scholarly journals Steelhead ( Oncorhynchus mykiss ) lineages and sexes show variable patterns of association of adult migration timing and age‐at‐maturity traits with two genomic regions

2020 ◽  
Vol 13 (10) ◽  
pp. 2836-2856
Author(s):  
Stuart C. Willis ◽  
Jon E. Hess ◽  
Jeff K. Fryer ◽  
John M. Whiteaker ◽  
Chris Brun ◽  
...  
Keyword(s):  
Oncorhynchus Mykiss ◽  
Age At Maturity ◽  
Migration Timing ◽  
Genomic Regions

scholarly journals Genetic coupling of life-history and aerobic performance in juvenile Atlantic salmon

2021 ◽  
Author(s):  
Jenni M. Prokkola ◽  
Eirik R Åsheim ◽  
Sergey Morozov ◽  
Paul Bangura ◽  
Jaakko Erkinaro ◽  
...  
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Metabolic Rate ◽  
Aerobic Performance ◽  
Age At Maturity ◽  
Life History Variation ◽  
Early Maturation ◽  
Genomic Regions ◽  
Late Maturation

1. The physiological underpinnings of life history adaptations in ectotherms are not well understood. Theories suggest energy metabolism influences life history variation via modulation of resource acquisition. However, the genetic basis of this relation and its dependence on ecological conditions, such as food availability, have rarely been characterized, despite being critical to predicting the responses of populations to environmental changes. 2. The Atlantic salmon (Salmo salar) is an emerging wild model species for addressing these questions; strong genetic determination of age-at-maturity at two unlinked genomic regions (vgll3 and six6) enables the use of complex experimental designs and tests of hypotheses on the physiological and genetic basis of life-history trait variation. 3. In this study, we crossed salmon to obtain individuals with all combinations of late and early maturation genotypes for vgll3 and six6 within full-sib families. Using more than 250 juveniles in common garden conditions, we tested (i) whether metabolic phenotypes (i.e., standard and maximum metabolic rates, and absolute aerobic scope) were correlated with the age-at-maturity genotypes and (ii) if high vs. low food availability modulated the relationship. 4. We found that salmon with vgll3 early maturation genotype had a higher aerobic scope and maximum metabolic rate, but not standard metabolic rate, compared to salmon with vgll3 late maturation genotype. This suggests that physiological or structural pathways regulating maximum oxygen supply or demand are potentially important for the determination of age-at-maturity in Atlantic salmon. 5. Vgll3 and six6 exhibited physiological epistasis, whereby maximum metabolic rate significantly decreased when late maturation genotypes were present concurrently in both loci compared to other genotype combinations. 6. The growth of the feed restricted group decreased substantially compared to the high food group. However, the effects of life-history genomic regions were similar in both feeding regimes, indicating a lack of genotype-by-environment interactions. 7. Our results indicate that aerobic performance of juvenile salmon may affect their age-at-maturity. The results may help to better understand the mechanistic basis of life-history variation, and the metabolic constrains on life-history evolution.

The influences of pre- and post-smolt captive rearing environments on growth, maturation, body size, and reproductive success of steelhead (Oncorhynchus mykiss) released as adults.

2021 ◽  
Author(s):  
Donald M Van Doornik ◽  
Barry A Berejikian ◽  
Megan E Moore ◽  
Andrew Claiborne ◽  
Mark Downen ◽  
...  
Keyword(s):  
Body Size ◽  
Reproductive Success ◽  
Oncorhynchus Mykiss ◽  
Age Differences ◽  
Survival Rates ◽  
Fish Population ◽  
Age At Maturity ◽  
Female Body Size ◽  
Rearing Conditions ◽  
Hatchery Program

Conservation hatcheries designed to aid in recovery of imperiled fish population often implement atypical rearing and release strategies. We evaluated a conservation hatchery program for steelhead (Oncorhynchus mykiss) that hydraulically removed naturally spawned eggs, and captively reared them in different freshwater hatcheries to the smolt stage, and reared smolts in both freshwater and seawater to sexual maturity, before releasing the sexually maturing adults onto the spawning grounds. The adult steelhead added to the spawning population, accounting for most of the adults observed during snorkel observations. They produced 32% of the juvenile offspring sampled, and females were 2.9 times more successful than males. Reproductive success was positively correlated with female body size, which was influenced by pre-smolt and post-smolt rearing conditions and their effects on growth rate and age-at-maturity. Juvenile offspring of the released adults showed size and age differences from offspring of naturally returning steelhead, but exhibited very similar early marine survival rates.

Behavioral thermoregulation and associated mortality trade-offs in migrating adult steelhead (Oncorhynchus mykiss): variability among sympatric populations

2009 ◽  
Vol 66 (10) ◽  
pp. 1734-1747 ◽  
Author(s):  
Matthew L. Keefer ◽  
Christopher A. Peery ◽  
Brett High
Keyword(s):  
Oncorhynchus Mykiss ◽  
Columbia River ◽  
Main Stem ◽  
Behavioral Thermoregulation ◽  
Temperature Threshold ◽  
Sympatric Populations ◽  
Thermal Refugia ◽  
Migration Timing ◽  
Trade Offs ◽  
Physiological Benefits

We used radiotelemetry to assess thermoregulatory behaviors for 14 populations (n = 3985) of adult summer steelhead ( Oncorhynchus mykiss ) as they passed through the Columbia River migration corridor. Steelhead use of small cool-water tributaries (“thermal refugia”) rapidly increased when the Columbia River reached a temperature threshold of about 19 °C. When main stem temperatures were warmest (i.e., >21 °C), more than 70% of the tagged fish used refugia sites and these fish had median refugia residence times of 3–4 weeks. Thermoregulatory responses were similar across populations, but there were large among-population differences in the incidence and duration of refugia use likely linked to population-specific migration timing patterns. In survival analyses using 1285 known-origin steelhead, fish that used thermal refugia were significantly less likely to survive to natal basins, were harvested at relatively high rates in refugia tributaries, and had greater unknown mortality in the main stem. These results highlight the trade-off between the presumed physiological benefits of thermal refugia use and a likely increase in harvest and other mortality risks that arise when preferred thermal habitats are severely constricted.

scholarly journals Growth genes are implicated in the evolutionary divergence of sympatric piscivorous and insectivorous rainbow trout (Oncorhynchus mykiss)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jared A. Grummer ◽  
Michael C. Whitlock ◽  
Patricia M. Schulte ◽  
Eric B. Taylor
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Large Body ◽  
Population Divergence ◽  
Phenotypic Traits ◽  
Evolutionary Divergence ◽  
Metabolic Rates ◽  
Genomic Divergence ◽  
Kootenay Lake ◽  
Genomic Regions

Abstract Background Identifying ecologically significant phenotypic traits and the genomic mechanisms that underly them are crucial steps in understanding traits associated with population divergence. We used genome-wide data to identify genomic regions associated with key traits that distinguish two ecomorphs of rainbow trout (Oncorhynchus mykiss)—insectivores and piscivores—that coexist for the non-breeding portion of the year in Kootenay Lake, southeastern British Columbia. “Gerrards” are large-bodied, rapidly growing piscivores with high metabolic rates that spawn north of Kootenay Lake in the Lardeau River, in contrast to the insectivorous populations that are on average smaller in body size, with lower growth and metabolic rates, mainly forage on aquatic insects, and spawn in tributaries immediately surrounding Kootenay Lake. We used pool-seq data representing ~ 60% of the genome and 80 fish per population to assess the level of genomic divergence between ecomorphs and to identify and interrogate loci that may play functional or selective roles in their divergence. Results Genomic divergence was high between sympatric insectivores and piscivores ($$F_{\text{ST}}$$ F ST = 0.188), and in fact higher than between insectivorous populations from Kootenay Lake and the Blackwater River ($$F_{\text{ST}}$$ F ST = 0.159) that are > 500 km apart. A window-based $$F_{\text{ST}}$$ F ST analysis did not reveal “islands” of genomic differentiation; however, the window with highest $$F_{\text{ST}}$$ F ST estimate did include a gene associated with insulin secretion. Although we explored the use of the “Local score” approach to identify genomic outlier regions, this method was ultimately not used because simulations revealed a high false discovery rate (~ 20%). Gene ontology (GO) analysis identified several growth processes as enriched in genes occurring in the ~ 200 most divergent genomic windows, indicating many loci of small effect involved in growth and growth-related metabolic processes are associated with the divergence of these ecomorphs. Conclusion Our results reveal a high degree of genomic differentiation between piscivorous and insectivorous populations and indicate that the large body piscivorous phenotype is likely not due to one or a few loci of large effect. Rather, the piscivore phenotype may be controlled by several loci of small effect, thus highlighting the power of whole-genome resequencing in identifying genomic regions underlying population-level phenotypic divergences.

scholarly journals Single-step genome-wide association study for resistance toPiscirickettsia salmonisin rainbow trout (Oncorhynchus mykiss)

2019 ◽  
Author(s):  
Rodrigo Marín-Nahuelpi ◽  
Agustín Barría ◽  
Pablo Cáceres ◽  
María E. López ◽  
Liane N. Bassini ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Candidate Genes ◽  
Genetic Improvement ◽  
Genetic Variance ◽  
Snp Array ◽  
Single Step ◽  
Genome Wide Association ◽  
Genome Wide ◽  
Genomic Regions

ABSTRACTOne of the main pathogens affecting rainbow trout (Oncorhynchus mykiss) farming is the facultative intracellular bacteriaPiscirickettsia salmonis. Current treatments, such as antibiotics and vaccines, have not had the expected effectiveness in field conditions. Genetic improvement by means of selection for resistance is proposed as a viable alternative for control. Genomic information can be used to identify the genomic regions associated with resistance and enhance the genetic evaluation methods to speed up the genetic improvement for the trait. The objectives of this study were to i) identify the genomic regions associated with resistance toP. salmonis; and ii) identify candidate genes associated with the trait. We experimentally challenged 2,130 rainbow trout withP. salmonisand genotyped them with a 57 K SNP array. Resistance toP. salmoniswas defined as time to death (TD) and as binary survival (BS). Significant heritabilities were estimated for TD and BS (0.48 ± 0.04 and 0.34 ± 0.04, respectively). A total of 2,047 fish and 26,068 SNPs passed quality control for samples and genotypes. Using a single-step genome wide association analysis (ssGWAS) we identified four genomic regions explaining over 1% of the genetic variance for TD and three for BS. Interestingly, the same genomic region located onOmy27was found to explain the highest proportion of genetic variance for both traits (2.4 and 1.5% for TD and BS, respectively). The identified SNP in this region is located within an exon of a gene related with actin cytoskeletal organization, a protein exploited byP. salmonisduring infection. Other important candidate genes identified are related with innate immune response and oxidative stress. The moderate heritability values estimated in the present study show it is possible to improve resistance toP. salmonisthrough artificial selection in the current rainbow trout population. Furthermore, our results suggest a polygenic genetic architecture and provide novel insights into the candidate genes underpinning resistance toP. salmonisinO. mykiss.

Relationship between smolt gill Na+, K+ ATPase activity and migration timing to avian predation risk of steelhead trout (Oncorhynchus mykiss) in a large estuary

2007 ◽  
Vol 64 (11) ◽  
pp. 1506-1516 ◽  
Author(s):  
Benjamen M Kennedy ◽  
William L Gale ◽  
Kenneth G Ostrand
Keyword(s):  
Atpase Activity ◽  
Oncorhynchus Mykiss ◽  
Predation Risk ◽  
Steelhead Trout ◽  
Avian Predation ◽  
Pit Tags ◽  
Migration Timing ◽  
Hatchery Fish ◽  
And Migration ◽  
Seawater Challenge

We examined avian predation risk of juvenile steelhead trout (Oncorhynchus mykiss) migrating through the Columbia River Estuary in relation to their osmoregulatory physiology, body length, rearing conditions (hatchery or wild), migration timing, and migration year. From 2003 to 2006, mean gill Na+, K+ ATPase activity of migrating wild steelhead was greater than hatchery steelhead. Hatchery steelhead were always longer than wild steelhead. Wild steelhead never had higher plasma [Na+] or osmolality levels than hatchery fish after seawater challenge trials conducted in 2004, 2005, and 2006. More passive integrated transponder (PIT) tags from hatchery fish (19%; 126 of 678 fish) were detected on East Sand Island among bird nesting colonies than PIT tags of wild fish (14%; 70 of 509 fish), presumably consumed by birds. As gill Na+, K+ ATPase activity and migration date within a year increased, the probability of an individual fish being eaten by an avian predator decreased. Length, rear type, and year were not related to predation risk. These results show that physiology and migration timing of juvenile steelhead play an important role in a migrant’s risk to avian predation within an estuary.

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