Eye fluke infection changes diet composition in juvenile European perch (Perca fluviatilis).

Intraspecific diet specialization, usually driven by resource availability, competition and predation, is common in natural populations. However, the role of parasites on diet specialization of their hosts has rarely been studied. Eye flukes can impair vision ability of their hosts and have been associated with alterations of fish feeding behavior.

mRNA expression of antioxidant and biotransformation enzymes in zebrafish (Danio rerio) embryos after exposure to the tricyclic antidepressant amitriptyline.

Now-a-days, the occurrence of antidepressant residues in surface waters has become a major concern. Amitriptyline (AMI) has been described to treat depression and other disorders for decades. However, little is known about its effect on non-target organisms.

Endocrine disruption by environmental gestagens in amphibians - A short review supported by new in vitro data using gonads of Xenopus laevis.

Endocrine disruption caused by various anthropogenic compounds is of persisting concern, especially for aquatic wildlife, because surface waters are the main sink of these so-called endocrine disruptors (ED). In the past, research focused on (anti)estrogenic, (anti)androgenic, and (anti)thyroidal substances, affecting primarily reproduction and development in vertebrates; however, other endocrine systems might be also targeted by ED. Environmental gestagens, including natural progestogens (e.

The synthetic gestagen levonorgestrel directly affects gene expression in thyroid and pituitary glands of Xenopus laevis tadpoles.

The synthetic gestagen levonorgestrel (LNG) was previously shown to perturb thyroid hormone-dependent metamorphosis in Xenopus laevis. However, so far the mechanisms underlying the anti-metamorphic effects of LNG remained unknown. Therefore, a series of in vivo and ex vivo experiments was performed to identify potential target sites of LNG action along the pituitary-thyroid axis of X.

Effects of the pharmaceuticals diclofenac and metoprolol on gene expression levels of enzymes of biotransformation, excretion pathways and estrogenicity in primary hepatocytes of Nile tilapia (Oreochromis niloticus).

The expression levels of key enzymes of the xenobiotic metabolism and excretion pathways concerning biotransformation phases I (cytochrome P4501A), II (glutathione S-transferase) and III (multidrug resistance protein) and of the estrogenic biomarker vitellogenin (vtg) were investigated in primary hepatocytes isolated from male Nile tilapia (Oreochromis niloticus) after exposure to diclofenac and metoprolol, two pharmaceuticals prevalent in the aquatic environment worldwide. The lowest test concentration (4×10(-9) M) was chosen to reflect an environmentally relevant exposure situation. Furthermore concentration dependent effects were investigated.

Biochemical and histopathological responses of Wistar rats to oral intake of microcystins and cyanobacterial biomass.

Objectives: Cyanobacteria are producers of potent and environmentally abundant microcystins, representing an emerging global health issue. In the present study, we investigated the impact of pure microcystins and cyanobacterial biomass on laboratory rats (Wistar albino rats, males, 30 days old) under different exposure scenarios.

Methods: The rats were fed diets containing fish meat with microcystins in various concentrations and forms (cyanobacterial biomass and isolated microcystins) for 28 days.

Concentrations of microcystins in tissues of several fish species from freshwater reservoirs and ponds.

The aim of this study is to summarise the determination of concentrations of microcystins (MCs) in muscle and liver of freshwater fish species caught in stagnant waters of the Czech Republic. Within the years 2007-2009, 351 muscle samples and 291 liver samples of 16 freshwater fish species derived from four fishponds, and four water reservoirs were analysed. MCs were detected in 53 liver samples.

Physiological responses of Xenopus laevis tadpoles exposed to cyanobacterial biomass containing microcystin-LR.

Cyanobacteria are the primary biomass producers and some species synthesize remarkable amounts of secondary metabolites, the so-called cyanotoxins. Several reports deal with the most common cyanotoxins, microcystins (MCs), and their effects on fishes but only a few studies investigated a natural exposure to MCs and limited information is available concerning the further aquatic vertebrate class, amphibians. In the present study, Xenopus laevis tadpoles at stage 52 (Nieuwkoop and Faber, 1994) were exposed for 1, 3, 7, and 21 days to diets containing lyophilized cyanobacterial biomass without and with microcystin-LR (MC-LR) at concentrations of 42.

The effect of peroral administration of toxic cyanobacteria on laboratory rats (Rattus norvegicus var. alba).

Objectives: The toxic cyanobacteria are a serious problem for water supply systems, recreation, and agriculture. Cyanobacteria produce numerous bioactive compounds including microcystins - the most studied cyanobacterial hepatotoxins. Only rare studies addressed realistic situation, i.

Impact of microcystin containing diets on physiological performance of Nile tilapia (Oreochromis niloticus) concerning detoxification.

Nile tilapia (Oreochromis niloticus) were fed by diets supplemented with cyanobacteria containing in part the cyanotoxin microcystin-LR (MC-LR) to determine the potential impacts on detoxification. Four different diets were prepared based on a commercial diet: (1) control, (2) MC-5% (containing 5% dried Microcystis sp. biomass with 4.

Impact of microcystin containing diets on physiological performance of Nile tilapia (Oreochromis niloticus) concerning stress and growth.

Diets containing Microcystis with considerable amounts of the cyanotoxin microcystin-LR (MC-LR) were fed to determine their impact on the physiological performance of the omnivorous Nile tilapia (Oreochromis niloticus) with regard to stress and growth performance. Four different diets were prepared based on a commercial diet (control, MC-5% [containing 5% dried Microcystis biomass], MC-20% [containing 20% dried Microcystis biomass], and Arthrospira-20% [containing 20% dried Arthrospira sp. biomass without toxin]) and fed to female Nile tilapia.