Search results for "Salmon"
showing 10 items of 354 documents
Selection on fish personality differs between a no-take marine reserve and fished areas
2021
9 pages, 2 tables, 3 figures.-- This is an open access article under the terms of the Creative Commons Attribution License
Short sea migration and precocious maturation in reared Atlantic salmon post-smolts in the northern Baltic Sea
2017
Abstract Atlantic salmon (Salmo salar L.) display significant variation in life history traits, including migration patterns and age at maturity. Hatchery rearing has been shown to affect the life history, and rearing-induced changes may include unfavourable consequences, e.g. shortened sea migration period and smaller size at maturity. We report on a new phenomenon of life history of reared Atlantic salmon in the Baltic Sea area: small-sized salmon returning to freshwater only a few months after release as smolts. These “one-sea-summer (1SS)” salmon were ca. 35 cm in length and weighed ca. 400 g, being clearly larger than smolts, but substantially smaller than one-sea-winter (1SW) salmon f…
Influence of warming temperatures on coregonine embryogenesis within and among species
2021
The greatest response of lakes to climate change has been the increase in water temperatures on a global scale. The responses of many lake fishes to warming water temperatures are projected to be inadequate to counter the speed and magnitude of climate change, leaving some species vulnerable to decline and extinction. We experimentally evaluated the responses of embryos from a group of cold, stenothermic fishes (Salmonidae Coregoninae) - within conspecifics across lake systems, between congeners within the same lake system, and among congeners across lake systems - to a thermal gradient using an incubation method that enabled global comparisons. Study groups included cisco (Coregonus artedi…
Migration strategies of brown trout (Salmo trutta) in a subarctic river system as revealed by stable isotope analysis
2018
We estimated the proportions of anadromous and freshwater‐resident brown trout (Salmo trutta) in different parts of the subarctic River Näätämöjoki/Neidenelva system (Finland and Norway) using carbon, nitrogen and hydrogen stable isotope analyses of archived scales as identifiers of migration strategy. Our results showed that carbon stable isotope values were the best predictor of migration strategy. Most individuals fell into two clearly distinct groups representing anadromous (47%) or freshwater‐resident (42%) individuals, but some fish had intermediate carbon values suggesting repeated movement between freshwater and the sea. The proportion of anadromous individuals decreased steadily wi…
Species interactions, environmental gradients and body size shape population niche width
2021
1. Competition for shared resources is commonly assumed to restrict population-level niche width of coexisting species. However, the identity and abundance of coexisting species, the prevailing environmental conditions, and the individual body size may shape the effects of interspecific interactions on species’ niche width. 2. Here we study the effects of interspecific and intraspecific interactions, lake area and altitude, and fish body size on the trophic niche width and resource use of a generalist predator, the littoral-dwelling large, sparsely rakered morph of European whitefish (Coregonus lavaretus; hereafter LSR whitefish). We use stable isotope, diet and survey fishing data from 14 …
Typhoid Fever
2008
Typhoid fever continues to be a serious public health problem, with approximately 22. million cases and more than 200. 000 deaths globally. The disease is most often acquired by ingestion of food or water contaminated by the feces and less frequently by urine or vomitus of patients and carriers. Prolonged low-grade fever, headache, dry cough, alterations of bowel habits, coated tongue, and rose spots are the typical clinical features. Definitive diagnosis requires the isolation of Salmonella enterica serovar Typhi. Supportive serological tests are also used. First-choice antibiotic treatment includes fluoroquinolones or third-generation cephalosporins and reduces the mortality rate from 20%…
Protective Effect of Cactus Cladode Extracts on Peroxisomal Functions in Microglial BV-2 Cells Activated by Different Lipopolysaccharides
2017
International audience; In this study, we aimed to evaluate the antioxidant and anti-inflammatory properties of Opuntia ficus-indica cactus cladode extracts in microglia BV-2 cells. Inflammation associated with microglia activation in neuronal injury can be achieved by LPS exposure. Using four different structurally and biologically well-characterized LPS serotypes, we revealed a structure-related differential effect of LPS on fatty acid β-oxidation and antioxidant enzymes in peroxisomes: Escherichia coli-LPS decreased ACOX1 activity while Salmonella minnesota-LPS reduced only catalase activity. Different cactus cladode extracts showed an antioxidant effect through microglial catalase activ…
Replacement of fishmeal with corn gluten meal in feeds for juvenile rainbow trout (Oncorhynchus mykiss) does not affect oxygen consumption during for…
2017
Abstract We compared oxygen consumption (MO 2 , mg/kg/h) of c. 80 g rainbow trout ( Oncorhynchus mykiss ) in an intermittent-flow swim respirometer at 15 °C. Before the tests the fish were grown in flow through tanks (15 °C) with either fishmeal (FM) or corn gluten meal (CGM) based diets (c. 52% protein) for a period of 3–4.5 months. Ten individuals from both treatment groups were fasted for 48 h before the swim test, which consisted of 18 loops of 210 s over three different periods: acclimation period (6 loops at 0.5 body lengths per s, BL/s), exercise period (8 loops at increased speed from 1 to 2.5 BL/s with recovery loops at 0.5 BL/s), and a recovery period (four loops at 0.5 BL/s). We …
Cytosine methylation patterns suggest a role of methylation in plastic and adaptive responses to temperature in European grayling (Thymallus thymallu…
2020
Temperature is a key environmental parameter affecting both the phenotypes and distributions of organisms, particularly ectotherms. Rapid organismal responses to thermal environmental changes have been described for several ectotherms; however, the underlying molecular mechanisms often remain unclear. Here, we studied whole genome cytosine methylation patterns of European grayling (Thymallus thymallus) embryos from five populations with contemporary adaptations of early life history traits at either 'colder' or 'warmer' spawning grounds. We reared fish embryos in a common garden experiment using two temperatures that resembled the 'colder' and 'warmer' conditions of the natal natural enviro…
Comparison of Migratory and Resident Populations of Brown Trout Reveals Candidate Genes for Migration Tendency
2018
Abstract Candidate genes associated with migration have been identified in multiple taxa: including salmonids, many of whom perform migrations requiring a series of physiological changes associated with the freshwater–saltwater transition. We screened over 5,500 SNPs for signatures of selection related to migratory behavior of brown trout Salmo trutta by focusing on ten differentially migrating freshwater populations from two watersheds (the Koutajoki and the Oulujoki). We found eight outlier SNPs potentially associated with migratory versus resident life history using multiple (≥3) outlier detection approaches. Comparison of three migratory versus resident population pairs in the Koutajoki…