Reared rainbow trout are vulnerable to environmental stressors, in particular seasonal water warming, which affects fish welfare and growth and induces a temperature response, which involves modifications in tissue lipid profiles. Dietary supplements of plant origin, including the studied mix of a flavonoid, dihydroquercetin and a polysaccharide, arabinogalactan (25 and 50 mg per 1 kg of feed, respectively), extracted from larch wood waste, were shown to facilitate stress tolerance in fish and also to be beneficial for the safety of natural ecosystems and the sustainability of aquaculture production. This four-month feeding trial aimed to determine the effects of the supplement on liver and muscle lipid accumulation and the composition in rainbow trout reared under environmental variables.
View Article and Find Full Text PDFThe objective of this study was to investigate the bactericidal activity of blood plasma from cultured rainbow trout obtained from two different fish farms. Plasma from trout naturally infected with the bacterial pathogen was found to inhibit the growth of in vitro. Incubation of in bacteriostatic trout plasma resulted in agglutination and growth retardation, without causing massive damage to the cell membrane.
View Article and Find Full Text PDFThe implantation of optical sensors is a promising method for monitoring physiological parameters of organisms in vivo. For this, suitable hydrogels are required that can provide a biocompatible interface with the organism's tissues. Amorphous hydrogel is advantageous for administration in animal organs due to its ease of injection compared to resilient analogs.
View Article and Find Full Text PDFNatural feed supplements have been shown to improve fish viability, health, and growth, and the ability to withstand multiple stressors related to intensive cultivation. We assumed that a dietary mix of plant-origin substances, such as dihydroquercetin, a flavonoid with antioxidative, anti-inflammatory, and antimicrobial properties, and arabinogalactan, a polysaccharide with immunomodulating activity, would promote fish stress resistance and expected it to have a protective effect against infectious diseases. Farmed rainbow trout fish, , received either a standard diet or a diet supplemented with 25 mg/kg of dihydroquercetin and 50 mg/kg of arabinogalactan during a feeding season, from June to November.
View Article and Find Full Text PDFinfection in aquacultured trout, besides its own harmful effects, can also make the fish more susceptible to other infections, both by swamping the host's immune system and by creating the skin lesions that serve as a direct gateway for opportunistic bacteria. Tissue samples were taken from the intestines, spleen and skin lesions of cage-grown rainbow trout suffering from natural infections of varying severity. In addition, a water sample was taken to document the planktonic bacteria inhabiting the fish farm at the time of the study.
View Article and Find Full Text PDFThis article describes the clinical manifestation of natural infection in rainbow trout (Oncorhynchus mykiss) during an outbreak on a fish farm. (i) Using an integrated approach, we characterized the pathogenesis of vibriosis from the morphological, hematological, and biochemical points of view. The molecular mechanisms associated with the host immune response were investigated using mass spectrometric analysis of trout plasma proteins.
View Article and Find Full Text PDFAims: The aim of the present study was to investigate the gastrointestinal (GI) microbiota and bacterium-specific fatty acid occurrence in the muscle and hepatic lipids of rainbow trout Oncorhynchus mykiss (Walbaum, 1792), both healthy and those naturally infected with bacterial pathogens.
Methods And Results: From June 2017 (L1) to September 2018 (L8), 74 specimens of rainbow trout Oncorhynchus mykiss (with an average weight from 139.2 ± 7.
Taxifolin is a natural flavonoid known for its antioxidant, anti-inflammatory, and antiproliferative effects on animals. In this work, we have studied the effect of this compound on rainbow trout, , a major object of aquaculture, under slowly increasing ambient temperature and flatworm infection. Transcriptomic profiling of liver samples performed by using the Illumina HiSeq 2500 sequencing platform shows that a combined taxifolin/heat treatment, unlike heat treatment alone, downregulates the production of isopentenyl diphosphate, likely affecting the production of cholesterol and other sterols.
View Article and Find Full Text PDFThe use of natural dietary supplements in aquaculture has received a great deal of attention in recent years. This article provides data describing body weight and length of rainbow trout juveniles fed with natural dietary supplements dihydroquercetin, arabinogalactan or a mixture of both in an aquaria experiment. Before feeding trial, rainbow trout were tagged to identify individuals.
View Article and Find Full Text PDFNatural infection of 2 to 6-year-old perch with the cestode parasites was shown to have minor effects on the studied components of the antioxidant defense system, nucleic acids degradation, and carbohydrate metabolism enzymes in the liver of the fish. The level of infection of 1-4 parasite larvae per fish observed in wild population of perch was shown to be moderate in terms of its effect on the health of the host fish. The activity of hepatic enzymes β-galactosidase, β-glucosidase, cathepsin D, and glutathione S-transferase showed different responses in infected males and females, which indicates different potential resistance of fish to the stress exposure between genders.
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