Search results for "Salmo"
showing 10 items of 442 documents
La remontée du saumon pour le frai dans le fleuve Tornionjoki, suivie au moyen d'un sonar à double faisceau horizontal.
2000
Fixed location split-beam horizontal echosounding was used to assess the size and timing of the Atlantic salmon (Salmo salar) spawning run in the River Tornionjoki. Four transducers, two on each river bank, were mounted across the river at the study site 4 km upstream from the river mouth. Net weirs were used on both shores to direct the passage of fish through the acoustic beams. Hydroacoustic monitoring covered 40-50% of the river cross-sectional area. Also test fishing and yearly catch statistics of salmon were used as an indication of the size of the spawning run in the river. Altogether, 7 700, 5 300 and 4 300 salmon-sized targets (target strength, TS ≥ -29 dB) moving upstream were det…
Impact of salmon farming on Atlantic cod spatio-temporal reproductive dynamics
2021
Salmon farming in marine net pens is a major activity in many temperate regions. This industry may affect coastal ecosystems in several ways, such as with waste pollution and parasite spillover. Less is known about the extent to which salmon farming disrupts the use of inshore spawning grounds by wild fish, such as the Atlantic cod Gadus morhua. Acoustic telemetry was therefore used to explore cod space use during the spawning season in a coastal region in mid-Norway with multiple salmon farms. Acoustic receivers were placed in clusters at 5 known cod spawning grounds and 6 nearby salmon farms. Data from 481 adult cod caught at the spawning grounds during 2017-2019 and equipped with acousti…
Isolation and Characterization of Structurally Novel Antimutagenic Flavonoids from Spinach (Spinacia oleracea)
2001
Thirteen compounds, isolated from spinach (Spinacia oleracea), acted as antimutagens against the dietary carcinogen 2-amino-3-methylimidazo[4,5-f]quinoline in Salmonella typhimurium TA 98. The antimutagens were purified by preparative and micropreparative HPLC from a methanol/water (70:30, v/v) extract of dry spinach (commercial product) after removal of lipophilic compounds such as chlorophylls and carotenoids by solid-phase extraction (SPE). Pure active compounds were identified by instrumental analysis including FT-IR, (1)H and (13)C NMR, UV-vis spectroscopy, and mass spectrometry. All of these compounds were flavonoids and related compounds that could be attributed to five groups: (A, m…
Assessment of contamination of Salmonella spp. in imported black pepper and sesame seed and salmonella inactivation by gamma irradiation
2021
This study shows the frequency of seeds samples contaminated by Salmonella spp. collected randomly from local markets; on 30 black pepper sample no contaminated sample was found while Salmonella spp. was detected in 3 of 36 (8.3%) analyzed sesame samples; three different serotypes were identified: S. Montevideo, S. Stanleyville e S. Tilene. The efficacy of gamma irradiation to inactivate Salmonella Montevideo in black pepper and sesame irradiated between 1 and 5 kGy was evaluated. 3 kGy is sufficient to reduce of 3-4 log CFU/g; whereas 5 kGy have been need to reduce 5.5-6 log CFU/g for samples of black pepper and sesame. No statistically significant differences were found between black pepp…
Antibacterial activity of the enniatin B, produced by Fusarium tricinctum in liquid culture, and cytotoxic effects on Caco-2 cells.
2011
The enniatins (ENs) are bioactive compounds of hexadepsipeptidic structure produced by several strains of Fusarium sp. The EN B was purified from extracts of Fusarium tricinctum growth on liquid culture of potato dextrose broth (PDB), using a semipreparative liquid chromatography (LC) followed by an analytical LC. The purity and the structure of the isolated compound were confirmed by the determination of the extinction coefficient and with electrospray ionization-mass spectrometry (ESI-MS) study. The pure fraction of EN B was utilized to determine the antibiotic effects on several bacterial strains that are considered normally pathogens of the intestinal tract: Escherichia coli, Enterococc…
Effects of Emergence Time and Early Social Rearing Environment on Behaviour of Atlantic Salmon: Consequences for Juvenile Fitness and Smolt Migration
2015
Consistent individual differences in behaviour have been well documented in a variety of animal taxa, but surprisingly little is known about the fitness and life-history consequences of such individual variation. In wild salmonids, the timing of fry emergence from gravel spawning nests has been suggested to be coupled with individual behavioural traits. Here, we further investigate the link between timing of spawning nest emergence and behaviour of Atlantic salmon (Salmo salar), test effects of social rearing environment on behavioural traits in fish with different emergence times, and assess whether behavioural traits measured in the laboratory predict growth, survival, and migration statu…
Polymorphism in Developmental Mode and Its Effect on Population Genetic Structure of a Spionid Polychaete, Pygospio elegans
2012
Population genetic structure of sedentary marine species is expected to be shaped mainly by the dispersal ability of their larvae. Long-lived planktonic larvae can connect populations through migration and gene flow, whereas species with nondispersive benthic or direct-developing larvae are expected to have genetically differentiated populations. Poecilogonous species producing different larval types are ideal when studying the effect of developmental mode on population genetic structure and connectivity. In the spionid polychaete Pygospio elegans, different larval types have been observed between, and sometimes also within, populations. We used microsatellite markers to study population st…
Male Investments in High Quality Sperm Improve Fertilization Success, but May Have Negative Impact on Offspring Fitness in Whitefish.
2015
Many ejaculate traits show remarkable variation in relation to male social status. Males in disfavoured (subordinate) mating positions often invest heavily on sperm motility but may have less available resources on traits (e.g., secondary sexual ornaments) that improve the probability of gaining matings. Although higher investments in sperm motility can increase the relative fertilization success of subordinate males, it is unclear whether status-dependent differences in sperm traits could have any consequences for offspring fitness. We tested this possibility in whitefish (Coregonus lavaretus L.) by experimentally fertilizing the eggs of 24 females with the sperm of either highly-ornamente…
Assessment of the bioactivity of creosote-contaminated sediment by liver biotransformation system of rainbow trout.
1999
A sediment site in the Lake Jamsanvesi (municipality of Petajavesi, Finland) contaminated by creosote was investigated to assess the possible ecotoxicological risks it may cause to benthic animals, including ones which may arise due to physical measures in remediating the site. It is suggested that polycyclic aromatic hydrocarbons (PAHs) are bioavailable to fish and other aquatic animals during exposure to contaminated water, sediment, and food. In order to assess toxicological risks of sediment contents to fish, juvenile rainbow trout (Onchorhynchus mykiss) were intraperitoneally dosed with extracts of the creosote-contaminated sediments and their elutriates. This was compared to pristine …
BIOAVAILABILITY TO JUVENILE RAINBOW TROUT (ONCORYNCHUS MYKISS) OF RETENE AND OTHER MIXED-FUNCTION OXYGENASE-ACTIVE COMPOUNDS FROM SEDIMENTS
2002
Retene (7-isopropyl-1-methylphenanthrene) is a naturally formed polycyclic aromatic hydrocarbon (PAH) that causes teratogenicity in fish larvae and induction of cytochrome P450 (CYP1A) enzymes. Retene occurs at high concentrations (or =3,300 microg/g dry wt) in surface sediments contaminated by resin acids from pulp mill effluents. To assess the environmental risks of retene, it is important to evaluate conditions affecting its bioavailability and accumulation by fish. Fingerling rainbow trout were exposed to retene-spiked or naturally contaminated sediments and sampled after 4 d to determine liver CYP1A activity and concentrations of retene metabolites in bile as indicators of retene accum…