Adaptive Variation in Rheotactic and Agonistic Behavior in Newly Emerged Fry of Chinook Salmon, Oncorhynchus tshawytscha, from Ocean- and Stream-Type Populations

1988 ◽  
Vol 45 (2) ◽  
pp. 237-243 ◽  
Author(s):  
Eric B. Taylor
Keyword(s):  
Life History ◽  
Chinook Salmon ◽  
Agonistic Behavior ◽  
Oncorhynchus Tshawytscha ◽  
Genetic Difference ◽  
Current Response ◽  
Body Morphology ◽  
Local Adaptations ◽  
Stream Type ◽  
Downstream Movement

Agonistic and rheotactic behavior and body morphology were compared in recently emerged, laboratory-reared chinook salmon (Oncorhynchus tshawytscha) from two "stream-type" and two "ocean-type" populations. Newly emerged chinook fry from the stream-type populations (Slim Creek and the Eagle River) were more aggressive than fry from the ocean-type populations (the Nanaimo and Harrison rivers). Slim Creek fry were consistently the most aggressive. There was no clear distinction in rheotactic behavior between stream- and ocean-type chinook; Harrison River, ocean-type chinook fry had the strongest downstream movement in "dark" current response tests, but fry from the other three populations had similar movement scores in both light and dark tests. Fry from the four populations were morphologically distinct; however, there was no clear separation in body morphology or coloration based on life history type. These differences exhibited in laboratory-reared fry indicate that they are, at least in part, inherited. I conclude that a fundamental genetic difference in agonistic behavior exists between stream- and ocean-type chinook juveniles. A genetic dichotomy between stream- and ocean-type chinook in rheotactic behavior and morphology, however, may be overidden by population-specific local adaptations, independent of life history type.

Individual variation in dispersal behaviour of newly emerged chinook salmon (Oncorhynchus tshawytscha) from the Upper Fraser River, British Columbia

1997 ◽  
Vol 54 (7) ◽  
pp. 1585-1592 ◽  
Author(s):  
M J Bradford ◽  
G C Taylor
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Population Variation ◽  
Fraser River ◽  
Movement Behaviour ◽  
Spawning Areas ◽  
Dispersal Distances ◽  
Stream Type ◽  
Downstream Movement

Immediately after emergence from spawning gravels, fry of stream-type chinook salmon (Oncorhynchus tshawytscha) populations from tributaries of the upper Fraser River, British Columbia, distribute themselves downstream from the spawning areas, throughout the natal stream, and into the Fraser River. We tested the hypothesis that this range in dispersal distances is caused by innate differences in nocturnal migratory tendency among individuals. Using an experimental stream channel, we found repeatable differences in downstream movement behaviour among newly emerged chinook fry. Fish that moved downstream were larger than those that held position in the channel. However, the incidence of downstream movement behaviours decreased over the first 2 weeks after emergence. We propose that the variation among individuals in downstream movement behaviour we observed leads to the dispersal of newly emerged fry throughout all available rearing habitats. Thus, between- and within-population variation in the freshwater life history observed in these populations may be caused by small differences in the behaviour of individuals.

Changes in life history parameters in a naturally spawning population of chinook salmon (Oncorhynchus tshawytscha) associated with releases of hatchery-reared fish

1997 ◽  
Vol 54 (6) ◽  
pp. 1235-1245 ◽  
Author(s):  
M J Unwin ◽  
G J Glova
Keyword(s):  
Life History ◽  
New Zealand ◽  
Chinook Salmon ◽  
Life History Traits ◽  
Oncorhynchus Tshawytscha ◽  
Fork Length ◽  
Age At Maturity ◽  
Natural Origin ◽  
Parent Stock ◽  
Stream Type

Chinook salmon (Oncorhynchus tshawytscha) spawning runs in Glenariffe Stream, New Zealand, exhibited significant changes in life history traits following supplementation releases of hatchery-reared juveniles. Total run strength did not change but the proportion of naturally produced fish declined to 34%. Attempts to separate spawners of natural and hatchery origin were unsuccessful, and 31-48% of natural spawners are now of hatchery origin. Hatchery males were smaller at age 2 and 3 than males of natural origin, and more often matured as jacks, producing an 86-mm decrease in mean fork length over 28 years. There was no change in length at age or age at maturity for female spawners. The proportion of jacks entering Glenariffe Stream each year was positively correlated with the proportion of jacks in the ensuing cohort. Most differences between fish of natural and hatchery origin were related to hatchery rearing practices, but the decline in age at maturity among naturally produced males appears to reflect traits inherited from parent stock of hatchery origin. Hatchery releases may also favour the survival of ocean-type fry over stream-type fry, possibly reversing a tendency for stream-type behaviour to evolve in response to the lack of estuaries on most New Zealand chinook salmon rivers.

Life History of Juvenile Ocean-type Chinook Salmon (Oncorhynchus tshawytscha) in the Situk River, Alaska

1992 ◽  
Vol 49 (12) ◽  
pp. 2621-2629 ◽  
Author(s):  
S. W. Johnson ◽  
J. F. Thedinga ◽  
K. V. Koski
Keyword(s):  
Life History ◽  
Chinook Salmon ◽  
Habitat Preference ◽  
Oncorhynchus Tshawytscha ◽  
Fork Length ◽  
Main Stem ◽  
Seawater Tolerance ◽  
History Of ◽  
Two Phases ◽  
Stream Type

Distribution, abundance, habitat preference, migration and residence timing, seawater tolerance, and size were determined for juvenile ocean-type (age 0) chinook salmon (Oncorhynchus tshawytscha) in the Situk River, Alaska. Chinook primarily occupied main-stem habitats (channel edges in spring, pools and willow edges in summer). Peak chinook densities in the upper and lower main stem were 96 and 76 fish/100 m2, respectively. Chinook migrated downstream in two phases: a spring dispersal of emergent fry and a summer migration. Chinook marked in the upper river in late June and early July were recaptured 20 km downstream in the lower river in late July. Marked chinook resided in the lower river up to 34 d. Mean fork length of chinook in the lower river increased from 40 mm in May to 80 mm in early August. By late August, chinook had emigrated from the lower river at a size of approximately 80 mm. Fish this size were seawater tolerant and had the physical appearance of smolts. Ocean-type chinook in the Situk River are unique because in most Alaskan streams, chinook are stream-type (rear in freshwater at least 1 yr).

Current Response and Agonistic Behavior in Newly Emerged Fry of Chinook Salmon, Oncorhynchus tshawytscha, from Ocean- and Stream- Type Populations

1986 ◽  
Vol 43 (3) ◽  
pp. 565-573 ◽  
Author(s):  
Eric B. Taylor ◽  
P. A. Larkin
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
River Estuary ◽  
Early Summer ◽  
Mirror Image ◽  
Current Response ◽  
Fraser River ◽  
Life History Pattern ◽  
Stream Type

In Slim Creek, a tributary to the upper Fraser River east of Prince George, B.C., chinook salmon (Oncorhynchus tshawytscha) fry summer and overwinter in their natal stream before migrating seaward as yearlings; they are "stream-type" in juvenile life history pattern. From the Harrison River, a tributary to the lower Fraser River, chinook fry migrate to the Fraser River estuary sometime during their first spring or early summer; they are "ocean-type." Newly emerged chinook fry from Slim Creek showed a stronger positive current response, were more aggressive in mirror image stimulation tests and intra- and inter-specific (with coho salmon (O. kisutch) fry) stream tank tests, and had larger and more brightly colored median fins than chinook fry from the Harrison River. These differences between Slim Creek and Harrison River chinook fry are in a direction consistent with their different patterns of length of freshwater residence as juveniles, since aggressive behavior, positive rheotaxis, and bright fin coloration are important components of extended stream residence in salmonids.

Rates of straying by hatchery-produced Pacific salmon (Oncorhynchus spp.) and steelhead (Oncorhynchus mykiss) differ among species, life history types, and populations

2013 ◽  
Vol 70 (5) ◽  
pp. 735-746 ◽  
Author(s):  
Peter A.H. Westley ◽  
Thomas P. Quinn ◽  
Andrew H. Dittman
Keyword(s):  
Life History ◽  
Oncorhynchus Mykiss ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Upstream Migration ◽  
Endocrine Factors ◽  
Species Specific ◽  
Stream Type

Here we ask whether straying differs among species, life history types, and populations of adult hatchery-produced Pacific salmon (Oncorhynchus spp.) and steelhead (Oncorhynchus mykiss) in the Columbia River basin. Previous estimates of straying have been confounded by various factors influencing the probability of individuals returning to non-natal sites (e.g., off-station releases), whereas analyses undertaken here of nearly a quarter million coded-wire tag recoveries control for these factors. Our results revealed large and generally consistent differences in the propensity to stray among species, life history types within species, and populations. Paired releases indicated that (i) Chinook salmon (Oncorhynchus tshawytscha) strayed more (mean population range 0.11%–34.6%) than coho salmon (Oncorhynchus kisutch) (0.08%–0.94%); (ii) ocean-type Chinook (5.2%–18.6%) strayed more than stream-type Chinook (0.11%–10%); and Chinook salmon (0.90%–54.9%) strayed more than steelhead (0.30%–2.3%). We conclude these patterns are largely the result of species-specific behavioral and endocrine factors during the juvenile life stages, but analyses also suggest that environmental factors can influence straying during the adult upstream migration.

Differences in Enzyme Frequency and Body Morphology among Three Juvenile Life History Types of Chinook Salmon (Oncorhynchus tshawytscha) in the Nanaimo River, British Columbia

1984 ◽  
Vol 41 (7) ◽  
pp. 1070-1077 ◽  
Author(s):  
L. M. Carl ◽  
M. C. Healey
Keyword(s):  
Genetic Variation ◽  
Life History ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
High Salinity ◽  
Salt Water ◽  
Salinity Adaptation ◽  
Significant Excess ◽  
Body Morphology ◽  
Seaward Migration

Chinook salmon (Oncorhynchus tshawytscha), in the Nanaimo River and elsewhere, exhibit three juvenile life history types characterized by different ages at seaward migration. One type migrates to sea immediately after emergence from the spawning gravel and rears in high-salinity estuarine habitats, a second migrates seaward after rearing for about 2 mo in freshwater, and a third type after rearing for a year in freshwater. Nanaimo River chinook were polymorphic at 10 of 31 loci examined electrophoretically. The frequency of allozymes differed significantly among the three life history types at 4 of the 10 loci. A significant deficiency of heterozygotes at the locus for PMI-2 characterized juveniles that reared in estuarine habitats. Fry that died on transfer to salt water in the laboratory had a significant excess of PMI-2 heterozygotes, suggesting that this locus may be associated with salinity adaptation. The three life history types also differed significantly in body morphology. Fish that reared in the estuary had slimmer bodies, smaller heads, and shorter fins than those that reared in the river. Those that spent a year in freshwater had the largest heads, deepest bodies, and longest fins. These observations corroborate the hypothesis that the three life history types represent genetically isolated subpopulations that appear to be physically adapted to their rearing environment. Current plans to increase the numbers of chinook available to commercial and recreational fishermen through artificial propagation of chinook must be made compatible with this degree of genetic variation.

Precocial male maturation in laboratory-reared populations of chinook salmon, Oncorhynchus tshawytscha

1989 ◽  
Vol 67 (7) ◽  
pp. 1665-1669 ◽  
Author(s):  
Eric B. Taylor
Keyword(s):  
Life History ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Evolutionary Ecology ◽  
Migration Distance ◽  
Pacific Salmonids

The incidence of precocial male maturation in yearling chinook salmon, Oncorhynchus tshawytscha, was examined in four laboratory-reared populations. Slim Creek and Bowron River chinook salmon were about 4 weeks older than Harrison and Nanaimo river chinook salmon when sampled (14 vs. 13 months of age), but were also 20–40 g smaller. Approximately 29, 12, 0, and 0% of all males were precocious in Bowron River, Slim Creek, Harrison River, and Nanaimo River chinook salmon, respectively. Precocial male chinook salmon had gonadosomatic indices of about 5–6%, whereas immature salmon from all populations had indices under 1%. Precocial male chinook salmon were more robust bodied than immature salmon; precocial males had deeper bodies, deeper heads, and larger adipose fins. Variation among the study populations in the incidence of precocial male maturation may be related to differences among the populations in migration distance to the sea or in juvenile freshwater rearing life history. The chinook salmon would probably be a productive species with which to study the evolutionary ecology of precocial maturity in Pacific salmonids.

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