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- Delling, Bo, 1964-
(författare)
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Evolution and disappearance of sympatric Coregonus albula ina changing environment—A case study of the only remainingpopulation pair in Sweden
- 2019
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 9:22, s. 12727-12753
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Tidskriftsartikel (refereegranskat)abstract
- During the past 50 years, Fennoscandian populations of spring‐spawning Baltic cisco(Coregonus albula), sympatric to common autumn‐spawners, have declined or disappeared;for example, three out of four known spring‐spawning populations in Swedenare regarded as extinct. Over the same period, the climate has changed and populationshave been subject to other anthropogenic stressors. We compared historic(1960s) and recent (1990–000s) morphological data from the still‐existent sympatriccisco populations in Lake Fegen, Sweden. Phenotypic changes were found forspring‐spawners making them more similar to the sympatric autumn‐spawners thathad remained virtually unchanged. Based on results for other salmoniform fishes,a phenotypically plastic response to increased temperature during early developmentappears unlikely. The recent material was also analyzed with microsatellitemarkers; long‐term effective population size in spring‐spawners was estimated tobe about 20 times lower than autumn‐spawners, with signs of long‐term gene flowin both directions and a recent genetic bottleneck in spring‐spawners. We suggestthe change toward a less distinct phenotype in spring‐spawners to reflect a recentincrease in gene flow from autumn‐spawners. Time since divergence was estimatedto onlyc. 1,900 years (95% CI: 400–5,900), but still the Fegen populations representthe most morphologically and genetically distinct sympatric populations studied.Consequently, we hypothesize that less distinct population pairs can be evenyounger and that spring‐spawning may have repeatedly evolved and disappeared inseveral lakes since the end of the last glaciation, concurrent with changed environmentalconditions.
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| 2. |
- Delling, Bo, 1964-, et al.
(författare)
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Genetic signs of multiple colonization events in Baltic ciscoes with radiation into sympatric spring- and autumnspawners confined to early postglacial arrival
- 2014
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 4:22, s. 4346-4360
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Tidskriftsartikel (refereegranskat)abstract
- Presence of sympatric populations may reflect local diversification or secondary contact of already distinct forms. The Baltic cisco (Coregonus albula) normally spawns in late autumn, but in a few lakes in Northern Europe sympatric autumn and spring- or winter-spawners have been described. So far, the evolutionary relationships and taxonomic status of these main life history forms have remained largely unclear. With microsatellites and mtDNA sequences, we analyzed extant and extinct spring- and autumn-spawners from a total of 23 Swedish localities, including sympatric populations. Published sequences from Baltic ciscoes in Germany and Finland, and Coregonus sardinella from North America were also included together with novel mtDNA sequences from Siberian C. sardinella. A clear genetic structure within Sweden was found that included two population assemblages markedly differentiated at microsatellites and apparently fixed for mtDNA haplotypes from two distinct clades. All sympatric Swedish populations belonged to the same assemblage, suggesting parallel evolution of spring-spawning rather than secondary contact. The pattern observed further suggests that postglacial immigration to Northern Europe occurred from at least two different refugia. Previous results showing that mtDNA in Baltic cisco is paraphyletic with respect to North American C. sardinella were confirmed. However, the inclusion of Siberian C. sardinella revealed a more complicated pattern, as these novel haplotypes were found within one of the two main C. albula clades and were clearly distinct from those in North American C. sardinella. The evolutionary history of Northern Hemisphere ciscoes thus seems to be more complex than previously recognized.
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| 3. |
- Delling, Bo, et al.
(författare)
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Morphologic and genetic characterisation of Corsican and Sardinian trout with comments on Salmo taxonomy
- 2020
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Ingår i: Knowledge & Management of Aquatic Ecosystems. - : EDP Sciences. - 1961-9502.
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Tidskriftsartikel (refereegranskat)abstract
- Both morphological and molecular data are presented and discussed for indigenous Salmo sp. from Corsica and Sardinia, here called Tyrrhenian trout. For comparison, morphological data obtained from museum specimens, including the Algerian S. macrostigma, are discussed in the light of recent and new molecular findings. In total, 29 measurements and 20 meristic characters were taken from each specimen. Out of the meristic characters, 12 were obtained by means of X-ray. One important morphometric character in the present study is the size of the head measured from premaxilla to posterior margin of preoperculum. This character was particularly stable in all Tyrrhenian trout, showing relatively large head compared to Atlantic trout and to S. macrostigma. On the contrary, other characters like body punctuations, black and white edges of fins, body depth or number of epurals in the caudal skeleton are quite polymorphic. In certain meristic characters, range of variation of Tyrrhenian trout even exceeds that of the extensive comparative material. Each trout has been genetically characterized. New haplotypes from Tyrrhenian trout were discovered, belonging to three mitochondrial lineages viz. Adriatic, marble and Mediterranean, however, Adriatic haplotypes are dominant. Comparing morphological and genetic data, observed morphology lacks any obvious correlation to mitochondrial lineages and it is concluded that Tyrrhenian trout show no particular affinity to S. macrostigma from Algeria.
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| 4. |
- Delling, Bo, et al.
(författare)
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Museomics reveals the phylogenetic position of the extinct Moroccan trout Salmo pallaryi
- 2023
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 102:3, s. 619-627
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Tidskriftsartikel (refereegranskat)abstract
- The authors used museomics to reconstruct the mitochondrial genome from two individuals of the Moroccan, endemic and extinct trout, Salmo pallaryi. They further obtained partial data from 21 nuclear genes previously used for trout phylogenetic analyses. Phylogenetic analyses, including publicly available data from the mitochondrial control region and the cytochrome b gene, and the 21 nuclear genes, place S. pallaryi among other North African trouts. mtDNA places S. pallaryi close to Salmo macrostigma within a single North African clade. Although the nuclear coverage of the genome was low, both specimens were independently positioned as sisters to one of two distantly related North African clades, viz. the Atlas clade with the Dades trout, Salmo multipunctatus. Phylogenetic discordance between mtDNA and nuclear DNA phylogenies is briefly discussed. As several specimens that were extracted failed to produce DNA of sufficient quality, the authors discuss potential reasons for the failure. They suggest that museum specimens in poor physical condition may be better for DNA extraction compared to better-preserved ones, possibly related to the innovation of formalin as a fixative before ethanol storage in the early 20th century.
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