Energetic status and bioelectrical impedance modeling of Arctic grayling Thymallus arcticus in interior Alaska Rivers

2019 ◽  
Vol 102 (11) ◽  
pp. 1337-1349
Author(s):  
Jeffrey A. Falke ◽  
Lauren T. Bailey ◽  
Kevin M. Fraley ◽  
Michael J. Lunde ◽  
Andrew D. Gryska
Keyword(s):  
Bioelectrical Impedance ◽  
Arctic Grayling ◽  
Interior Alaska ◽  
Impedance Modeling ◽  
Thymallus Arcticus

Selection of Positions by Drift-Feeding Salmonids in Dominance Hierarchies: Model and Test for Arctic Grayling (Thymallus arcticus) in Subarctic Mountain Streams, Interior Alaska

1992 ◽  
Vol 49 (10) ◽  
pp. 1999-2008 ◽  
Author(s):  
Nicholas F. Hughes
Keyword(s):  
Bottom Topography ◽  
Lateral Diffusion ◽  
Distribution Patterns ◽  
Mountain Stream ◽  
Physical Habitat ◽  
Dominance Hierarchies ◽  
Arctic Grayling ◽  
Drift Feeding ◽  
Stream Salmonids ◽  
Thymallus Arcticus

In this work I describe a model to predict position choice by each individual in a dominance hierarchy of drift-feeding stream salmonids. This is an adaptation of Hughes and Dill's model (1990. Can. J. Fish. Aquat. Sci. 47: 2039–2048) of position choice by solitary fish. I have included the effect that prey consumption, lateral diffusion of drifting invertebrates, and entry of invertebrates into the drift have on the density of prey downstream of feeding fish and the restrictions that dominant fish place on freedom of choice by their subordinates. l assume that each fish chooses the most profitable position that its rank in the hierarchy will allow. There was an encouraging match between the distribution patterns predicted by the model and the distribution patterns actually adopted by Arctic grayling (Thymallus arcticus) in two pools of a mountain stream. This result suggests that Arctic grayling locate and rank positions based on their profitability. The predictions of reduced models, and the location of positions in relation to bottom topography and current flow, suggest that the physical habitat forms the template for distribution patterns by determining the location and ranking of the most profitable positions.

scholarly journals Consumption of Shrews, Sorex spp., by Arctic Grayling, Thymallus arcticus

2004 ◽  
Vol 118 (1) ◽  
pp. 111 ◽  
Author(s):  
Jonathan W. Moore ◽  
G. J. Kenagy
Keyword(s):  
Stable Isotopes ◽  
Dietary Habits ◽  
Riparian Zones ◽  
Stream Fishes ◽  
Nitrogen Stable Isotopes ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Southwestern Alaska

In an investigation of the dietary habits of Arctic Grayling (Thymallus arcticus) we found that two individuals out of 93 sampled in southwestern Alaska (approximately 59°N, 159°W) contained a total of five shrews (Sorex spp.). These shrews contained enriched levels of nitrogen stable isotopes, suggesting utilization of nutrients derived from salmon. We hypothesize that normally terrestrial shrews accidentally enter streams while foraging along the productive riparian zones of creeks with high densities of salmon. Shrews are apparently susceptible to opportunistic predation by resident stream fishes, including Arctic Grayling, when they enter the streams.

Breeding Tubercles Occur on Male and Female Arctic Grayling (Thymallus arcticus)

Copeia ◽  
1978 ◽  
Vol 1978 (1) ◽  
pp. 185 ◽  
Author(s):  
L. F. Kratt ◽  
R. J. F. Smith
Keyword(s):  
Male And Female ◽  
Arctic Grayling ◽  
Thymallus Arcticus

Rheotactic Differentiation between Fluvial and Lacustrine Populations of Arctic Grayling (Thymallus arcticus), and Implications for the Only Remaining Indigenous Population of Fluvial "Montana Grayling"

1991 ◽  
Vol 48 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Calvin M. Kaya
Keyword(s):  
Indigenous Population ◽  
Arctic Grayling ◽  
Artificial Stream ◽  
Light Intensities ◽  
Thymallus Arcticus ◽  
Permanent Stream

Rheotactic behavior of young Arctic grayling (Thymallus arcticus) from fluvial (Big Hole River) and lacustrine (Red Rocks Lake) populations in Montana was assessed in an artificial stream to see if fluvial grayling are adapted to life-long residence in streams by having an innately greater tendency to hold position and lesser tendency to go downstream. Responses of young tested at 0–10 d post-swimup contradicted the hypothesis; the fluvial grayling had strong downstream responses similar to or greater than those of the lacustrine grayling. When tested 18–31 d post-swimup, however, rheotactic responses of the fluvial and lacustrine grayling were consistent with the hypothesis, at three light intensities (full and dim lighting and darkness). Rheotactic differences were even greater in trials at 47–72 d post-swimup (conducted only under full lighting). Big Hole River grayling appear to be adapted to permanent stream residence. Such adaptation reinforces the importance of conserving this last indigenous fluvial population of the geographically disjunct, genetically identifiable "Montana grayling."

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