| 1. |
- Faulks, Leanne, et al.
(författare)
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Genetic and morphological divergence along the littoral–pelagic axis in two common and sympatric fishes : perch, Perca fluviatilis (Percidae) and roach, Rutilus rutilus (Cyprinidae)
- 2015
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Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 114:4, s. 929-940
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Tidskriftsartikel (refereegranskat)abstract
- Individuals are constantly in competition with one another and, on both ecological and evolutionary timescales, processes act to reduce this competition and promote the gain of fitness advantages via diversification. Here we have investigated the genetic (AFLP) and morphological (geometric morphometrics) aspects of the littoral–pelagic axis, a commonly observed resource polymorphism in freshwater fishes of postglacial lakes. We found a large degree of variation in the genetic and morphological divergence between littoral and pelagic perch and roach across Swedish lakes. Although there was evidence of assortative mating (elevated kinship values) in both species, we could not find any significant coupling of morphology and genetic divergence. Instead, there was evidence that the extent of resource polymorphism may be largely caused by phenotypic plasticity. These results suggest that assortative mating, which can lead to genetically determined adaptive divergence, does occur in these species, particularly perch, but not according to genetically fixed morphological traits. The behavioural mechanisms facilitating associative mating need to be investigated to explore the interaction between phenotypic plasticity and adaptive genetic divergence and their roles in diversification.
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| 2. |
- Faulks, Leanne, et al.
(författare)
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Intraspecific Niche Variation Drives Abundance-Occupancy Relationships in Freshwater Fish Communities
- 2015
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Ingår i: American Naturalist. - : University of Chicago Press. - 0003-0147 .- 1537-5323. ; 186:2, s. 272-283
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Tidskriftsartikel (refereegranskat)abstract
- A positive relationship between occupancy and average local abundance of species is found in a variety of taxa, yet the mechanisms driving this association between abundance and occupancy are still enigmatic. Here we show that freshwater fishes exhibit a positive abundance-occupancy relationship across 125 Swedish lakes. For a subset of 9 species from 11 lakes, we estimated species-specific diet breadth from stable isotopes, within-lake habitat breadth from catch data for littoral and pelagic nets, adaptive potential from genetic diversity, abiotic niche position, and dispersal capacity. Average local abundance was mainly positively associated with both within-lake habitat and diet breadth, that is, species with larger intraspecific variation in niche space had higher abundances. No measure was a good predictor of occupancy, indicating that occupancy may be more directly related to abundance or abiotic conditions than to niche breadth per se. This study suggests a link between intraspecific niche variation and a positive abundance-occupancy relationship and implies that management of freshwater fish communities, whether to conserve threatened or control invasive species, should initially be aimed at niche processes.
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| 3. |
- Faulks, Leanne, et al.
(författare)
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Ragged mountain ranges, droughts and flooding rains : The evolutionary history and conservation of Australian freshwater fishes
- 2014
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Ingår i: Austral Ark. - Cambridge : Cambridge University Press. - 9781139519960 - 9781107033542 ; , s. 492-511
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Bokkapitel (refereegranskat)abstract
- Australia hosts a unique assemblage of flora and fauna derived from a combination of Gondwanan relict and more recently evolved endemic taxa and is recognised as one of the world’s megadiverse countries. Despite the continent’s high species biodiversity, the Australian freshwater fish fauna is relatively depauperate. The conservation of freshwater fishes in Australia is of increasing importance as many species are listed as threatened by the IUCN. The major threatening processes for Australian freshwater fishes are habitat degradation, river regulation, anthropogenic barriers to dispersal, introduced species, disease and climate change. The use of molecular genetic tools to infer evolutionary history and to inform conservation is well recognised and is one way of predicting how fish may respond to these threatening processes. Nonetheless, there are few Australian cases that allow a bigger picture assessment of evolutionary processes across a broad range of environments, yet within a single taxonomic group. The temperate freshwater perches of the genus Macquaria provide an exception. This chapter uses this fish group as a case study in phylogeography and population genetics to explore and identify evolutionary processes relevant for aquatic conservation across a large section of eastern and central Australia. Australian freshwater fishes: biodiversity and conservation Australia hosts a unique assemblage of flora and fauna derived from a combination of Gondwanan relict and more recently evolved endemic taxa (Allen et al., 2002; Sanmartin & Ronquist,2004)and is recognised as one of the world's megadiverse countries (Mittermeier et al., 1997).
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| 4. |
- Liao, Yi-Fan, et al.
(författare)
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Stress tolerance and population stability of rock pool Daphnia in relation to local conditions and population isolation
- 2015
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Ingår i: Hydrobiologia. - : Springer Science and Business Media LLC. - 0018-8158 .- 1573-5117. ; 742:1, s. 267-278
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Tidskriftsartikel (refereegranskat)abstract
- Small fragmented populations can lose genetic variability, which reduces population viability through inbreeding and loss of adaptability. Current and previous environmental conditions can also alter the viability of populations, by creating local adaptations that determine responses to stress. Yet, most studies on stress tolerance usually consider either the effect of genetic diversity or the local environment, missing a more holistic perspective of the factors contributing to stress tolerance among natural populations. Here, we studied how salinity stress affects population growth of Daphnia longispina, Daphnia magna, and Daphnia pulex from rock pools with varying degrees of population isolation and salinity conditions. Standing variation of in situ rock pool salinity conditions explained more variation in salt tolerance than the standing variation of population isolation or genetic diversity, in both a pulse and a press disturbance experiment. This indicates that the level of stress, which these natural populations experience, influences their response to that stress, which may have important consequences for the conservation of fragmented populations. However, long-term population stability in the field decreased with population isolation, indicating that natural populations experience a variety of stresses; thus, population isolation and genetic diversity may stabilize population dynamics over larger spatiotemporal scales.
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| 5. |
- Marklund, Maria H. K., et al.
(författare)
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Asymmetrical habitat coupling of an aquatic predator : The importance of individual specialization
- 2019
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 9:6, s. 3405-3415
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Tidskriftsartikel (refereegranskat)abstract
- Predators should stabilize food webs because they can move between spatially separate habitats. However, predators adapted to forage on local resources may have a reduced ability to couple habitats. Here, we show clear asymmetry in the ability to couple habitats by Eurasian perch—a common polymorphic predator in European lakes. We sampled perch from two spatially separate habitats—pelagic and littoral zones—in Lake Erken, Sweden. Littoral perch showed stronger individual specialization, but they also used resources from the pelagic zone, indicating their ability to couple habitats. In contrast, pelagic perch showed weaker individual specialization but near complete reliance on pelagic resources, indicating their preference to one habitat. This asymmetry in the habitat coupling ability of perch challenges the expectation that, in general, predators should stabilize spatially separated food webs. Our results suggest that habitat coupling might be constrained by morphological adaptations, which in this case were not related to genetic differentiation but were more likely related to differences in individual specialization.
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| 6. |
- Östman, Örjan, et al.
(författare)
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Genetic Diversity and Hybridisation between Native and Introduced Salmonidae Fishes in a Swedish Alpine Lake
- 2016
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the processes underlying diversification can aid in formulating appropriate conservation management plans that help maintain the evolutionary potential of taxa, particularly under human-induced activities and climate change. Here we assessed the microsatellite genetic diversity and structure of three salmonid species, two native (Arctic charr, Salvelinus alpinus and brown trout, Salmo trutta) and one introduced (brook charr, Salvelinus fontinalis), from an alpine lake in sub-arctic Sweden, Lake Ann. The genetic diversity of the three species was similar and sufficiently high from a conservation genetics perspective: corrected total heterozygosity, H'(T) = 0.54, 0.66, 0.60 and allelic richness, A(R) = 4.93, 5.53 and 5.26 for Arctic charr, brown trout and brook charr, respectively. There were indications of elevated inbreeding coefficients in brown trout (G(IS) = 0.144) and brook charr (G(IS) = 0.129) although sibling relationships were likely a confounding factor, as a high proportion of siblings were observed in all species within and among sampling locations. Overall genetic structure differed between species, Fst = 0.01, 0.02 and 0.04 in Arctic charr, brown trout and brook charr respectively, and there was differentiation at only a few specific locations. There was clear evidence of hybridisation between the native Arctic charr and the introduced brook charr, with 6% of individuals being hybrids, all of which were sampled in tributary streams. The ecological and evolutionary consequences of the observed hybridisation are priorities for further research and the conservation of the evolutionary potential of native salmonid species.
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