Search results for "rainbow"

Retene causes multifunctional transcriptomic changes in the heart of rainbow trout (Oncorhynchus mykiss) embryos

2015

Fish are particularly sensitive to aryl hydrocarbon receptor (AhR)-mediated developmental toxicity. The molecular mechanisms behind these adverse effects have remained largely unresolved in salmonids, and for AhR-agonistic polycyclic aromatic hydrocarbons (PAHs). This study explored the cardiac transcriptome of rainbow trout (Oncorhynchus mykiss) eleuteroembryos exposed to retene, an AhR-agonistic PAH. The embryos were exposed to retene (nominal concentration 32 μg/L) and control, their hearts were collected before, at and after the onset of the visible signs of developmental toxicity, and transcriptomic changes were studied by microarray analysis. Retene up- or down-regulated 122 genes. Th…

Suppression of Saprolegnia infections in rainbow trout (Oncorhynchus mykiss) eggs using protective bacteria and ultraviolet irradiation of the hatche…

2014

Since formalin is widely used in prevention of Sapro- legnia infections in salmonid fish hatcheries, there is a need for more environmentally safe treatment methods. Therefore, we screened 360 bacterial iso- lates against their ability to antagonize the growth of Saprolegnia parasitica hyphae in vitro, and best strains were selected according to their antagonistic proper- ties and colonization capability on rainbow trout egg surface. Protective bacterial cultures of Pseudomonas sp. M162, Pseudomonas sp. M174 and Janthinobacte- rium M169 were tested for prevention of Saprolegnia sp. infections during incubation trials of rainbow trout (Oncorhynchus mykiss )e ggs with UV irradiated (400 mWs c…

2019

Aquaculture production has increased tremendously during the last decades, and new techniques have been developed, e.g., recirculating aquaculture systems (RAS). In RAS, the majority of water volume is circulated via mechanical and biological filters and reused in the tanks. However, the prevention and treatment of diseases in these systems are challenging, as the pathogens spread throughout the system, and the addition of chemicals and antibiotics disrupts the microbiome of the biofilters. The increasing antibiotic resistance has made phage therapy a relevant alternative for antibiotics in food production. Indeed, as host-specific and self-replicating agent they might be optimal for target…

Interactions between Rainbow Trout Eyed Eggs and Flavobacterium spp. Using a Bath Challenge Model:Preliminary Evaluation of Bacteriophages as Pathoge…

2021

The microbial community surrounding fish eyed eggs can harbor pathogenic bacteria. In this study we focused on rainbow trout (Oncorhynchus mykiss) eyed eggs and the potential of bacteriophages against the pathogenic bacteria Flavobacterium psychrophilum and F. columnare. An infection bath method was first established, and the effects of singular phages on fish eggs was assessed (survival of eyed eggs, interaction of phages with eyed eggs). Subsequently, bacteria-challenged eyed eggs were exposed to phages to evaluate their effects in controlling the bacterial population. Culture-based methods were used to enumerate the number of bacteria and/or phages associated with eyed eggs and in the su…

Contrasting coping styles meet the wall: A dopamine driven dichotomy in behavior and cognition

2017

Individual variation in the ability to modify previously learned behaviour is an important dimension of trait correlations referred to as coping styles, behavioral syndromes or personality. These trait clusters have been shaped by natural selection, and underlying control mechanisms are often conserved throughout vertebrate evolution. In teleost fishes, behavioral flexibility and coping style have been studied in the high (HR) and low-responsive (LR) rainbow trout lines. Generally, proactive LR trout show a behaviour guided by previously learned routines, while HR trout show a more flexible behaviour relying on environmental cues. In mammals, routine dependent vs flexible behavior has been …

Anaphylatoxin-like molecules generated during complement activation induce a dramatic enhancement of particle uptake in rainbow trout phagocytes.

2004

Here we have identified a serum fraction containing approximately 8-kDa molecules with an unexpected capacity to greatly enhance particle uptake in trout head kidney leukocytes (HKLs). This approximately 8-kDa particle-uptake enhancing fraction (PUEF-8) was purified from complement-activated serum by gel filtration chromatography. Mass spectrometric analysis and reactivity of anti-trout C3-1 and C4 antibodies, indicated the presence of C3a, C4a and C5a molecules in PUEF-8. Using a newly developed flow cytometric assay that measures the capacity of cells to ingest fluorescent beads, we showed that PUEF-8 induced a striking enhancement (344+/-50% higher than the PBS control value) in the numb…

Efektivitas ikan pelangi arfak, Melanotaenia arfakensis, Allen 1990 dalam mencari makan pada tingkat kekeruhan air yang berbeda: suatu pendekatan lab…

2018

The research on feeding effectivity of arfak rainbowfish conducted at Fisheries Laboratory, Faculty of Fishes and Marine Scince, University of Papua in July to December 2016. The purpose of this research is to describe feeding effectivity of the fish at several levels of water turbidity. The fish samples used in the treatment, collected from Nimbai Stream, Prafi River system, Manokwari were acclimatized for a month in the laboratory. The fish were selected based on the body length and categorized into six size classes. Each individual of the fish was treated with 200 individuals of mosquito larvae (instar IV stage) at seven turbidity levels (2.54, 25.07, 50.52, 100.20, 500.60, and 800.40 Ne…

Accelerated Solvent Extraction and Pulsed Electric Fields for Valorization of Rainbow Trout (Oncorhynchus mykiss) and Sole (Dover sole) By-Products: …

2021

Fishery by-products are rich in biologically active substances and the use of green and efficient extraction methods to recover these high-added-value compounds is of particular importance. In this study, head, skin and viscera of rainbow trout and sole were used as the target matrices and accelerated solvent extraction (ASE) (45–55 °C, 15 min, pH 5.2–6.8, 103.4 bars) and pulsed electric fields (PEF) (1–3 kV/cm, 123–300 kJ/kg, 15–24 h) were applied as extraction technologies. The results showed that ASE and PEF significantly increased the protein extract efficiency of the fish by-products (p < 0.05) by up to 80%. SDS-PAGE results showed that ASE and PEF treatments changed the molecular size…

A link between ectoparasite infection and susceptibility to bacterial disease in rainbow trout

2006

Rainbow trout, Oncorhynchus mykiss, were infected concomitantly with Argulus coregoni and Flavobacterium columnare and their survival was compared with that of fish infected with either the parasite or the bacterium alone. The mortality of fish challenged with A. coregoni was negligible while infection with F. columnare alone led to significantly lower survival. However, compared with single infections, the mortality was significantly higher and the onset of disease condition was earlier among fish, which were concomitantly infected by A. coregoni and F. columnare. This data presents, for the first time, experimental support for the hypothesis that an ectoparasite infection increases suscep…

Management of Arfak Rainbow Fish Based on Bioecologycal Aspect (Case in Some River in Manokwari)

2018

The aim of this research is to study the bioecological aspect of Arfak Rainbowfish, distribution long-wieght frequency and management of endemic arfak rainbow fish in Manokwari. This study conducted for five months from 7 September 2015 to 9 Januari 2016. Fish sample were collected from Prafi river, Nimbai river and Aimasi river and brought to fisheries laboratory. The method of this research is descriptive methode with field observation. The result of water quality parameters are temperature average 30.01oC±1,06oC, flow rate is slow 0.92±0,12, the pH 7,80±0,12, oxygen solute 5,38±0,24, average biological oxygen demand for Prafi river 4 mg/L, Nimbai river 3.1 mg/L, Aimasi river 5.2 mg/L and…