Acute Stress Effects over Time on the Gene Expression and Neurotransmitter Patterns in the Carp () Brain.

Changes in gene expression in carps' brains over time following acute stressors has not been studied in detail so far. Consequently, a stress trial with juvenile common carp was conducted to investigate transcriptomic differences in four brain parts in response to acute negative stressors and feed reward, focusing on appetite-related genes, serotonergic and dopaminergic pathways, and other involved systems, at 30, 60, and 90 min after treatments. The treatments showed pronounced effects on the gene expression patterns across brain parts compared to control fish.

Multiple faces of stress in the zebrafish () brain.

The changing expressions of certain genes as a consequence of exposure to stressors has not been studied in detail in the fish brain. Therefore, a stress trial with zebrafish was conducted, aiming at identifying relevant gene regulation pathways in different regions of the brain. As acute stressors within this trial, feed rewarding, feed restriction, and air exposure have been used.

Effects of different acute stressors on the regulation of appetite genes in the carp ( L.) brain.

Our understanding of the timing of stress responses and specific roles of different regulatory pathways that drive stress responses is incomplete. In particular, the regulation of appetite genes as a consequence of exposure to different stressors has not been studied in sufficient detail in fish. Therefore, a stress trial was conducted with koi carp, aiming at identifying typical effects of stress on regulation of appetite genes.

The Occurrence of Mycotoxins in Raw Materials and Fish Feeds in Europe and the Potential Effects of Deoxynivalenol (DON) on the Health and Growth of Farmed Fish Species-A Review.

The first part of this study evaluates the occurrence of mycotoxin patterns in feedstuffs and fish feeds. Results were extrapolated from a large data pool derived from wheat ( = 857), corn ( = 725), soybean meal ( = 139) and fish feed ( = 44) samples in European countries and based on sample analyses by liquid chromatography/tandem mass spectrometry (LC-MS/MS) in the period between 2012-2019. Deoxynivalenol (DON) was readily present in corn (in 47% of the samples) > wheat (41%) > soybean meal (11%), and in aquafeeds (48%).

Distress Regulates Different Pathways in the Brain of Common Carp: A Preliminary Study.

In this study, a stress trial was conducted with common carp, one of the most important species in aquaculture worldwide, to identify relevant gene regulation pathways in different areas of the brain. Acute distress due to exposure to air significantly activated the expression of the immediate early gene in the telencephalon. In addition, evidence for regulation of the two corticotropin-releasing factor () genes in relation to their binding protein (corticotropin-releasing hormone-binding protein, ) is presented in this preliminary study.

Preliminary investigation of an idiopathic muscle disease in farmed burbot Lota lota.

The rearing of less established fish species in recirculating aquaculture systems (RASs) is increasing, but may require adaptations of the rearing facilities if health impairments occur. We observed several health issues in burbot Lota lota reared for up to 2 yr in a RAS and used microbiological, histological and molecular-biological methods to identify the causative agents. Minor skin trauma led to the development of ulcers.

Occurrence of Fungi and Fungal Toxins in Fish Feed During Storage.

Periods of unfavorable storing conditions can lead to changes in the quality of fish feeds, as well as the development of relevant mycotoxins. In the present study, a commercial fish feed was stored under defined conditions for four weeks. The main findings indicate that even storing fish feeds under unsuitable conditions for a short duration leads to a deterioration in quality.

Risk assessment for mycotoxin contamination in fish feeds in Europe.

Mycotoxins are difficult to monitor continuously, and a tool to assess the risk would help to judge if there is a particular risk due to the inclusion of certain feed ingredients. For this, the toxin contents of 97 commercial fish feeds have been estimated, and the most prominent toxins in fish feed are calculated to be deoxynivalenol, zearalenone, fumonisins and enniatins. These pose a risk to fish well-being, as can be calculated by the Bayesian models for determining the critical concentrations 5% (CC5) for the different toxins.

Ethoxyquin: a feed additive that poses a risk for aquatic life.

Ethoxyquin (EQ) is an antioxidant that has, to date, been commonly used in feed production. Reports on the detrimental effects of this substance on vertebrates are growing, but effects in aquatic systems have rarely been described. Therefore, the present study was conducted using serial concentrations of EQ ranging from 0.

Toxicity of Ochratoxin to Early Life Stages of Zebrafish ().

Ochratoxin A (OTA) is a known contaminant in fish feed but its effect on fish health remains rather unknown. A study was conducted to investigate the effects of different concentrations of ochratoxin on early life stages of zebrafish (). The tests with ochratoxin A showed a correlation between the exposure to mycotoxin and the amount of damage.

Zearalenone (ZEN) and Its Influence on Regulation of Gene Expression in Carp (Cyprinus carpio L.) Liver Tissue.

Zearalenone (ZEN) is a frequently-occurring mycotoxin in both animal and fish feeds. In order to characterize its effects on carp, three groups of fish were fed for 28 days with feeds contaminated with three different levels of ZEN (low: 332 µg kg, medium: 621 µg kg, and high: 797 µg kg feed). The reversibility of the effects of ZEN was assessed by feeding all of the groups with uncontaminated feed for a further 14 days.

Physiological responses of carp (Cyprinus carpio L.) to dietary exposure to zearalenone (ZEN).

Zearalenone (ZEN) is a frequent contaminant of animal feeds, but systemic effects on fish and possible metabolic costs have not yet been investigated. In order to fill this gap a feeding trial with juvenile carp was conducted. The fish were fed ZEN-contaminated diets at three concentrations (low: 332μgkg(-1), medium: 621μgkg(-1), and high: 797μgkg(-1) final feed, respectively) for four weeks.

Immunomodulation by Zearalenone in Carp (Cyprinus carpio L.).

The mycotoxin zearalenone (ZEN) is a frequent contaminant of animal feeds, but its effects on fish have not yet been investigated extensively. In order to fill this gap a feeding trial with juvenile carp was conducted. Three groups of fish were fed feeds contaminated with ZEN at three concentrations (low: 332 μg kg(-1), medium: 621 μg kg(-1), and high: 797 μg kg(-1) feed) for four weeks.

Effects of Dietary Exposure to Zearalenone (ZEN) on Carp (Cyprinus carpio L.).

The mycotoxin zearalenone (ZEN) is frequently contaminating animal feeds including feed used in aquaculture. In the present study, the effects of dietary exposure to ZEN on carp (Cyprinus carpio L.) were investigated.

Acute and subchronic effects on immune responses of carp (Cyprinus carpio L.) after exposure to deoxynivalenol (DON) in feed.

The mycotoxin deoxynivalenol (DON) has been shown to regularly occur at relevant concentrations in feed designed for aquaculture use, but little is known about the consequences of its presence on the organisms that consume the DON-contaminated feed. Previous studies indicated a down-regulation of pro-inflammatory responses in carp (Cyprinus carpio L.) after 4 weeks of feeding DON.

Cytotoxic effects of pentachlorophenol (PCP) and its metabolite tetrachlorohydroquinone (TCHQ) on liver cells are modulated by antioxidants.

The worldwide distribution and high bioaccumulation potential of pentachlorophenol (PCP) in aquatic organisms imply a high toxicological impact in aquatic systems. Firstly, our investigations show that, similar to mammalian cell lines, PCP can be metabolized to tetrachlorohydroquinone (TCHQ) in the permanent cell line derived from rainbow trout liver cells (RTL-W1). Moreover, we demonstrate that PCP as well as its metabolite TCHQ is capable of influencing the viability of these cells.

Natural mineral particles are cytotoxic to rainbow trout gill epithelial cells in vitro.

Worldwide increases in fluvial fine sediment are a threat to aquatic animal health. Fluvial fine sediment is always a mixture of particles whose mineralogical composition differs depending on the sediment source and catchment area geology. Nonetheless, whether particle impact in aquatic organisms differs between mineral species remains to be investigated.

Unraveling the mechanisms involved in zearalenone-mediated toxicity in permanent fish cell cultures.

The world-wide occurrence of zearalenone (ZEN) as a contaminant in feed for farm animals and fish requires the evaluation of toxicity mechanisms of action of ZEN. The present study investigates possible metabolization of ZEN in fish cell lines suggesting that mainly glucuronidation takes place. It demonstrates that concentrations up to 20,000 ng ml(-1) ZEN are capable of influencing cell viability in permanent fish cell cultures in a dose-response manner with different response patterns between the five tested cell lines, whereby lysosomes appeared to be the main target of ZEN.

In vivo effects of deoxynivalenol (DON) on innate immune responses of carp (Cyprinus carpio L.).

Deoxynivalenol (DON) is one of the most important members of Fusarium toxins since it often can be found in relevant concentrations in animal feeds. The effects of this group of toxins on fish are mostly unknown. The present study shows results from a feeding trial with carp (Cyprinus carpio L.

Organ damage and hepatic lipid accumulation in carp (Cyprinus carpio L.) after feed-borne exposure to the mycotoxin, deoxynivalenol (DON).

Deoxynivalenol (DON) frequently contaminates animal feed, including fish feed used in aquaculture. This study intends to further investigate the effects of DON on carp (Cyprinus carpio L.) at concentrations representative for commercial fish feeds.

Occurrence of deoxynivalenol and zearalenone in commercial fish feed: an initial study.

The control of mycotoxins is a global challenge not only in human consumption but also in nutrition of farm animals including aquatic species. Fusarium toxins, such as deoxynivalenol (DON) and zearalenone (ZEN), are common contaminants of animal feed but no study reported the occurrence of both mycotoxins in fish feed so far. Here, we report for the first time the occurrence of DON and ZEN in samples of commercial fish feed designed for nutrition of cyprinids collected from central Europe.

Frequent biphasic cellular responses of permanent fish cell cultures to deoxynivalenol (DON).

Contamination of animal feed with mycotoxins is a major problem for fish feed mainly due to usage of contaminated ingredients for production and inappropriate storage of feed. The use of cereals for fish food production further increases the risk of a potential contamination. Potential contaminants include the mycotoxin deoxynivalenol (DON) which is synthesized by globally distributed fungi of the genus Fusarium.

Endocrine disruption in aquatic vertebrates.

Environmental compounds can interfere with endocrine systems of wildlife and humans. The main sink of such substances, called endocrine disrupters (ED), are surface waters. Thus, aquatic vertebrates, such as fish and amphibians, are most endangered.

Progestogens cause immunosuppression of stimulated carp (Cyprinus carpio L.) leukocytes in vitro.

The involvement of steroid hormones in direct and indirect regulation and modulation of immune responses is well recognized in mammals. Here, we demonstrate that progestogens are capable of influencing the innate immunity in fish as well. Therefore, we confirmed the known immunosuppressive effects of natural progesterone (P4), and compared them to influences of 17alpha,20beta-dihydroxy progesterone (DHP4) and the synthetic progestins, medroxyprogesterone acetate (MPA) and levonorgestrel (LEV), on NO release by in vitro-stimulated carp leukocytes derived from both, head and trunk kidney, respectively.

Production of nitric oxide by carp (Cyprinus carpio L.) kidney leukocytes is regulated by cyclic 3',5'-adenosine monophosphate.

The inducible nitric oxide synthase (iNOS) plays a central role in the inflammatory reactions that follow infection or tissue damage. Induction of nitric oxide (NO) synthesis by bacterial lipopolysaccharide (LPS) depends on activation of G protein-coupled receptors in mammals. Thus, it was our intention to evaluate whether similar mechanisms are involved in iNOS activation in fish leukocytes.