Effect of azadirachtin on haematological and biochemical parameters of Argulus-infested goldfish Carassius auratus (Linn. 1758)

Argulosis hampers aquaculture production and alters the host physiology and growth. Azadirachtin is recognized as a potential antiparasitic agent against Argulus sp. The present study aimed to investigate the effect of different concentration of azadirachtin solution on haematological and serum biochemical parameters of Argulus-infested goldfish Carassius auratus. Ninety Argulus-infested goldfish were randomly divided into six equal groups. Fish of group 1-5 were treated with azadirachtin solution through bath of 1, 5, 10, 15 and 20 mg L(-1) as T1, T2, T3, T4 and T5, respectively, and group 6 was exposed to 2% DMSO solution without azadirachtin and considered as negative control T0(-). Along with six treatment groups, a positive control T0(+) of healthy goldfish free from Argulus infestation was also maintained. Parasitic mortality was evaluated after 3 days of consecutive bath treatment. After 7 days of post-treatment, the blood and serum were drawn from each of the treatment groups and haematological and serum biochemical parameters were evaluated. Total leucocyte count (TLC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), blood glucose, total protein (TP), globulin, serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) were significantly (p < 0.05) high in negative control group when compared with positive control group. It could be concluded that Argulus infestation altered marked haematological and serum biochemical parameters. However, in treated groups complete elimination of Argulus was found in T4 and T5 groups. Also significant (p < 0.05) reduction in haematological and serum biochemical parameters of all the treatment groups were recorded in comparison with negative control group. In addition, T4 and T5 groups showed significantly (p < 0.05) high superoxide dismutase (SOD), catalase, total erythrocyte count (TEC) and haemoglobin (Hb). However, higher mean corpuscular haemoglobin concentration (MCHC), blood glucose and lactate dehydrogenase (LDH) levels in T5 group revealed that higher concentration of azadirachtin have notable effects on activity of vital tissues function and physiology of the host. Argulus spp. from infested goldfish could be eliminated using bath treatment with solution of azadirachtin having concentration of 15 mg L(-1) and that also shifted haematological and serum biochemical parameters towards homeostasis.

Dietary Aloe vera components' effects on cholesterol lowering and estrogenic responses in juvenile goldfish, Carassius auratus

Aloes are now considered a very interesting source of bioactive compounds among which phytosterols should play a major role. The present study is an attempt to investigate the hypocholesterolemic activity of Aloe vera associated with its impact on the reproductive status of juvenile goldfish. Therefore, the short- and long-term effects of feeding supplementary diet containing aloe components (20 mg aloe/g diet; 2%) on plasma lipids, plasma vitellogenin, and hepatic estrogen receptor α/β1 mRNA levels in goldfish were examined. Results of GC-MS for phytosterols show high abundance of β-sitosterol in freeze-dried powder of Aloe vera whole leaves. Moreover, a 2% aloe powder dietary supplement was not found estrogenic in juvenile goldfish after either 7- or 30-day treatment, but was consistent in plasma hypocholesterolemic effects following long-term exposure. The present data further support that plasma cholesterol modulation induced by phytosterols may not be related to estrogen-like activity.

Reproductive impairment and endocrine disruption in goldfish by feeding diets containing soybean meal

A long-term feeding experiment was conducted to investigate the inclusion of soybean meal in diets for goldfish (Carassius auratus) on fish reproduction. In the present study, 20 weeks after hatching, goldfish with an initial average weight of 2±0.03g (mean±SD) were divided into 12 groups (three tanks per dietary treatment) and fed 400gkg(-1) crude protein diets. The four experimental diets were as follows: diet 1, fish meal (FM); diet 2, 35% soybean meal (SBM35%); diet 3, 65% soybean meal (SBM65%); diet 4, 100% soybean meal (SBM100%). After feeding with experimental diets, the impact on reproduction was investigated. In both males and females, the plasma testosterone (T) was significantly decreased, while 17β-estradiol (E2) levels were significantly increased. Levels of 17α, hydroxyprogesterone. (17-OH-P) did not differ as a result of soybean meal feeding in either males or females. The average number of eggs spawned and sperm quality were reduced on feeding with soybean inclusion. Histological examination showed impact on oocyte maturation progress and spermatogenesis process in female and male fish, respectively. In addition, feeding goldfish with soybean meal until maturation caused reduction in fertilization and hatching rates in parallel to increasing soybean meal inclusion. The results demonstrated that inclusion of soybean meal might cause sex hormone biosynthesis disruption and reproductive impairments in fish, ultimately decreased fertilization as well as hatching rates in the offspring.

Goldfish can recover after short-term exposure to 2,4-dichlorophenoxyacetate: use of blood parameters as vital biomarkers

This study investigated the effects of 2,4-dichlorophenoxyacetic acid (2,4-D), a widely used herbicide, on the metabolism of goldfish, Carassius auratus, using only vital (non-lethal) approaches. After 96 h exposure to 1, 10 or 100 mg/L of 2,4-D selected hematological (total hemoglobin and hematocrit) and biochemical (glucose content, aspartate transaminase and acetylcholinesterase activities) parameters were unchanged in blood of exposed fish. At 100 mg/L of 2,4-D lymphocyte numbers decreased by 8%, whereas promyelocyte and metamyelocyte numbers increased by 7- and 2-fold, respectively. Exposure to 100 mg/L of 2,4-D also elevated carbonyl protein levels (by 2-fold), triglyceride content (by 43%) and alanine transaminase activity (by 46%) in goldfish plasma. All of these hematological and biochemical parameters reverted to control values after a 96 h recovery period. These data indicate that 2,4-D has toxicological effects on goldfish that can be monitored with multiple diagnostic tests using non-lethal blood testing.

Oxidative stress responses in blood and gills of Carassius auratus exposed to the mancozeb-containing carbamate fungicide Tattoo

Intensive use of pesticides, particularly dithiocarbamates, in agriculture often leads to contamination of freshwater ecosystems. To our knowledge, the mechanisms of toxicity to fish by the carbamate fungicide Tattoo that contains mancozeb [ethylenebis(dithiocarbamate)] have not been studied. The present study aimed to evaluate the effects of Tattoo on goldfish gills and blood, tissues that would have close early contact with the pollutant. Exposure of goldfish Carassius auratus to 3, 5 or 10mgL(-1) of Tattoo for 96h resulted in moderate lymphopenia (by 8 percent) with a concomitant increase in both stab (by 66-88 percent) and segmented (by 166 percent) neutrophils. An increase in the content of protein carbonyl groups in blood (by 137-184 percent) together with decreased levels of protein thiols (by 23 percent) and an enhancement of lipid peroxide concentrations (by 29 percent) in gills after exposure to 10mgL(-1) of Tattoo demonstrated the induction of mild oxidative stress in response to Tattoo exposure. At the same time, the activities of selected antioxidant enzymes were enhanced in gills: superoxide dismutase by 18-25 percent and catalase by 27 percent. A 34 percent increment in low molecular mass thiol concentrations (mainly represented by glutathione) also occurred in gills and could be related to increased activity (by 13-30 percent) of glucose-6-phosphate dehydrogenase. The results indicate that Tattoo exposure perturbs free radical processes, i.e. induces mild oxidative stress and enhances the activity of certain antioxidant and associated enzymes in goldfish gills. It is clear that goldfish respond to the presence of waterborne pesticide by adjusting antioxidant defenses through upregulation of activities of antioxidant and associated enzymes.

Erythrocyte damage of crucian carp (Carassius auratus) caused by microcystin-LR: in vitro study

Fish suffer from anemia and hypovolemic hypotensive shock after in vivo exposure with microcystins.However, except for in vivo causes for anemia and hypotension, an in vitro study of fish erythrocytes exposed to MC is necessary. For a better understanding of hematology toxicity of MC, the main aim of the present study was to investigate the toxic effects of microcystin on fish erythrocytes in vitro. Crucian carp erythrocytes were incubated in vitro with microcystin-LR (MC-LR) at doses of 0, 1, 10, 100 and 1,000 nM.The level of lipid peroxidate significantly increased in MC-LR treatment groups. Glutathione decreased after exposure to MC-LR. The activities of antioxidative enzymes, including superoxide dismutase, catalase,glutathione peroxidase and glutathione-S-transferase,were significantly increased after exposure with MC-LR.The hemolysis was significantly increased, while the activities of acetylcholinesterase, Na?–K?-ATPase and Ca2?–Mg2?-ATPase were significantly decreased. In addition, pathological alterations in agglomerated and jagged erythrocytes were observed in blood smears. The findings indicate that damages to erythrocytes should also be responsible for anemia and hypotensive shock or even death.

Thyrotropic activity of recombinant human glycoprotein hormone analogs and pituitary mammalian gonadotropins in goldfish (Carassius auratus): insights into the evolution of thyrotropin receptor specificity

Thyrotropin (TSH) is a pituitary glycoprotein hormone heterodimer that binds to its G-protein coupled receptor (TSH-R) at the thyroid to promote the synthesis and secretion of thyroid hormone. Very little is known about TSH-TSH-R interactions in teleost fish. Mammalian gonadotropins have been reported to have an intrinsic ability to activate teleost fish TSH-Rs, suggesting the TSH-R in teleost fish is more promiscuous than in other vertebrates. In this study we utilized the goldfish T(4)-release response and recombinant human TSH analogs as in vivo tools to evaluate the structural constraints on hormone-receptor interactions. We found that four positively charged lysines substituted for neutral or negatively charged amino acids within positions 11-20 of the glycoprotein hormone subunit α (GSUα) significantly increased biological activity of hTSH in fish, as it does in mammals. We further found that bovine follicle stimulating hormone but not luteinizing hormone, whose GSUα subunits also contain four lysine or arginine amino acid residues in the N-terminal portion of GSUα, was thyrotropic in goldfish, suggesting gonadotropin β subunit contributes to the heterothyrotropic activity. Though recombinant human FSH did not produce a dose-dependent increase in T(4), thyrotropic activity could be acquired with the addition of positively charged amino acids at the N-terminal portion of its GSUα, confirming the importance of the charge on those amino acids for activation of the goldfish TSH-R. These studies demonstrate that mammalian glycoprotein hormone analogs can be utilized to evaluate the conservation of receptor binding and activation mechanisms between fish and mammals.

[Composition of leucocytes of the head kidney of the crucian carp Carassius auratus gibelio (Cypriniformes: Cyprinidae) as affected by invasion of cestode Digramma interrupta (Cestoda; Pseudophyllidea)]

The composition of leucocytes of the head kidney is studied in the crucian carps (Carassius auratus) either contaminated or uncontaminated with Digramma interrupta. The composition of leucocytes in the pronephros of the crucian carp from Lake Baikal basin has a lymphoid character. Compared to the crucian carp from the European part of Russia, in the fish from Baikal the granulocytopoetic processes are more pronounced. This is proved by the high content of young forms of granulocytes. In the fish infected with digramma, the immune suppression of proliferation of blasts and young forms of eosinophils was revealed. On the other hand, the inflammatory and humoral specific immune reactions are enhanced. Partial suppression of the immune response of C. auratus to invasion by D. interrupta facilitates development of the parasite.

Parathyroid hormone 1 (1-34) acts on the scales and involves calcium metabolism in goldfish

The effect of fugu parathyroid hormone 1 (fugu PTH1) on osteoblasts and osteoclasts in teleosts was examined with an assay system using teleost scale and the following markers: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Synthetic fugu PTH1 (1-34) (100pg/ml-10ng/ml) significantly increased ALP activity at 6h of incubation. High-dose (10ng/ml) fugu PTH1 significantly increased ALP activity even after 18h of incubation. In the case of TRAP activity, fugu PTH1 did not change at 6h of incubation, but fugu PTH1 (100pg/ml-10ng/ml) significantly increased TRAP activity at 18h. Similar results were obtained for human PTH (1-34), but there was an even greater response with fugu PTH1 than with human PTH. In vitro, we demonstrated that both the receptor activator of the NF-κB ligand in osteoblasts and the receptor activator NF-κB mRNA expression in osteoclasts increased significantly by fugu PTH1 treatment. In an in vivo experiment, fugu PTH1 induced hypercalcemia resulted from the increase of both osteoblastic and osteoclastic activities in the scale as well as the decrease of scale calcium contents after fugu PTH1 injection. In addition, an in vitro experiment with intramuscular autotransplanted scale indicated that the ratio of multinucleated osteoclasts/mononucleated osteoclasts in PTH-treated scales was significantly higher than that in the control scales. Thus, we concluded that PTH acts on osteoblasts and osteoclasts in the scales and regulates calcium metabolism in goldfish.

Impact of a secondary treated bleached Kraft pulp mill effluent in both sexes of goldfish (Carassius auratus L.)

The aim of the present study was to assess the toxic effects of a secondary treated effluent from a modern pulp mill processing Eucalyptus globulus on both sexes of goldfish. The effects in the exposed fish were investigated by measuring biomarkers which have been used to assess the effects of BKME on aquatic biota, with particular emphasis in fish. However, few studies have been focused on effluents from pulp mill plants processing eucalyptus. The relative proportion of cytochrome P450 (CYP1A) and vitellogenin (VTG) induction were analyzed in the livers of males and females goldfish, exposed to different concentrations of a bleached Kraft pulp mill (BKPM) effluent. Somatic indices such as HSI (hepatosomatic index) and GSI (gonadosomatic index) were calculated and a significant reduction was found in males GSI. A significant increase of HSI was recorded for both sexes exposed to 50% BKPM effluent. Exposure to BKPM effluent induced CYP1A synthesis in both sexes and decreased VTG synthesis in females according to the different effluent concentrations suggesting that the secondary treated effluent contained compounds that affect fish negatively. The results suggest that BKPM effluent can cause sex-related biochemical changes in xenobiotic metabolism.

Effects of monocrotophos on the reproductive axis in the female goldfish (Carassius auratus)

Monocrotophos (MCP) is a highly toxic organophosphorus pesticide. To elucidate the influence of MCP on female fish reproduction, plasma 17beta-estradiol, testosterone and gonadotropin levels and aromatase and gonadotropin beta subunit gene expression levels were examined in female goldfish (Carassius auratus) following a 21-day exposure to 0.01, 0.10 and 1.00 mg L-(1) 40% MCP-based pesticide in a semi-static exposure system. The results indicated that MCP induced increases in plasma 17beta-estradiol levels and the 17beta-estradiol/testosterone ratio via interference with the reproductive axis at multiple potential sites through two mechanisms: (a) MCP exposure enhanced the mRNA expression of gonadal aromatase, the enzyme that converts androgens into estrogens, consequently reducing plasma testosterone levels and increasing plasma concentrations of 17beta-estradiol; and (b) MCP treatment increased follicle-stimulating hormone beta subunit mRNA expression and secretion and decreased luteinizing hormone beta subunit mRNA expression and secretion, leading to the disruption of reproductive endocrine control and androgen and estrogen balance. This study provided convincing evidence for reproductive toxicology of MCP by disrupting of the HPG axis at multiple sites in female goldfish.

E-screen and vitellogenin assay for the detection of the estrogenic activity of alkylphenols and trace elements

The estrogenic potential of 4-nonylphenol (4-NP), 4-octylphenol (4-OP), p-t-octylphenol (p-t-OP) and three trace elements, lead (Pb), copper (Cu) and cadmium (Cd(NO(3))(2) and CdCl(2)), were compared in two different tests, a proliferation assay with estrogen receptor-positive human MCF-7 breast cancer cells (E-screen) and the induction of vitellogenin (Vtg) in juvenile goldfish (Carassius auratus). The results showed differences in the bioassays' sensitivity and potency with the following order: E-screen>Vtg. Among alkylphenols, both in vitro and in vivo, 4-NP and 4-OP showed the highest estrogen-like activity while p-t-OP was inferior. For trace elements, Pb and Cu showed estrogenic activity in vitro and they were also active in vivo. A range of estrogenicity was observed for different species of cadmium (Cd(NO(3))(2) and CdCl(2)) which showed the highest relative proliferative effect (RPE %) in vitro, when compared with the 17beta-estradiol (E(2); RPE=100%) but, Cd(NO(3))(2) was not estrogenic in vivo. The results suggest that an integrated approach using in vitro and in vivo assays is necessary for a correct risk assessment of the endocrine disrupting activity induced by environmental contaminants.

Genetic, biochemical, and individual responses of the teleost fish Carassius auratus to uranium

Carassius auratus were exposed for 96 h to different concentrations of uranyl nitrate (corresponding to 0, 100, 450, and 2,025 microg U L(-1)) and killed after different postexposure periods (0, 48, and 96 h) to assess uranium bioaccumulation, peroxisome proliferation (catalase [CAT]), lipid peroxidation (thiobarbituric acid reactive substances [TBARS]), and DNA integrity in erythrocytes (comet assay). In addition, feeding behaviour was recorded as a general response to toxicant exposure. Results provided evidence of uranium bioaccumulation in muscle of C. auratus after exposure to the highest concentrations (450 and 2,025 microg U L(-1)). This tissue was able to depurate uranium to control levels 96 h after exposure ceased. However, no perturbations in feeding behaviour or cell damage were observed in the tested organisms, except for the apparent irreversible inhibition of CAT activity immediately after exposure in the highest concentration tested. Data on DNA integrity (comets) showed that waterborne uranium exposure was able to induce genotoxicity in C. auratus erythrocytes because fish exposed to all concentrations exhibited higher DNA damage than controls 96 h after exposure. No DNA damage repair was apparent throughout the postexposure period, which was contrary to a recovery scenario. This experiment provides evidence of uranium's ability to induce physiologic impairment and genotoxicity in freshwater fish at environmentally relevant concentrations.

Study on environmental estrogen pollution in Yangtze River (Nanjing section) by an in vivo bioassay

Estrogenic activities and main causative fractions in three representative sections of Yangtze River (Nanjing section) were determined. The results showed that significant vitellogenin (VTG) and 17beta-estradiol (E(2)) induction and gonad atrophy were observed. Estradiol equivalents of actual water samples from Jiangxinzhou section, Sanchahe section and Daqiao section were 0.3651, 0.1301 and 0.5060 ng L(-1), respectively. Polar contaminants were responsible for the estrogenic activities in Jiangxinzhou section and Daqiao section while mid-polar and nonpolar contaminants resulted in majority of the estrogenic activity in Sanchahe section. To Jiangxinzhou section, Sanchahe section and Daqiao section, good positive correlations between VTG and E(2) (the correlation coefficients were 0.737, 0.690 and 0.817, respectively) and good inverse correlations between VTG and gonado-somatic index (GSI; the correlation coefficients were -0.838, -0.540 and -0.794, respectively) were obtained, whereas the correlations between E(2) and GSI were relatively poor (the correlation coefficients were only -0.557, -0.620 and -0.509, respectively).

[Influence of copper ions on hematological and cytogenetic parameters of fresh-water fishes Carassius auratus gibelio]

Influence of copper ions on white blood cells parameters in Carassius auratus gibelio was investigated. Changes in cytogenetic parameters and instability in erythrocytes and epithelial cells of gills were estimated in reply to influence of copper solutions. The frequency of epithelial gill cells at a stage of apoptosis was investigated. The opportunity to use the hematological parameters and cytogenetic instability set for xenobiotics effects in fishes was shown.

Herbal supplementation diets on hematology and innate immunity in goldfish against Aeromonas hydrophila

Goldfish, Carassius auratus (47 + or - 3 g, n = 300) were inoculated intramuscularly (50 microl) with Aeromonas hydrophila (1.8 x 10(6) cells ml(-1)). On the 6th day of post-infection the fishes were divided into i) control, without infection fed with normal diet (C), ii) infected fish, fed with normal diet (IU), and infected fishes treated with different doses of iii) 100 mg kg(-1), iv) 200 mg kg(-1), iv) 400 mg kg(-1) and vi) 800 mg kg(-1) mixed herbal extracts supplementation diets. Hematological and immunological parameters were determined on week 1, 2 and 4. In infected goldfish were fed diets containing 100 and 200 mg kg(-1) of mixed herbal extracts supplementation feeds, the white blood cell (WBC) levels significantly increased (P < 0.05) throughout the experimental trial compared to the control. During the experimental period, the red blood cell (RBC) and haemoglobin (Hb) level in goldfish significantly decreased (P < 0.05) when fish fed with 100 and 200 mg kg(-1) of mixed herbal extracts supplementation feeds while it was restored near control when infected fish fed with 400 or 800 mg kg(-1) of herbal extracts supplementation feeds. On the other hand, the haematocrit (Ht) values decline significantly (P < 0.05) in 100, 200 and 400 mg kg(-1) of mixed herbal supplementation feeding groups on weeks 2 and 4 when compared to control group. The mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) values almost significantly differ from the control values. The infected goldfish and treated with 100 or 200 mg kg(-1) of herbal supplementation feeds exhibited significantly decline (P < 0.05) in total protein (TP), glucose (GLU) and cholesterol (CHO) levels on week 1-4 whereas it was restored when infected fish fed with 400 or 800 mg kg(-1) of herbal supplementation feeds on week 4. In comparison to untreated control goldfish, the respiratory burst activity and phagocytic activity of blood cells was significantly enhanced in infected fish feeding with 200, 400 and 800 mg kg(-1) of herbal supplementation feeds compared to the control. On the other hand, infected fish fed with all the doses of mixed herbal supplementation feeds, the lysozyme activity was significantly enhanced throughout the experimental period. This study shows that the infected goldfish treated with 400 and 800 mg kg(-1) of herbal supplementation feeds preceding the challenge with live A. hydrophila had 30% and 25% mortality. However, 100 and 200 mg kg(-1) of herbal supplementation feeds treated groups were found the percentage mortality 50% and 45%, respectively. Our results indicate that 400 or 800 mg kg(-1) of mixed herbal supplementation feeds were restored the altered hematological parameters and triggering the innate immune system of goldfish against A. hydrophila.

Vitellogenin induction by a mixture of steroidal estrogens in freshwater fishes and relevant risk assessment

The study method on combined effects of environmental contaminant mixture and ecological risk assessment was discussed. Batch tests were conducted to assess the in vivo potency of binary mixtures of estrogens using plasma vitellogenin concentrations in male crucian carp as the endpoint. The estrogenic potencies of 17beta-estradiol (E(2)) and 17alpha-ethynylestradiol (EE(2)) were determined following 14 day exposure to the individual chemicals and equipotent binary mixtures. A Nonlinear regression was obtained and 95% confidence limits of effect concentration were achieved using the bootstrap method. Concentration-response curve for fixed ratio binary mixtures of E(2) and EE(2) was compared with those for individual chemicals, using the biomathematical models of concentration addition (CA) and independent action (IA). A complete overlap was found for the CA predictions with the 95% confidence interval of the best-fit regression line of the observed responses, and the IA predictions was shown lower than the observations. The observed mixture effects were considerably higher than those of the hormone alone and far exceeded the 95% confidence interval of the estrogen regression lines. The predicted effects of binary mixtures at different mixture ratios indicated that the potential impact of components on mixture would depend predominantly on its concentration, the mixture ratio and its relative potency. Results suggested that E(2) and EE(2) acted together in an additive manner and the combined effects can be accurately predicted in whole range of exposure concentration by the models of CA and IA, the model of CA might be realistic, but more useful for ecological risk assessment.

In vitro and in vivo studies of the use of some medicinal herbals against the pathogen Aeromonas hydrophila in goldfish

Aeromonas hydrophila is a ubiquitous and opportunistic bacterial pathogen that produces ulcerative dermatitis under stress conditions and inflicts severe losses on global fisheries and fish culture. This study evaluates the antimicrobial potency of aqueous and ethanolic decoction (individual extract) and concoction (mixed extract) of three common medicinal herbs, turmeric Curcuma longa, Tulsi plant Ocimum sanctum, and neem Azadirachta indica, against the in vitro growth of A. hydrophila. Among the decoctions, A. indica exhibited the most potent antibacterial property (P < 0.05) against A. hydrophila. Among the concoctions, both the aqueous and ethanolic triherbal extracts mixed in the ratio of 1:1:1 had higher antibacterial activity (P < 0.05) than the other concoctions and decoctions. Goldfish Carassius auratus (10 +/- 2 g) were challenged with A. hydrophila intramuscularly in the caudal region with two separate doses (days 1 and 3) of 50 microL/fish (1.8 x 10(3) colony-forming units per milliliter). On days 9 (early) and 15 (late) of infection, fish were held in a net and dip treated for 5 min daily in a 1-L solution of 1% aqueous triherbal concoction. Red blood cell (RBC) count, hemoglobin, and hematocrit levels of the infected group were significantly higher (P < 0.05) than those of the control group. In the early treated group, all of the affected profile values returned to near normal, while the late-treated group registered a partial recovery, such as improved RBC count. The derived hematological values, such as mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration, of the early and late-treated groups also significantly declined (P < 0.05) but were restored to near normal (P > 0.05) only in the early treated group. The results suggest that dip treatment of A. hydrophila-infected goldfish in an aqueous triherbal concoction had a synergistic restorative effect on the hematological variables.

Melatonin reduces body weight in goldfish (Carassius auratus): effects on metabolic resources and some feeding regulators

The objective of the present study was to analyze the effects of chronic melatonin (10 microg/g body weight) on body weight and the main energetic reserves, particularly hepatic and muscle content of proteins, lipids and glycogen in goldfish. In addition, we studied plasma leptin and ghrelin, and hypothalamic content of neuropeptide Y (NPY) and monoamines after chronic melatonin treatment in order to elucidate a possible interplay between melatonin and these feeding regulators on the body weight regulation in this species. Body weight gain and specific growth rate were reduced (74% and 76%, respectively) after chronic (10 days) intraperitoneal (i.p.) treatment with melatonin. The carbohydrate and lipid metabolism was regulated by melatonin in goldfish, because this indoleamine reduced muscle glycogen stores and increased lipid mobilization. A suppressive trend, but not statistically significant, in circulating ghrelin was observed after chronic treatment with melatonin. Chronic melatonin administration significantly reduced noradrenergic metabolism and increased dihydroxiphenylacetic acid content in the hypothalamus, without significant modifications in the serotoninergic system. Thus, it could be suggested that melatonin may mediate its action on energy balance in fish, at least in part, via interactions with hypothalamic catecholaminergic system. Plasma leptin and hypothalamic NPY remained unaltered after melatonin treatment, suggesting that these feeding regulators may not be involved in the effects of melatonin on energy homeostasis in fish.

Reproductive and stress hormone levels in goldfish (Carassius auratus) exposed to oil sands process-affected water

Athabasca oil sands mining in northern Alberta produces process-affected waters that are characterized by the presence of naphthenic acids, polycyclic aromatic hydrocarbons, and high salinity. The purpose of this study was to examine the impact of these process-affected waters on reproductive and stress related endpoints in mature goldfish, Carassius auratus. In two separate studies, testosterone and 17beta-estradiol levels in the plasma were significantly reduced in both male and female goldfish caged for 19 days in process-affected waters relative to controls. This effect was most pronounced in goldfish caged at a site containing mature fine tailing and tailings pond water (P5). Ovarian and testicular tissues from fish in the caging studies were incubated in vitro to evaluate potential differences in basal steroid production levels and responsiveness to human chorionic gonadotropin (hCG). Basal levels of testosterone were reduced significantly in males and females from P5 compared with the control pond (P1) demonstrating that the gonads from exposed fish had a diminished steroidogenic capacity. Gonadal tissues of fish from all ponds responded similarly to hCG suggesting that the steroid biosynthetic pathway remained functionally intact. Plasma cortisol levels were significantly higher in male goldfish caged in a pond containing mature fine tailings and capped with uncontaminated water (P3) and in P5 compared with P1. Collectively, these studies suggest that waste products of oil sands mining have the potential to disrupt the normal endocrine functioning in exposed fish through alterations to both reproductive and glucocorticoid hormone biosynthesis. In additional laboratory studies, exposure of goldfish to a naphthenic acid extract for 7 days failed to replicate the effects of processes-affected waters on plasma steroid levels and the causative agent(s) responsible for the effects on steroid biosynthesis remains to be identified.

The acute lethality and endocrine effect of 1,2,3,7,8-PeCDD in juvenile goldfish (Carassius auratus) in vivo

1,2,3,7,8-PeCDD was administrated to juvenile goldfish (Carassius auratus) by peritoneal injections to explore the acute lethality and endocrine effects of 1,2,3,7,8-PeCDD in vivo. The value of acute median lethal dosage (LD50) of 1,2,3,7,8-PeCDD was determined in acute lethality tests. The endocrine effect of 1,2,3,7,8-PeCDD, whose exposed concentrations were determined based on the LD50 (1.84 mg/kg), was studied by measuring the plasma vitellogenin (Vtg) content in juvenile male goldfish with enzyme-linked immunosorbent assays (ELISA). Due to its significant induction of the plasma Vtg after one week's exposure in vivo in the 1/2 LD50 and LD30 groups, 1,2,3,7,8-PeCDD might be one of the important contributors to the estrogenic effect of PCDDs in the environment. The values of 1/2 LD50 and LD30 were within the range of the effective dosages of 1,2,3,7,8-PeCDD, indicating that there was a certain relationship between the estrogenic effective dosages and the LD50.

Vertebrate osmoregulation: a student laboratory exercise using teleost fish

Here, we describe a laboratory experiment as part of an upper-level vertebrate physiology course for biology majors to investigate the physiological response of vertebrates to osmoregulatory challenges. The experiment involves measuring plasma osmolality and Na+-K+-ATPase activity in gill tissue of teleost fish acclimated to water of differing salinity. We describe results obtained using the widely available goldfish (Carassius auratus) and a common baitfish, the Gulf killifish (Fundulus grandis). The procedures described are generally applicable to other fish species, and they provide an alternative to the experimental use of humans or other mammalian species to investigate osmoregulation mechanisms. In addition to reenforcing the conceptual material covered in lecture, this laboratory exercise trains students in a wide range of laboratory and analytical skills, such as calculating and performing dilutions, pipetting, tissue sampling and homogenizing, preparing standard curves, conducting enzymatic assays, and analyzing and interpreting results. Typical student results are presented and discussed, as are common experimental and conceptual mistakes made by students.

Detection of cytogenetic and DNA damage in peripheral erythrocytes of goldfish (Carassius auratus) exposed to a glyphosate formulation using the micronucleus test and the comet assay

Glyphosate is a widely used broad-spectrum weed control agent. In the present study, an in vivo study on the genotoxic effects of a technical herbicide (Roundup) containing isopropylamine salt of glyphosate was carried out on freshwater goldfish Carassius auratus. The fish were exposed to three doses of glyphosate formulation (5, 10 and 15 ppm). Cyclophosphamide at a single dose of 5 mg/l was used as positive control. Analysis of micronuclei, nuclear abnormalities and DNA damage were performed on peripheral erythrocytes sampled at intervals of 48, 96 and 144 h posttreatment. Our results revealed significant dose-dependent increases in the frequencies of micronuclei, nuclear abnormalities as well as DNA strand breaks. Our findings also confirmed that the alkaline comet assay and nuclear deformations in addition to micronucleus test on fish erythrocytes in vivo are useful tools in determining the potential genotoxicity of commercial herbicides.

A novel enzyme-linked immunosorbent assay system for the quantitative analysis of Carassius auratus vitellogenin

A sandwich enzyme-linked immunosorbent assay (ELISA) was developed to quantitatively detect Carassius auratus vitellogenin (VTG) levels. The protein levels in fish plasma are useful aquatic biomarkers of estrogenic compounds. This procedure involved an ELISA using monoclonal antibodies of CVmA2 and CVmA7 against Carassius auratus VTG, and CVmA7 conjugated to horseradish peroxidase as the detection antibody. The assay range was between 1 and 401.5 ng/ml and the recovery of the VTG added to Carassius auratus plasma was 92.5-109%. An in vitro assay was performed to measure low levels of the VTG, using primary hepatocytes of Carassius auratus induced by 17-beta estradiol (E2). The detection limit was 1 ng/ml and 137 ng/ml at the maximum. Within each sex of wild Carassius auratus, VTG levels from the river next to sewage treatment works (STWs) were much higher than those from the feeding stream. The Carassius auratus VTG bioassay could be a sensitive and useful tool for quantification of estrogenic principles in aquatic environments.

[Genetic structure of crucian carp (Cypriniformes, Cyprinidae, Carassius L. 1758) populations of middle-Dnieper basin]

Comparative analysis of Middle Dnieper crucian carp's population structure was made by means of biochemical gene marking, cytometry and biological analysis. As a result the structure was found, which may by expounded like association of the genetically related species and forms. This association consists of diploid C. auratus (which predominates in population), C. carassius (which was found in the some of north-eastern reservoirs only) and triploid C. gibelio. In Ukraine the homogeneous populations of C. gibelio can be found on the north-east of Eastern Ukraine only. Though some of individuals maybe present with diploid C. auratus. Besides were found hybrid form: diploid C. auratus-C. carassius and presumably tetraploid C. auratus-C. gibelio and C. gibelio-C. carassius. However in the tetraploid's spectra were absent a number of specific alleles, that marking C. species-one of the parental species of triploid C. gibelio. Therefore presumptive tetraploids have not difference from C. auratus and diploid C. auratus-C. carassius on the gene markers level. Nevertheless they are neatly diagnose by the erythrocytes which have good difference and are bigger then diploid species erythrocytes in 40% (C. auratus-C. gibelio) and 100% (C. gibelio-C. carassius).