Mechanics of foraging success and optimal microhabitat selection in Alaskan Arctic grayling (Thymallus arcticus)

2019 ◽  
Vol 76 (5) ◽  
pp. 815-830 ◽  
Author(s):  
Bryan B. Bozeman ◽  
Gary D. Grossman
Keyword(s):  
Prey Capture ◽  
Water Velocity ◽  
Net Energy ◽  
Arctic Grayling ◽  
Drift Feeding ◽  
Reactive Distance ◽  
Negative Effect ◽  
Thymallus Arcticus ◽  
Alaskan Arctic ◽  
Size Rank

Most fishes residing in temperate streams in the Northern Hemisphere are drift-feeders. Despite this fact, little is known about the mechanisms of drift-feeding itself. We used Alaskan Arctic grayling (Thymallus arcticus), an abundant boreal drift-feeder, to examine the effects of water velocity on several aspects of drift-feeding behavior and test predictions of the Grossman et al. (2002) net energy intake model for microhabitat choice. Water velocity had a negative effect on prey capture, a positive effect on holding velocity, and little effect on reactive distance. We also found that dominance was a better predictor of prey capture success than size rank, although neither of these variables influenced holding velocity or reactive distance. The Grossman et al. (2002) model successfully predicted holding velocities of grayling in one Alaskan stream, but not another. Model failure might have occurred due to higher turbulence, increased predation, or interspecific competition with Dolly Varden (Salvelinus malma). These results help inform the study of habitat selection in drift-feeding fishes as well as management and conservation of Arctic grayling.

Position Choice by Drift-Feeding Salmonids: Model and Test for Arctic Grayling (Thymallus arcticus) in Subarctic Mountain Streams, Interior Alaska

1990 ◽  
Vol 47 (10) ◽  
pp. 2039-2048 ◽  
Author(s):  
Nicholas F. Hughes ◽  
Lawrence M. Dill
Keyword(s):  
Energy Intake ◽  
Water Depth ◽  
Focal Point ◽  
Water Velocity ◽  
Net Energy ◽  
Intake Rate ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Net Energy Intake ◽  
Energy Intake Rate

We develop a model to predict position choice of drift-feeding stream salmonids, assuming a fish chooses the position that maximizes its net energy intake rate. The fish's habitat is represented as a series of stream cross-profiles, each divided into vertical strips characterized by water depth and velocity. The fish may select a focal point in any of these strips, and include several neighbouring strips in its foraging area. The number of prey the fish encounters depends on its reaction distance to prey, water depth, and water velocity; the proportion of detected prey the fish is able to capture declines with water velocity. The fish's net energy intake rate is its gross energy intake rate from feeding minus the swimming cost calculated by using water velocity at the fish's focal point. There was a close match between the positions predicted by this model and those chosen by solitary Arctic grayling (Thymallus arcticus) in the pools of a mountain stream in Alaska.

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.

Water velocity influences prey detection and capture by drift-feeding juvenile coho salmon (Oncorhynchus kisutch) and steelhead (Oncorhynchus mykiss irideus)

2008 ◽  
Vol 65 (2) ◽  
pp. 266-275 ◽  
Author(s):  
John J Piccolo ◽  
Nicholas F Hughes ◽  
Mason D Bryant
Keyword(s):  
Oncorhynchus Mykiss ◽  
Prey Capture ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Species Interaction ◽  
Water Velocity ◽  
Capture Probability ◽  
Prey Detection ◽  
Detection Distance ◽  
Drift Feeding

We examined the effects of water velocity on prey detection and capture by drift-feeding juvenile coho salmon (Oncorhynchus kisutch) and steelhead (sea-run rainbow trout, Oncorhynchus mykiss irideus) in laboratory experiments. We used repeated-measures analysis of variance to test the effects of velocity, species, and the velocity × species interaction on prey capture probability, prey detection distance, and swimming speeds during prey capture. We used 3D video analysis to assess the spatial and temporal characteristics of prey detection and capture. Coho and steelhead showed significant, velocity-dependent decreases in capture probability (~65% to 10%, with an increase of velocity from 0.29 to 0.61 m·s-1) and prey detection distance, with no effect of species and no velocity × species interaction. Neither velocity nor species affected prey interception speed; fish intercepted prey at their predicted maximum sustainable swimming speed (Vmax) at all velocities. Speed of return to the focal point increased significantly with increasing velocity, with no effect of species. At faster velocities, return speeds were faster than Vmax, indicating potential increases in energetic cost because of anaerobic swimming. The 3D analysis suggests that the reduction in capture probability was due to both reduced prey detection distance and a uniform decline in detection probability within the prey capture area.

Examining feeding strategies and position choice of drift-feeding salmonids using an individual-based, mechanistic foraging model

2001 ◽  
Vol 58 (3) ◽  
pp. 446-457 ◽  
Author(s):  
G R Guensch ◽  
T B Hardy ◽  
R C Addley
Keyword(s):  
Habitat Selection ◽  
Energy Intake ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Prey Capture ◽  
Feeding Strategies ◽  
Net Energy ◽  
Intake Rate ◽  
Drift Feeding ◽  
Energy Intake Rate

We demonstrated the ability of a mechanistic habitat selection model to predict habitat selection of brown trout (Salmo trutta) and mountain whitefish (Prosopium williamsoni) during summer and winter conditions in the Blacksmith Fork River, Utah. By subtracting energy costs and losses from the gross energy intake rate (GEI) obtained through simulation of prey capture, the model calculates the potential net energy intake rate (NEI) of a given stream position, which is essentially the rate of energy intake available for growth and reproduction. The prey capture model incorporates the size, swimming speed, and reaction distance of the fish; the velocity, depth, temperature, and turbidity of the water; and the density and size composition of the drifting invertebrates. The results suggest that during both summer and winter, the brown trout and mountain whitefish in our study reach avoided locations providing low NEI and preferred locations providing a high ratio of NEI to the swimming cost (SC) at the focal position of the fish (NEI/SC). This supports the idea that the drift-feeding fish in this study selected stream positions that provided adequate NEI for the least amount of swimming effort.

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

Negative effect of turbidity on prey capture for both visual and non‐visual aquatic predators

2020 ◽  
Vol 89 (11) ◽  
pp. 2427-2439
Author(s):  
Jean C. G. Ortega ◽  
Bruno R. S. Figueiredo ◽  
Weferson J. Graça ◽  
Angelo A. Agostinho ◽  
Luis M. Bini
Keyword(s):  
Prey Capture ◽  
Negative Effect ◽  
Aquatic Predators

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.

Sign in / Sign up

Export Citation Format

Share Document