Genetic Variation in Populations of Steelhead Trout (Salmo gairdneri) in British Columbia

1984 ◽  
Vol 41 (10) ◽  
pp. 1412-1420 ◽  
Author(s):  
Eric A. Parkinson
Keyword(s):  
British Columbia ◽  
Genetic Variants ◽  
Large Scale ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
Isolated Populations ◽  
Gene Frequencies ◽  
Geographic Scale ◽  
Biochemical Genetic ◽  
Pattern Of Variation

The geographic distributions of biochemical genetic variants at four loci in indigenous British Columbia steelhead (Salmo gairdneri) populations indicated that there was a large-scale subdivision of the species into three major groups. At intermediate geographic scales, gene frequencies were uniform over unexpectedly large areas, but at the smallest geographic scale, significant differentiation was observed between populations in adjacent streams. This pattern of variation supports the view that this species is subdivided into a large number of semi-isolated populations each having the potential to evolve adaptations to local environmental conditions.

Effect of Stocking Density on the Survival, Growth, and Dispersal of Steelhead Trout Fry (Salmo gairdneri)

1987 ◽  
Vol 44 (2) ◽  
pp. 271-281 ◽  
Author(s):  
Jeremy M. B. Hume ◽  
Eric A. Parkinson
Keyword(s):  
British Columbia ◽  
Overall Survival ◽  
Stocking Density ◽  
Mortality Rates ◽  
Wild Fish ◽  
Density Effect ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
Density Dependent ◽  
Coastal British Columbia

In a coastal British Columbia stream a stocking density of between 0.3 and 0.7 fry/m2 maximized the production of steelhead trout (Salmo gairdneri) parr and smolts. A severe autumn flood doubled the mortality rates of fry stocked at densities of 0.7 fry/m2 or higher but had little effect on fry stocked at lower densities (<0.15 fry/m2). Overall survival to smolts appeared to be lower than measured elsewhere for wild fish (2 vs. 4.5 – 18%). The proportion (<10%) of surviving fry found below the stocked sections was considered to be an indicator of potential displacement mortality in streams with no vacant downstream areas. This downstream dispersal was not density dependent and was small in comparison with the mortality of nondispersing fish. Although initial fry and parr sizes were density dependent, there was no detectable density effect on older parr or smolt sizes.

Kudoa thyrsites (Gilchrist, 1924) (Myxozoa) in the cardiac muscle of Pacific salmon (Oncorhynchus spp.) and steelhead trout (Salmo gairdneri)

1989 ◽  
Vol 67 (2) ◽  
pp. 341-342 ◽  
Author(s):  
Z. Kabata ◽  
D. J. Whitaker
Keyword(s):  
British Columbia ◽  
Cardiac Muscle ◽  
Pacific Salmon ◽  
Oncorhynchus Nerka ◽  
Salmo Gairdneri ◽  
Oncorhynchus Keta ◽  
Steelhead Trout ◽  
Myxozoan Parasite ◽  
Kudoa Thyrsites ◽  
Pacific Salmonids

An examination of the cardiac muscle of returning adults of all species of British Columbia Pacific salmonids, including steelhead trout (Salmo gairdneri), for infection by the myxozoan parasite Kudoa thyrsites showed that all species but chum (Oncorhynchus keta) and sockeye (Oncorhynchus nerka) are susceptible to infection. The prevalence of observed infection was low. Its intensity was not determined, but the small numbers of spores observed suggest that it was low. The possible causes of these observations are discussed.

Ceratomyxa shasta Noble, 1950 (Myxozoa: Myxosporea) present in the Fraser River system of British Columbia

1983 ◽  
Vol 61 (9) ◽  
pp. 1991-1994 ◽  
Author(s):  
T. E. McDonald
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Drainage Basin ◽  
Coho Salmon ◽  
Cutthroat Trout ◽  
River System ◽  
Salmo Gairdneri ◽  
Fraser River ◽  
Steelhead Trout

An examination of 220 chinook salmon (Oncorhynchus tshawytscha), 84 coho salmon (O. kisutch), 145 steelhead trout (Salmo gairdneri), and 21 cutthroat trout (S. clarki) for Ceratomyxa shasta (Myxozoa: Myxosporea) from 16 localities in the Fraser River drainage, British Columbia, showed that at all sites examined these salmonid species were infected, with a prevalence ranging between 11 and 100%. The study concludes that C. shasta, the causative agent of the salmonid disease ceratomyxosis, is widely distributed in the Fraser drainage basin and discusses these results in relation to proposed fish culture in the region.

Role of Off-Channel Ponds in the Life Cycle of Coho Salmon (Oncorhynchus kisutch) and Other Juvenile Salmonids in the Coldwater River, British Columbia

1989 ◽  
Vol 46 (2) ◽  
pp. 232-242 ◽  
Author(s):  
S. Swales ◽  
C. D. Levings
Keyword(s):  
British Columbia ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
River Population ◽  
Main Species ◽  
Main River ◽  
Density And Biomass

Off-channel ponds in the upper reaches of the Coldwater River, British Columbia, were major rearing areas for juvenile coho salmon (Oncorhynchus kisutch). Chinook salmon (Oncorhynchus tshawytscha), steelhead trout (Salmo gairdneri), and Dolly Varden char (Salvelinus malma) were generally scarce in the ponds, although they were numerous in the main river. Coho salmon were predominant at "natural" river sites while steelhead trout was the main species at sites with "rip-rap" bank stabilization. Catches of juvenile coho were much lower in the main river than in the ponds where they were the main species, and were more variable in the river. Population density and biomass estimates of juvenile coho in the ponds ranged from 0.100 fish∙m−2 and 1.00 g∙m−2 to 1.00 fish∙m−2 and 5.15 g∙m−2, compared with density estimates of 0.08–0.23 fish∙m−2 in the river. The coho population in the ponds consisted of 0+ and 1+ age-groups in similar proportions, while in the main river the 0+ age-group was much more abundant. The growth rate of coho in the ponds was faster than in the main river, with pond fish reaching mean lengths of 62–79 mm at the end of the first growing season, compared with 53 mm in the main river. Smolt outmigration from the main study pond occurred in late spring with peak outmigration in May and June coinciding with peak river discharge and increasing water temperatures in the main river and pond.

scholarly journals Variability in Life History Characteristics of Steelhead Trout (Salmo gairdneri) Along the Pacific Coast of North America

1966 ◽  
Vol 23 (3) ◽  
pp. 365-393 ◽  
Author(s):  
I. L. Withler
Keyword(s):  
British Columbia ◽  
Pacific Coast ◽  
Salt Water ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
Central California ◽  
Late Entry ◽  
Northern Areas ◽  
The Pacific ◽  
Variation Range

Steelhead enter spawning streams in the lower mainland of British Columbia throughout all months. Those ascending streams between November 1 and April 30 are termed "winter steelhead," while "summer steelhead" enter streams between May 1 and September 30. Cheakamus River is exceptional in that initial stream entry of winter steelhead is delayed until April 1, with most fish entering during April and May. Late entry is related to delayed freshet conditions within this stream. Almost twice as many female as male steelhead were angled. Comparison with trapping results suggests that sport fisheries select for females of anadromous rainbow trout populations. Repeat spawning of winter steelhead was found to range from 5.0% for fish from the Seymour River to 31.3% for Cheakamus River. Repeat spawning among summer steelhead ranged from 4.4% (Seymour River) to 6.3% (Coquihalla River). Mean fork lengths of populations of winter and summer steelhead showed little variation (range 26.3–31.0 inches). Winter steelhead from the Cheakamus River were larger than fish from all other populations while summer steelhead from the Coquihalla River had the least mean length. In general, mean fork lengths of winter and summer steelhead were not greatly different, despite the 5–8-month shorter term of saltwater residence of the latter. However, variations in mean lengths of steelhead between different river systems may result from differences in duration of saltwater residence since mean lengths of these populations did increase with longer saltwater residence. Steelhead spent from 1 to 4 years in fresh water and from 1 to 4 years in salt water.Along the Pacific coast from central California to southern British Columbia, timing of initial stream entry showed little variation. Sex ratios were nearly 1:1. Incidence of repeat spawning decreased from south to north. Mean fork lengths of steelhead populations were greater in northern areas where fish spent more years in fresh and more years in salt water.

An Evaluation of Morphometrics and Meristics for Stock Separation of Pacific Herring (Clupea harengus pallasi)

1984 ◽  
Vol 41 (3) ◽  
pp. 414-422 ◽  
Author(s):  
Hans Jürg Meng ◽  
Max Stocker
Keyword(s):  
British Columbia ◽  
Large Scale ◽  
Function Analysis ◽  
Clupea Harengus ◽  
Pacific Herring ◽  
Geographic Scale ◽  
Meristic Characters ◽  
Morphometric Characters ◽  
Strait Of Georgia ◽  
Clupea Harengus Pallasi

We conducted an analysis to determine if Pacific herring (Clupea harengus pallasi) stocks occurring in different localities in British Columbia waters could be separated using morphometric and meristic characters. Discriminant function analysis was applied to morphometric and meristic characters taken from food herring samples. Herring found in northern British Columbia waters were detectably different from those found in the Strait of Georgia. We recommend using meristic characters for separation on a broad geographic scale and using "best" morphometric characters for finer resolution within the established broader groups. We defined a set of 12 best morphometric characters for further large-scale studies.

A Note on Two Stocks of Steelhead Trout (Salmo gairdneri) in Capilano River, British Columbia

1960 ◽  
Vol 17 (5) ◽  
pp. 739-742 ◽  
Author(s):  
S. B. Smith
Keyword(s):  
British Columbia ◽  
Salmo Gairdneri ◽  
Steelhead Trout

not available

scholarly journals Large-Scale Adaptive Hitchhiking Upon High Recombination inDrosophila simulans

Genetics ◽  
2003 ◽  
Vol 165 (2) ◽  
pp. 895-900 ◽  
Author(s):  
Humberto Quesada ◽  
Ursula E M Ramírez ◽  
Julio Rozas ◽  
Montserrat Aguadé
Keyword(s):  
Genetic Linkage ◽  
Large Scale ◽  
Intermediate Frequency ◽  
Core Region ◽  
Adaptive Mutation ◽  
Nucleotide Variation ◽  
Extended Haplotype ◽  
Major Haplotype ◽  
Pattern Of Variation

AbstractNatural selection is expected to leave a characteristic footprint on neighboring nucleotide variation through the effects of genetic linkage. The size of the region affected is proportional to the strength of selection and greatly reduced with the recombinational distance from the selected site. Thus, the genomic footprint of selection is generally believed to be restricted to a small DNA stretch in normal and highly recombining regions. Here, we study the effect of selection on linked polymorphism (hitchhiking effect) by surveying nucleotide variation across a highly recombining ∼88-kb genomic fragment in an African population of Drosophila simulans. We find a core region of up to 38 kb with a major haplotype at intermediate frequency. The extended haplotype structure that gradually vanishes until disappearing is unusual for a highly recombining region. Both the presence in the structured genomic domain of a single major haplotype depleted of variability and the detected spatial pattern of variation along the ∼88-kb fragment are incompatible with neutral predictions in a panmictic population. A major role of demographic effects could also be discarded. The observed pattern of variation clearly provides evidence that directional selection has acted recently on this region, sweeping out variation around a strongly adaptive mutation. Our findings suggest a major role of positive selection in shaping DNA variability even in highly recombining regions.

scholarly journals Genetic Polymorphisms of Pharmacogenes among the Genetically Isolated Circassian Subpopulation from Jordan

2020 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Laith N. AL-Eitan ◽  
Doaa M. Rababa’h ◽  
Nancy M. Hakooz ◽  
Mansour A. Alghamdi ◽  
Rana B. Dajani
Keyword(s):  
Genetic Variants ◽  
Rare Variants ◽  
Optimal Dose ◽  
Nucleotide Polymorphisms ◽  
Treatment Efficiency ◽  
Isolated Populations ◽  
Single Nucleotide ◽  
Interindividual Variations ◽  
Different Populations ◽  
Pharmacogenomic Studies

Several genetic variants have been identified that cause variation among different populations and even within individuals of a similar descent. This leads to interindividual variations in the optimal dose of the drug that is required to sustain the treatment efficiency. In this study, 56 single nucleotide polymorphisms (SNPs) within several pharmacogenes were analyzed in 128 unrelated subjects from a genetically isolated group of Circassian people living in Jordan. We also compared these variant distributions to other ethnic groups that are available at two databases (Genome 1000 and eXAC). Our results revealed that the distribution of allele frequencies within genes among Circassians in Jordan showed similarities and disparities when compared to other populations. This study provides a powerful base for clinically relevant SNPs to enhance medical research and future pharmacogenomic studies. Rare variants detected in isolated populations can significantly guide to novel loci involved in the development of clinically relevant traits.

scholarly journals Large-Scale Evaluation of Genetic Variants in Candidate Genes for Colorectal Cancer Risk in the Nurses' Health Study and the Health Professionals' Follow-up Study

2008 ◽  
Vol 17 (2) ◽  
pp. 311-319 ◽  
Author(s):  
Aditi Hazra ◽  
Stephen Chanock ◽  
Edward Giovannucci ◽  
David G. Cox ◽  
Tianhua Niu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Risk ◽  
Candidate Genes ◽  
Health Professionals ◽  
Genetic Variants ◽  
Large Scale ◽  
Health Study ◽  
Scale Evaluation ◽  
Follow Up Study
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