Population structure, biomass, and diet of landlocked Arctic charr (Salvelinus alpinus) in a small, shallow High Arctic lake

Arctic charr (Salvelinus alpinus) are phenotypically plastic with multiple dietary-morphological relationships observed throughout their circumpolar range. Feeding strategies often differ between Arctic charr life histories and can impact size-at-age and morphological attributes. We examined growth, condition, and body morphology for two high Arctic populations of Arctic charr with anadromous and landlocked life histories. Anadromous Arctic charr had higher growth rates, achieving mean lengths two times those of landlocked Arctic charr by age 10 and had higher overall condition, particularly in the fall. Ontogenetic shifts in diet were suspected in both populations, with an abrupt shift to marine feeding in the anadromous population and a gradual shift to piscivory in the landlocked population. Morphological differences between life histories manifested most predominantly in larger eye diameter, longer pectoral and pelvic fins, and longer upper jaws of landlocked Arctic charr, suggestive of piscivorous feeding specialization of landlocked fish >350mm. Our findings emphasize the benefits that marine feeding can have for growth and condition of freshwater fishes in Arctic environments and also convey the necessity of adaptive feeding strategies to optimize growth and condition in fishes inhabiting low-production lacustrine habitats.

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Recorded bimodal length frequency distributions of Arctic charr, Salvelinus alpinus (L.), and brown trout, Salmo trutta L.: an effect of both population structure and sampling bias

Polar Biology ◽

10.1007/s00300-015-1650-y ◽

2015 ◽

Vol 38 (6) ◽

pp. 895-903 ◽

Cited By ~ 1

Author(s):

Reidar Borgstrøm ◽

Morten Haugen ◽

Kjell Eivind Madsen ◽

Martin-A. Svenning

Keyword(s):

Population Structure ◽

Brown Trout ◽

Salmo Trutta ◽

Salvelinus Alpinus ◽

Arctic Charr ◽

Sampling Bias ◽

Length Frequency ◽

Frequency Distributions ◽

Brown Trout Salmo Trutta

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Respiration of Arctic Char (Salvelinus alpinus) From a High Arctic Lake

Journal of the Fisheries Research Board of Canada ◽

10.1139/f73-128 ◽

1973 ◽

Vol 30 (6) ◽

pp. 717-723 ◽

Cited By ~ 34

Author(s):

G. F. Holeton

Keyword(s):

Oxygen Consumption ◽

Oxygen Uptake ◽

Cold Adaptation ◽

Metabolic Response ◽

Salvelinus Alpinus ◽

High Arctic ◽

Arctic Char ◽

Short Term ◽

Arctic Lake ◽

Wet Weight

The routine of resting oxygen consumption of Arctic char (Salvelinus alpinus) from a high arctic lake (74°42′N) was measured at 2 (acclimated) and 6 C (unacclimated). The oxygen uptake versus wet weight relation at 2 C was: Log O2 uptake = 0.7316 Log weight – 1.0944. Oxygen uptake was low, not showing any evidence of "cold adaptation," and was comparable to projections of oxygen uptake versus temperature relations of other salmonid fish from lower latitudes.The short term metabolic response to a rise in temperature of 4 C was independent of body size except with fish with yolk sacs and weighing less than 0.125 g.

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Summer osmoregulatory capacity of the world's northernmost living salmonid

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1997.272.3.r743 ◽

1997 ◽

Vol 272 (3) ◽

pp. R743-R749 ◽

Cited By ~ 5

Author(s):

K. J. Nilssen ◽

O. A. Gulseth ◽

M. Iversen ◽

R. Kjol

Keyword(s):

Salvelinus Alpinus ◽

Arctic Charr ◽

Challenge Test ◽

Plasma Osmolality ◽

High Arctic ◽

Svalbard Archipelago ◽

Anadromous Arctic Charr ◽

Osmoregulatory Capacity ◽

Seawater Tolerance ◽

Seawater Challenge

Anadromous Arctic charr (Salvelinus alpinus L.) were caught on their way to and from the sea with the use of a fish trap placed in the Dieset watercourse located on the Spitsbergen Island (79 degrees 10' Northern latitude) within the high-Arctic Svalbard archipelago. When subjected to a seawater challenge test (34 parts/thousand at 4-5 degrees C), charr on their way to the sea showed only minor and temporary changes in blood plasma osmolality and Na+ and Mg2+ concentrations. The seawater tests also revealed good hypoosmoregulatory capacity for Arctic charr returning from the marine environment 4 wk later. A progressive decrease in seawater tolerance was first documented 7-11 days after their return to the freshwater habitat. Thus the Svalbard charr, being the northernmost anadromous salmonid and probably a direct descendant from the first Salvelinus immigrants to freshwater systems, undergoes a preparatory increase of hypoosmoregulatory capacity (smoltification) before entering the oceanic water bodies. Furthermore, the termination of their short annual seawater stay is probably elicited by factors controlling body systems other than osmoregulation.

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