Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 815-830 |
| Number of pages | 16 |
| Journal | Canadian Journal of Fisheries and Aquatic Sciences |
| Volume | 76 |
| Issue number | 5 |
| DOIs | |
| State | Published - 2019 |
| Externally published | Yes |
Funding
We thank the many individuals who aided in various aspects of this research, including J. Ankeny, D. Bullock, R. Chandler, S. Corsetti, A. Grossman, B. Grossman, B. Irwin, J. Neuswanger, T. Simon, J. Martin, Jittery Joes, Two Story, and Creature Comforts. BBB also acknowledges the many years of support and mentorship of D. Bozeman. The North Pacific Research Board (grant No. 1424) and the Graduate School and Daniel B. Warnell School of Forestry and Natural Resources of the University of Georgia provided financial and material support for this project. A version of the manuscript was reviewed by E. Donofrio, R. Chandler, J. Cullen, B. Irwin, J. Neuswanger, and T. Simon. This research was completed under AUP No. A2014 05-030-R1 approved by the IACUC of the University of Georgia. We thank the many individuals who aided in various aspects of this research, including J. Ankeny, D. Bullock, R. Chandler, S. Corsetti, A. Grossman, B. Grossman, B. Irwin, J. Neuswanger, T. Simon, J. Martin, Jittery Joes, Two Story, and Creature Comforts. BBB also acknowledges the many years of support and mentor-ship of D. Bozeman. The North Pacific Research Board (grant No. 1424) and the Graduate School and Daniel B. Warnell School of Forestry and Natural Resources of the University of Georgia provided financial and material support for this project. A version of the manuscript was reviewed by E. Donofrio, R. Chandler, J. Cullen, B. Irwin, J. Neuswanger, and T. Simon. This research was completed under AUP No. A2014 05-030-R1 approved by the IACUC of the University of Georgia.
| Funders | Funder number |
|---|---|
| University of Georgia | A2014 05-030-R1 |
| North Pacific Research Board | 1424 |
