, and field voles had synchronous 3-4 year density cycles with variable amplitudes which averaged about 200-fold in each species. Cycles of vole predators (red fox and Tengmalm's owl), and their (foxes') alternative prey (mountain hare and forest grouse) lagged behind the vole cycles.

    The nomadic Tengmalm's owl responded with a very rapid and strong numerical increase to the initial cyclic summer increase of voles (the owl’s staple food). Owl breeding densities in the springs were highly correlated with vole supply in the previous autumns. This suggested that the number of breeding owls was largely determined in the autumn at the time of the owl's nomadic migrations, and that immigration was crucial for the rapid rise in owl numbers. The owl's numerical response was reinforced by the laying of earlier and larger clutches when food was plentiful. In addition, the owl has an early maturation at one year of age.

    The transition between subsequent vole cycles was characterized by a distinct shift in rate of change in numbers from low to high or markedly higher values in both summer and winter. Regulation increased progressively throughout the cycle since the rate of change decreased continuously in the summers. Moreover, there was a similar decrease of the rate of change in winter. Rate of change was delayed density-dependent. The delayed density-dependence had an 8 month time-lag in the summers and a 4 month time-lag in the winters relative to the density in previous autumns and springs, respectively. These findings suggest that vole cycles are likely to be generated by a time-lag mechanism. On theoretical grounds, it has been found that a delayed density- dependence of population growth rate with a 9 month time-lag caused stable limit cycles with a period between 3 and 4 years. Some mechanisms for the delayed density-dependence are suggested and discussed. The mechanisms are assumed to be related to remaining effects of vole populations past interactions with predators, food supplies, and/or diseases.

    Unlike the other voles, the bank vole had regular and distinct seasonal declines in density over winter. These declines are proposed to be due to predation, mainly by Tengmalm's owl. Supranivean foraging for epiphytic tree lichens and conifer seeds most likely explains why this species was frequently taken by the owl under snow-rich conditions.

    The alternative prey hypothesis predicts that a reduction of predator numbers should increase the number of alternative prey. Alternative prey should be less effectively synchronized to the vole cycle by predation at declining and low vole (main prey) densities; they may also lose their 3-4 year cyclicity. The appearance of sarcoptic mange among foxes in northern Sweden in the mid 1970s provided an opportunity to "test" these ideas, and these were found to be supported. In areas with highest mange infection rates, foxes declined markedly from the late 1970s to mid 1980s, whereas hare numbers rose rapidly and appeared non-cyclic.

  • 31. Ilmonen, Jari
    et al.
    Adler, Peter H
    Malmqvist, Björn
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Cywinska, Alina
    The Simulium vernum group (Diptera: Simuliidae) in Europe: multiple character sets for assessing species status2009In: Zoological Journal of the Linnean Society, ISSN 0024-4082, E-ISSN 1096-3642, Vol. 156, no 4, p. 847-863Article in journal (Refereed)
    Abstract [en]

    The value of using characters from multiple sources - chromosomes, ecology, gene sequences, and morphology - to evaluate the species status of closely related black flies is demonstrated for three European members of the Simulium vernum group: Simulium crenobium (Knoz, 1961), Simulium juxtacrenobium Bass & Brockhouse, 1990, and Simulium vernum s.s. Macquart, 1826. Simulium juxtacrenobium is a chromosomally, molecularly, and morphologically distinct species that diverged from S. crenobium and S. vernum s.s. about 2 Mya. It is specialized for intermittent streams, is univoltine, and is recorded for the first time from northern Europe, based on collections from Finland and Sweden, representing a range extension of about 1800 km. In contrast, S. crenobium, although confirmed as a distinct species, differs from S. vernum s.s. by only a few larval and chromosomal characters, and by a breeding habitat restricted to mountain spring brooks. Whereas all four character sets independently support the specific distinctness of S. juxtacrenobium and S. vernum s.s., multiple character sets are required to establish the specific validity of S. crenobium.

  • 32. Jiguet, Frédéric
    et al.
    Arlettaz, Raphaël
    Bauer, Hans-Günther
    Belik, Viktor
    Copete, José Luis
    Couzi, Laurent
    Czajkowski, Michel Alexandre
    Dale, Svein
    Dombrovski, Valery
    Elts, Jaanus
    Ferrand, Yves
    Hargues, Régis
    Kirwan, Guy M.
    Minkevicius, Simonas
    Piha, Markus
    Selstam, Gunnar
    Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine).
    Skierczynski, Michal
    Siblet, Jean-Philippe
    Sokolov, Aleksandr
    An update of the European breeding population sizes and trends of the Ortolan Bunting (Emberiza hortulana)2016In: Ornis Fennica, ISSN 0030-5685, Vol. 93, no 3, p. 186-196Article, review/survey (Refereed)
    Abstract [en]

    Following recent updates proposed by BirdLife International and further updates across Europe gathered in the context of a continent-wide study of the migration strategy of the species, we propose here an update of national population sizes and associated recent trends of the Ortolan Bunting (Emberiza hortulana). Previous estimates for the period 1999-2002 reported 5,200,000 to 16,000,000 breeding pairs, for an area extending east to European Russia, and south to the Caucasus and Turkey. The countries holding the largest populations were Turkey (3-10 million pairs) and Russia (1.5-5.0 million pairs). The updated results give approximately 3,319,000 to 7,057,000 pairs in Europe (for the period 2012-2014), representing a c. 50% decrease in numbers over the last decade. This decrease is partly due to overestimates proposed in previous reports for the key country, Turkey, which is now considered to support only 500,000 to 1,000,000 pairs. Russia still holds 2.0-4.3 million pairs, although with an estimated decline of c.15-30% since 2000. Overall, within the 39 European countries assessed here, recent decadal trends (on average 2000-2012) in population size are reported as unknown in 15 countries, increasing in 2 countries (Germany and Serbia), stable or fluctuating in 6 countries, and decreasing in 16 countries including recent extinctions in Belgium, Hungary, Slovakia and the Netherlands. Overall, declining populations are mostly located in northern Europe, and fourteen of the 15 northern European countries with a known national trend have declining breeding populations, suggesting that northern breeders are of particular conservation concern.

  • 33. Johansson, Maria
    et al.
    Sandström, Camilla
    Umeå University, Faculty of Social Sciences, Department of Political Science.
    Pedersen, Eja
    Ericsson, Göran
    Factors governing human fear of wolves: moderating effects of geographical location and standpoint on protected nature2016In: European Journal of Wildlife Research, ISSN 1612-4642, E-ISSN 1439-0574, Vol. 62, no 6, p. 749-760Article in journal (Refereed)
    Abstract [en]

    This study analyses psychological antecedents of feelings of fear of wolves in a proportional sample of the Swedish population (national sample, n = 545) and in a sample of people in counties with wolf presence (regional sample, n = 1,892). Structural equation modelling of survey data suggests a dual pathway to self-reported fear. One path encompasses the appraisal of the environmental context operationalised as a potential wolf encounter. The second path concerns the appraisal of the social context assessed as social trust in managing authorities. The relative importance of the paths differs between the national and the regional sample, and between people in the administrative centre of the region and the regional periphery. We show that the public's fear of wolves should be addressed both at an individual level, focusing on situations with potential encounters, and at a collective level, by strengthening the trust between the public and authorities, and regional variation should be considered.

  • 34.
    Larsson, Niklas
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Claesson Lingehall, Helena
    Umeå University, Faculty of Medicine, Department of Nursing.
    Al Zaidi, Nefar
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Claesson, Jonas
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Jensen-Waern, Marianne
    Lehtipalo, Stefan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Percutaneously inserted long-term central venous catheters in pigs of different sizes2015In: Laboratory Animals. Journal of the Laboratory Animal Science Association, ISSN 0023-6772, E-ISSN 1758-1117, Vol. 49, no 3, p. 215-219Article in journal (Refereed)
    Abstract [en]

    Pigs are used for long-term biomedical experiments requiring repeated injections, infusions and collections of blood samples. Thus, it is necessary for vascular catheters to be indwelling to avoid undue stress to the animals and the use of restraints. We propose a refined model of percutaneous insertion of long-term central venous catheters to minimize the surgical trauma and postoperative complications associated with catheter insertion. Different sizes of needles (18 Ga versus 21 Ga) for initial puncture of the veins were compared. In conventional pigs weighing less than 30 kg, catheter insertion may be facilitated by using a microintroducer set with a 21 Ga needle. In pigs weighing 50 kg, a standard 18 Ga needle may be preferable.

  • 35. Larsson, Stefan
    et al.
    Byström, Pär
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Berglund, Johnny
    Carlsson, Ulf
    Veneranta, Lari
    Larsson, Sylvia H.
    Hudd, Richard
    Characteristics of anadromous whitefish (Coregonus lavaretus (L.)) rivers in the Gulf of Bothnia2013In: BIOLOGY AND MANAGEMENT OF COREGONID FISHES - 2011, 2013, p. 189-201Conference paper (Refereed)
    Abstract [en]

    In order to study anadromous whitefish spawning river requirements, we sampled 41 rivers in the Gulf of Bothnia for newly hatched whitefish larvae for one to three consecutive years. Chemical and morphological data (e.g. flow rate, topography, pH, estuary fetch and distance to coastal sandy areas) were collected for each river. Newly-hatched whitefish were caught in 19 rivers whereas whitefish were not confirmed present in 22 rivers. By applying partial least squares discriminant analysis (PLS-DA), data for rivers confirmed to support whitefish were contrasted with data for rivers in which whitefish were not found. The single most important factor was annual average water flow rate. Whitefish larvae were observed in 93% of the rivers with annual mean flow rate > 5 m(3) s(-1) (N = 14). In contrast, newly-hatched whitefish were only found in 22% of the smaller rivers (N = 27).

  • 36.
    Leonardsson, Kjell
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Variation in age and size at maturation in two benthic crustaceans in the Gulf of Bothnia1990Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The thesis deals with variation in age and size at maturation in Saduria entomon and Pontoporeia affinis along a depth gradient in the Gulf of Bothnia, Sweden. I have analysed at what sizes and ages animals should mature in relation to growth and mortality conditions. The thesis also deals with predator-prey interactions within and between the two species.

    The isopod Saduria entomon matured during winter at an age of three years at 5 m depth in the Norrby archipelago (63° 30'N, 19° 50'E). Males matured eariier and at larger sizes (27-48 mm) than females (23-36 mm). The offspring were released in early summer. The adult size increased with increasing depth. Outside the archipelago, at 125 m depth, the sexes reached a size of 84 and 54 mm respectively. No evidence for temporal restriction in the release of the young was found at the deep area. The species was shown to have a high capacity for cannibalism on small conspecifics, although the small ones have the potential to avoid aggregations of large conspecifics. The number of small conspecifics eaten was related both to the absolute and relative densities of the alternative prey Pontoporeia affinis. The cannibalistic behaviour have the potential to act as a stabilizing mechanism in the Saduria-Pontoporeia system. Fourhom sculpin (Myoxocephalus quadricornis) was the fish species of utmost importance as a predator on S.entomon, and it mainly preferred large specimens.

    The amphipod Pontoporeia affinis matured at an age of two years in the littoral zone and at a very deep (210 m) locality. Between these depths it mainly reached maturation at an age of three years. In some years in densely populated areas, they delayed reproduction another year and reproduced as four year old. The variation in age at maturation in P.affinis in relation to depth could be quantitatively predicted by maximizing fitness in the Euler-Lotka equation.

    The size variation at maturation in S.entomon could be qualitatively predicted by maximizing fitness in the Euler-Lotka equation. The general condition for a smaller size at maturity to be adaptive at high temperatures (i.e. shallow areas) is that mortality rate should increase faster than growth rate with increasing temperature. When mortality is higher in young stages than in older and larger ones the pattern is also predicted when growth increases faster than mortality. Small animals may prefer warmer habitats than large ones, because of the presence of a size dependent trade-off between temperature induced growth and mortality. More exactly, the optimum solution of the trade-off between growth and mortality in hazardous environments was suggested to approach maximization of the expression s(W+g)/W, where s is survival rate, W is body weight, and g is growth rate.

  • 37. Lewandowska, Aleksandra M.
    et al.
    Hillebrand, Helmut
    Lengfellner, Kathrin
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Sommer, Ulrich
    Temperature effects on phytoplankton diversity - The zooplankton link2014In: Journal of Sea Research, ISSN 1385-1101, E-ISSN 1873-1414, Vol. 85, p. 359-364Article in journal (Refereed)
    Abstract [en]

    Recent climate warming is expected to affect phytoplankton biomass and diversity in marine ecosystems. Temperature can act directly on phytoplankton (e.g. rendering physiological processes) or indirectly due to changes in zooplankton grazing activity. We tested experimentally the impact of increased temperature on natural phytoplankton and zooplankton communities using indoor mesocosms and combined the results from different experimental years applying a meta-analytic approach. We divided our analysis into three bloom phases to define the strength of temperature and zooplankton impacts on phytoplankton in different stages of bloom development. Within the constraints of an experiment, our results suggest that increased temperature and zooplankton grazing have similar effects on phytoplankton diversity, which are most apparent in the post-bloom phase, when zooplankton abundances reach the highest values. Moreover, we observed changes in zooplankton composition in response to warming and initial conditions, which can additionally affect phytoplankton diversity, because changing feeding preferences of zooplankton can affect phytoplankton community structure. We conclude that phytoplankton diversity is indirectly affected by temperature in the post-bloom phase through changing zooplankton composition and grazing activities. Before and during the bloom, however, these effects seem to be overruled by temperature enhanced bottom-up processes such as phytoplankton nutrient uptake.

  • 38.
    Liess, Antonia
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Rowe, Owen
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Guo, Junwen
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Thomsson, Gustaf
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Lind, Martin I.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. University of Sheffield, UK and Uppsala University, Sweden.
    Hot tadpoles from cold environments need more nutrients - life history and stoichiometry reflects latitudinal adaptation2013In: Journal of Animal Ecology, ISSN 0021-8790, E-ISSN 1365-2656, Vol. 82, no 6, p. 1316-1325Article in journal (Refereed)
    Abstract [en]

    1. High-latitude species (and populations within species) are adapted to short and cold summers. They often have high growth and development rates to fully use the short growing season and mature before the onset of winter. Within the context of ecological stoichiometry theory, this study combines ecology with evolution by relating latitudinal life-history adaptations to their molecular consequences in body nutrient composition in Rana temporaria tadpoles. Temperature and food quality were manipulated during the development of tadpoles from Arctic and Boreal origins. We determined tadpole growth rate, development rate, body size and nutrient content, to test whether (i) Arctic tadpoles could realize higher growth rates and development rates with the help of higher-quality food even when food quantity was unchanged, (ii) Arctic and Boreal tadpoles differed in their stoichiometric (and life history) response to temperature changes, (iii) higher growth rates lead to higher tadpole P content (growth rate hypothesis) and (iv) allometric scaling affects tadpole nutrient allocation. We found that especially Arctic tadpoles grew and developed faster with the help of higher-quality food and that tadpoles differed in their stoichiometric (and life history) response to temperature changes depending on region of origin (probably due to different temperature optima). There was no evidence that higher growth rates mediated the positive effect of temperature on tadpole P content. On the contrary, the covariate growth rate was negatively connected with tadpole P content (refuting the growth rate hypothesis). Lastly, tadpole P content was not related to body size, but tadpole C content was higher in larger tadpoles, probably due to increased fat storage. We conclude that temperature had a strong effect on tadpole life history, nutrient demand and stoichiometry and that this effect depended on the evolved life history.

  • 39.
    McCallum, Erin
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Mantises see in 3D, but not like you and me2018In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 221, no 9Article in journal (Other academic)
  • 40.
    McCallum, Erin
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Speed limits for the animal kingdom2017In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 220, no 21, p. 3841-3841Article in journal (Other (popular science, discussion, etc.))
  • 41. Meissner, Kristian
    et al.
    Juntunen, Antti
    Malmqvist, Björn
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Muotka, Timo
    Predator-prey interactions in a variable environment: responses of a caddis larva and its blackfly prey to variations in stream flow2009In: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 46, no 3, p. 193-204Article in journal (Other academic)
    Abstract [en]

    Predator-prey studies in streams have traditionally focused on mayfly-stonefly interactions in relatively constant flow conditions. In reality, however, lotic prey encounter multiple types of predators, most of which are restricted to low-velocity microhabitats. By contrast, some invertebrate prey may occur in very high current velocities. For example, many blackfly species are able to feed at velocities of 100 cm s(-1), whereas even moderate currents reduce the hunting efficiency of their invertebrate predators. The caddisfly larvae of the genus Rhyacophila, however, may be an exception to the pattern of reducing predator efficiency with increasing velocity. Using a combination of laboratory and field experiments and behavioral field observations, we examined the interaction between predatory Rhyacophila caddis larvae and larval blackflies along a velocity gradient of 20-120 cm s(-1). In laboratory experiments, Rhyacophila preferred currents slower than 50 cm s(-1) while blackflies exhibited a wide tolerance of currents and frequently occurred in currents exceeding 100 cm s(-1). In direct field observations, total activity and distance moved by Rhyacophila were similar at all current velocity regimes tested, but frequency of predation attempts on blackflies was lowest at the highest velocities (> 100 cm s(-1)). In a field colonization study, blackflies avoided substrates with the slowest velocities (< 40 cm s(-1)), as also did the caddis larvae. Only velocities approaching 100 cm s(-1) provide blackflies with refuge from predation by Rhyacophila. Being able to maneuver across a wide range of velocities, Rhyacophila may have more pervasive effects on their prey than other lotic invertebrate predators.

  • 42.
    Mobley, Kenyon B.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Kvarnemo, Charlotta
    Ahnesjo, Ingrid
    Partridge, Charlyn
    Berglund, Anders
    Jones, Adam G.
    The effect of maternal body size on embryo survivorship in the broods of pregnant male pipefish2011In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 65, no 6, p. 1169-1177Article in journal (Refereed)
    Abstract [en]

    The occurrence of male pregnancy in the family Syngnathidae (seahorses, pipefishes, and sea dragons) provides an exceptionally fertile system in which to investigate issues related to the evolution of parental care. Here, we take advantage of this unique reproductive system to study the influence of maternal body size on embryo survivorship in the brood pouches of pregnant males of the broad-nosed pipefish, Syngnathus typhle. Males were mated with either two large females, two small females, a large then a small female, or a small then a large female. Our results show that offspring survivorship depends on an interaction between female body size and the number of eggs transferred by the female. Eggs of larger females deposited in large numbers are more likely to result in viable offspring than eggs of smaller females laid in large numbers. However, when females deposited smaller numbers of eggs, the eggs from smaller females were more likely to produce viable offspring compared to those from larger females. We found no evidence that this result was based on mating order, the relative sizes of competing females, or egg characteristics such as dry weight of eggs. Additionally, male body size did not significantly influence the survivorship of offspring during brooding. Our results suggest that the factors underlying offspring survivorship in pipefish may be more complex than previously believed, with multiple factors interacting to determine the fitness of individual offspring within the broods of pregnant males.

  • 43.
    Norman, Anita J.
    et al.
    Sveriges lantbruksuniversitet.
    Street, Nathaniel Robert
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Spong, Goran
    Sveriges lantbruksuniversitet.
    De Novo SNP Discovery in the Scandinavian Brown Bear (Ursus arctos)2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 11, p. e81012-Article in journal (Refereed)
    Abstract [en]

    Information about relatedness between individuals in wild populations is advantageous when studying evolutionary, behavioural and ecological processes. Genomic data can be used to determine relatedness between individuals either when no prior knowledge exists or to confirm suspected relatedness. Here we present a set of 96 SNPs suitable for inferring relatedness for brown bears (Ursus arctos) within Scandinavia. We sequenced reduced representation libraries from nine individuals throughout the geographic range. With consensus reads containing putative SNPs, we applied strict filtering criteria with the aim of finding only high-quality, highly-informative SNPs. We tested 150 putative SNPs of which 96% were validated on a panel of 68 individuals. Ninety-six of the validated SNPs with the highest minor allele frequency were selected. The final SNP panel includes four mitochondrial markers, two monomorphic Y-chromosome sex-determination markers, three X-chromosome SNPs and 87 autosomal SNPs. From our validation sample panel, we identified two previously known parent-offspring dyads with reasonable accuracy. This panel of SNPs is a promising tool for inferring relatedness in the brown bear population in Scandinavia.

  • 44.
    Novikova, Liudmila N
    et al.
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Novikov, Lev N
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Kellerth, J O
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    BDNF abolishes the survival effect of NT-3 in axotomized Clarke neurons of adult rats2000In: Journal of Comparative Neurology, ISSN 0021-9967, E-ISSN 1096-9861, Vol. 428, no 4, p. 671-680Article in journal (Refereed)
    Abstract [en]

    Neurotrophin-3 (NT-3) and brain-derived neurotrophic factor (BDNF) have previously been shown to support survival and axonal regeneration in various types of neurons. Also, synergistic neuroprotective effects of these neurotrophins have been reported in descending rubrospinal neurons after cervical spinal cord injury (Novikova et al., [2000] Eur. J. Neurosci. 12:776-780). The present study investigates the effects of intrathecally delivered NT-3 and BDNF on the survival and atrophy of ascending spinocerebellar neurons of Clarke nucleus (CN) after cervical spinal cord injury in adult rats. At 8 weeks after cervical spinal cord hemisection, 40% of the axotomized CN neurons had been lost, and the remaining cells exhibited marked atrophy. Microglial activity was significantly increased in CN of the operated side. Intrathecal infusion of NT-3 for 8 weeks postoperatively resulted in 91% cell survival and a reduction in cell atrophy, but did not reduce microglial activity. In spite of the fact that the CN neurons expressed both TrkC and TrkB receptors, only NT-3 had a neuroprotective effect, whereas BDNF was ineffective. Furthermore, when a combination of BDNF and NT-3 was administered, the neuroprotective effect of NT-3 was lost. The present results indicate a therapeutic potential for NT-3 in the treatment of spinal cord injury, but also demonstrate that in certain neuronal populations the neuroprotection obtained by a combination of neurotrophic factors may be less than that of a single neurotrophin.

  • 45.
    Oksanen, Tarja
    Umeå University, Faculty of Science and Technology, Ecology and Environmental Science.
    Predator-prey dynamics in small mammals along gradients of primary productivity1990Doctoral thesis, comprehensive summary (Other academic)
  • 46.
    Olsson, Tommy I.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Lateral movements versus stationarity: adaptive alternatives in benthic invertebrates to the seasonal environment in a boreal river1982Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Benthic invertebrates inhabiting boreal rivers are exposed to very large seasonal variations in their physical environment. The extremes are in winter when the littoral area freezes solid and in spring when water flow increases rapidly.

    In the North Swedish river Vindelälven, the invertebrates fell into three main categories according to their seasonal lateral distribution. One category of animals was stationary in the littoral zone and let itselt freeze into the ice, adopting a "take it" alternative. The category consisted of many species belonging to several higher taxa. By overwintering in ice, the animals avoided predation for nearly half the year and they were in the productive littoral at the same time as they thawed out from the ice in spring. On the other hand the animals had to withstand sub-zero temperatures. A typical representative for this category of animals was the semivoltine snail Gyraulus acronicus. It is a less mobile species connected to dense stands of macrophytes, which are found only in the littoral zone of the river. Nearly the whole population was found overwintering successfully enclosed in ice. Its shell and epiphragm could serve as mechanical protection when frozen into the ice. G. acronicus was cold-hardy only during late autumn and early winter, but it could stand prolonged sub-zero exposure during the proper time. A second category of animlas avoided being frozen by performing lateral movements to deeper parts of the river, adopting the Vleave it" alternative. No species tested in this category were found cold-hardy. It consisted of mobile species known to utilize sedimentated detritus which was only found in greater amounts in the littoral zone of the river. In springtime, prior to spring flood peak, these species colonized promptly the former frozen zone. This behaviour was most pronounced in several lentie mayfly species. An extreme case of migratory behaviour was found in the mayfly Pararneletus chelifer which not only moved towards the river bank but continued up into small tributaries. The shoreward movements of mayflies both allowed the nymphs to avoid the high current velocities in the central part of the river during spring flood time and to utilize the food resources in the flooded areas. A third category of animals avoided the ice by living stationary in the sublittoral zone, adopting the "never face it" alternative. This category was dominated by filter feeders.

  • 47. Ostman, Carina
    et al.
    Borg, Fredrik
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Roat, Carsten
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Kultima, Jens Roat
    Wong, Sau Yu Grace
    Cnidae in the sea anemone Sagartiogeton viduatus (Muller, 1776) (Cnidaria, Anthozoa); A comparison to cnidae in the sea anemone Metridium senile (Linnaeus, 1761) (Cnidaria, Anthozoa)2013In: Acta Zoologica (Stockholm), ISSN 0001-7272, E-ISSN 1463-6395, Vol. 94, no 4, p. 392-409Article in journal (Refereed)
    Abstract [en]

    The cnidom of the sea anemone Sagartiogeton viduatus (Muller, 1776) is described from interference-contrast light micrographs (LMs) and scanning electron micrographs (SEMs). Special attention is given to nematocyst maturation, including the differentiation of the shaft into proximal and main regions as helical folding of the shaft wall proceeds. Comparisons are made with Metridium senile (Linnaeus, 1761), whose cnidom, with a few exceptions, is closely similar to that of S.viduatus. The two anemones possess b- and p-mastigophores, p-amastigophores, isorhizas and spirocysts. Although the majority of cnidae in S.viduatus is smaller than corresponding ones in M.senile, they are grouped into the same size classes as those of M.senile, namely small, medium and large. The main differences from M.senile cnidae are the followings: (1) Large acontia p-amastigophores are the largest nematocysts in S.viduatus. (2) They are noticeably larger than the large acontia b-mastigophores, and (3) they are separated from the p-amastigophores of M.senile by the sinusoid pattern of their U-shaped capsular matrix. (4) The large acontia b-mastigophores are microbasic and not mesobasic as in M.Senile, and (5) they do not produce darts. (6) Another difference from M.senile is the absence of catch-tentacle isorhizas.

  • 48. Ostman, Carina
    et al.
    Roat Kultima, Jens
    Roat, Carsten
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Tentacle cnidae of the sea anemone Metridium senile (Linnaeus, 1761) (Cnidaria: Anthozoa)2010In: Scientia Marina, ISSN 0214-8358, E-ISSN 1886-8134, Vol. 74, no 3, p. 511-521Article in journal (Refereed)
    Abstract [en]

    Tentacle cnidae of Metridium senile (Linnaeus, 1761) were examined by light microscopy. In addition to spirocysts, feeding-tentacles had 3 nematocyst categories grouped into medium and small size-classes, including 5 types. Spirocysts dominated, especially distally, followed by medium b-mastigophores. The density of cnidae decreased towards the tentacle base. Early cnidoblasts were numerous on the tentacle tip. Late cnicloblasts appeared in a moderate number on the mid-tentacle. Catch-tentacles, found in two Metridium specimens, had a maturity gradient of isorhizas and gland cells along their length. Their tip had two distinct types of mature isorhizas in great numbers and large gland cells, but lacked spirocysts. Mature isorhizas and gland cells decreased in number towards the tentacle base. On the mid-tentacle differentiating ages of isorhizas were numerous. Ordinary feeding-tentacle cnidae, abundant at the tentacle base, decreased in number distally along the tentacle.

  • 49. Ostman, Carina
    et al.
    Roat Kultima, Jens
    Roat, Carsten
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Rundblom, Karl
    Acontia and mesentery nematocysts of the sea anemone Metridium senile (Linnaeus, 1761) (Cnidaria: Anthozoa)2010In: Scientia Marina, ISSN 0214-8358, E-ISSN 1886-8134, Vol. 74, no 3, p. 483-497Article in journal (Refereed)
    Abstract [en]

    Acontia and mesentery nematocysts of Metridium senile (Linnaeus, 1761) are described from interference-contrast light micrographs (LMs) and scanning electron micrographs (SEMs). The acontia have 2 nematocyst categories grouped into small, medium and large size-classes, including 5 types: of these, large b-mastigophores and large p-amastigophores are the largest and most abundant. Mesenterial tissues, characterised by small p-mastigophores and medium p-amastigophores, have 3 nematocyst categories grouped as small and medium, including 6 types. Attention is given to nematocyst maturation, especially to the differentiation of the shaft into proximal and main regions as helical folding of the shaft wall proceeds. Groups of differentiating nematoblasts occur along acontia, and near the junction between acontia and mesenterial filaments. Nematoblasts are sparsely found throughout mesenterial tissues.

  • 50.
    Persson, Jens
    et al.
    Inst. för skoglig zooekologi, SLU Umeå.
    Zachrisson, Anna
    Umeå University, Faculty of Social Sciences, Department of Political Science.
    Sandström, Camilla
    Umeå University, Faculty of Social Sciences, Department of Political Science.
    Ericsson, Göran
    Inst. för skoglig zooekologi, SLU Umeå.
    Lokal förvaltning av stora rovdjur: en kunskapssammanställning2004Report (Other academic)
    Abstract [sv]

    Hur våra gemensamma resurser bäst kan och ska förvaltas är både en komplicerad och ofta konfliktfylld fråga. Det framgår inte minst av debatten kring hur och på vilken nivå våra storarovdjur ska förvaltas. Eftersom rovdjuren vanligtvis lever i glesa populationer, spridda över mycket stora områden, men också är förknippade med såväl ekonomiska som sociala konflikter harden centrala nivån ansetts bäst lämpad att förvalta rovdjuren.Det har bland annat medfört att de som lever nära rovdjuren och riskerar att drabbas av rovdjuren upplever att de har småmöjligheter att påverka politikens och förvaltningens utformning.Det har i sin tur skapat konflikter kring hur och på vilketsätt rovdjuren bäst förvaltas (SOU 1999:146).

    I en strävan att öka förtroendet för den svenska rovdjurspolitikenoch överbrygga den klyfta mellan centralmakt och lokalnivå eller mellan stad och land som uppstått har riksdagenbeslutat att lokala aktörer på olika sätt ska involveras i förvaltningen.Inom ramen för en sammanhållen rovdjurspolitik harbland annat regionala rovdjursgrupper, sammansatta av olikaberörda intressen, bildats. Den svenska decentraliseringen avrovdjurspolitiken, följer den av FN fastslagna andra Malawi-principensom slår fast att förvaltning av ekosystem ska decentraliserastill lägsta ändamålsenliga nivå (UNEP/CBD/COP/4/inf.9).

    Att decentralisera förvaltningen av gemensamma resurser,i det här fallet stora rovdjur, är förknippat med en rad specifikaproblem. Förutom att det krävs biologisk kunskap om rovdjuren,är det nödvändigt att reda ut vilka sociala, ekonomiska och kulturellaaspekter som bör beaktas vid förvaltningen. Det är ocksånödvändigt att finna en acceptabel balans mellan decentraliseringoch centralisering av beslutsprocessen. Lokal förvaltningav rovdjur är relativt nytt även internationellt sett. Det är fortfarandetill stora delar okänt vad som egentligen krävs för attlokal förvaltning av rovdjur ska fungera. Det är emellertid möjligtatt vi kan lära något av de försök som redan genomförts. Syfte med den här rapporten är därför dels att sammanställakunskap om lokal eller decentraliserad förvaltning av stora rovdjur, främst utifrån biologiska, socioekonomiska och förvaltningspolitiskaförutsättningar, dels att skapa ett underlag för fortsattforskning inom ramen för forskningsprogrammet FjällMistra.

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