Does presmolt growth rate in steelhead trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch) predict growth rate in seawater?

1997 ◽  
Vol 54 (2) ◽  
pp. 430-433 ◽  
Author(s):  
J I Johnsson ◽  
J Blackburn ◽  
W C Clarke ◽  
R E Withler
2018 ◽  
Vol 75 (12) ◽  
pp. 2184-2197 ◽  
Author(s):  
Ann-Marie K. Osterback ◽  
Cynthia H. Kern ◽  
Emerson A. Kanawi ◽  
Jeffrey M. Perez ◽  
Joseph D. Kiernan

We investigated how extreme drought conditions influenced the abundance, growth, movement, and seawater readiness of juvenile coho salmon (Oncorhynchus kisutch) and steelhead trout (Oncorhynchus mykiss) in a small central California coastal lagoon. In 2015, the seasonal sandbar at the mouth of Scott Creek formed over 2 months earlier than average, effectively trapping fish in the lagoon for 7 additional months (mid-May through December) before outmigration opportunities eventually resumed. Monthly mark–recapture sampling demonstrated that juvenile coho salmon and steelhead were able to persist in the lagoon during extended periods of high water temperature and low dissolved oxygen concentration. Both salmonid species exhibited similar temporal trends in abundance, growth, and Na+-K+-ATPase activity levels during lagoon residence; however, abundance and growth rates were consistently higher for steelhead. Stationary passive integrated transponder tag antenna detections revealed recurrent movement of individuals between the warm lagoon and cooler lower mainstem creek, suggesting individuals regulated key physiological processes by moving between the adjacent habitats. Our study provides new insight concerning the consequences of drought for imperiled salmonid populations and underscores the importance of life-history diversity during extreme climatic events.


2008 ◽  
Vol 65 (2) ◽  
pp. 266-275 ◽  
Author(s):  
John J Piccolo ◽  
Nicholas F Hughes ◽  
Mason D Bryant

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.


1993 ◽  
Vol 50 (3) ◽  
pp. 480-487 ◽  
Author(s):  
Jörgen I. Johnsson ◽  
W. Craig Clarke ◽  
Ruth E. Withler

We tested the hypothesis that hybridization with domesticated rainbow trout (Oncorhynchus mykiss) reduces the seasonal variation in growth in both fresh and salt water in anadromous steelhead trout (O. mykiss). The seasonal variation in freshwater growth was more pronounced in the steelhead trout than in the hybrid and domesticated trout. Consequently, differences in growth rate among groups were considerably higher during winter than in fall or spring. We suggest that high feeding activity during unfavourable winter conditions in natural waters is maladaptive, but is not selected against in protected hatchery environments with a continuous food supply. This may lead to genetic divergence in feeding physiology and/or behaviour between steelhead trout and domesticated rainbow trout. Growth rates in experimental groups transferred to seawater in December relative to groups transferred in April were faster in rainbow and hybrid trout than in steelhead trout. The results support the hypothesis that seasonal variation in seawater growth in steelhead trout is reduced by crossing with domesticated rainbow trout.


1997 ◽  
Vol 75 (2) ◽  
pp. 335-337 ◽  
Author(s):  
Anthony P. Farrell ◽  
William Bennett ◽  
Robert H. Devlin

We examined the consequence of remarkably fast growth rates in transgenic fish, using swimming performance as a physiological fitness variable. Substantially faster growth rates were achieved by the insertion of an "all-salmon" growth hormone gene construct in transgenic coho salmon (Oncorhynchus kisutch). On an absolute speed basis, transgenic fish swam no faster at their critical swimming speed than smaller non-transgenic controls, and much slower than older non-transgenic controls of the same size. Thus, we find a marked trade-off between growth rate and swimming performance, and these results suggest that transgenic fish may be an excellent model to evaluate existing ideas regarding physiological design.


Sign in / Sign up

Export Citation Format

Share Document