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1.
Rainbow trout were exposed to 200 g cadmium/l in the water during four months at 6–10°C. The liver, kidney and gills were analyzed for cadmium, copper, zinc, metallothionein and metallothionein mRNA. Cadmium accumulated in all three organs and reached the highest concentration in the kidney. The tissue zine and copper concentrations showed no major alterations during the experiment. The cytosolic distribution of cadmium, copper and zinc was followed during four months of exposure by Sephadex G-75 chromatography. It was found that cadmium was predominantly associated with proteins of an apparent molecular vieght of 10,000 daltons. These proteins were further identified as metallothioneins after fast protein liquid chromatography on a Mono-Q column. The metallothionein concentration was significantly higher in liver of exposed fish than in control fish after only one month. The kidneys reached significantly elevated levels of metallothionein in the exposed group after three months. In the gills, elevated metallothionein concentrations were observed after four months of exposure. After four months of exposure, the metallothionein mRNA content of liver and kidney was analyzed using a rainbow trout anti-sense RNA probe. Elevated MT mRNA levels were observed in both kidney and liver. These results demonstrate thatde novo synthesis of metallothionein is induced by cadmium in rainbow trout after exposure to the metalvia water.  相似文献   

2.
As aquaculture evolves from extensive pond culture to intensive tank and cage systems, chemical dips and baths are increasingly being used to treat a concomitant increase in ectoparasitic and bacterial infestations. Some of the main disease‐causing agents are ectoparasites on the skin and gills of fish. Consequently, application of chemotherapeutics is increasing in aquaculture industries in order to control outbreaks of parasitic infestations. However, the toxic effect of commonly used chemotherapeutic agents on specific aquacultured fish species is often unknown. The present work was performed to test the effect of four commonly used chemical treatments on rabbitfish, Siganus rivulatus. The lethal concentrations for 50% of population (LC50) of formalin, copper sulfate, potassium permanganate, and hydrogen peroxide for S. rivulatus juveniles treated for 1 h were assessed. Formalin and potassium permanganate tolerance values were determined by calculating 72‐h LC50 values through probit analysis. The 72‐h LC50 values for the formalin toxicity tests were 551.0 and 1.68 mg/L, respectively. LC50 of copper sulfate and hydrogen peroxide could not be determined from the concentrations tested but were found to be >3 and >700 mg/L, respectively. Accordingly, treatment concentrations of formalin and potassium permanganate used for other fish species could be lethal to S. rivulatus, but the species appears to be quite tolerant to copper sulfate and hydrogen peroxide.  相似文献   

3.
A histopathological screening was performed on juvenile Senegalese soles exposed to environmentally realistic concentrations of waterborne Cd (0.5, 5 and 10 μg L?1) for 28 days. The severity and dissemination of histopathological changes were variable and limited to the kidney, liver, spleen, gills and skin goblet cells. Contradicting available literature that refers the liver as the most affected organ upon acute exposure and the kidney following chronic exposure, the liver was the most impacted organ (even at the lowest concentration), in a trend that could relate to the duration of exposure and Cd concentration. The most noticeable hepatic alterations related to inflammation, although hepatocellular alterations like lipidosis and eosinophilic foci also occurred. The trunk kidney of exposed fish endured moderate inflammation, apoptosis and necrosis, however, without a clear time-dependent effect. The spleen of fish subjected to the highest concentrations revealed diffuse necrotic foci accompanied by melanomacrophage intrusion. The gills, albeit the most important apical uptake organ of dissolved toxicants, sustained only moderate damage, from epithelial hyperplasia and pavement cell detachment to the potentially more severe chloride cell alterations. In the skin, an increase in goblet cell size occurred, most notoriously correlated to Cd concentration at earlier stages of exposure. The results show that a metal-naïve juvenile fish can endure deleterious effects when exposed to low, ecologically relevant, concentrations of a common toxic metal and that the pattern of Cd-induced histopathological alterations can be complex and linked to organ-specific responses and metal translocation within the organism.  相似文献   

4.
Copper is an essential element, but at high concentrations, it is toxic for living organisms. The present study investigated the responses of goldfish, Carassius auratus, to 96 h exposure to 30, 300, or 700 μg L?1 of copper II chloride (Cu2+). The content of protein carbonyls was higher in kidney (by 158%) after exposure to 700 mg L?1 copper, whereas in gills, liver, and brain, we observed lower content of protein carbonyls after exposure to copper compared with control values. Exposure to copper resulted in increased levels of lipid peroxides in gills (76%) and liver (95–110%) after exposure to 300 and 700 μg L?1 Cu2+. Low molecular mass thiols were depleted by 23–40% in liver and by 29–67% in kidney in response to copper treatment and can be used as biomarkers toxicity of copper. The activities of primary antioxidant enzymes, superoxide dismutase and catalase, were increased in liver as a result of Cu2+ exposure, whereas in kidney catalase activity was decreased. The activities of glutathione-related enzymes, glutathione peroxidase, glutathione-S-transferase, and glutathione reductase were decreased as a result of copper exposure, but glutathione reductase activity increased by 25–40% in liver. Taken together, these data show that exposure of fish to Cu2+ ions results in the development of low/high intensity oxidative stress reflected in enhanced activities of antioxidant and associated enzymes in different goldfish tissues.  相似文献   

5.
Unscrupulous inclusion of melamine in fish feeds can be harmful to fish and may be hazardous to human health. An eight‐week feeding trial examined the effects of melamine (inclusion levels; 5–30 g kg?1 feed) on the growth performance, feed efficiency, histopathological changes and melamine residues in sex‐reversed red tilapia, Oreochromis niloticus (L.) × O.mossambicus (Peters). Fish which received melamine‐containing feeds grew less, utilized feeds less efficiently and performed poorly, besides exhibiting defects such as fin erosion, anorexia, sluggish swimming behaviour, paling/darkening of skin and low survival. Melamine concentration in the fish reflected its inclusion level in the feeds, and the content was higher in the viscera than in the fish fillet or whole fish. Histopathological alterations were evident in the kidney, liver and gills of fish subjected to melamine treatment – the severity of lesions corresponded to its dosage. Enlargement of renal tubules was observed in the kidney of fish fed with ≥10 g melamine kg?1 feed, although, crystals were not deposited. Fish subjected to melamine insult had more prominent lesions in liver than in kidney. Toxic effects on the gills manifested as epithelial hyperplasia of the primary and secondary lamellae. The anomalies were severe at higher intake levels of melamine.  相似文献   

6.
Carp liver, gills, intestine, kidneys, heart and spleen were studied by histology after the fish were exposed to microcystins by gavage, immersion and intraperitoneal administration. Intraperitoneal inoculation with microcystins caused necrosis or dose- dependent degeneration in the liver, gills and kidneys. Gavaging with microcystins caused changes in the histopathology of the liver and gills. Cellular degeneration and necrosis occurred in the liver, gills and kidneys when carp were introduced to a tank containing 1.7 μg ml?1 of microcystins. Lesions were not observed in the heart, spleen or intestines from any of the treated carp. Microcystins administered by intraperitoneal injection at a concentration of 50 μg kg?1 were lethal to all fish within 8 h, while gavaging with 250 μg kg?1 of microcystins caused minimal damage in the tissues studied.  相似文献   

7.
患鳠锥体虫病大鳍鳠的血液学和组织学观察   总被引：2，自引：0，他引：2  
采用血液学和组织学研究了鳠锥体虫病对大鳍鳠(Mystus macropterus)外周血及部分组织器官(鳃、肝脏、肾脏、头肾及脾脏)造成的病理变化。结果显示:在感染的的早期和中期,有虫组的红细胞(RBC)数量和血红蛋白含量(Hb)均有所下降,白细胞(WBC)数目增多,但在感染末期个体三者均显著下降,并且白细胞血式发生改变。各项血清指标显示有虫组的肝脏、肾脏出现一定程度的损伤,感染末期个体损伤较严重。组织切片观察显示,鳠锥体虫病能使大鳍鳠的血液、肝脏、肾脏、头肾和脾脏均发生不同程度的病理变化,主要表现为局部鳃丝断裂、出血;肾脏、头肾和脾脏出现不同程度充血,肝细胞呈水样变性,感染末期个体的肾脏、肝脏等出现细胞空泡化。  相似文献   

8.
The aim of the present study was to evaluate bioaccumulation of metals in various tissues of the freshwater fish Cyprinus carpio L. exposed to cadmium and copper (a xenobiotic and a microelement). The fish were subjected to short-term (3 h, Cd-S and Cu-S) or long-term (4 weeks, Cd-L and Cu-L) exposures to 100 % 96hLC50 or 10 % 96hLC50, respectively. Blood, gill, liver, head and trunk kidney were isolated weekly from 5 fish of each group for 4 weeks (post-short-term exposure and during long-term exposure). Atomic absorption spectrophotometry technique was applied to measure concentrations of metals (Cd and Cu) in fish tissues. Initial concentrations of copper in fish tissues were higher than levels of cadmium. Cadmium and copper levels increased in all tissues of metal-exposed fish. After short-term exposures (at higher concentration) and during long-term exposures (at lower concentration), similar changes in metal concentrations were observed. The values of accumulation factor (ratio of final to initial metal concentration) were higher for cadmium as compared to copper. Comparison of metal levels and accumulation factors in various tissues revealed that cadmium and copper showed very high affinity to head kidney of common carp (higher than to other tissues), but accumulation factors for cadmium in trunk, head kidney and liver were much higher than for copper. The concentrations of copper in organs of Cu-exposed fish increased only slightly and quickly returned to the control level, which shows that fish organism easily buffered metal level. On the other hand, concentrations of cadmium considerably increased and remained elevated for a long time which suggests that activation of mechanisms of sequestration and elimination of cadmium required more time.  相似文献   

9.
Abstract. The Formosa snakehead, Channa maculata (Lacepède), and the largemouth bass, Micropterus salmoides (Lacepède), were given an intraperitoneal (i.p.) and/or intramuscular (i.m.) inoculation of Nocardia asteroides isolated from cultured Formosa snakehead, Typical granulomatous lesions induced by the experimental fish were similar to the naturally infected cases. The Formosa snakehead showed 100% and 93% mortality at 14 and 35 days after i.m. inoculation with 8 mg and 0·8 mg of bacterial suspension, respectively. The largemouth bass was slightly resistant to N. asteroides but still had 95% mortality at 35 days after inoculation (i.m.) with 8 mg bacterial suspension. The bacteria were easily reisolated from spleen and kidney of the experimental fish. Many typical multifocal granulomata were found at the sites of injection and the internal organs such as liver, spleen, kidneys, pancreas, intestine, gills, eyes and brain. The result indicated that the N. asteroides isolated from the field ease was pathogenic to Formosa snakehead and largemouth bass.  相似文献   

10.
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11.
This publication reports on analytical data from a large-scale experiment, using 3360 Atlantic salmon, Salmo salar L., distributed into 12 sea cages. Salmon were grown from an average 600 g to an average 3.5 kg. Samples for analyses were taken when fish were in the range of 1.8 and 3.5 kg. Dietary changes between groups were increased starch from 24 to 230 g kg?1 and balanced with protein. The diets were isolipic. All salmon showed small stores of glycogen in all analysed organs, and only in heart, gills and kidney of large fish (3.5 kg) were the levels correlated with dietary starch. Minor differences between groups were found in liver NADPH production, but with substantially decreased NADPH production per g protein as the fish grew from 1.8 to 3.5 kg, indicating that increasing dietary starch did not lead to induction of liver hexokinase, and that the activity of this enzyme may decline as fish size increases. An increase in plasma glucose concentrations was found as dietary starch increased, but all levels were moderate and ranged within reference values. Plasma total protein concentrations did not, however, vary according to decreased dietary protein, but increased substantially in all groups as the fish grew from 1.8 to 3.5 kg. Dietary treatments had no influence on haematological parameters, except for decreased haemoglobin concentrations as dietary starch increased in large fish (3.5 kg). No impared liver function was detected, evaluated by activities of ASAT, ALAT and LDH, and by histological analyses. Low serum lysozyme activities were recorded in all groups, and were not correlated with plasma glucose or liver glycogen concentrations.  相似文献   

12.
The purpose of this work was to determine the tissue accumulation of lead (Pb) and its effects on osmoregulatory processes of the freshwater fish Prochilodus lineatus. Juvenile fish were exposed to Pb (from 1.7 to 0.7 mg of dissolved Pb L?1) for 6, 24 and 96 h and Pb accumulation was analyzed in the gills, liver, kidneys, blood cells and muscle. The following parameters were also analyzed: hematologic (hemoglobin content, hematocrit and number of red blood cells), metabolic (blood glucose), endocrine (blood cortisol), osmo ionic (plasma osmolality and Na+, K+, Cl? and Ca+2 concentrations), gill enzymes (Na+/K+-ATPase and carbonic anhydrase), chloride cell (CC) density and CC location in the gills. Pb accumulated in all the analyzed tissues, with the kidneys showing the highest concentration, followed by the gills and liver. The lowest Pb concentrations were found in blood cells and muscle. Pb promoted an increase in blood glucose after 6 and 24 h exposure. Gill Na+/K+-ATPase was inhibited after 24 h of exposure, but its activity was restored at 96 h, probably due to the increase in CC in gill lamellae. Plasma Na+ was reduced after 6 and 96 h, while K+ concentrations increased at all the experimental times. Fish exposed to Pb showed reduced plasma Ca+2 at all experimental periods. Hematologic parameters remained unchanged. Overall, this study demonstrated that Pb interferes in osmoregulatory processes of P. lineatus and the proliferation of CC in the gills is a response in order to reestablish adequate ion concentrations.  相似文献   

13.
A feeding experiment was carried out to determine the effect of a diet lacking n-3 and n-6 highly unsaturated fatty acids (HUFA) on lipid and fatty acid content in intestine and gills of male gilthead seabream (Sparus aurata L.) broodstock at different stages of the reproductive cycle: November (pre-spermatogenesis), March (spermatogenesis), and June (post-spermatogenesis). For this purpose, gilthead seabream broodstock were fed either a control diet (C) or an n-3 and n-6 HUFA-deficient diet (D). The results showed no changes in fatty acid content of polar lipids of intestine and gills from fish fed diet C at different stages of the reproductive cycle. However, significant changes were observed in the fatty acid content of neutral lipids in intestine but not in gills in this group. Thus, between November and March, saturates and n-3 HUFA decreased while monoenes increased. In June, the contents of these fatty acids had returned to their initial values (November). Moreover, in fish fed diet D, the fatty acid content of neutral lipid changed in both intestine and gills. In intestine NL, a decrease in saturates and n-3 HUFA and an increment in monoenes were observed from November to June. In gills, a decrease was also observed in n-3 HUFA from NL along the cycle. Nevertheless, n-6 HUFA content remained unchanged. These results show both tissue specificity in seasonal mobilization of fatty acids linked to reproductive processes and the influence of dietary fatty acids on body composition.  相似文献   

14.
Kynurenic acid (KYNA) is an endogenous substance produced on the kynurenine pathway which is primarily known for its neuroactive properties. Recently, it has been proven that KYNA is a selective ligand for G protein‐coupled receptor (GPR 35), presented on immunocompetent cells such as T lymphocytes. This opens up new possibilities of its application as an immunostimulating substance in aquaculture. Thus far, no histopathological investigations in fish have been completed to evaluate influence of KYNA supplementation in feed. This study has been undertaken to determine the effect of feed supplementation with KYNA (2.5, 25, 250 mg kg?1 of feed) for 28 days on the liver, gills and kidney in healthy fish and experimentally infected with Yersinia ruckeri. In a control group were observed a fatty liver, which is natural for this fish species in the autumn and winter season. As the dose of the supplement was increased, the fat liver changed, it decreased or completely disappeared. Additionally, inflammatory changes occurred in all the analysed organs, and their intensification was dose dependent. In the fish experimentally infected, KYNA caused aggravation of the signs in the liver, kidneys and gills, and the effect was dose dependent. The results implicate that KYNA may be a stressor for fish.  相似文献   

15.
The objective of this study was to investigate the toxic effects of buprofezin insecticide on Nile tilapia (Oreochromis niloticus). The fish were exposed to buprofezin at 100 mg/L for 28 days. Compared to control, activity of serum transferases and levels of urea and creatinine showed significant increases. Oxidative stress was recorded manifested by elevated levels of malondialdehyde (MDA), reduced concentrations of reduced glutathione (GSH) and inhibition of activities of superoxide dismutase (SOD) and catalase (CAT) in liver and kidney. Examination of peripheral RBCs revealed elevated frequency of micronucleated cell. Interleukin 1 beta (IL‐1β) gene was upregulated in liver, muscle and brain, while that of cyclooxygenase 2 (COX‐2) gene increased in liver and muscle, but not in brain. Histopathological alterations were recorded in liver, kidneys, brain, gills, pancreas, spleen, intestine, muscle and ovaries. The immunohistochemical detection of caspase‐3 in the liver revealed no differences between treated and control groups; however, the expression of inducible nitric oxide synthase (iNOS) was demonstrated in hepatocytes and hepatopancreas in buprofezin‐treated group compared to control. It has been concluded that the tissue damage induced by buprofezin in Nile tilapia is mediated by oxidative stress and inflammatory response but not by apoptosis.  相似文献   

16.
Proliferative gill disease (PGD) is a serious problem in the farm-raised channel catfish Ictalurus punctatus industry. Interrupting the life cycle of the sporozoan causative agent by eliminating Dero digitata worms from culture ponds would be one method of controlling PGD. Eight chemicals—sodium chloride, hydrogen peroxide, formalin, potassium permanganate, liquid copper sulfate, chloramine-T, rotenone and Bayluscide—were tested for acute toxicity against D. digitata . Static, single compound acute toxicity tests were conducted using three replications (10 worm/replicate) of six chemical concentrations and a control. Spearman-Karber analysis was used to calculate 24- and 48-h LC50 concentrations based on active ingredient for each compound. Calculated 24-h LC50 values were: sodium chloride 6,800 mg/L, hydrogen peroxide 13.2 μL/L, formalin 23.3 μL/L, potassium perrnanganate 5.7 mg/L, copper sulfate 7.6 mg/L, chloramine-T 29.5 mg/L, rotenone 0.26 μL/L, and Bayluscide 0.24 mg/L. Formalin and hydrogen peroxide may be options for eliminating D. digitata populations in ponds with fish because their LC50 concentrations were consistent with safe concentrations for fish. Rotenone, Bayluscide, chloramine-T, formalin, and potassium permanganate may be useful as a pond sterilization strategy by treating fingerling ponds prior to stocking fish each year. However, the presence of substrate and organic matter in ponds could impact the efficacy of the chemicals and D. digitata's response to treatment. Treatments should be further evaluated to determine field efficacy, procedures for use, and effects on cost of production.  相似文献   

17.
Abstract. In recent years, jaundice disease in farmed hybrid catfish in Thailand has caused high levels of mortalities. Affected fish are lethargic and anorexic and show yellow pigmentation of the skin and gills. Internally, the spleen, kidney and gall bladder are enlarged, and the spleen, kidney, liver and body fat are a pale yellow colour. Most fish contain a yellow ascitic fluid in their abdomen. Histological examination of tissues from diseased fish revealed heavy deposits of haemosiderin and ceroid in the spleen, kidney and liver. Haematological measurements showed that haematocrit values, RBC count, haemoglobin concentration, MCH and MCHC were significantly decreased in affected fish while MCV, total bilirubin and direct reacting bilirubin were significantly increased. The results indicate that the fish are suffering from a haemolytic anaemia associated with lipoid liver degeneration. The disease is thought to be due to the feeding of rancid chicken viscera.  相似文献   

18.
The invasion pathway of Aeromonas hydrophila in vivo was studied in Crucian carp (Carassius auratus gibelio) with a virulent strain A. hydrophila J-1 transformed with a plasmid encoding green fluorescent protein (pGFPuv) (A. h J-1GFP), which had similar virulence characteristics (haemolysin, extracellular proteases production, toxicity for EPC cells, survival in fish serum and LD50 value) as the parent strain. Fish were divided into four experimental groups: (1) normal fish; (2) bacteria bath challenged, unwounded fish; (3) skin artificially wounded by scalpel, bacterial bath challenged fish; and (4) skin mucus layer partially removed by paper towel, bacterial bath challenged fish. The number of bacteria from blood, gills, kidney, muscle, liver and intestine were detected at 2, 4, 8, 12, and 24 h post-challenge. High bacterial numbers were observed in the muscle of the artificial wound group, in the kidney of the mucus removed group and in the gills of all groups. In conclusion, the gills and damaged skin are likely to be the main routes of entry for A. hydrophila, and GFP can be used as a real-time biomarker to study intimate host–pathogen interaction in fish.  相似文献   

19.
A histopathological study was carried out on ayu, Plecoglossus altivelis, with bacterial haemorrhagic ascites. The fish were obtained from culture ponds in Wakayama Prefecture in 2003. The causative agent was identified as Pseudomonas plecoglossicida by a slide agglutination test using anti-P. plecoglossicida FPC941 serum. Histopathological studies revealed lesions in spleen, kidney, liver, intestine, heart and gills. Lesions in the spleen and haematopoietic tissue were prominent and invaded by P. plecoglossicida. Necrotic lesions accompanied by haemorrhage, fibrin deposition and oedema occurred in the splenic pulp and sheathed tissue, and in the kidney. The liver also had necrotic lesions and abscess formations. However, the intestine, heart and gills were only slightly invaded by P. plecoglossicida. No lesions or bacteria were observed in the brain.  相似文献   

20.
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