Life History of Two Isolated Populations of Arctic Char (Salvelinus alpinus) in Spring-Fed Tributaries of the Canning River, Alaska

1973 ◽  
Vol 30 (8) ◽  
pp. 1215-1220 ◽  
Author(s):  
P. McCart ◽  
P. Craig

Two isolated populations of Arctic char (Salvelinus alpinus) in spring-fed tributaries of the Canning River, Alaska, had meristic characters that corresponded to those of the Western Arctic–Bering Sea form of Arctic char. The two populations demonstrated slight differences in growth rates, age at maturity, longevity, and food habits. The fish were characterized by small size (maximum 235 mm), low growth rates, low fecundities (maximum 199 eggs), and annual spawning after maturity. Mature fish were darkly pigmented and parr marks were retained throughout life. The spawning season appeared to be sometime in November, when the eggs of mature females averaged 3.8 mm in diameter.


1971 ◽  
Vol 28 (1) ◽  
pp. 115-118 ◽  
Author(s):  
P. McCart ◽  
P. Craig

Both anadromous and freshwater-resident populations of Arctic char (Salvelinus alpinus) occur in the Sagavanirktok River drainage, Alaska. A comparison of the gill-raker and pyloric-caeca counts of populations of the two types revealed that anadromous fish had lower gill-raker and pyloric-caeca counts than freshwater-resident fish. Freshwater-resident populations correspond meristically to McPhail's Eastern Arctic form, and anadromous population scor-respond to his Western Arctic–Bering Sea form (McPhail, J. Fish. Res. Bd. Canada 18: 793–816, 1961). It is suggested that the former was the original inhabitant of the area but has been replaced by the latter except in inaccessible, headwater lakes.



1981 ◽  
Vol 38 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Irv Kornfield ◽  
Kenneth F. Beland ◽  
John R. Moring ◽  
Frederick W. Kircheis

Five isolated populations of landlocked Arctic char (Salvelinus alpinus) from eastern United States and Canada were compared electrophoretically with anadromous Arctic char from the Northwest Territories. Mean heterozygosity was relatively low (0.03) with allelic variation observed at 7 of the 26 isozyme loci examined. The Sunapee and blueback char of Maine, and the Quebec red char of Parc des Laurentides, Québec, were very similar (IN = 0.925–0.999). The genetic differences separating these eastern North American char are probably of limited evolutionary consequence. However, we consider it prudent to characterize these endemics as potentially threatened unique populations and suggest that conservative management is warranted.Key words: Salvelinus alpinus, endemic populations, electrophoresis, species management





1978 ◽  
Vol 35 (12) ◽  
pp. 1537-1541 ◽  
Author(s):  
P. J. Rombough ◽  
S. E. Barbour ◽  
J. J. Kerekes

Landlocked Arctic char, Salvelinus alpinus, from Candlestick Pond, Gros Morne National Park, Newfoundland, were characterized by slow growth, short life span (max 7 yr), and small size (max fork length = 164 mm). Sexual maturity was obtained at age 3, fecundity was low (max 104 ova per fish), and spawning annual. Major food items were zooplankton and aquatic insect larvae. Eight morphometric and eight meristic characters were examined and compared with available literature data for nonanadromous S. alpinus in eastern North America. Arctic char from Candlestick Pond were not significantly different from S. alpinus oquassa from Quebec and Maine but were significantly different from char from Labrador and other locations in insular Newfoundland. It is proposed that Arctic char from Candlestick Pond are descendents of an aboriginal form of S. alpinus that has been largely displaced along the Atlantic coast of North America. Key words: Salvelinus alpinus, Newfoundland, life history, taxonomic status



1988 ◽  
Vol 45 (9) ◽  
pp. 1514-1524 ◽  
Author(s):  
Henrik Mosegaard ◽  
Henrik Svedäng ◽  
Kjell Taberman

Experiments were conducted to study the effect of temperature, fish size, and somatic growth rate on mean daily otolith growth rate in Arctic char (Salvelinus alpinus) fry fed maximum rations. Long-term experiments at two different temperatures (8 and 13 °C) showed exponential relationships between otolith weight and fish wet weight, with the exponent of wet weight for the higher temperature being significantly higher than for the lower temperature. Increasing exponents at each sampling date indicated a difference in growth rates of the char and its otoliths. Short-term experiments showed that specific growth rate of the fry at six different temperatures was that of an optimum curve whereas the otolith growth rate continued to increase with increasing temperatures. A clear uncoupling between otolith growth rate and fish growth rate was demonstrated whereas temperature and fish wet weight modeled otolith growth rate reasonably well. It was found that otolith growth rate expressed as daily increase in weight gave a model with better fit and higher generality than growth rate along various radii. Several examples of uncoupling between fish growth rate and otolith growth rate in the literature were reexamined, and an explanation of otolith growth rate in terms of a metabolic expression was suggested.



1998 ◽  
Vol 76 (2) ◽  
pp. 212-220 ◽  
Author(s):  
Anders Alanärä ◽  
Svante Winberg ◽  
Eva Brännäs ◽  
Anders Kiessling ◽  
Erik Höglund ◽  
...  

The relationships between feeding activity, brain serotonergic activity level, and energy reserves in eight groups of Arctic char (Salvelinus alpinus) were evaluated using self-feeders in combination with passive integrated transponder (PIT) tags. Serotonin concentrations were measured in the brain stem, telencephalon, and hypothalamus. Energy reserves were measured, as fat levels, in muscle and mesenteric tissue. The self-feeding activity level was found to correlate positively (P < 0.05) with the growth rate and negatively (P < 0.05) with the serotonergic activity levels in the brain stem and telencephalon. No significant relationship was found, however, between the number of trigger activations and the muscle or mesenteric tissue lipid level. One or, in some cases, two fish in each group clearly dominated the activation of the trigger, and showed the highest growth rates and lowest stress levels, measured as brain serotonergic activity. Subordinate fish (one to three individuals) hardly ever activated the trigger, but showed relatively high growth rates and brain serotonergic activity levels that did not differ significantly from those of dominant fish. The remaining individuals showed very little feeding activity and low growth rates. In addition, brain serotonergic activity levels were significantly higher than in fish in the former two categories, indicating that the subordinate fish suffered from stress and had a low social rank.



2018 ◽  
Vol 130 (1) ◽  
pp. 71-76
Author(s):  
E Lewisch ◽  
T Frank ◽  
H Soliman ◽  
O Schachner ◽  
A Friedl ◽  
...  


2020 ◽  
Vol 634 ◽  
pp. 175-197 ◽  
Author(s):  
LN Harris ◽  
DJ Yurkowski ◽  
MJH Gilbert ◽  
BGT Else ◽  
PJ Duke ◽  
...  


1996 ◽  
Vol 35 (4I) ◽  
pp. 399-417 ◽  
Author(s):  
John W. Mellor

The right to the flow of income from water is vigorously pursued, protected, and fought over in any arid part of the world. Pakistan is of course no exception. Reform of irrigation institutions necessarily changes the rights to water, whether it be those of farmers, government, or government functionaries. Those perceived rights may be explicit and broadly accepted, or simply takings that are not even considered legitimate. Nevertheless they will be fought over. Pakistan has a long history of proposals for irrigation reform, little or none being implemented, except as isolated pilot projects. Thus, to propose major changes in irrigation institutions must be clearly shown to have major benefits to justify the hard battles that must be fought and the goodwill of those who might win those battles for reform. Proponents of irrigation institution reform have always argued the necessity of the reforms and the large gains to be achieved. Perhaps, however, those arguments have not been convincing. This paper will briefly outline the failed attempts at irrigation reform to provide an element of reality to the discussion. It will then proceed to make the case of the urgency of reform in a somewhat different manner to the past. Finally, current major reform proposals will be presented. This paper approaches justification of irrigation reform by focusing on the agricultural growth rate. It does so because that is the critical variable influencing poverty rates and is a significant determinant of over-all economic growth rates. The paper decomposes growth rates and suggests a residual effect of deterioration of the irrigation system that is large and calls for policy and institutional reform. The data are notional, suggesting the usefulness of the approach and paves the way for more detailed empirical analysis and enquiry for the future.



2021 ◽  
Author(s):  
Stephen L. Klobucar ◽  
Jessica A. Rick ◽  
Elizabeth G. Mandeville ◽  
Catherine E. Wagner ◽  
Phaedra Budy


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