Constancy of synaptic ribbon numbers in the retina of the arctic chary, Salvelinus alpinus

1990 ◽  
Vol 27 (2) ◽  
pp. 131-137 ◽  
Author(s):  
Sarah Perreault ◽  
M. Ather Ali ◽  
Sk�li Sk�lason ◽  
David L. G. Noakes
Keyword(s):  
Salvelinus Alpinus ◽  
The Arctic ◽  
Synaptic Ribbon

Summer stream habitat preferences of Nunavik anadromous Arctic char (Salvelinus alpinus) fry and parr

2022 ◽  
Author(s):  
Véronique Dubos ◽  
André St-Hilaire ◽  
Normand E Bergeron
Keyword(s):  
Habitat Use ◽  
Salvelinus Alpinus ◽  
Habitat Preferences ◽  
Arctic Region ◽  
Arctic Char ◽  
The Arctic ◽  
Stream Habitat ◽  
Physical Habitat ◽  
High Plasticity ◽  
Slow Velocity

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.

scholarly journals Do the fastest sperm within an ejaculate swim faster in subordinate than in dominant males of Arctic char?

2006 ◽  
Vol 84 (7) ◽  
pp. 1019-1024 ◽  
Author(s):  
Jonathan Vaz Serrano ◽  
Ivar Folstad ◽  
Geir Rudolfsen ◽  
Lars Figenschou
Keyword(s):  
Swimming Speed ◽  
Social Dominance ◽  
Salvelinus Alpinus ◽  
Theoretical Models ◽  
Arctic Char ◽  
The Arctic ◽  
Sperm Cells ◽  
Sperm Velocity ◽  
Mean Velocity ◽  
Sperm Swimming Speed

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.

Effect of temperature on the P4501A response in winter- and summer-acclimated Arctic char (Salvelinus alpinus) after oral benzo[a]pyrene exposure

1999 ◽  
Vol 56 (8) ◽  
pp. 1370-1375
Author(s):  
Even H Jørgensen ◽  
Johannes Wolkers
Keyword(s):  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Hydrocarbon Contamination ◽  
The Arctic ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Protein Levels ◽  
Biomarker Response ◽  
P450 Enzyme ◽  
Polycyclic Aromatic

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.

Does the Arctic charr (Salvelinus alpinus) exhibit a seasonal change in seawater tolerance?

Aquaculture ◽  
1989 ◽  
Vol 82 (1-4) ◽  
pp. 383-384 ◽  
Author(s):  
Bengt Finstad ◽  
Kjell J. Nilssen ◽  
Arne M. Arnesen
Keyword(s):  
Seasonal Change ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
The Arctic ◽  
Seawater Tolerance

REGULAR ARTICLES / ARTICLES RÉGULIERS Whether to reproduce or not: immune suppression and costs of parasites during reproduction in the Arctic charr

2001 ◽  
Vol 79 (2) ◽  
pp. 271-278 ◽  
Author(s):  
Frode Skarstein ◽  
Ivar Folstad ◽  
Ståle Liljedal
Keyword(s):  
Immune Suppression ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Indirect Evidence ◽  
The Arctic ◽  
Parasitic Infections ◽  
Intermediate Hosts ◽  
Parasite Infections ◽  
Gamete Production ◽  
The Difference

Secondary sexual characters are assumed to be costly to develop, and the costs of parasite infections and immune suppression are currently an active area of research within sexual selection. We investigated differences in parasitic infections and immunological activity between reproductively active and inactive Arctic charr (Salvelinus alpinus). Spawning fish were found to have higher intensities of macroparasite infections than nonspawning or resting fish. The difference in intensity between spawning and resting fish was only observed in males, and can be explained by differences in exposure or susceptibility to parasites. However, there is indirect evidence that the difference in parasite intensities does not stem from varying exposure originating from group differences in consumption of carotenoid-containing intermediate hosts. We show, rather, that spawning males may be more susceptible, since they have a smaller spleen, which is an important lymphocyte-producing organ, than resting males. As these costs of spawning are found predominantly among males, they are unlikely to be the result of energetic investment in gamete production, as gamete production in general is thought to be more energetically demanding in females than in males. Rather, we suggest that the observed costs of reproduction result from immune suppression related to ornamental development and spermatogenesis.

Influence of nutritional status on biomarker responses to PCB in the Arctic charr (Salvelinus alpinus)

1999 ◽  
Vol 44 (4) ◽  
pp. 233-244 ◽  
Author(s):  
Even H Jørgensen ◽  
Bjørn E Bye ◽  
Malcolm Jobling
Keyword(s):  
Nutritional Status ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
The Arctic

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
Keyword(s):  
Newfoundland And Labrador ◽  
Salvelinus Alpinus ◽  
First Record ◽  
Arctic Char ◽  
The Arctic ◽  
Secondary Contact ◽  
Loop Region ◽  
Multiple Sampling ◽  
Sampling Locations ◽  
D Loop

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.

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