Distinct patterns of inheritance shape life-history traits in steelhead trout.

Life-history variation is the raw material of adaptation, and understanding its genetic and environmental underpinnings is key to designing effective conservation strategies. We used large-scale genetic pedigree reconstruction of anadromous steelhead trout (Oncorhynchus mykiss) from the Russian River, CA, USA, to elucidate sex-specific patterns of life-history traits and their heritability. SNP data from adults returning from sea over a 14-year period were used to identify 13,474 parent-offspring trios.

Plasma proteomic profiling of bacterial cold water disease-resistant and -susceptible rainbow trout lines and biomarker discovery.

Genetic variation for disease resistance is present in salmonid fish; however, the molecular basis is poorly understood, and biomarkers of disease susceptibility/resistance are unavailable. Previously, we selected a line of rainbow trout for high survival following standardized challenge with (), the causative agent of bacterial cold water disease. The resistant line (ARS-Fp-R) exhibits over 60 percentage points higher survival compared to a reference susceptible line (ARS-Fp-S).

Cryopreservation effect on DNA methylation profile in rainbow trout spermatozoa.

Spermatozoa are the cells that are most commonly used for cryopreservation of valuable genetic resources in aquaculture. It is known that fish spermatozoa transmit to the embryo not only their genetic but also their epigenetic profile, especially DNA methylation. Therefore, any alteration of the DNA methylation profile in spermatozoa induces the risk of transmitting epigenetic alterations to the offspring.

Farm level bio-economic modelling of aquatic animal disease and health interventions.

A farm level bio-economic model, for aquatic animal production, of the relationships between inputs (e.g. purchased animals), outputs (e.

Cold-blooded vertebrates evolved organized germinal center-like structures.

Germinal centers (GCs) or analogous secondary lymphoid microstructures (SLMs) are thought to have evolved in endothermic species. However, living representatives of their ectothermic ancestors can mount potent secondary antibody responses upon infection or immunization, despite the apparent lack of SLMs in these cold-blooded vertebrates. How and where adaptive immune responses are induced in ectothermic species in the absence of GCs or analogous SLMs remain poorly understood.

Dietary Uptake of Highly Hydrophobic Chemicals by Rainbow Trout (Oncorhynchus Mykiss).

Rainbow trout (Oncorhynchus mykiss) was exposed through the diet to a mixture of non-ionic organic chemicals for 28 d, followed by a depuration phase, in accordance with OECD method 305. The mixture included hexachlorobenzene (HCB), 2,2',5,5'-tetrachlorobiphenyl (PCB-52), 2,2',5,5'-hexachlorobiphenyl (PCB-153), decachlorobiphenyl (PCB-209), decabromodiphenyl ether (BDE209), decabromodiphenyl ethane (DBDPE), bis-(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH), perchloro-p-terphenyl (p-TCP), perchloro-m-terphenyl (m-TCP), and perchloro-p-quaterphenyl (p-QTCP), the latter six of which are considered highly hydrophobic based on n-octanol/water partition coefficients (K) greater than 10. All chemicals had first-order uptake and elimination kinetics except p-QTCP, whose kinetics could not be verified due to limitations of analytical detection in the elimination phase.

Metagenomic and metabolomic analysis of changes in intestinal contents of rainbow trout () infected with infectious hematopoietic necrosis virus at different culture water temperatures.

Infectious hematopoietic necrosis (IHN) is a major disease that limits the culture of rainbow trout. In practical production, it has been found that the temperature of the culture water is a crucial factor affecting its mortality. Currently, little is known about how temperature affects the immune response of rainbow trout gut microbiota and metabolites to IHNV.

Stream hydrology and a pulse subsidy shape patterns of fish foraging.

Pulsed subsidy events create ephemeral fluxes of hyper-abundant resources that can shape annual patterns of consumption and growth for recipient consumers. However, environmental conditions strongly affect local resource availability for much of the year, and can heavily impact consumer foraging and growth patterns prior to pulsed subsidy events. Thus, a consumer's capacity to exploit pulse subsidy resources may be influenced by antecedent environmental conditions, but this has rarely been shown in nature and is unknown in aquatic ecosystems.

Septicemic Outbreak in A Rainbow Trout Intensive Aquaculture System: Clinical Finds, Etiological Agents, and Predisposing Factors.

On the 23rd of September 2022, a small intensive aquaculture unit populated with rainbow trout () reported increased mortality in adults and juvenile fish. The unit comprised 12 enclosed concrete basins with a capacity of ten cubic meters of water, populated with 150 kg of fish each. Fish were subjected to a clinical examination on the site, after which whole fish were harvested for a bacteriological and histopathological examination.

Characterization and Pathogenicity of Isolated from Rainbow Trout () in Korea.

is the causative agent of bacterial cold-water disease in salmonids and rainbow trout fry syndrome. This pathogen has attained a global presence and can spread both horizontally and vertically. However, it was not documented in Korea before September 2018.

L-methionine supplementation modulates IgM B cell responses in rainbow trout.

The interest in dietary amino acids (AAs) as potential immunomodulators has been growing the recent years, since specific AAs are known to regulate key metabolic pathways of the immune response or increase the synthesis of some immune-related proteins. Methionine, tryptophan and lysine are among the ten essential AAs for fish, meaning that they cannot be produced endogenously and must be provided through the diet. To date, although dietary supplementation of fish with some of these AAs has been shown to have positive effects on some innate immune parameters and disease resistance, the effects that these AAs provoke on cells of the adaptive immune system remained unexplored.

Environmental and biodiversity performance of a novel single cell protein for rainbow trout feed.

Seafood has an important role to play to achieve a sustainable food system that provides healthy food to a growing world population. Future seafood production will be increasingly reliant on aquaculture where feed innovation is essential to reduce environmental impacts and minimize feed and food competition. This study aimed to investigate whether a novel single cell protein feed ingredient based on Paecilomyces variotii grown on a side stream from the forest industry could improve environmental sustainability of farmed rainbow trout (Oncorhynchus mykiss) by replacing the soy protein concentrate used today.

Preliminary examination of sounds produced by Pacific salmon (Oncorhynchus spp.) during their fall spawning migrationa).

A preliminary description of sounds produced by three species of Pacific salmon was conducted to address the lack of quantified call characteristics in previous studies. Wild Chinook salmon (Oncorhynchus tshawytscha), pink salmon (O. gorbuscha), and coho salmon (O.

The first direct measurements of ventilatory flow and oxygen utilization after exhaustive exercise and voluntary feeding in a teleost fish, Oncorhynchus mykiss.

A new "less invasive" device incorporating an ultrasonic flow probe and a divided chamber, but no stitching of membranes to the fish, was employed to make the first direct measurements of ventilatory flow rate (V̇w) and % O utilization (%U) in juvenile rainbow trout (37 g, 8ºC) after exhaustive exercise (10-min chasing) and voluntary feeding (2.72% body mass ration). Under resting conditions, the allometrically scaled V̇w (300 ml kg min for a 37-g trout = 147 ml kg min for a 236-g trout exhibiting the same mass-specific O consumption rate, ṀO) and the convection requirement for O (CR = 4.

Evidence for infection influencing survival of the freshwater copepod Salmincola californiensis, a parasite of Pacific salmon and trout.

Objective: We explore apparent infection of Salmincola californiensis arising during investigations involving this lernaeopodid copepod parasitic on Pacific salmon and trout Oncorhynchus spp.

Methods: We noted occasional unusual coloration of adult female copepods collected from the wild. These females were bright blue and pink in contrast to the cream white coloration characteristic of the copepod.

Development of Fibro-PeN, a clinical prediction model for moderate-to-severe fibrosis in children with nonalcoholic fatty liver disease.

Background And Aims: Liver fibrosis is common in children with NAFLD and is an important determinant of outcomes. High-performing noninvasive models to assess fibrosis in children are needed. The objectives of this study were to evaluate the performance of existing pediatric and adult fibrosis prediction models and to develop a clinical prediction rule for identifying moderate-to-severe fibrosis in children with NAFLD.

Farmed fish welfare during slaughter in Italy: survey on stunning and killing methods and indicators of unconsciousness.

Information on slaughter procedures for farmed fish in aquaculture is limited, both in Europe and in Italy, due to a general lack of field data. The aim of this study was to gather information on the procedures used to slaughter fish in Italy and to discuss them considering the WOAH and EFSA recommendations on fish welfare. Using a questionnaire survey, data were collected by official veterinarians in 64 slaughtering facilities where 20 different species of fish were slaughtered.

High temperature stress induced oxidative stress, gut inflammation and disordered metabolome and microbiome in tsinling lenok trout.

Tsinling lenok trout (Brachymystax lenok tsinlingensis Li) is a species of cold-water salmon that faces serious challenges due to global warming. High temperature stress has been found to damage the gut integrity of cold-water fish, impacting their growth and immunity. However, limited research exists on the causal relationship between gut microbial disturbance and metabolic dysfunction in cold-water fish induced by high temperature stress.

Azithromycin reduces hemoglobin-induced innate neuroimmune activation.

Neonatal intraventricular hemorrhage (IVH) releases blood products into the lateral ventricles and brain parenchyma. There are currently no medical treatments for IVH and surgery is used to treat a delayed effect of IVH, post-hemorrhagic hydrocephalus. However, surgery is not a cure for intrinsic brain injury from IVH, and is performed in a subacute time frame.

Differences in Role and Support Between Volunteer and Paid Community Health Workers in the State of Nebraska.

Despite the growing importance of community health workers (CHWs) in public health, it has been difficult to characterize the roles and scope of services for this workforce in part because of the variability in the employment status of CHWs, ranging from full-time, part-time, to volunteer. Based on analysis of survey data from a statewide assessment of the CHW workforce in Nebraska (n = 142) conducted between 2019 and 2020, the proportions of CHWs who worked full-time, part-time, or volunteer were respectively 64%, 12%, and 21%. Over three quarters (76.

Migration patterns and navigation cues of Atlantic salmon post-smolts migrating from 12 rivers through the coastal zones around the Irish Sea.

The freshwater phase of the first seaward migration of juvenile Atlantic salmon (Salmo salar) is relatively well understood when compared with our understanding of the marine phase of their migration. In 2021, 1008 wild and 60 ranched Atlantic salmon smolts were tagged with acoustic transmitters in 12 rivers in England, Scotland, Northern Ireland and Ireland. Large marine receiver arrays were deployed in the Irish Sea at two locations: at the transition of the Irish Sea into the North Atlantic between Ireland and Scotland, and between southern Scotland and Northern Ireland, to examine the early phase of the marine migration of Atlantic salmon smolts.

Fish processing side streams are promising ingredients in diets for rainbow trout (Oncorhynchus mykiss) - Effects on growth physiology, appetite, and intestinal health.

Due to the growth of aquaculture and the finite supply of fishmeal and oil, alternative marine protein and lipid sources are highly sought after. Particularly promising is the use of side streams from the fish processing industry, allowing for the recovery and retention of otherwise lost nutrients in the food production chain. The aim of the present study was to evaluate the potential of three fish processing side streams as fish feed ingredients.

Behaviour of anadromous brown trout (Salmo trutta) in a hydropower regulated freshwater system.

Many Norwegian rivers and lakes are regulated for hydropower, which affects freshwater ecosystems and anadromous fish species, such as sea trout (Salmo trutta). Lakes are an important feature of many anadromous river systems. However, there is limited knowledge on the importance of lakes as habitat for sea trout and how hydropower affects the behaviour of sea trout in lakes.

Leached Compounds from Smoked Cigarettes and Their Potential for Bioaccumulation in Rainbow Trout ().

Cigarette butts are one of the most prevalent forms of litter worldwide and may leach toxic compounds when deposited in aquatic environments. Previous studies demonstrated that smoked cigarette leachate is toxic toward aquatic organisms. However, the specific bioavailable chemicals from the leachate and the potential for human and wildlife exposure through the food chain were unknown.

Effect of climate change on fillet quality and shelf-life of Oncorhynchus mykiss under controlled conditions.

Background: Temperature, which affects numerous physiological processes, has been described as the 'main ecological factor' for fish. The aim of this modeling study is to explore the impact of climate-induced temperature changes on fish fillet quality and shelf life.

Results: Temperature stress in rainbow trout affected ash and moisture, and inhibited myofibril fragmentation in the fillets.