In order to provide information on the state of hydration of broilers during marketing, 7-week-old Ross broilers of mixed sex were kept at 17 or 23 degrees C and deprived of food, or food and water, for 24 h. Measurements were made of live weight, carcass weight, muscle moisture, packed cell volume, plasma glucose, corticosterone, total protein, osmolality and sodium. There was a decrease in live weight, carcass weight, plasma glucose and plasma total protein, and an increase in packed cell volume and corticosterone, in birds deprived of food, or food and water. Muscle moisture increased in birds deprived of food and decreased in birds deprived of food and water. Osmolality decreased in birds deprived of food, the decrease being greater in birds at 23 degrees C. Plasma sodium levels were higher in birds kept at 23 degrees C and increased only in birds deprived of food and water at 23 degrees C.

The estrogenic effect of butylparaben was investigated in a rainbow trout Oncorhynchus mykiss test system. Butylparaben was administered orally to sexually immature rainbow trout every second day for up to 10 days in doses between 4 and 74 mg kg(-1) 2 d(-1) and in the water at 35 and 201 microgram l(-1) for 12 days. Plasma vitellogenin was measured before and during the exposures and the concentrations of butylparaben in liver and muscle were determined at the end of experiments. Increases in average plasma vitellogenin levels were seen at oral exposure to 9 mg butylparaben kg(-1) 2 d(-1). The ED50 values for increase in vitellogenin synthesis were 46, 29 and 10.5 mg butylparaben kg(-1) 2 d(-1), respectively, at day 3, 6 and 12. Exposure to 201 microgram butylparaben l(-1) increased vitellogenin synthesis, but exposure to 35 microgram l(-1) did not. Butylparaben showed little tendency to bioaccumulation in rainbow trout; less than 1 per thousand of the total amount of butylparaben administered orally at 51 mg kg(-1) 2 d(-1) over the 12 days experimental period was retained in liver at the end of the experiment. After 12 days exposure to 35 and 201 microgram butylparaben l(-1), plasma concentrations were 9 and 183 microgram l(-1), respectively, and for the fish exposed to 201 microgram l(-1) there was a positive correlation between concentrations of vitellogenin and butylparaben in the plasma. On the assumption that butylparaben removed from the water phase during water exposure were taken up into the fish, butylparaben uptake rates in the fish exposed to 35 and 201 microgram butylparaben l(-1) were 13 and 78 mg kg(-1) day(-1), respectively.

The link between metal exposure and toxicity is complicated by numerous factors such as exposure route. Here, we exposed a marine fish (juvenile blackhead seabream Acanthopagrus schlegelii schlegelii) to copper either in a commercial fish diet or in seawater. Copper concentrations in intestine/liver were correlated linearly with influx rate, but appeared to be less influenced by uptake pathway (waterborne or dietary exposure). Influx rate best predicted Cu accumulation in the intestine and liver. However, despite being a good predictor of mortality within each pathway, influx rate was not a good predictor of mortality across both exposure pathways, as waterborne Cu caused considerably higher mortality than dietary Cu at a given influx rate. We show that the use of gill Cu accumulation irrespective of the exposure route as a model for observed fish mortality provided a clear relationship between accumulation and toxicity. Investigation of gill Cu accumulation may shed light on the different accumulation strategies from the two exposure pathways. This correlation offers potential for the use of branchial Cu concentration as an indicator of long-term Cu toxicity, allowing for differences in the relative importance of the uptake pathways in different field situations.

Microcystins appear to be considered one of the most dangerous cyanobacterial toxins in the world. The accumulation and change of microcystins MC-LR and MC-RR in the “cyanobacteria–cladocera–fish” food chain were studied. Microcystis aeruginosa was fed to Moina macrocopa at three densities, 5.0 × 10³, 5.0 × 10⁵, and 5.0 × 10⁶ cells/mL, and then passed to Cyprinus flammans. The total amount of MCs in the cyanobacteria cell extract increased with increasing density. The content of MCs in M. macrocopa increased with the feeding density of M. aeruginosa. In the final stage of experiments, MC-RR was the only MC that could be transmitted by M. macrocopa and persisted in red carp. In this study, changes in the concentrations of MC-LR and MC-RR in the liver of red carp seem to indicate some kind of transformation or degradation mechanism. It shows the possibility of MCs concentration-controlled biodefense in eutrophic waters.

Pejerrey, Odontesthes bonariensis, is an euryhaline fish of commercial importance in Argentina. This work aimed to determine if water salinity affects the expression of genes involved in somatic growth (gh; ghr-I; ghr-II; igf-I), lipid metabolism (Δ6-desaturase) and food intake (nucb2/nesfatin-1). First, we identified the full-length cDNA sequences of Δ6-desaturase (involved in lipid metabolism) and nesfatin-1 (an anorexigen). Then, pejerrey juveniles were reared during 8weeks in three different water salinity conditions: 2.5g/L (S2.5), 15g/L (S15) and 30g/L (S30) of NaCl. Brain, pituitary, liver and muscle samples were collected in order to analyze mRNA expression. The expression of gh and ghr-II mRNAs increased in the pituitary of fish reared at S2.5 and S30 compared with the S15 group. The expression of ghr-I was higher in the liver of S30 group compared to S2.5 and S15. Igf-I mRNA expression in liver increased with the increment of water salinity, while it decreased in the muscle of S15 and S30 groups. Δ6-desaturase expression increased in S2.5 group compared to S15 in both liver and muscle. S30 caused a decrease in the Δ6-desaturase expression in liver compared to S15. The S30 treatment produced an increase in nucb2/nesfatin-1 mRNA expression in the brain and liver compared to S2.5 and S15. The changes in gene expression observed could help pejerrey perform better during salinity challenges. The S30 condition would likely promote pejerrey somatic growth in the long term.

An on-line flow injection pre-concentration-flame atomic absorption spectrometry method was developed to determine trace zinc in water (tap, dam, and well water), biological (hair and nail), and liver samples. As a solid phase extractant, a synthesized new chelating resin, poly(2-thiozylmethacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propane sulfonic acid) was used. The resin was characterized by Fourier transform infrared spectroscopy, elemental analysis, and surface area by nitrogen sorption. A pre-concentration factor of 40-fold for a sample volume of 12.6mL was obtained by using the time-based technique. The detection limit for the pre-concentration method was found to be 2.2μgL⁻¹. The precision (as RSD,%) for 10 replicate determinations at the 0.04μgmL⁻¹ Zn concentration was 1.2%. The calibration graph using the pre-concentration system for zinc was linear with a correlation coefficient of 0.998 in the concentration range from 0.005 to 0.05μgmL⁻¹. The applicability and accuracy of the developed method were estimated by the analysis spiked water, biological, liver samples (83–105%), and also certified reference material TMDA-70 (fortified lake water) and SPS-WW1 Batch 111-Wastewater. The results were in agreement with the certified values.

The effect of oral administration of three fungicides namely: Triadimefon, Carbendazim and Captan at low and high doses on body weight gain, food consumption, weight of certain organs and water content of the liver in male rats has been investigated. Significant reduction in body weight gain concomitant with significant loss in food consumption was detected in rats which had received high dosses of triadimefon and carbendazim.

Wild Atlantic salmon smolts were captured during spring out-migration in the Northwest Miramichi River, New Brunswick, Canada, and placed on an isotopically distinct hatchery diet to determine the relative contributions of growth and metabolic turnover to isotopic change. As expected for an ectothermic species, growth explained a large amount of isotopic variation in changing stable carbon ratios of muscle tissue (average r ²= 0.46) for the 3 years of study. Turnover rates of muscle carbon in all 3 years in growing fish (0.24–0.66 month⁻¹) were higher than previously reported values for other ectothermic species, but there was little evidence for isotopic change in non-growers (average r ²= 0.041, p > 0.1). It is unlikely that non-growers had consumed any of the hatchery diet over a 2-month period, thus preventing them from acquiring the new carbon isotopic signature. This period of food deprivation resulted in nitrogen-15 enrichment in liver relative to muscle (p= 0.003). It is advised that future isotope studies of metabolic turnover rates in ectotherms be conducted on slow-growing animals over a long time period. This would serve to avoid the obscuring effects of growth on isotopic change, and provide stronger comparisons to endothermic tissue turnover rates.

The ability of 17α-ethinylestradiol (EE2) to elevate vitellogenin levels were investigated in male flounder Platichthys flesus and vitellogenin concentrations in flounders from the Danish coastal environment were determined. Male flounders were exposed to 17α-ethinylestradiol (EE2) via food or water. Average vitellogenin concentrations in the control fish ranged between 25 and 100 ng mL−1. Exposure to 5.1, 8.1 and 16.8 ng EE2 L−1 in water and 500 and 5000 ng EE2 kg−1 body weight (bw) every second day in the food increased the plasma vitellogenin concentration in a concentration and time dependent manner, whereas exposure to 2.7 ng EE2 L−1 in water for 21 d and 5 and 50 ng EE2 kg−1 bw for 12 days in the food did not. EE2 could be detected in liver and testes (but not in muscle) after exposure to 8.1 and 16.8 ng EE2 L−1 in the water and 5000 ng EE2 kg−1 bw in the food; the highest concentration was 6 ng g−1 wet weight in liver. The majority of the male flounders collected from nine coastal Danish sites from 1999 to 2004 had vitellogenin concentrations below 100 ng mL−1, and only at two sites moderate estrogenic inputs were indicated.