scholarly journals Extensive Secondary Contact Among Three Glacial Lineages of Arctic Char (Salvelinus alpinus) in Newfoundland and Labrador

2018 ◽  
Author(s):  
Sarah J. Salisbury ◽  
Gregory R. McCracken ◽  
Donald Keefe ◽  
Robert Perry ◽  
Daniel E. Ruzzante

ABSTRACTWe sequenced a portion of the D-loop region in over 1000 Arctic char (Salvelinus alpinus) samples from 67 locations across Newfoundland and Labrador to assess the extent of secondary contact among the Arctic, Atlantic, and Acadian glacial lineages in Newfoundland and Labrador. Within Labrador, the Arctic and Atlantic lineages were widespread. Two locations (one landlocked and one with access to the sea) also contained individuals of the Acadian lineage, constituting the first record of this lineage in Labrador. Atlantic and Acadian lineage individuals were found in both eastern and western Newfoundland. Multiple sampling locations in Newfoundland and Labrador contained fish of two or more different glacial lineages, implying their introgression. Glacial lineage did not appear to dictate contemporary genetic divergence between the pale and dark morph of char present in Gander Lake, Newfoundland. Both were predominately of the Atlantic lineage, suggesting the potential for their divergence in sympatry. This study reveals Newfoundland and Labrador to be a unique junction of three glacial lineages which have likely hybridized extensively in this region.

Author(s):  
Véronique Dubos ◽  
André St-Hilaire ◽  
Normand E Bergeron

Arctic char is a fish species known to occupy diverse habitats within the Arctic region. However, summer habitat use during the juvenile stage of the anadromous form is largely unknown. The present study aims to characterize fry and parr summer habitat preferences. Surveys were conducted by electrofishing, associated with physical habitat characterization on several rivers of the Ungava Bay, Nunavik, Canada. At the microhabitat and station scales, fry showed significant habitat preferences for shallow water and slow velocity. At the mesohabitat scale, fry showed a significant habitat selectivity for riffles. This habitat selectivity implies that habitat models can be built to evaluate the potential of habitat suitability for Arctic char fry. However, no significant habitat selectivity was found for parr. Parr size was nonetheless positively correlated with velocity, which was found to be a limitative factor for juvenile habitat use. This first attempt at modeling juvenile anadromous Arctic char habitat in rivers emphasizes the importance of selecting an appropriate spatial scale and reiterates the fact that parr showed relatively high plasticity in stream habitat selection.


2006 ◽  
Vol 84 (7) ◽  
pp. 1019-1024 ◽  
Author(s):  
Jonathan Vaz Serrano ◽  
Ivar Folstad ◽  
Geir Rudolfsen ◽  
Lars Figenschou

Theoretical models predict that subordinate males should have higher sperm velocity to compensate for their disadvantaged mating role and because they experience sperm competition more frequently than dominant males. Differences in mean velocity between sperm of dominants and subordinates in the predicted direction are also documented for a few species, including the Arctic char, Salvelinus alpinus (L., 1758). Yet, this difference in mean velocity does not imply that the fastest sperm within an ejaculate, which are those most likely to fertilize eggs, swim faster in subordinates than in dominants. We studied the 5% and 10% fastest sperm cells in ejaculates of dominant and subordinate Arctic char. Before individuals attained their status, there were no differences in velocity between the fastest sperm of males that later became dominant or subordinate. Yet, after establishment of social position, subordinates showed significantly higher sperm swimming speed of the fastest cells in the first 30 s post activation (i.e., at 15, 20, and 30 s post activation). Males that became subordinates showed no change in sperm speed of the fast cells compared with those at pre-trial levels, whereas males that became dominant reduced the speed of their sperm (15 s post activation) compared with those at pre-trial levels. Our results suggest that males which attain social dominance are unable to maintain high sperm velocity, even among the small fraction of the fastest cells.


1999 ◽  
Vol 56 (8) ◽  
pp. 1370-1375
Author(s):  
Even H Jørgensen ◽  
Johannes Wolkers

In this study, the time-dependent P450 response to oral benzo[a]pyrene exposure at 1 and 10°C was investigated in winter- and summer-acclimated Arctic char (Salvelinus alpinus). In both seasons, a strong induction of CYP1A activities and protein levels (measured only in the winter experiment) were seen at both 1 and 10°C. At 1°C, the responses were delayed and more long-lasting than at 10°C. No within-season difference between 1 and 10°C in the magnitude of the induction response was found, but due to elevated baseline CYP1A activities, the induction response was seven times lower in winter- as compared with the response in summer-acclimated Arctic char. The results show that the CYP1A enzymes of the Arctic char respond to temperature changes in a compensatory way, and they are promising with respect to the applicability of the P450 enzyme system of the Arctic char as a biomarker for monitoring polycyclic aromatic hydrocarbon contamination in high-latitude environments. More studies are needed, however, to reveal seasonal differences in the biomarker response to pollutants.


ARCTIC ◽  
2016 ◽  
Vol 69 (3) ◽  
pp. 231
Author(s):  
Les N. Harris ◽  
David A. Bogsuski ◽  
Colin P. Gallagher ◽  
Kimberly L. Howland

Where anadromous fishes occur in the Canadian Arctic, they provide the mainstay of local subsistence fisheries of varying intensities. Many of these fisheries harvest a mixture of stocks at discrete locations and it is often not known which stocks, specifically, are being harvested and to what extent. In the Darnley Bay area of the Northwest Territories, Arctic char, Salvelinus alpinus, in particular have long provided an important subsistence resource to residents of Paulatuk, and char from two systems (the Hornaday and Brock Rivers) are thought to contribute to the coastal fishery for this species. Genetic mixed-stock analysis (GMA) is routinely applied for resolving stock contributions to such fisheries, yet studies incorporating GMA to understand specifically which stocks are being harvested in the Canadian Arctic, and to what extent, are relatively scarce. In this study, we assayed microsatellite DNA variation among 987 Arctic char from two important coastal subsistence fisheries and several inland sampling locations in the Darnley Bay area to (1) assess the degree of genetic structuring between the Hornaday and Brock Rivers and (2) resolve the proportional contributions of these stocks to coastal mixed-stock fisheries in the region using GMA. Overall, genetic differentiation was relatively high and significant (θ = 0.117; 95% C.I. = 0.097–0.142) among baseline sampling locations. Overall patterns of genetic stock structure also support previous hypotheses that additional life history types (e.g., landlocked or freshwater-resident char, or both) exist in the Hornaday system, as indicated by elevated levels of genetic differentiation between some of our sampling locations. The GMA suggested that, while both river systems contribute to the coastal fishery, catches were dominated by Arctic char from the Hornaday River, which highlights the importance of this system. All told, our results may be relevant to the management of the subsistence fishery in Darnley Bay and for furthering the collective understanding of char biodiversity and life history variation in the Canadian Arctic.


2019 ◽  
Vol 485 (2) ◽  
pp. 242-246
Author(s):  
A. A. Makhrov ◽  
I. N. Bolotov ◽  
V. M. Spitsyn ◽  
M. Yu. Gofarov ◽  
V. S. Artamonova

Samples from 11 populations of the Arctic char of the North-European part of Russia belonging to the anadromous and resident forms and two samples from Lake Sobach'e (Taimyr) were studied. The nucleotide sequence of the mitochondrial COI gene was determined in 60 individuals. In the majority of populations, the same COI haplotype was found. In some populations of the resident chars, haplotypes differing from the widespread haplotype in a single nucleotide substitution were found. The obtained genetic data give no reason to distinguish the resident form of the Arctic char from lakes of Karelia and the Kola Peninsula as an independent species, Salvelinus lep- echini. The adaptation of the Arctic char to the unstable environmental conditions is ensured primarily by its phenotypic plasticity.


2015 ◽  
Vol 72 (6) ◽  
pp. 855-863 ◽  
Author(s):  
Arne Johan Jensen ◽  
Ola Håvard Diserud ◽  
Bengt Finstad ◽  
Peder Fiske ◽  
Audun Håvard Rikardsen

A long-term study in the River Halselva in the Arctic region of Norway demonstrated that movements between watersheds were considerably higher in anadromous brown trout (Salmo trutta) than anadromous Arctic char (Salvelinus alpinus). Fourteen smolt year classes of both species were captured in a fish trap, individually tagged, and thereafter registered each time they passed the trap during their migration between the sea and fresh water every summer. Annual mean survival (i.e., recovery rate) after the first entry to sea as smolts was estimated as 31.4% in Arctic char and 26.6% in brown trout. Most surviving Arctic char returned to the River Halselva to overwinter after the same summer that they migrated to sea as smolts. However, several brown trout overwintered one to four times in other watersheds, mainly the considerably larger River Altaelva, before most eventually returned to the River Halselva upon maturation. The substantial difference in movement rate between watersheds between Arctic char (2.2%) and brown trout (39.6%) is expected to be a consequence of local geographic conditions combined with different habitat preferences of the two species.


1971 ◽  
Vol 55 (1) ◽  
pp. 213-222
Author(s):  
R. A. ROBERTS

1. The degree of euryhalinity in a fresh-water resident population of the arctic char, Salvelinus alpinus, has been determined. 2. Although isolated in fresh water for c. 10000-12000 years these fish still show a high degree of salinity tolerance characteristic of their ancestral stock, but this is variably developed in individuals. 3. In fresh water, blood sodium concentration is regulated at 150 mM/l and chloride at 130 mM/l. These increase to 233 and 218 mm/l respectively in sea water. 4. Fish in sea water show a large increase in muscle sodium, although the potassium concentration is only slightly higher than that maintained in fresh water. The total sodium content of the fish reflects the increase observed in the intracellular and extracellular compartments. 5. The rate of sodium turnover in sea-water-adapted fish is some ten times higher than in fresh-water-adapted fish, although it is significantly lower than that observed in most sea-water-adapted teleosts.


1993 ◽  
Vol 50 (12) ◽  
pp. 2574-2580 ◽  
Author(s):  
Johan Hammar ◽  
Per Larsson ◽  
Maris Klavins

Two extreme growth fractions of introgressed sympatric populations of the Arctic char (Salvelinus alpinus) species complex from Lake Blåsjön, northern Sweden, were sampled for individual concentrations of persistent pollutants originating from atmospheric deposition. Slow growing char (dwarfs) had significantly higher levels of SPCB (sum of PCB congeners found) and p,p-DDE (dominating DDT-compound) than fast growing char (normals). Besides demonstrating a highly divergent growth pattern the introgressed populations also inhabit a great range of depths, and the seasonal food consumption rates may differ between extreme growth fractions, although the same major invertebrates (introduced Mysis relicta and Pallasea quadrispinosa) are consumed over the year. However, of the life history parameters differing in late spring, individual growth rate was the most important factor explaining the variation in the levels of the pollutants studied. The results support the hypothesis of a biomass "dilution" of pollutants in fish, illustrated by lower levels in fast growing char and higher levels in the slow-growing dwarfs. Individuals with alternative growth strategies in sympatric conspecific communities thus provide unique opportunities to study growth rate as a variable influencing levels of persistent pollutants in fish.


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