Kimmel C.B.,University of Oregon |
Watson S.,University of Oregon |
Couture R.B.,Oregon Hatchery Research Center |
Mckibben N.S.,University of Oregon |
And 3 more authors.
Evolution and Development | Year: 2015
What is the nature of evolutionary divergence of the jaw skeleton within the genus Oncorhynchus? How can two associated bones evolve new shapes and still maintain functional integration? Here, we introduce and test a "concordance" hypothesis, in which an extraordinary matching of the evolutionary shape changes of the dentary and angular articular serves to preserve their fitting together. To test this hypothesis, we examined morphologies of the dentary and angular articular at parr (juvenile) stage, and at three levels of biological organization-between salmon and trout, between sister species within both salmon and trout, and among three types differing in life histories within one species, Oncorhynchus mykiss. The comparisons show bone shape divergences among the groups at each level; morphological divergence between salmon and trout is marked even at this relatively early life history stage. We observed substantial matching between the two mandibular bones in both pattern and amount of shape variation, and in shape covariation across species. These findings strongly support the concordance hypothesis, and reflect functional and/or developmental constraint on morphological evolution. We present evidence for developmental modularity within both bones. The locations of module boundaries were predicted from the patterns of evolutionary divergences, and for the dentary, at least, would appear to facilitate its functional association with the angular articular. The modularity results suggest that development has biased the course of evolution. © 2015 Wiley Periodicals, Inc. Source
Putman N.F.,Oregon State University |
Lohmann K.J.,University of North Carolina at Chapel Hill |
Putman E.M.,519 NW 14th Street |
Quinn T.P.,University of Washington |
And 3 more authors.
Current Biology | Year: 2013
In the final phase of their spawning migration, Pacific salmon use chemical cues to identify their home river, but how they navigate from the open ocean to the correct coastal area has remained enigmatic . To test the hypothesis that salmon imprint on the magnetic field that exists where they first enter the sea and later seek the same field upon return [2-4], we analyzed a 56-year fisheries data set on Fraser River sockeye salmon, which must detour around Vancouver Island to approach the river through either a northern or southern passageway [5, 6]. We found that the proportion of salmon using each route was predicted by geomagnetic field drift: the more the field at a passage entrance diverged from the field at the river mouth, the fewer fish used the passage. We also found that more fish used the northern passage in years with warmer sea surface temperature (presumably because fish were constrained to more northern latitudes). Field drift accounted for 16% of the variation in migratory route used, temperature 22%, and the interaction between these variables 28%. These results provide the first empirical evidence of geomagnetic imprinting in any species and imply that forecasting salmon movements is possible using geomagnetic models. © 2013 Elsevier Ltd. Source
Romer J.D.,Oregon State University |
Leblanc C.A.,Oregon State University |
Ferguson J.A.,Oregon State University |
Ferguson J.A.,Alaska Department of Fish and Game |
And 5 more authors.
Environmental Biology of Fishes | Year: 2013
Anadromous salmonids are viewed as a prized commodity and cultural symbol throughout the Pacific coast of North America. Unfortunately, several native salmonid populations are threatened or at risk of extinction. Despite this, little is known about the behavior and survival of these fish as the juveniles transition from freshwater to the ocean. Our primary objectives were to estimate survival of juvenile steelhead migrating between trapping sites and the ocean and evaluate whether survival in the estuary varies temporally (within a year) or spatially (within and between estuaries) within the same distinct population segment. We also evaluated whether flow or fork length were correlated with survival and collected information on variables that have been demonstrated to affect smolt survival in other studies to lend insight regarding differences in survival estimates between basins. We compared run timing, migration rate, survival, condition factor, age composition and time of residence in the estuary for steelhead outmigrants from each basin and measured parasite loads in outmigrating steelhead to evaluate potential differences in parasite density and parasite community between basins. In 2009, we implanted acoustic transmitters in 139 wild steelhead smolts in two small rivers on the Oregon Coast. In general, only 40-50 % of the wild steelhead smolts tagged at upstream smolt traps were detected entering the ocean. The majority of mortality occurred in the lower estuary near the ocean. Wild steelhead smolts typically spent less than 1 day in the estuary in both basins. Using similar data from previous studies in the Nehalem and Alsea basins, we showed that survival appears to be negatively correlated with flow in most releases, and in 2009 fork length was not correlated with survival. Our observations provide baseline information on factors that could influence smolt survival through the estuary as well as smolt to adult survival in these basins, and emphasize the importance of monitoring smolt survival in the estuary. © 2012 Springer Science+Business Media B.V. Source
Putman N.F.,Oregon State University |
Putman N.F.,National Oceanic and Atmospheric Administration |
Jenkins E.S.,Pacific Salmon Commission |
Michielsens C.G.J.,Pacific Salmon Commission |
And 2 more authors.
Journal of the Royal Society Interface | Year: 2014
Animals navigate using a variety of sensory cues, but how each is weighted during different phases of movement (e.g. dispersal, foraging, homing) is controversial. Here, we examine the geomagnetic and olfactory imprinting hypotheses of natal homing with datasets that recorded variation in the migratory routes of sockeye (Oncorhynchus nerka) and pink (Oncorhynchus gorbuscha) salmon returning from the Pacific Ocean to the Fraser River, British Columbia. Drift of the magnetic field (i.e. geomagnetic imprinting) uniquely accounted for 23.2% and 44.0% of the variation in migration routes for sockeye and pink salmon, respectively. Ocean circulation (i.e. olfactory imprinting) predicted 6.1% and 0.1% of the variation in sockeye and pink migration routes, respectively. Sea surface temperature (a variable influencing salmon distribution but not navigation, directly) accounted for 13.0% of the variation in sockeye migration but was unrelated to pink migration. These findings suggest that geomagnetic navigation plays an important role in long-distance homing in salmon and that consideration of navigation mechanisms can aid in the management of migratory fishes by better predicting movement patterns. Finally, given the diversity of animals that use the Earth's magnetic field for navigation, geomagnetic drift may provide a unifying explanation for spatio-temporal variation in the movement patterns of many species. © 2014 The Author(s) Published by the Royal Society. All rights reserved. Source
Billman E.J.,Oregon State University |
Whitman L.D.,U.S. Geological Survey |
Schroeder R.K.,U.S. Geological Survey |
Sharpe C.S.,U.S. Geological Survey |
And 4 more authors.
Journal of Fish Biology | Year: 2014
Body morphology of juvenile Chinook salmon Oncorhynchus tshawytscha in the upper Willamette River, Oregon, U.S.A., was analysed to determine if variation in body shape is correlated with migratory life-history tactics followed by juveniles. Body shape was compared between migrating juveniles that expressed different life-history tactics, i.e. autumn migrants and yearling smolts, and among parr sampled at three sites along a longitudinal river gradient. In the upper Willamette River, the expression of life-history tactics is associated with where juveniles rear in the basin with fish rearing in downstream locations generally completing ocean ward migrations earlier in life than fish rearing in upstream locations. The morphological differences that were apparent between autumn migrants and yearling smolts were similar to differences between parr rearing in downstream and upstream reaches, indicating that body morphology is correlated with life-history tactics. Autumn migrants and parr from downstream sampling sites had deeper bodies, shorter heads and deeper caudal peduncles compared with yearling smolts and parr from the upstream sampling site. This study did not distinguish between genetic and environmental effects on morphology; however, the results suggest that downstream movement of juveniles soon after emergence is associated with differentiation in morphology and with the expression of life-history variation. © 2014 The Fisheries Society of the British Isles. Source