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Seasonal Changes in Microhabitat Selection by Rainbow Trout in a Small Stream
Author(s) -
Baltz Donald M.,
Vondracek Bruce,
Brown Larry R.,
Moyle Peter B.
Publication year - 1991
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1991)120<0166:scimsb>2.3.co;2
Subject(s) - rainbow trout , substrate (aquarium) , ontogeny , biology , trout , environmental science , streams , ecology , fishery , fish <actinopterygii> , zoology , computer network , genetics , computer science
Shifts in microhabitat selection by rainbow trout Oncorhynchus mykiss were related to seasonal and ontogenetic factors in a small stream characterized by short riffles, small pools, and boulder substrate. Resource availability did not differ significantly between summer and November sampling dates for most variables related to water velocity, substrate, and cover, although depths were greater and temperatures were significantly lower in November. Ontogenetic shifts were found for total depth, focal elevation, mean water column velocity, focal velocity, surface velocity, and substrate, but not for relative depth or temperature. When microhabitat selection was adjusted for fish size, selection was significantly different between seasons, most notably for velocity. Ontogenetic shifts in microhabitat use by young‐of‐year rainbow trout were interrupted by cooling winter temperatures. These changes resulted in substantially different microhabitat requirements for all rainbow trout size‐classes in different seasons.