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.

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.

Food and Habitat Utilization by Juvenile Salmonids in the Campbell River Estuary

1987 ◽  
Vol 44 (6) ◽  
pp. 1233-1246 ◽  
Author(s):  
J. Stevenson Macdonald ◽  
I. K. Birtwell ◽  
G. M. Kruzynski
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Saline Water ◽  
Salt Water ◽  
River Estuary ◽  
Stomach Contents ◽  
Water Velocity ◽  
Interspecific Differences ◽  
Marine Influence ◽  
Outer Estuary

Salmonid behaviour and abundance in several microhabitats within the Campbell River estuary was observed monthly, from May to July, by divers using snorkels and face masks. Concurrent vertical profiles of physical and biological parameters at each microhabitat were taken to characterize habitats frequented by the fish. Data were collected at high and low tide to record behavioural reactions to changes in water velocity, salinity, and temperature associated with tidal height and salt wedge intrusion. Samples of plankton collected at each microhabitat were compared with stomach contents of salmonids caught nearby to determine if interspecific differences in diet could be correlated with differences in the habitats they occupied. Fish occurred in loose assemblages, aligned with the current, feeding near estuarine banks. As water velocities increased with the ebbing tide, the fish concentrated in a shear region near the mouth of a slough and behind large rocks and submerged vegetation. At both high and low tide, larger coho (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha) (usually hatchery reared) were in deeper, frequently more saline water and further from shore than the smaller conspecifics. Hatchery chinook, however, were also seen in sloughs where water velocity was low. Marine influence as reflected in plankton composition and salmonid diet was greater in the outer estuary and in the deep salt water that intrudes the inner regions of the estuary. Differences in the habitats occupied by the fish were reflected in differences in their diets.

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.

Sperm traits in Chinook salmon depend upon activation medium: implications for studies of sperm competition in fishes

2009 ◽  
Vol 87 (10) ◽  
pp. 920-927 ◽  
Author(s):  
P. Rosengrave ◽  
R. Montgomerie ◽  
V. J. Metcalf ◽  
K. McBride ◽  
N. J. Gemmell
Keyword(s):  
Sperm Competition ◽  
Fresh Water ◽  
Swimming Speed ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Salt Water ◽  
Computer Assisted ◽  
Ovarian Fluid ◽  
Sperm Swimming Speed ◽  
Sperm Traits

Sperm traits of externally fertilizing fish species are typically measured in fresh (or salt) water, even though the spawning environment of their ova contains ovarian fluid. In this study, we measured sperm traits of Chinook salmon ( Oncorhynchus tshawytscha (Walbaum in Artedi, 1792)) in both fresh water and dilute ovarian fluid at 10 and 20 s postactivation, using a computer-assisted sperm analysis system. Spermatozoa swam faster, and had both higher percent motility and a straighter path trajectory for a longer period of forward motility when activated in ovarian fluid compared with activation in fresh water. Comparing sperm activity of 10 males in water versus ovarian fluid, we found a weak but significant correlation for sperm swimming speed at 10 s postactivation (r = 0.34, p = 0.01), but not for any other sperm traits measured. Most important, across males, mean sperm swimming speed in water accounted for <10% of the observed variation in mean sperm swimming speed in ovarian fluid. Thus, we argue that sperm traits measured in fresh water are not particularly relevant to those same traits during normal spawning in this species. We suggest that sperm performance measured in fresh water should be used with caution when comparing the potential for individual males to fertilize ova, especially in studies of sperm competition in externally fertilizing species.

scholarly journals Correlated contemporary evolution of life history traits in New Zealand Chinook salmon, Oncorhynchus tshawytscha

Heredity ◽  
2011 ◽  
Vol 106 (3) ◽  
pp. 448-459 ◽  
Author(s):  
M T Kinnison ◽  
T P Quinn ◽  
M J Unwin
Keyword(s):  
Life History ◽  
New Zealand ◽  
Chinook Salmon ◽  
Life History Traits ◽  
Oncorhynchus Tshawytscha ◽  
Contemporary Evolution ◽  
Evolution Of Life

scholarly journals Juvenile life-history diversity and population stability of spring Chinook salmon in the Willamette River basin, Oregon

2016 ◽  
Vol 73 (6) ◽  
pp. 921-934 ◽  
Author(s):  
R. Kirk Schroeder ◽  
Luke D. Whitman ◽  
Brian Cannon ◽  
Paul Olmsted
Keyword(s):  
Life History ◽  
River Basin ◽  
Chinook Salmon ◽  
Life Histories ◽  
Oncorhynchus Tshawytscha ◽  
Juvenile Salmon ◽  
Population Stability ◽  
Willamette River ◽  
June July ◽  
Willamette River Basin

Migratory and rearing pathways of juvenile spring Chinook salmon (Oncorhynchus tshawytscha) were documented in the Willamette River basin to identify life histories and estimate their contribution to smolt production and population stability. We identified six primary life histories that included two phenotypes for early migratory tactics: fry that migrated up to 140–200 km shortly after emergence (movers) and fish that reared for 8–16 months in natal areas (stayers). Peak emigration of juvenile salmon from the Willamette River was in June–July (subyearling smolts), March–May (yearling smolts), and November–December (considered as “autumn smolts”). Alternative migratory behaviors of juvenile salmon were associated with extensive use of diverse habitats that eventually encompassed up to 400 rkm of the basin, including tributaries in natal areas and large rivers. Juvenile salmon that reared in natal reaches and migrated as yearlings were the most prevalent life history and had the lowest temporal variability. However, the total productivity of the basin was increased by the contribution of fish with dispersive life histories, which represented over 50% of the total smolt production. Life-history diversity reduced the variability in the total smolt population by 35% over the weighted mean of individual life histories, providing evidence of a considerable portfolio effect through the asynchronous contributions of life histories. Protecting and restoring a diverse suite of connected habitats in the Willamette River basin will promote the development and expression of juvenile life histories, thereby providing stability and resilience to native salmon populations.

Smolt Transformation and Seaward Migration in 0-Age Progeny of Adult Spring Chinook Salmon (Oncorhynchus tshawytscha) Matured Early with Photoperiod Control

1986 ◽  
Vol 43 (4) ◽  
pp. 885-888 ◽  
Author(s):  
W. S. Zaugg ◽  
J. E. Bodle ◽  
J. E. Manning ◽  
E. Wold
Keyword(s):  
Atpase Activity ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Seaward Migration ◽  
And Behavior ◽  
Photoperiod Control

Maturation of hatchery-held adult spring-run chinook salmon (Oncorhynchus tshawytscha) was accelerated by decreasing photoperiods. Spawning occurred 1 mo earlier than with nontreated fish. Because of early hatching, progeny from the photoperiod regulated adults were larger and exhibited signs of parr–smolt transformation such as changes in coloration and behavior, elevation of gill Na+-K+ ATPase activity, and active seaward migration at age 0, nearly 1 yr prior to usual releases of juveniles from normally spawned adults.

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