Hunger and the Capture of Grayling and Char

1974 ◽  
Vol 31 (12) ◽  
pp. 1945-1948 ◽  
Author(s):  
J. E. Bryan
Keyword(s):  
Sex Ratio ◽  
Salvelinus Alpinus ◽  
Yukon Territory ◽  
Arctic Char ◽  
Remote Areas ◽  
Size Selection ◽  
Arctic Grayling ◽  
Thymallus Arcticus

Arctic grayling, Thymallus arcticus, and Arctic char, Salvelinus alpinus, were collected by angling and seining in remote areas of northern Yukon Territory. Stomach samples were observed to test the hypothesis that fish caught by angling had eaten less food than those caught by seining. The hypothesis was supported by the data for grayling. The data for char were consistent with the hypothesis, but the results were not statistically significant. There was no difference in the sex ratio of fish caught by the two methods. Angling selected larger char than did seining, but there was no evidence of size selection in grayling.

Movements and Growth of Arctic Grayling (Thymallus arcticus) and Juvenile Arctic Char (Salvelinus alpinus) in a Small Arctic Stream, Alaska

1975 ◽  
Vol 32 (5) ◽  
pp. 689-697 ◽  
Author(s):  
P. C. Craig ◽  
V. A. Poulin
Keyword(s):  
Growth Rate ◽  
Sexual Maturity ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Nursery Area ◽  
Fish Movements ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Prudhoe Bay ◽  
Age Determinations

Fish movements were monitored in a small arctic stream that drains into the Kavik River near Prudhoe Bay, Alaska. The stream, which flows only during summer, served as a spawning and nursery area for Arctic grayling (Thymallus arcticus). Adult grayling entered the stream shortly after breakup and left again after spawning. Juvenile grayling also entered soon after breakup and many remained throughout the summer. Grayling fry emerged from the gravel in late June or early July and remained until freeze-up (mid-September). Small numbers of Arctic char (Salvelinus alpinus) juveniles also entered the stream to feed.The growth rate of grayling in the study stream was among the fastest recorded for arctic populations. Otolith-based age determinations were preferred as scales tended to underestimate the ages of old fish. Maximum observed age was 16 and age at sexual maturity ranged from 5 to 8.

Late Pleistocene fish fossils of Coregonus, Stenodus, Thymallus, Catostomus, Lota, and Cottus from the Old Crow basin, northern Yukon, Canada

1981 ◽  
Vol 18 (11) ◽  
pp. 1740-1754 ◽  
Author(s):  
Stephen L. Cumbaa ◽  
Don E. McAllister ◽  
Richard E. Morlan
Keyword(s):  
North America ◽  
Geographic Variation ◽  
Glacial Refugia ◽  
Yukon Territory ◽  
The Arctic ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Freshwater Sculpin ◽  
Longnose Sucker ◽  
First Time

Fossils of the broad whitefish, Coregonus nasus; the inconnu, Stenodus leucichthys; the longnose sucker, Catostomus catostomus; and the burbot, Lota lota, are reported for the first time from North America and a freshwater sculpin, Cottus, for the first time from Yukon Territory. The known fossil occurrence of the Arctic grayling, Thymallus arcticus, in North America is extended from 32 000 to about 60 000 years BP. These six fossils represent about one sixth of the present-day Yukon freshwater ichthyofauna of 35 species.These fossils provide a major test for the method of determining glacial refugia based on geographic variation of morphological or protein characters. They confirm that these taxa were present prior to and presumably survived the Wisconsinan glaciation in a Beringian refugium.The occurrence of these fossils, all subarctic or subarctic–boreal species known at present in the same area, does not suggest a paleoenvironment greatly different from the present one.

scholarly journals Sex matters in Massive Parallel Sequencing: Evidence for biases in genetic parameter estimation and investigation of sex determination systems

2016 ◽  
Author(s):  
Laura Benestan ◽  
Jean-Sébastien Moore ◽  
Ben J. G. Sutherland ◽  
Jérémy Le Luyer ◽  
Halim Maaroufi ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Genetic Differentiation ◽  
Massively Parallel Sequencing ◽  
Salvelinus Alpinus ◽  
Genetic Parameter ◽  
Homarus Americanus ◽  
Arctic Char ◽  
Accurate Estimation ◽  
Sequencing Data ◽  
Parallel Sequencing

AbstractUsing massively parallel sequencing data from two species with different life history traits -- American lobster (Homarus americanus) and Arctic Char (Salvelinus alpinus) -- we highlighted how an unbalanced sex ratio in the samples combined with a few sex-linked markers may lead to false interpretations of population structure and thus to potentially erroneous management recommendations. Multivariate analyses revealed two genetic clusters that separated males and females instead of showing the expected pattern of genetic differentiation among ecologically divergent (inshore vs. offshore in lobster) or geographically distant (east vs. west in Arctic Char) sampling locations. We created several subsamples artificially varying the sex ratio in the inshore/offshore and east/west groups, and then demonstrated that significant genetic differentiation could be observed despite panmixia for lobster, and that Fst values were overestimated for Arctic Char. This pattern was due to 12 and 94 sex-linked markers driving differentiation for lobster and Arctic Char, respectively. Removing sex-linked markers led to nonsignificant genetic structure (lobster) and a more accurate estimation of Fst (Arctic Char). We further characterized the putative functions of sex-linked markers. Given that only 9.6% of all marine/diadromous population genomic studies to date reported sex information, we urge researchers to collect and consider individual sex information. In summary, we argue that sex information is useful to (i) control sex ratio in sampling, (ii) overcome “sex-ratio bias” that can lead to spurious genetic differentiation signals and (iii) fill knowledge gaps regarding sex determining systems.

Responses of Arctic Grayling (Thymallus arcticus) to Acute and Prolonged Exposure to Yukon Placer Mining Sediment

1987 ◽  
Vol 44 (3) ◽  
pp. 658-673 ◽  
Author(s):  
D. J. McLeay ◽  
I. K. Birtwell ◽  
G. F. Hartman ◽  
G. L. Ennis
Keyword(s):  
Stress Responses ◽  
Prolonged Exposure ◽  
Feeding Activity ◽  
River System ◽  
Mining Area ◽  
Yukon Territory ◽  
Short Exposure ◽  
Arctic Grayling ◽  
Organic Sediment ◽  
Thymallus Arcticus

Underyearling Arctic grayling (Thymallus arcticus) from the Yukon River system were expsed for 4 d to suspensions of fine inorganic (≤ 250 g∙L−1) and organic (≤ 50 g∙L−1) sediment and for 6 wk to inorganic sediment (≤ 1000 mg∙L−1) under laboratory conditions. The test sediments were collected from an active placer mining area near Mayo, Yukon Territory. The exposures evoked sublethal responses but did not cause gill damage. Mortalities (10 and 20%) occurred only in experiments at 5 °C with inorganic sediment concentrations ≤ 20 g∙L−1. Six weeks of exposure to sediment concentrations > 100 mg∙L−1 impaired feeding activity, reduced growth rates, caused downstream displacement, colour changes, and decreased resistance to the reference toxicant pentachlorophenol, but did not impair respiratory capabilities. Stress responses (elevated and/or more varied blood sugar levels, depressed leucocrit values) were recorded after short exposure (1–4 d) to organic sediment concentrations as low as 50 mg∙L−1. Inorganic sediment strengths ≥ 10 g∙L−1 caused fish to surface. The lethal and sublethal responses of Arctic grayling to pentachlorophenol were similar to those determined for other healthy salmonid fishes.

Pleistocene grayling, Thymallus, from Yukon, Canada

1969 ◽  
Vol 6 (5) ◽  
pp. 1185-1190 ◽  
Author(s):  
D. E. McAllister ◽  
C. R. Harington
Keyword(s):  
North America ◽  
Yukon Territory ◽  
The Arctic ◽  
Fish Scales ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Fossil Records ◽  
Pleistocene Deposit

Eleven cycloid fish scales or scale fragments with scalloped anterior margins were obtained from a Pleistocene deposit in the Old Crow area, Yukon Territory. Shells from the same horizon as the scales were radiocarbon dated at 32 400 ± 770 yr B.P. The scales are from the Arctic grayling, Thymallus arcticus, providing the first fossil records of the genus and of the subfamily Thymallinae for North America.

First confirmation of salmonid alphavirus infection in Arctic char Salvelinus alpinus and in Austria

2018 ◽  
Vol 130 (1) ◽  
pp. 71-76
Author(s):  
E Lewisch ◽  
T Frank ◽  
H Soliman ◽  
O Schachner ◽  
A Friedl ◽  
...  
Keyword(s):  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Alphavirus Infection

scholarly journals Investigating the morphological and genetic divergence of arctic char ( Salvelinus alpinus) populations in lakes of arctic Alaska

2021 ◽  
Author(s):  
Stephen L. Klobucar ◽  
Jessica A. Rick ◽  
Elizabeth G. Mandeville ◽  
Catherine E. Wagner ◽  
Phaedra Budy
Keyword(s):  
Genetic Divergence ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Arctic Alaska

Influence of Parr Growth, Lake Morphology, and Freshwater Parasites on the Degree of Anadromy in Different Populations of Arctic Char (Salvelinus alpinus) in Northern Norway

1994 ◽  
Vol 51 (6) ◽  
pp. 1229-1246 ◽  
Author(s):  
Knut Kristoffersen ◽  
Morten Halvorsen ◽  
Lisbeth Jørgensen
Keyword(s):  
Salvelinus Alpinus ◽  
Relative Size ◽  
Significant Negative Correlation ◽  
Relative Volume ◽  
Arctic Char ◽  
Northern Norway ◽  
Length Relationship ◽  
Lake Morphology ◽  
Different Populations ◽  
Profundal Zone

Anadromy of nine lake populations of Arctic char (Salvelinus alpinus) in northern Norway was scored on the following criteria: prevalence of marine parasites, fish size, and size at maturity. In general, anadromy dominated in shallow lakes and residency dominated in deep lakes. The anadromy scores of the populations were significantly higher in lakes without a profundal zone compared with lakes with a profundal zone. There was also a significant negative correlation between the relative volume of the profundal zone (RPV) and the degree of anadromy and between RPV and mean parr length at ages 2+ and 3+. However, differences in parr growth could not explain all the observed variation in anadromy, and the correlation between mean parr length at ages 2+ and 3+ and the degree of anadromy in the different populations was not significant. In addition to the effect on parr growth, lake morphology seemed to influence the degree of anadromy through the relative size of different habitats, which in turn affects the number of available niches. The parr weight/length relationship and infection with the freshwater parasites Phyllodistomum umblae and Diphyllobothrium spp. did not affect the degree of anadromy.

Respiratory development in Arctic char Salvelinus alpinus under conditions of normoxia and chronic hypoxia

1977 ◽  
Vol 55 (9) ◽  
pp. 1461-1467 ◽  
Author(s):  
D. G. McDonald ◽  
B. R. McMahon
Keyword(s):  
Heart Rate ◽  
Surface Morphology ◽  
Chronic Hypoxia ◽  
Prolonged Exposure ◽  
Salvelinus Alpinus ◽  
Ventilation Rate ◽  
Arctic Char ◽  
Adult Fish ◽  
Weighted Averages ◽  
Secondary Lamellae

Changes in surface morphology of the gills, ventilation rate, and heart rate were examined in Arctic char larvae exposed to normoxia (pO2 = 121 ± 6 (SE) mmHg) or chronic hypoxia (pO2 = 33 ± 3.5 mmHg) for 47 days after hatching. A modified weighted-averages technique was developed to measure aspects of gill morphology.Early development of the gills was characterized by rapid increases in filament size and number, and the emergence and proliferation of secondary lamellae. Variations in the dimensions of the gills, as noted in adult fish, were particularly evident in the larval fish.Hypoxia caused increases in both ventilation rate and heart rate. Prolonged exposure led to a retardation of gill growth, particularly the proliferation of secondary lamellae. However, growth of individual lamellae was stimulated between 38 and 47 days.

Sign in / Sign up

Export Citation Format

Share Document