scholarly journals Population genetics reveal patterns of natural colonisation of an ecologically and commercially important invasive fish

2021 ◽  
pp. 1-15
Author(s):  
Ciar O’Toole ◽  
Karl P. Phillips ◽  
Caroline Bradley ◽  
Jamie Coughlan ◽  
Eileen Dillane ◽  
...  
Keyword(s):  
Salmo Trutta ◽  
Isolation By Distance ◽  
Dispersal Patterns ◽  
Genetic Population ◽  
The North ◽  
Brown Trout Salmo Trutta ◽  
Population Structuring ◽  
Nj Tree ◽  
Commercially Important ◽  
North And South

Although historical records of introductions that trigger successful biological invasions are common, subsequent patterns of dispersal and colonisation routes are unclear. We use microsatellites to examine genetic population structuring of established invasive brown trout (Salmo trutta) populations in Newfoundland, Canada, for evidence of “natural” dispersal, human-mediated introductions, and colonisation routes. We also explored ancestry of contemporary populations relative to presumed progenitors. Results analysed using STRUCTURE, DAPC, a NJ tree and FST comparisons support records of historical introductions; current Newfoundland populations are largely descended from Scottish stock, with St. John’s the primary introduction site. Subsequent dispersal of these trout was facilitated principally by anadromy, largely consistent with a classic stepping-stone model, with significant isolation-by-distance. With one exception, dispersal along the north and south coasts of the Avalon peninsula appears to be natural and independent, involving stochastic processes resulting in unique outcomes for population composition. This study is a good example of dispersal patterns during a contemporary invasion underscoring the potential for non-anadromous founders to re-express anadromy, facilitating colonization of distant sites.

Divergence of brown trout (Salmo trutta) within glacial refugia

2000 ◽  
Vol 57 (11) ◽  
pp. 2201-2210 ◽  
Author(s):  
Núria Sanz ◽  
José-Luis García-Marín ◽  
Carles Pla
Keyword(s):  
Population Structure ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Allelic Variation ◽  
Glacial Refugia ◽  
Species Differentiation ◽  
Gene Pools ◽  
Genetic Population ◽  
Geographical Patterns ◽  
Brown Trout Salmo Trutta

The Pleistocene glaciations produced a range of changes that affected the genetic population structure of fish species. Usually, studies focused on the population structure of species in postglacial recolonized areas and less attention was devoted to species differentiation within refuge areas. Allelic frequencies for 21 polymorphic protein-coding loci were compared among 25 collections within a northwestern Iberian glacial refuge of brown trout (Salmo trutta) using adjusted frequencies for nine populations to account for introgressions with exogenous hatchery fish. The high divergence observed (FST = 0.645) and geographical patterns of allelic variation are interpreted to reflect the existence of strong population structuring among native populations of this refuge. Four major geographic groups were defined within the region: (i) in the Tajo River, (ii) in the Duero River, (iii) in the Sil River, and (iv) among Cantabrian Sea flowing rivers including present anadromous populations. These gene pools have diverged genetically and ecologically in response to climatic oscillations. Anthropogenic effects on habitat and fish populations seriously compromise their future.

scholarly journals Genetic population structure constrains local adaptation in sticklebacks

2020 ◽  
Author(s):  
Petri Kemppainen ◽  
Zitong Li ◽  
Pasi Rastas ◽  
Ari Löytynoja ◽  
Bohao Fang ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Isolation By Distance ◽  
Regulatory Element ◽  
Morphological Data ◽  
Genetic Isolation ◽  
Genetic Population ◽  
Population Structuring ◽  
Different Populations ◽  
Trait Locus ◽  
Genomic Regions

AbstractRepeated and independent adaptation to specific environmental conditions from standing genetic variation is common. However, if genetic variation is limited, the evolution of similar locally adapted traits may be restricted to genetically different and potentially less optimal solutions, or prevented from happening altogether. Using a quantitative trait locus (QTL) mapping approach, we identified the genomic regions responsible for the repeated pelvic reduction (PR) in three crosses between nine-spined stickleback populations expressing full and reduced pelvic structures. In one cross, PR mapped to linkage group 7 (LG7) containing the gene Pitx1, known to control pelvic reduction also in the three-spined stickleback. In the two other crosses, PR was polygenic and attributed to ten novel QTL, of which 90% were unique to specific crosses. When screening the genomes from 27 different populations for deletions in the Pitx1 regulatory element, these were only found in the population in which PR mapped to LG7, even though the morphological data indicated large effect QTL for PR in several other populations as well. Consistent with the available theory and simulations parameterised on empirical data, we hypothesise that the observed variability in genetic architecture of PR is due to heterogeneity in the spatial distribution of standing genetic variation caused by strong population structuring and genetic isolation by distance in the sea.

Small-scale dispersal and population structure in stream-living brown trout (Salmo trutta) inferred by mark–recapture, pedigree reconstruction, and population genetics

2012 ◽  
Vol 69 (9) ◽  
pp. 1513-1524 ◽  
Author(s):  
Leif Asbjørn Vøllestad ◽  
Dimitar Serbezov ◽  
Arthur Bass ◽  
Louis Bernatchez ◽  
Esben Moland Olsen ◽  
...  
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Isolation By Distance ◽  
Juvenile Fish ◽  
Age Groups ◽  
Small Scale ◽  
Mark Recapture ◽  
Small Stream ◽  
Brown Trout Salmo Trutta ◽  
Mature Fish

Many animals move among habitats, and even small-scale dispersal of individuals between habitat patches may have strong implications for population dynamics and structure. Here, we use long-term mark–recapture data combined with extensive genotyping and parentage assignment to investigate the importance of small-scale location change of resident brown trout ( Salmo trutta ) in a small stream (1500 m). During the first summer, juvenile fish dispersed downstream (mean displacement 200 m), with smaller juveniles dispersing longer distances. Downstream movement was also predominant during the first winter, but older fish moved little. This limited dispersal resulted in a significant isolation-by-distance structure for ages 1 and 2, but not for older age groups or for the mature fish. Individual pairwise relatedness coefficients decreased with waterway distance for mature fish during the 2002 and 2003 spawning seasons, but only weakly. Overall, between-site genetic differentiation was stronger for the younger age classes, and the signal decayed with age, indicating that the genetic structure observed in the stream is mainly driven by spatial aggregation of close relatives.

Peromyscus populations and their Cuterebra parasites display congruent phylogeographical structure

Parasitology ◽  
2005 ◽  
Vol 131 (2) ◽  
pp. 237-245 ◽  
Author(s):  
S. NOËL ◽  
B. ANGERS ◽  
F.-J. LAPOINTE
Keyword(s):  
Parasite Species ◽  
Isolation By Distance ◽  
Deer Mouse ◽  
Genetic Distances ◽  
Limited Sample ◽  
The North ◽  
Mitochondrial Sequences ◽  
North And South ◽  
White Footed Mouse ◽  
St Lawrence River

The relationships between populations of the Deer Mouse (Peromyscus maniculatus) and the White-footed Mouse (P. leucopus) and their respective Cuterebra parasites were examined. Population genetic structure of hosts and parasites was inferred using cytochrome oxidase mitochondrial sequences of specimens from 7 populations. Genetic analyses revealed that isolation-by-distance applies for P. maniculatus and its associated parasite (C. grisea). A significant correlation was also observed between the genetic distances of these host and parasite species. Furthermore, populations of P. maniculatus and C. grisea from the North and South shores of the St Lawrence River were found to be significantly different. This structure may be explained by the St Lawrence River being a dispersal barrier for both species. A robust analysis of the other species pair (P. leucopus and C. fontinella) could not be performed because of limited sample sizes.

scholarly journals Proliferative Kidney Disease and Proliferative Darkening Syndrome are Linked with Brown Trout (Salmo trutta fario) Mortalities in the Pre-Alpine Isar River

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 177 ◽  
Author(s):  
Arndt ◽  
Fux ◽  
Blutke ◽  
Schwaiger ◽  
El-Matbouli ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Renal Tissue ◽  
Contributing Factors ◽  
Proliferative Kidney Disease ◽  
The North ◽  
Brown Trout Salmo Trutta ◽  
Tetracapsuloides Bryosalmonae ◽  
Salmo Trutta Fario

For many years, brown trout (Salmo trutta fario) mortalities within the pre-alpine Isar River in Germany were reported by the Bavarian Fisheries Association (Landesfischereiverband Bayern e.V.) and local recreational anglers during August and September. Moribund fish seemed to be affected by proliferative darkening syndrome (PDS). In addition, proliferative kidney disease (PKD) caused by Tetracapsuloides bryosalmonae was discussed. To investigate this phenomenon, the present field study monitored brown trout mortalities by daily river inspection in 2017 and 2018. Moribund brown trout (n = 31) were collected and examined using histology, immunohistochemistry, qPCR, and quantitative stereology. Our investigations identified 29 (93.5%) brown trout affected by PKD. Four brown trout (12.9%) displayed combined hepatic and splenic lesions fitting the pathology of PDS. The piscine orthoreovirus 3, suspected as causative agent of PDS, was not detectable in any of the samples. Quantitative stereological analysis of the kidneys revealed a significant increase of the renal tissue volumes with interstitial inflammation and hematopoietic hyperplasia in PKD-affected fish as compared to healthy brown trout. The identified T. bryosalmonae strain was classified as part of the North American clade by phylogenetical analysis. This study highlights PKD and PDS as contributing factors to recurrent autumnal brown trout mortalities.

scholarly journals Seasonal and sex-related variations in serum steroid hormone levels in wild and farmed brown trout Salmo trutta L. in the north-west of Spain

2013 ◽  
Vol 11 (4) ◽  
pp. 720-728 ◽  
Author(s):  
Juan M. Fregeneda-Grandes ◽  
Salvador Hernández-Navarro ◽  
Ignacio A. Fernandez-Coppel ◽  
Adriana Correa-Guimaraes ◽  
Norlan Ruíz-Potosme ◽  
...  
Keyword(s):  
Brown Trout ◽  
Salmo Trutta ◽  
Seasonal Pattern ◽  
Serum Cortisol ◽  
Mature Female ◽  
North West ◽  
The North ◽  
Steroid Profiles ◽  
Brown Trout Salmo Trutta ◽  
Wild Trout

Serum steroid profiles were investigated in order to evaluate the potential use of circulating sex steroid levels as a tool for sex identification in brown trout. Changes in the serum concentrations of testosterone (T), progesterone (P), 17-β-estradiol (E2), and cortisol (F) in wild and farmed mature female and male brown trout, Salmo trutta L., were measured in each season (January, May, July, and October) in six rivers and four hatcheries located in the north-west of Spain. Serum cortisol levels in farmed brown trout were significantly higher and showed a seasonal pattern opposite to that found in wild trout. Because levels of the hormones under study can be affected by disruptive factors such as exposure to phytoestrogens (which alters the hypothalamic–pituitary–gonadal axis) and infection with Saprolegnia parasitica (which alters the hypothalamic–pituitary–adrenal axis), both factors are taken into account.

Sign in / Sign up

Export Citation Format

Share Document