Stress load on harvest‐size common carp (Cyprinus carpio L.) just before harvest, during harvest and during the post‐harvest storage were assessed using haematological and biochemical indices. The study was carried out at the 60 ha Dřemliny pond for 28, 7 and 1 day before harvest, during 3‐day harvest and after a 28‐day post‐harvest period. Indices monitored included the relative spleen weight (SSI), erythrocyte count (Er), haemoglobin levels (Hb), haematocrit (PCV), MCV, MCH, MCHC, leucocrit (Bc), differential leucocyte count (leucogram), blood plasma cortisol, glucose, total proteins (TP), cholesterol and chloride. During harvest, a significant decrease of SSI (P<0.05; P<0.01), increase of PCV (P<0.01), decrease of Bc (P<0.01, P<0.05), lymphopenia (P<0.05) and neutrophilia (P<0.01) were observed. A significant increase in the levels of blood plasma cortisol was found 1 day before harvest (P<0.05) due to draining off the pond before harvest itself, hyperglycaemia was observed 1 day before harvest (P<0.05) and during harvest (P<0.01); a decrease, on the other hand, was found in cholesterol and chloride levels (P<0.01). The relationships between oxygen content in water and SSI and MCHC were positive (P>0.05) and between oxygen and glucose were negative (P>0.01). A 28‐day post‐harvest storage returned the indices investigated back to physiological interval of values. Persistently lower levels of Bc, lymphopenia, neutrophilia and lower TP concentrations are indicative of deepening immunosuppression during the post‐harvest storage period. Changes of haematological and biochemical indices during harvest in relation to hypoxia, fish handling and higher stocking rates are also discussed.

In this study, the origin and pathways of detoxication of ammonia in the body of fish are analysed. Ammonia is toxic for an organism even in trace amount. The role of direct deamination of amino acids such as histidine, serine, asparagine and glutamine is emphasized with regard to ammonia production, the functional association of transamination and deamination is reflected in a transdeamination reaction, where the central role is played by the enzyme glutamate dehydrogenase. Furthermore, less known sources of ammonia occurring during natural restoration of body cells and tissues are discussed. Particularities of biochemical processes in fish, such as the non-existence of ureosynthetic cycle along with a sudden change of environmental conditions can easily disturb the balance between production and excretion. If the detoxication abilities of fish are exceeded, ammonia acts as a toxicant, thus leading to accidental mortalities of fish.

Recent reports have shown that stressful situations may affect the production of unconjugated pterins (neopterin and biopterin). The aim of the study was to investigate the effect of castration on neopterin and biopterin plasma concentrations in piglets, using 2 groups of 12 piglets allocated to castrated and uncastrated (control) groups. Pterin concentrations were determined by HPLC with fluorescence detection. Blood samples were also analzyed for leukocyte profiles and plasma cortisol concentrations. A time × treatment interaction (P < 0.05) was detected for neopterin concentrations, such that neopterin was greater (P < 0.01) at 1 h after surgery in castrated piglets compared with precastration concentrations, and neopterin was greater (P = 0.05) in castrated than in control piglets at 1 h. Castration had no effect on biopterin concentration (P > 0.1). Time effects (P < 0.05) for neutrophil and lymphocyte concentrations and neutrophil-to-lymphocyte ratios were found. A time × treatment interaction (P < 0.01) was detected for plasma cortisol concentrations, such that cortisol was greater (P < 0.01) at 1 and 24 h after surgery in castrated piglets compared with precastration concentrations and was greater (P < 0.01) in castrated than in control piglets at 1 and 24 h. This study showed that castration activated the immune system of piglets as demonstrated by an increase in plasma neopterin concentrations.

Phthalates are organic substances used mainly as plasticisers in the manufacture of plastics. They are ubiquitous in the environment. Although tests in rodents have demonstrated numerous negative effects of phthalates, it is still unclear whether the exposure to phthalates may also damage human health. This paper describes phthalate toxicity and toxicokinetics, explains the mechanisms of phthalate action, and outlines the issues relating to the presence of phthalates in foods. &nbsp;

No abstract

Background, aim, and scope Restoration of lakes and reservoirs with extensive cyanobacterial water bloom often requires evaluation of the sediment quality. Next to the chemical analysis of known pollutants, sediment bioassays should be employed to assess toxicity of the present contaminants and to make predictions of associated risk. Brno reservoir in the Czech Republic is a typical example of water bodies with long-term problems concerning cyanobacterial water blooms. Comprehensive assessment of reservoir sediment quality was conducted since successful reservoir restoration might require sediment removal. An important part of this survey focused on an examination of the utility of Tubifex tubifex and its sublethal biochemical markers for the assessment of direct sediment toxicity. Materials and methods This complex study included chemical analysis of contaminants (heavy metals, organic pollutants), ecotoxicity testing of sediment elutriates (tests with Daphnia magna, Pseudomonas putida, Sinapis alba, Scenedesmus subspicatus), and other parameters. We have tested in more detail the applicability of T. tubifex as a test organism for direct evaluation of contact sediment toxicity. Survival tests after 14 days of exposure were complemented by an assessment of parameters serving as biomarkers for sublethal effects [such as total glutathione content (GSH), activities of the enzymes glutathione transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR)]. The data matrix was subjected to multivariate analysis to interpret relationships between different parameters and possible differences among locations. Results The multivariate statistical techniques helped to clearly identify the more contaminated upstream sites and separate them from the less contaminated and reference samples. The data document closer relationships of the detected sediment contamination with results of direct sediment exposure in the T. tubifex test regarding mortality but namely regarding the sublethal endpoints rather than the results obtained with other test organisms exposed to sediment elutriates. Aside from the reduction in T. tubifex survival, the sediments with organic pollution caused an increase in glutathione content and increased activities of glutathione S-transferase and glutathione peroxidase in the exposed T. tubifex worms. Discussion Results of our study confirm the suitability of T. tubifex for toxicity testing of raw waters and sediments. This longer-lasting direct contact test has proven more sensitive and appropriate to reflect a lower level of pollution than do the elutriate tests. Sensitive biochemical changes in T. tubifex, including an elevation in GSH levels and GST activities, reflect a general stimulation of detoxification metabolisms in the presence of xenobiotics. The results also suggest an important role of glutathione and related enzymes in detoxification processes and possible involvement of oxidative stress in toxicity mechanisms in benthic sedimentdwelling worms such as T. tubifex. Conclusion...

The aim of the study was to determine the differences in the composition of fatty acids of intramuscular lipids between diploid (2n) and triploid (3n) tench of identical genetic specifications and raised under the same conditions, in relation to sex (F-female vs. M-male) and age (T 3 -36 months vs. T 3+ -42 months). A total of 137 tench (Tinca tinca L.) siblings were analyzed. The control group consisted of 72 diploid tench (39 F and 33 M) and the experimental group of 65 triploid tench (38 F and 27 M). Elevated levels of fatty acids C16:0, C16:1n-9c and C18:1n-9c were found in lipids of tench of both age groups (T 3 and T 3+ ). Among T 3 tench, significant ploidy-level related differences were ascertained in the content of specific SFA (C12:0, C13:0, C14:0, C15:0; p < 0.01) and C22:1n-9 (p < 0.05) in favour of 2n males. A significant effect of sex was found only in the diploid tench population: C14:0, p < 0.01 and C14:1n-9c, p < 0.05 in favour of 2n male tench and C18:1n-9c, p < 0.01 in favour of 2n female tench. In the T 3+ age group, the ploidy-level effect was apparent in both sexes (C15:0, P < 0.05 and C18:2n-9c, t11, p < 0.05 in favour of 2n female tench, C16:1n-9c, p < 0.01 in favour of 3n male tench, C18:2n-6c, p < 0.01 and C18:3n-3, p < 0.05 in favour of 2n male tench). In the T 3+ age group, the effect of sex was apparent for both ploidy levels (C16:1n-9c, p < 0.01 in favour of 2n female tench, and C14:0, p < 0.05 in favour of 3n male tench). The qualitative as well as quantitative composition of lipids of specific fatty acids was significantly affected (p < 0.05, p < 0.01, p < 0.05) by age. The study demonstrated that the factors monitored (ploidy, sex and age) may, under specific experimental conditions, influence the composition of lipid fatty acids of the tench. Fatty acids, diploid and triploid tench, genome polyploidyThe existing inter-and intra-species variability in the composition of fatty acids of fish lipids (and of the specific PUFA in particular) is usually explained by the existence of a large number of external factors (type of aquatic environment, type of rearing and the fish culture composition, trophic aspects -interaction, type and composition of diet, season of the year -water temperature) and internal factors (fish species, feeding regime and digestion, lifecycle stage, quantitative and qualitative characteristics of lipids -triacylglycerols, phospholipids and their topographical origin -dorsal vs. ventral part of muscle tissue).In recent years, there has been a large number of experimental studies (e.g. Csengeri et al. 1978;Farkas et al. 1978;Vanderwesthuyzen et al. 1984;Suzuki et al. 1986;Viola et al. 1988;Bieniarz et al. 2000) into some of the above factors (dealt with separately or in combination) causing changes in the composition of fatty acids in various fish species. Other authors have studied the impact that various types of heat treatment will have on the fatty acid composition (e.g. G all et al. 1983;Maeda et al. 1985;Tothmarkus and Sasskiss 1993;Fajmonová et al. 2003).I...

The effects of aqueous root extracts from five species of the family Papaveraceae on the growth of cyanobacteria, algae, and other non-target aquatic organisms were investigated to evaluate their potential use as algicides or cyanocides in the aquatic environment. Dicranostigma lactucoides and Sanguinaria canadensis featured the highest toxicity while Macleaya microcarpa was found to be the least toxic to all aquatic organisms tested. The Chelidonium majus extract had the best properties as a potential algicide or cyanocide because of its significant toxicity to phytoplankton and lower toxicity to non-target aquatic organisms as compared with the other Papaveraceae family members.