Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2023
Forfattere
Simo Maduna Ólöf Dóra Bartels Jónsdóttir Albert Kjartan Dagbjartarson Imsland Davíð Gíslason Patrick Reynolds Lauri Kapari Thor Arne Hangstad Kristian Meier Snorre HagenSammendrag
Aquaculture of the lumpfish (Cyclopterus lumpus L.) has become a large, lucrative industry owing to the escalating demand for “cleaner fish” to minimise sea lice infestations in Atlantic salmon mariculture farms. We used over 10K genome-wide single nucleotide polymorphisms (SNPs) to investigate the spatial patterns of genomic variation in the lumpfish along the coast of Norway and across the North Atlantic. Moreover, we applied three genome scans for outliers and two genotype–environment association tests to assess the signatures and patterns of local adaptation under extensive gene flow. With our ‘global’ sampling regime, we found two major genetic groups of lumpfish, i.e., the western and eastern Atlantic. Regionally in Norway, we found marginal evidence of population structure, where the population genomic analysis revealed a small portion of individuals with a different genetic ancestry. Nevertheless, we found strong support for local adaption under high gene flow in the Norwegian lumpfish and identified over 380 high-confidence environment-associated loci linked to gene sets with a key role in biological processes associated with environmental pressures and embryonic development. Our results bridge population genetic/genomics studies with seascape genomics studies and will facilitate genome-enabled monitoring of the genetic impacts of escapees and allow for genetic-informed broodstock selection and management in Norway.
Forfattere
Juliana D. Klein Simo Maduna Matthew L. Dicken Charlene Da Silva Michelle Soekoe Meaghen E. McCord Warren M. Potts Snorre Hagen Aletta E Bester-van der MerweSammendrag
Adaptive divergence in response to environmental clines are expected to be common in species occupying heterogeneous environments. Despite numerous advances in techniques appropriate for non-model species, gene–environment association studies in elasmobranchs are still scarce. The bronze whaler or copper shark (Carcharhinus brachyurus) is a large coastal shark with a wide distribution and one of the most exploited elasmobranchs in southern Africa. Here, we assessed the distribution of neutral and adaptive genomic diversity in C. brachyurus across a highly heterogeneous environment in southern Africa based on genome-wide SNPs obtained through a restriction site-associated DNA method (3RAD). A combination of differentiation-based genome-scan (outflank) and genotype–environment analyses (redundancy analysis, latent factor mixed models) identified a total of 234 differentiation-based outlier and candidate SNPs associated with bioclimatic variables. Analysis of 26,299 putatively neutral SNPs revealed moderate and evenly distributed levels of genomic diversity across sites from the east coast of South Africa to Angola. Multivariate and clustering analyses demonstrated a high degree of gene flow with no significant population structuring among or within ocean basins. In contrast, the putatively adaptive SNPs demonstrated the presence of two clusters and deep divergence between Angola and all other individuals from Namibia and South Africa. These results provide evidence for adaptive divergence in response to a heterogeneous seascape in a large, mobile shark despite high levels of gene flow. These results are expected to inform management strategies and policy at the national and regional level for conservation of C. brachyurus populations.
Forfattere
Albert Kjartan Dagbjartarson Imsland Patrick Reynolds Lauri Teemu Kapari Simo Maduna Snorre Hagen Anna Hanssen Ólöf Dóra Bartels JónsdóttirSammendrag
The aim of this study was to evaluate whether sea lice grazing efficiency, behaviour, size variation and cataract development can be improved through selective breeding of lumpfish. A series of studies was conducted over a four-year period where distinctive lumpfish families were established initially from wild caught mature fish and latterly from established breeding lines. Four subsequent trials (called: Phase I-IV) with ten families of lumpfish (N = 480) with a mean (± SD) weight of 46.4 ± 9.4 g (Phase I), 54.8 ± 9.2 g (Phase II), 42.0 ± 7.4 g (Phase III) and 31.3 ± 2.4 g (Phase IV) were distributed among ten sea cages (5 × 5 × 5 m) during autumn 2018 to spring 2022, each stocked with 400–404 Atlantic salmon with an average initial mean (± SD) of 387 ± 9 g (Phase I), 621 ± 15 g (Phase II), 280 ± 16 g (Phase III) and 480 ± 66 g (Phase IV). All the ten cages were stocked with 48 lumpfish (12% stocking density). In all phases there was a large inter-family variation of lice grazing of lumpfish of both L. salmonis and C. elongatus. When sea lice grazing was scaled in relation to sea lice infestation numbers on the salmon the highest sea lice grazing activity was found in Phase IV and in particular in families sired from farmed parents. There was a general trend for mean start weights and standard deviations to decrease as the phases continued. A significant increase was found in frequency of behaviour associated with feeding on natural food sources and grazing sea lice from salmon during each subsequent phase. The increase in incidence of cataracts from start to end of each trial phase was significantly reduced from Phase I (16%) to Phase IV (2%). Overall, present findings showed that sea lice grazing of both L. salmonis and C. elongatus, size variation, cataract prevalence and behaviour types can be enhanced through selection and targeted breeding programs.
Sammendrag
The adults of the new species Zachvatkinibates svanhovdi A. Seniczak & S. Seniczak sp. nov. are described and illustrated from Norway, and this is the first finding of Zachvatkinibates Shaldybina, 1973 in Fennoscandia. This species is the most similar to Z. quadrivertex (Halbert, 1920), but differs from it mainly by the shape of notogastral setae, posterior tectum of notogaster and lack of postanal porose area Ap, which in Z. quadrivertex is present. In Z. svanhovdi, the prodorsal seta in is long, translamella is narrow, notogastral setae are short and distally pliable, notogastral porose areas are usually oval and of medium size, but Aa can be larger, especially in males. Dorsal crest on tarsus I is present. The cytochrome oxidase I (COI) barcodes (length: 658 bp) of five specimens of the new species are provided; the maximum variation within the species was 2.41% (p-dist). The morphology and ecology of the new species is compared with other Zachvatkinibates species. The knowledge on family Punctoribatidae in Fennoscandia is updated, and Mycobates carli (Schweizer, 1922) is first reported from Norway.
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Det er ikke registrert sammendrag
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Det er ikke registrert sammendrag
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The morphological ontogeny of Nanhermannia sellnicki Forsslund, 1958 is described and illustrated. In all juvenile stages the bothridial seta is minute, and two pairs of exobothridial setae are present (exa reduced to its alveolus, exp short). In the larva, the seta f1 is setiform but in the nymphs it is unobservable among cuticular tubercles. Most prodorsal and gastronotal setae of the larva are short while thouse of nymphs are long; seta in and all gastronotal and adanal setae are inserted in small individual depressions. In all instars the leg segments are oval in cross section and relatively thick, and most setae on tarsi are relatively short, thick or conical. The seta d accompanies solenidion σ on all genua, φ1 on tibia I and φ on other tibiae.
Sammendrag
The morphological ontogeny of Zachvatkinibates svanhovdi A. Seniczak & S. Seniczak, 2023 is described and illustrated. The juveniles of this species are light brown with slightly darker colour on the prodorsum, gastronotal shield, surrounding of gla opening, and legs. The larva has 12 pairs of gastronotal setae, most are of medium size and barbed; the nymphs have 15 pairs, most are short and smooth. In all juveniles, the setae of c-series are inserted on unsclerotized integument. In the larva, the pygidial shield is absent but, in the nymphs, the gastronotal shield is present and the setae p2 and p3 are inserted on unsclerotized integument. In the larva, a humeral organ is absent but is present in the nymphs.
Forfattere
Paul Eric Aspholm Benedicte Beddari Ingrid Søvik Ida Marie Bardalen Fløistad Monika Strasser Englund Ellen Katrin Enge Marit Vadset Eldbjørg Sofie Heimstad Snorre HagenSammendrag
Under høstjakta på elg (Alces alces) i 2020 ble det tatt vevsprøver til analyser av tungmetaller og PCB. Tungmetallprøver ble tatt av 24 individer; 4 hunnkalver, 4 hannkalver, 3 hanner av åringer og 13 okser (voksne hanner). PCB analyser ble gjort av vevsprøver som ble tatt av 2 hunnkalver, 3 hannkalver, 2 hann-åringer og 9 okser (totalt 16 dyr). De felte dyrene har god geografisk spredning fra sør til nord og nord-øst i kommunen. Tungmetallene som ble analysert var krom (Cr), nikkel (Ni), kobber (Cu), sink (Zn), arsen (As), sølv (Ag), kadmium (Cd), tinn (Sn), bly (Pb) og kvikksølv (Hg). PCB ble analysert for 34 kongenere pluss sumPCB6 og sumPCB7. De fleste konsentrasjonene av tungmetallene var svært lave og flere var under deteksjonsgrensene. Ellers var det bare sporadiske lave forekomster av de 32 PCBene som ble funnet i noen av de undersøkte elgene. Det var bare heksaklorbensen som ble detektert i alle prøvene fra elgene).
Sammendrag
Through their ephemeral reproductive structures (fruiting bodies), ectomycorrhizal forest soil fungi provide a resource for a plethora of organisms. Thus, resolving what biotic and abiotic factors determine the occurrence and abundance of fruiting bodies is fundamental for understanding the dynamics of forest trophic networks. While the influence of abiotic factors such as moisture and temperature on fungal fruiting are relatively well established, little is known about how these processes interact with the evolutionary history of fungal species to determine when, where, and in which abundance fungal fruiting bodies will emerge. A specific knowledge gap relates to whether species' responses to their environment are phylogenetically structured. Here, we ask whether related fungal taxa respond similarly to climatic factors and forest habitat characteristics, and whether such correlated responses will affect the assembly of fungal fruiting communities. To resolve these questions, we fitted joint species distribution models combining data on the species composition and abundance of fungal fruiting bodies, environmental variation, and phylogenetic relationships among fungal taxa. Our results show that both site-level forest characteristics (dominant tree species and forest age) and climatic factors related to phenology (effective heat sum) greatly influence the occurrence and abundance of fruiting bodies. More importantly, while different fungal species responded unequally to their shared environment, there was a strong phylogenetic signal in their responses, so that related fungal species tended to fruit under similar environmental conditions. Thus, not only are fruiting bodies short-lived and patchily distributed, but the availability of similar resources will be further aggregated in time and space. These strong constraints on resource availability for fungus-associated taxa highlight the potential of fungus-based networks as a model system for studies on the ecology and evolution of resource–consumer relations in ephemeral systems of high spatiotemporal patchiness.