Sodium chloride treatment effects on rainbow trout suffering from proliferative kidney disease caused by Tetracapsuloides bryosalmonae.

The aim of the present study was to evaluate the effect of a long-term sodium chloride bath on rainbow trout Oncorhynchus mykiss naturally infected by Tetracapsuloides bryosalmonae. A total of 106 infected fish were divided into 2 groups. One group was left untreated and the other was treated with sodium chloride in increasing doses up a concentration of 0.

Proliferative kidney disease in rainbow trout (Oncorhynchus mykiss) under intensive breeding conditions: Pathogenesis and haematological and immune parameters.

Proliferative kidney disease (PKD) is an endoparasitic disease of salmonid fish caused by Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea). This study presents a comprehensive view on PKD development in rainbow trout (Oncorhynchus mykiss) reared at an intensive fish breeding facility, with focus on mortality, pathology/histopathology, haematological findings and immune functions. Diseased and reference fish were sampled monthly and time course of natural infection was followed up from the onset of clinical signs (September 2014) to full recovery (January 2015).

Effect of arsenic and cyanobacterial co-exposure on pathological, haematological and immunological parameters of rainbow trout (Oncorhynchus mykiss).

Objectives: Under environmental conditions, fish are simultaneously exposed to multiple stressors. This study provides new knowledge on the effects of controlled exposure to multiple stressors, namely cyanobacterial biomass and food contaminated with arsenic.

Methods: Rainbow trout were divided into six groups of 25 fish and exposed to different contaminant combinations for 30 days: 1) control group, 2) cyanobacterial biomass, 3 & 4) two groups exposed to arsenic at concentrations of 5 mg.

Degradation rate of praziquantel and fenbendazole in rainbow trout following oral administration.

Objectives: The aim of this study was to evaluate and compare the rate of degradation and elimination of praziquantel and fenbendazole antiparasitics following oral administration to salmonids. In addition, we determine whether the length of the legal withdrawal period is sufficient for complete elimination of antiparasitic residue from the body. The use of these drugs in fish is currently considered off-label and data on degradation are not available for rainbow trout.

Influence of arsenic and cyanobacteria co-exposure on plasmatic parameters of rainbow trout (Oncorhynchus mykiss W.).

Objectives: Fish can be exposed under environmental conditions to multiple stressors including natural toxins and environmental or feed contamination at the same time. This study brings new knowledge about the effects of controlled exposure to multiple stressors in fish. The aim of this study was to test the hypothesis that influence of cyanobacterial biomass and arsenic in feed can combine to enhance the effects on fish.

Modulation of biochemical indices in common carp (Cyprinus carpio L.) under the influence of toxic cyanobacterial biomass in diet.

Cyanobacteria are producers of potent and environmentally abundant microcystins, representing an emerging global health issue. In the present study, we investigated the impact of cyanobacterial biomass on biochemical indices of common carp (Cyprinus carpio L., average weight of 246 ± 73 g) under laboratory conditions.

Fish tapeworm Khawia sinensis: an indicator of environmental microcystins?

Objectives: Parasites have recently been recognized as accumulation indicators that take up and bio-concentrate substances from environmental pollution. Interestingly, helminths of fish are known to accumulate metals from the ambient environment and to contain several orders of magnitude higher concentrations than hosts. While the majority of reports mention inorganic toxin accumulation in parasites, studies concerning effects of organic pollution are infrequent and little is known about the potential of parasites to bio-accumulate microcystins.

In vivo effects of microcystins and complex cyanobacterial biomass on rats (Rattus norvegicus var. alba): changes in immunological and haematological parameters.

Toxic cyanobacteria represent a serious health and ecological problem in drinking and recreational waters worldwide. Some previous toxicological studies investigated effects of isolated microcystins on laboratory rodents including mice and rats. However, much less attention has been paid to more realistic exposure situations such as the effects of MCs accumulated in food.

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.

Influence of cyanobacteria on water activity and dry matter of muscles in the common carp (Cyprinus carpio L.) and rainbow trout (Oncorhynchus mykiss W.).

Objectives: Cyanobacteria are studied from the viewpoint of the issue of risks to water supply, agriculture and recreational activities for a long time. Cyanobacteria produce a wide range of substances which can be toxic and can influence the safety and quality of fish products. The aim of this study was to determine whether the diet with the content of cyanobacteria can affect the water activity and the dry matter of fish muscle and whether this diet can contribute significantly to the shelf life of fish muscles.

Combined exposure of carps (Cyprinus carpio L.) to cyanobacterial biomass and white spot disease.

Objectives: Under environmental conditions, fish can be exposed to multiple stressors including natural toxins and infectious agents at the same time. This study brings new knowledge on the effects of controlled exposure to multiple stressors in fish. The aim of this study was to test the hypothesis that influence of cyanobacterial biomass and an infection agent represented by the white spot disease can combine to enhance the effects on fish.

Accumulation of microcystins in Nile tilapia, Oreochromis niloticus L., and effects of a complex cyanobacterial bloom on the dietetic quality of muscles.

The aim of this study was to investigate the kinetics of accumulation and elimination of microcystins in the tissues of Nile tilapia (Oreochromis niloticus) and to evaluate the effect of cyanobacterial exposure on fish muscle quality (levels of total fat and ash, protein, dry matter and the composition of saturated, monounsaturated and polyunsaturated fatty acids). Fish were exposed for 28 days to a natural cyanobacterial bloom with total microcystin concentration around 1,200 μg g⁻¹ biomass dry weight. The hepatopancreas accumulated microcystins up to 350 ng g⁻¹ fresh weight, but concentrations in muscle were generally below the detection limit (2 ng g⁻¹ fresh weight).

Microcystin kinetics (bioaccumulation and elimination) and biochemical responses in common carp (Cyprinus carpio) and silver carp (Hypophthalmichthys molitrix) exposed to toxic cyanobacterial blooms.

Two species of common edible fish, common carp (Cyprinus carpio) and silver carp (Hypophthalmichthys molitrix), were exposed to a Microcystis spp.-dominated natural cyanobacterial water bloom for two months (concentrations of cyanobacterial toxin microcystin, 182-539 microg/g biomass dry wt). Toxins accumulated up to 1.

Effect of different cyanobacterial biomasses and their fractions with variable microcystin content on embryonal development of carp (Cyprinus carpio L.).

While numerous studies focused on the effects of microcystins, the role of other components of complex cyanobacterial water blooms in toxicity is poorly understood. In this study we have evaluated effects of various fractions of cyanobacterial biomass with different composition and microcystin content on embryolarval development of carp (Cyprinus carpio). The following samples (fractions) of four natural water blooms were prepared and tested: complex cyanobacterial biomass, crude aqueous extract of biomass, cellular pellet remaining from aqueous extract, permeate (i.