Skip to Main Content
Demographic and phenotypic responses of juvenile steelhead trout to spatial predictability of food resourcesAuthor(s): Matthew R. Sloat; Gordon H. Reeves
Publication Series: Scientific Journal (JRNL)
Station: Pacific Northwest Research Station
PDF: Download Publication (523.76 KB)
DescriptionWe manipulated food inputs among patches within experimental streams to determine how variation in foraging behavior influenced demographic and phenotypic responses of juvenile steelhead trout (Oncorhynchus mykiss) to the spatial predictability of food resources. Demographic responses included compensatory adjustments in fish abundance, mean fish size, and size inequality. These responses paralleled shifts in individual foraging behavior, which increased the strength of exploitative competition relative to interference competition in streams with lower spatial predictability of food resources. Variation in the spatial predictability of food resources also favored different physiological phenotypes, as inferred from selection on an index of standard metabolic rate (SMR) based on fish otolith size. We observed positive directional selection on SMR in streams with spatially predictable food resources, disruptive selection for SMR at intermediate levels of spatial predictability, and negative directional selection for SMR in streams with the lowest level of spatial predictability of food resources. Thus, variation in the spatial predictability of food resources resulted in changes in individual behavior and modes of population regulation, and produced physiologically divergent cohorts of stream salmonids.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationSloat, Matthew R.; Reeves, Gordon H. 2014. Demographic and phenotypic responses of juvenile steelhead trout to spatial predictability of food resources. Ecology. 95(9): 2423-2433.
Keywordscompetition, exploitation, interference, emigration, growth depensation, intraspecific competition, Oncorhynchus mykiss, phenotypic selection, population dynamics, regulation, spatial predictability, standard metabolic rate, steelhead trout
- Individual condition and stream temperature influences early maturation of rainbow and steelhead trout, Oncorhynchus mykiss
- Coho salmon and steelhead trout of JDSF
- Spatial ecological processes and local factors predict the distribution and abundance of spawning by steelhead (Oncorhynchus mykiss) across a complex riverscape
XML: View XML