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1.
Ecotoxicol Environ Saf ; 212: 111982, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33529921

RESUMO

Abattoirs are positioned close to freshwaters in most developing countries where untreated wastewaters are discharged into with potential risk to aquatic life such as fish and ultimately human health. We assessed physicochemical parameters, antibiotics (oxytetracycline and diclofenac) and algal load of effluent collected from a major abattoir in Nigeria. Furthermore, liver function enzymes, genotoxic and haemotoxic effects of subacute concentration (10% of 96 hLC50 value) of the wastewater were evaluated over a period of 28 d in Clarias gariepinus (The African Sharptooth Catfish). The 96 hLC50 value of the abattoir wastewater against C. gariepinus was 154.14 mL/L (15.4%). Nitrates, phosphates, sulphates, chloride, ammonia, TDS, TSS, BOD5 and heavy metals (Fe and Pb) in the wastewater were above permissible limits while diclofenac and oxytetracycline were below detection limit (BDL). Microalgae in the wastewater were mostly Bacilliariophyta (Navicula spp.) (45.64%) and euglenoids (Euglena and Phacus spp.) (49.48%). Liver function enzymes (LDH, AST, ALT) level were higher in exposed fishes except for ALP which was lower at day 28 compared to control levels. Erythrocytic genotoxic indices (nuclear abnormalities) were significantly higher (p < 0.05) in the exposed fishes particularly at day 28 compared to control. Haematologic indices level such as WBC, MCV MCH, MCHC increased significantly (p < 0.05) while lymphocytes, HGB, RBC, HCT levels decreased significantly (p < 0.05) in the exposed C. gariepinus by day 28 compared to control. These results demonstrate potential adverse effects posed to aquatic fish species in the Ogun River by the discharge of the abattoir effluent. The microalgae species identified in the effluent may be explored for pre-treatment of the effluent before discharge in order to prevent eutrophication and increased pollutant load in the River. The study results will contribute to evidence-based environmental risk management of the River which is relevant to the UN SDGs 6 (clean water and sanitation), 11 (sustainable cities and communities) and 14 (sustaining life below water).


Assuntos
Matadouros , Antibacterianos/toxicidade , Peixes-Gato/fisiologia , Poluentes Químicos da Água/toxicidade , Amônia , Animais , Biomarcadores , Diclofenaco , Água Doce , Humanos , Fígado/química , Metais Pesados/toxicidade , Nigéria , Rios , Águas Residuárias
2.
Arch Environ Contam Toxicol ; 80(2): 414-425, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33386433

RESUMO

The hepatotoxic effects of sub-lethal concentrations of atrazine (2.5, 25, 250, and 500 µg L-1) on Clarias gariepinus juveniles were assessed for 28 days in a quality-controlled laboratory procedure. The study was designed to determine the effects of atrazine on selected liver function biomarkers: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), albumin (ALB) and total protein (TP), and to analyze the liver tissues of the fish using a quantitative and qualitative histology-based health assessment protocol. The levels of ALB and TP in exposed specimens were observed to decrease with increasing concentrations of atrazine. However, the activities of ALT, AST, and ALP showed significant (p < 0.05) increase with increasing concentrations of atrazine. Hepatic assessment of the liver tissues revealed marked histopathological alterations, including structural changes (necrotic/apoptotic liver tissue, poor hepatic cord structure, and loss of normal architecture) in 52.2% of the liver tissues in the treatment groups; plasma alterations (vacuolation or fat inclusions, 22.9%) of hepatocytes; hypertrophied hepatocyte (55.2%); nuclear alterations (52.1%); focal necrosis (16.7%); complete degeneration of hepatocytes (60.45%); sinusoids congested with red blood cells or vascular congestion (70.8%); and karyolysis of the nucleus (18.8%). Findings from this study suggest that atrazine interferes with liver function markers and disrupts the normal architectural and structural components of the liver resulting in noninfectious liver injury. This condition resulted in repeated cycles, cell deaths, and inflammation, which could result in the eventual death of the exposed fish if exposure duration was prolonged.


Assuntos
Atrazina/toxicidade , Peixes-Gato/fisiologia , Poluentes Químicos da Água/toxicidade , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Biomarcadores/metabolismo , Peixes-Gato/metabolismo , Eritrócitos/efeitos dos fármacos , Fígado/metabolismo
3.
Ecotoxicol Environ Saf ; 207: 111266, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32919194

RESUMO

Microcystin-LR (MC-LR) is a potent hepatotoxin that can cause liver inflammation and injury. However, the mode of action of related inflammatory factors is not fully understood. PfHMGB1 is an inflammatory factor induced at the mRNA level in the liver of juvenile yellow catfish (Pelteobagrus fulvidraco) that were intraperitoneally injected with 50 µg/kg MC-LR. The PfHMGB1 mRNA level was highest in the liver and muscle among 11 tissues examined. The full-length cDNA sequence of PfHMGB1 was cloned and overexpressed in E. coli, and the purified protein rPfHMGB1 demonstrated DNA binding affinity. Endotoxin-free rPfHMGB1 (6-150 µg/mL) also showed dose-dependent hepatotoxicity and induced inflammatory gene expression of primary hepatocytes. PfHMGB1 antibody (anti-PfHMGB1) in vitro reduced MC-LR (30 and 50 µmol/L)-induced hepatotoxicity, suggesting PfHMGB1 is important in the toxic effects of MC-LR. In vivo study showed that MC-LR upregulated PfHMGB1 protein in the liver. The anti-PfHMGB1 blocked its counterpart and reduced ALT/AST activities after MC-LR exposure. Anti-PfHMGB1 partly neutralized MC-LR-induced hepatocyte disorganization, nucleus shrinkage, mitochondria, and rough endoplasmic reticula destruction. These findings suggest that PfHMGB1 promotes MC-LR-induced liver damage in the yellow catfish. HMGB1 may help protect catfish against widespread microcystin pollution.


Assuntos
Peixes-Gato/fisiologia , Fígado/efeitos dos fármacos , Toxinas Marinhas/toxicidade , Microcistinas/toxicidade , Animais , Peixes-Gato/metabolismo , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , DNA Complementar/metabolismo , Escherichia coli/genética , Expressão Gênica , Hepatócitos/efeitos dos fármacos , Hepatopatias , Proteínas/metabolismo , RNA Mensageiro/metabolismo
4.
PLoS One ; 15(12): e0244017, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33382718

RESUMO

Hormonal changes such as increased cortisol level in blood plasma in response to stress and social environmental stimuli are common among vertebrates including humans and typically accompanied by other physiological processes, such as changes in body pigmentation and/or pupil dilatation. The role of pupil size variation (PSV) as a response to stress have yet to be investigated in fish. We exposed albino and pigmented European catfish to short-term stress and measured changes in pupil size and cortisol level. Albinos showed lower pupil dilatation and higher cortisol levels than did pigmented conspecifics. A clear positive relationship between pupil dilatation and cortisol concentrations was observed for both pigmented and albino specimens, suggesting that PSV can be used as a stress indicator in fish, irrespective of albino's inability to express social communication by coloring. During the follow-up, we investigated whether a penultimate contest between albino individuals would impact contestants' social stress during subsequent contact. We observed PSV during the contact of unfamiliar albino catfish with different penultimate experiences (winner (W) and/or loser (L)). Then, the following treatment combinations were tested: WW, WL and LL. Twenty-four-hour contact of two unfamiliar catfish resulted in higher pupil dilatation among individuals with previous winner experience. Among treatment combinations, a WL contest displayed the highest pupil dilatation for winners. PSV reflected socially induced stress in individuals that was accompanied by the "winner" experience and dominancy in albinos. To conclude, the present study validates pupil dilatation as a non-invasive method to evaluate stress level in pigmented as well as albino fish in various contexts.


Assuntos
Comunicação Animal , Peixes-Gato/fisiologia , Pupila/fisiologia , Estresse Psicológico/fisiopatologia , Animais , Hidrocortisona/sangue , Pigmentação da Pele , Estresse Psicológico/sangue
5.
PLoS One ; 15(10): e0239920, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33002087

RESUMO

The fitness of a predator depends upon its ability to locate and capture prey; and thus, increasing dietary specialization should favor the evolution of species-specific foraging tactics tuned to taxon-specific habitats and cues. Within marine environments, prey detectability (e.g., via visual or chemical cues) is affected by environmental conditions (e.g., water clarity and tidal flow), such that specialist predators would be expected to synchronize their foraging activity with cyclic variation in such conditions. In the present study, we combined behavioral-ecology experiments on captive sea snakes and their prey (catfish) with acoustic tracking of free-ranging sea snakes, to explore the use of waterborne chemical cues in this predator-prey interaction. In coral-reef ecosystems of New Caledonia, the greater sea snake (Hydrophis major) feeds only upon striped eel catfish (Plotosus lineatus). Captive snakes became more active after exposure to waterborne chemical cues from catfish, whereas catfish did not avoid chemical cues from snakes. Movement patterns of tracked snakes showed that individuals were most active on a rapidly falling tide, which is the time when chemical cues from hidden catfish are likely to be most readily available to a foraging predator. By synchronizing foraging effort with the tidal cycle, greater sea snakes may be able to exploit the availability of chemical cues during a rapidly falling tide to maximize efficiency in locating and capturing prey.


Assuntos
Comportamento Predatório , Serpentes/fisiologia , Ondas de Maré , Animais , Peixes-Gato/fisiologia , Recifes de Corais , Sinais (Psicologia) , Natação
6.
Ecotoxicology ; 29(9): 1522-1537, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32710163

RESUMO

One of the major problems affecting the ecosystem health is the exposure of heavy metals due to anthropogenic activities. These exposures may induce toxiogenetic damage and carcinogenesis in aquatic organism. DNA damage biomarkers for fish species detect genotoxic parameters for ecological risk assessment. In the present study, the effect of heavy metals (Cr, Cd, Cu, Fe and Mn) on DNA damage and oxidative stress of Clarias gariepinus was examined by Comet assay at Reference site and two different sampling sites of the Orontes River. Moreover, the relationship between DNA damage and physiological response to oxidative stress caused in C. gariepinus was investigated by sampling seasonal water and fish samples for one year. In this study, Cr, Cd and Cu in water column of Orontes River and the concentrations of Fe and Mn in liver tissue of C. gariepinus were highly exceed the maximum permissible limit set by EPA (1999, 2016) WHO (1989) and TEG (2012) that can cause adverse effects on environment health. SOD activities in liver tissues were significantly higher than those in muscle tissues. SOD, CAT activity and MDA levels of both Site 1 and Site 2 at Orontes River were higher than those of the Reference site. In result of the COMET analysis, the highest levels of DNA damage were found at gill and liver tissues in Site 2 (17.746 ± 1.072% T-DNA; 16.014 ± 0.710% T-DNA respectively) at Orontes river. A higher level of DNA damage in gill cells compared to liver cells was observed in all regions of the Orontes River. In Principal component analysis (PCA), the heavy metals Cd, Cr and Cu (in the water column) and MDA in liver and muscle revealed strong contribution to the observed DNA damage that were scattered opposite to each other's along the principal components. Moreover, correlations between parameters revealed a positive significant relationship between Cd, Cr and Cu in water and DNA damage levels in C. gariepinus. Pearson correlation analysis detected a positive relationship between MDA, CAT and SOD and DNA damage levels in African catfish. Consequently, this study exposed genotoxic damage and oxidative stress of C. gariepinus due to metal pollution in Orontes River and lead to the better understanding of genotoxicty, oxidative stress and heavy metal relationships.


Assuntos
Peixes-Gato/fisiologia , Monitoramento Ambiental , Metais Pesados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Metais Pesados/toxicidade , Estresse Oxidativo , Rios , Poluentes Químicos da Água/toxicidade
7.
J Environ Sci Health B ; 55(8): 749-755, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32558613

RESUMO

This study assessed the hematological, enzymatic and osmoregulatory responses of silver catfish (Rhamdia quelen) exposed to sublethal concentrations (1.125 and 3.750 µg/L) of a commercial thiamethoxam-containing insecticide used on rice crops. Groups of 6 fish per tank (in triplicate, n = 3, total 54 fish) were exposed for up to 96 h to different concentrations of the compound. After this period, fish were placed in clean water for 48 h. Two fish from each tank (6 per treatment) that had been exposed to the insecticide for 24 h were anesthetized with eugenol and blood was collected to evaluate hematological and biochemical parameters. Blood, liver and muscle were collected for determination of metabolic parameters, plasma cortisol, Cl-, Na+ and K+ levels and H+-ATPase and Na+/K+-ATPase activity in the gill. H+-ATPase activity was higher in fish exposed to 1.125 µg/L insecticide at 24 h compared to control (0.0 µg/L). Differences in cortisol levels were evidenced throughout the experimental period. These results indicated that exposure to the insecticide changed the hematological, biochemical and metabolic profile of the animals, suggesting concern about environmental safety. Therefore, we discourage the use of this pesticide in areas that come into contact with water bodies inhabited by fish.


Assuntos
Peixes-Gato/fisiologia , Inseticidas/toxicidade , Tiametoxam/toxicidade , Adenosina Trifosfatases/metabolismo , Animais , Peixes-Gato/sangue , Ecotoxicologia/métodos , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Hidrocortisona/sangue , Fígado/efeitos dos fármacos , Músculos/efeitos dos fármacos , Músculos/metabolismo , Potássio/metabolismo , Sódio/metabolismo , Testes de Toxicidade Aguda , Poluentes Químicos da Água/toxicidade
8.
Ecotoxicol Environ Saf ; 201: 110855, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32540620

RESUMO

Total dissolved gas (TDG) supersaturation generated by discharged flood water may cause the death of fish downstream of dams and severely threaten their survival during the flood season. No study has performed to investigate the effects of TDG on fish dwelling in shallows in China. Furthermore, varied TDG levels are caused by the varied flow of flood water during the spill season. Fish may alternatingly experience intermittent TDG exposure from equilibrated water and TDG-supersaturated water. However, little research on the effects of intermittent TDG exposure on fish has been conducted. To evaluate the tolerance of fish to continuous acute TDG exposure, juvenile yellow catfish living in the shallows were exposed to TDG-supersaturated water at 125%, 130%, 135% and 140% TDG for 96 h. The results showed that the juvenile yellow catfish exhibited obvious gas bubble disease (GBD) and abnormal behaviours (e.g., exophthalmos and bubbles on fins). The survival probability declined with the arising TDG levels. The median survival time (ST50) of yellow catfish was 8.57, 18.1, 33.86 and 58.84 h at above TDG levels, respectively. To further investigate the effects of intermittent TDG exposure on juvenile yellow catfish, the fish were subjected to varied TDG levels (125%, 130%, 135% and 140%) for a specific duration (3 h and 6 h) and then underwent a period of recovery (3, 6 and 9 h) in equilibrated water. The results showed that an increase in recovery time (or decreasing exposure time) can prolong the survival time of yellow catfish and improve their survival probability at the same exposure time (or same recovery time). Compared with that under continuous acute exposure, the ST50 of juvenile yellow catfish increased significantly with intermittent exposure. Intermittent exposure can enhance the tolerance of juvenile yellow catfish to TDG. The application of the results may contribute to the protection of aquatic organisms and the formulation of the scheme of reservoir operation in the Yangtze River.


Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Peixes-Gato/fisiologia , Gases/toxicidade , Rios/química , Poluentes da Água/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , China , Gases/análise , Probabilidade , Análise de Sobrevida , Movimentos da Água , Poluentes da Água/análise , Qualidade da Água
9.
Exp Parasitol ; 216: 107916, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32590020

RESUMO

Complex life cycle parasites can manipulate the behavior of intermediate hosts in order to reduce their fitness and increase the chance of completing life cycle. In order to understand the effects of the trematode parasites of the genus Clinostomum on host fish Loricariichthys platymetopon, a filmed experiment was carried out to quantify the foraging activity of hosts with different intensities of infection. The results suggest that hosts with higher parasite intensities reduced foraging activity early in the morning when compared to hosts with low intensities. This period may be critical for hosts since birds, the target hosts of such trematodes, forage intensively at dawn.


Assuntos
Peixes-Gato/fisiologia , Peixes-Gato/parasitologia , Doenças dos Peixes/parasitologia , Trematódeos/fisiologia , Infecções por Trematódeos/veterinária , Adaptação Biológica , Animais , Comportamento Animal , Evolução Biológica , Brasil , Comportamento Alimentar , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/fisiopatologia , Interações Hospedeiro-Parasita , Prevalência , Rios , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/fisiopatologia , Gravação em Vídeo
10.
Chemosphere ; 259: 127379, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32590174

RESUMO

4-Nonylphenol (4-NP) is a nephrotoxic substance that is highly prevalent in aquatic environments. Nigella sativa seed (NSS) has many biological activities and is widely used throughout the world as a medicinal product. Therefore, in the present study, we investigated the cytoprotective effect of NSS on 4-NP-induced renal damage in African catfish (Clarias gariepinus). Thirty fish were divided into five equal groups: an untreated control group and four groups that were challenged with 4-NP at a dose of 0.1 mg L-1 of aquarium water and fed a basal diet supplemented with 0%, 1%, 2.5%, and 5% NSS, respectively, for 3 weeks. Histological, histochemical, and ultrastructural features of the kidney were then assessed as biomarkers for renal tissue damage. Our results confirmed that 4-NP was a potent cytotoxic agent for the kidney tissue and induced renal damage, with 4-NP-intoxicated fish showing necrosis in the epithelial cells of the renal corpuscles, renal proximal convoluted tubules, and intertubular hematopoietic tissue, as well as loss of or a decrease in microvilli, a decrease in mitochondria, and an increase in the lysosomes in the epithelial cells of the proximal convoluted tubules. The kidneys of 4-NP-intoxicated fish also showed increased numbers of Perls' Prussian blue-positive melanomacrophage centers and intraepithelial T-lymphocytes in the proximal convoluted tubules and plasma cells. The administration of NSS to 4-NP-challenged fish significantly minimized the cytotoxic effect of 4-NP, maintaining the normal kidney structure, with concentrations of 2.5% and 5% of feed being most effective for protecting the kidney against 4-NP-induced renal damage.


Assuntos
Peixes-Gato/fisiologia , Nigella sativa , Fenóis/toxicidade , Extratos Vegetais/farmacologia , Substâncias Protetoras/farmacologia , Animais , Biomarcadores , Suplementos Nutricionais , Rim/efeitos dos fármacos , Extratos Vegetais/química , Sementes/efeitos dos fármacos
11.
J Nutr ; 150(7): 1790-1798, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32470978

RESUMO

BACKGROUND: Dietary carbohydrate affects intestinal glucose absorption and lipid deposition, but the underlying mechanisms are unknown. OBJECTIVES: We used yellow catfish and their isolated intestinal epithelial cells (IECs) to test the hypothesis that sodium/glucose cotransporters (SGLTs) 1/2 and acetylated carbohydrate response element binding protein (ChREBP) mediated glucose-induced changes in glucose absorption and lipid metabolism. METHODS: Yellow catfish (mean ± SEM weight: 4.68 ± 0.02 g, 3 mo old, mixed sex) were fed diets containing 250 g carbohydrates/kg from glucose (G, control), corn starch (CS), sucrose (S), potato starch (PS), or dextrin (D) for 10 wk. IECs were isolated from different yellow catfish and incubated for 24 h in a control or glucose (15 mM) solution with or without a 2-h pretreatment with an inhibitor [sotagliflozin (LX-4211) or tubastatin A (TBSA)]. Human embryonic kidney cells (HEK293T cells) were transfected with a Flag-ChREBP plasmid to explore ChREBP acetylation. Triglyceride (TG) and glucose concentrations and enzymatic activities were measured in the intestine and IECs of yellow catfish. They also were subjected to immunofluorescence, immunoprecipitation, qPCR, and immunoblotting. Immunoblotting and immunoprecipitation were performed with HEK293T cells. RESULTS: The G group had greater intestine TGs (0.99- to 2.30-fold); activities of glucose 6-phospate dehydrogenase, 6-phosphogluconate dehydrogenase, and isocitrate dehydrogenase (0.12- to 2.10-fold); and expression of lipogenic genes (0.32- to 2.34-fold) than the CS, PS, and D groups. The G group had greater intestine sglt1/2 mRNA and protein expression than the CS, S and D groups (0.35- to 1.12-fold and 0.40- to 4.67-fold, respectively), but lower mRNA amounts of lipolytic genes (48.6%-65.8%) than the CS and PS groups. LX-4211 alleviated the glucose-induced increase in sglt1/2 mRNA (38.2%-47.4%) and SGLT1 protein (48.0%) expression, TGs (29.3%), and lipogenic enzyme activities (27.7%-42.1%) and gene expression (38.0%-55.5%) in the IECs. TBSA promoted the glucose-induced increase in TGs (11.3%), fatty acid synthase activity (32.6%), and lipogenic gene expression (21.6%-34.4%) in the IECs and acetylated ChREBP (10.5%) in HEK293T cells. CONCLUSIONS: SGLT1/2 signaling and acetylated ChREBP mediated glucose-induced changes in glucose absorption and lipid metabolism in the intestine and IECs of yellow catfish.


Assuntos
Peixes-Gato/fisiologia , Dieta/veterinária , Glucose/administração & dosagem , Mucosa Intestinal/efeitos dos fármacos , Transportador 1 de Glucose-Sódio/metabolismo , Transportador 2 de Glucose-Sódio/metabolismo , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Transporte Biológico , Glicemia , Sobrevivência Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Metabolismo dos Lipídeos , Transdução de Sinais , Transportador 1 de Glucose-Sódio/genética , Transportador 2 de Glucose-Sódio/genética , Triglicerídeos
12.
J Fish Biol ; 96(6): 1538-1542, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32297313

RESUMO

The cuckoo catfish Synodontis multipunctatus and S. grandiops are endemic to Lake Tanganyika and the only known nonavian vertebrates that exhibit obligate interspecific brood parasitism. Seven maternal mouth-brooding cichlid fish species are reported to be natural hosts of the parasitic catfish and share a common reproductive behaviour that the catfish exploits: cichlid females spawn eggs on the bottom, allowing the catfish female to place her eggs near the cichlid eggs, and the cichlid females collect the catfish eggs by mouth together with their own eggs. However, so far it has not been reported that the cuckoo catfish exploit different spawning behaviours. The genus Cyprichromis consists of five maternal mouth-brooding species endemic to Lake Tanganyika, most of which spawn and collect eggs in open water. This study reports that the cuckoo catfish also parasitizes the open-water spawning Cyprichromis coloratus, although it may not be a regular host.


Assuntos
Peixes-Gato/fisiologia , Ciclídeos/parasitologia , Comportamento de Nidação/fisiologia , Animais , Feminino , Lagos , Reprodução/fisiologia , Tanzânia
13.
Chemosphere ; 253: 126630, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32278189

RESUMO

In this study, we have investigated biotransformation and oxidative stress responses in relation to tissue contaminant burden in the African sharptooth catfish (Clarias gariepinus) exposed to simulated leachate from a solid waste dumpsite in Calabar, Nigeria. Fish were exposed to simulated leachate, diluted to 0:0 (negative control), 1:10, 1:50, 1:100 and phenanthrene (a PAH: 50 µg/L used as a positive control) for 3, 7 and 14 days. Hepatic transcripts for cat, sod1, gpx1, gr, gst, cyp1a, cyp2d3, and cyp27 were analyzed by real-time PCR, while enzymatic assays for ethoxyresorufin O-deethylase (EROD), buthoxyresorufin O-deethylase (BROD), methoxyresorufin O-deethylase (MROD), pentoxyresorufin O-deethylase (PROD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), uridine diphospho-glucuronosyltransferase (UDPGT) and lipid peroxidase (LPO) were measured using standard methods. In addition, protein expression for CYP1A, CYP3A and metallotheionin (MT) were measured by immunoblotting. Fish muscle samples were analyzed for selected group of contaminants after 14 days exposure showing significantly high uptake of heavy metals (Cd, Hg and Pb), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorophenols, organochlorine (OC) and organophosphate pesticides in exposed fish. We observed significant concentration- and time-specific increases in biotransformation and oxidative stress responses at transcript and functional (enzyme and protein) levels, that paralleled tissue contaminants bioaccumulation patterns, after exposure to the simulated leachates. Our results highlighted the potential environmental, wildlife and public health consequences from improper solid waste disposal. In addition, it also provides a scientific basis for local sensitization and inform legislative decisions and policy formulation towards sustainable environmental management of solid wastes in Nigeria and other developing countries.


Assuntos
Peixes-Gato/fisiologia , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/metabolismo , Animais , Biotransformação , Catalase/metabolismo , Peixes-Gato/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Glutationa Peroxidase , Glutationa Transferase/metabolismo , Metais Pesados/análise , Nigéria , Estresse Oxidativo , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Resíduos Sólidos/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
14.
Sci Rep ; 10(1): 6122, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32273527

RESUMO

Sea lamprey (Petromyzon marinus) is a unique jawless vertebrate among the most primitive of all living vertebrates. This migratory fish is endangered in much of its native area due to dams, overfishing, pollution, and habitat loss. An introduced predator, the European catfish (Silurus glanis), is now widespread in Western and Southern European freshwaters, adding a new threat for sea lamprey migrating into freshwater to spawn. Here, we use a new prototype predation tag coupled with RFID telemetry on 49 individuals from one of the largest sea lamprey European populations (Southwestern France) to quantify the risk of predation for adult sea lampreys during its spawning migration in rivers with large populations of European catfish. We found that at least 80% of tagged sea lampreys (39 among 49) were preyed upon within one month, and that 50% of the released lampreys were rapidly consumed on average 8 days after tagging. This very high predation rate suggests that the European catfish represents a supplementary serious threat of extirpation for the native sea lamprey population we studied. This threat is likely to happen throughout most of the native lamprey distribution area, as the European catfish is becoming established almost everywhere the sea lamprey is.


Assuntos
Migração Animal , Peixes-Gato/fisiologia , Espécies em Perigo de Extinção , Lampreias/fisiologia , Comportamento Predatório , Animais , Reprodução
15.
Environ Pollut ; 260: 114001, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32041020

RESUMO

Application of biomarkers is an effective approach for a better understanding of varying toxicity in aquatic organisms during the seasonal and diurnal changes in the natural environment. This report describes the toxicity of sub-lethal concentrations of triclosan (TCS) at different pH (6.5, 7.5 and 8.5) based on selected biomarkers related to oxidative stress, metabolism and genotoxicity in Pangasianodon hypophthalmus. The 96 h LC50 of TCS for P. hypophthalmus was lower at pH 6.5 when compared to higher pH. The sub-lethal concentration of TCS exhibited a significant decrease in hematological parameters related to complete blood counts except for total leukocyte count (TLC), mean cell haemoglobin concentration (MCHC) and red cell distribution width (RDW). Multivariate data analysis showed a significant interaction of TCS and pH in metabolizing enzymes like glutamic oxaloacetate transaminase (GOT), glutamic pyruvic transaminase (GPT), Lactate dehydrogenase (LDH), antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione-s-transferase (GST) and neurotransmitter enzyme acetylcholinesterase (AChE). A significant increase in DNA damage and micronuclei frequency in liver and blood cells of TCS exposed fish at pH 6.5 indicate that the TCS exposure has pronounced effects on genetic materials. The findings of present study establish that enzymes like SOD, LDH, GOT, AChE, DNA damage and micronuclei frequency can be successfully deployed as biomarkers for the assessment of toxicity of TCS in fish.


Assuntos
Peixes-Gato/fisiologia , Triclosan/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Catalase , Concentração de Íons de Hidrogênio , Estresse Oxidativo , Superóxido Dismutase
16.
Sci Rep ; 10(1): 2425, 2020 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-32051528

RESUMO

This study investigated the use of electric-shock in inducing triploidy in African catfish Clarias gariepinus. To achieve this, three voltages (9, 12, 21 V) were applied for different durations (3, 5, 10 min). The shock was initiated approximately three minutes after fertilization followed by incubation in ambient temperature. After incubation, hatchability and survival rates were determined while ploidy status of the treatment fishes was confirmed in one-month-old fingerlings using the exclusive triploid range of the erythrocyte major axis previously reported for the same species (11.9-14.9 µm) and by cytogenetic analysis of the chromosome. The results showed triploidy were achieved in 10 to 85% of the treatment groups. A consistent trend of decrease in hatchability and an increase in triploidy rate was observed with increased electroporation voltages and shock durations. The mean erythrocyte major axis length of triploid progenies (3n = 84) was observed to be between 11.3-14.6 µm and was higher than the range of 7.0-10.5 µm recorded for diploid progenies (2n = 56). It was concluded that electric shock can be used to induce triploidy in African catfish C. gariepinus.


Assuntos
Peixes-Gato/genética , Eletroporação , Triploidia , Animais , Peixes-Gato/fisiologia , Diploide , Eletroporação/métodos , Eritrócitos/citologia , Eritrócitos/metabolismo , Feminino , Fertilização , Masculino
17.
Environ Toxicol Pharmacol ; 75: 103324, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31926371

RESUMO

Pendimethalin (PM) is a selective herbicide, widely present in aquatic environment. It causes detrimental effects in fishes, but little is known regarding its reproductive toxicity. The present study was carried out in Clarias batrachus exposed to sub lethal concentrations of PM for 30, 45 and 60 days. Male fish showed a significant increase in plasma 17ß-estradiol (E2) however plasma E2 in females was not affected. Plasma testosterone levels were significantly decreased in both sexes. In male plasma vitellogenin (VTG) and gonadal aromatase activity was increased irrespective of herbicide concentration and exposure duration. In females concentration and time dependent reduction in plasma VTG but no significant change in the gonadal aromatase activity were observed. Results indicated that PM act as endocrine disruptor but act differentially in male and female fishes and plasma E2, T and VTG levels and aromatase activity can be considered as reliable biomarkers for PM toxicity in fishes.


Assuntos
Compostos de Anilina/toxicidade , Aromatase/metabolismo , Vitelogeninas/sangue , Poluentes Químicos da Água/toxicidade , Animais , Peixes-Gato/fisiologia , Disruptores Endócrinos/toxicidade , Feminino , Herbicidas , Masculino
18.
Fish Physiol Biochem ; 46(1): 177-186, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31709461

RESUMO

The full-length cDNA coding IGF-I was cloned from the liver of Yellow catfish Pelteobagrus fulvidraco. The tissue distributions of IGF-I in adults were then analyzed by using real-time PCR. The effects of starvation (3 weeks) and subsequent refeeding (3 weeks) on the compensatory growth performance in juvenile fish weighing 3.80 ± 0.78 g and hepatic IGF-I mRNA expressions were also investigated. The cDNA obtained covered 884 bp with an open reading frame of 480 bp encoding 159 amino acids. It is composed of a signal peptide with 41 amino acids (AAs), a mature peptide comprising the B, C, A, and D domains (71 AAs) and E domain of 47 AAs. Sequence alignment and phylogenetic analysis revealed a high degree of conservation (71-87%) among the species of Siluriformes and some closely related species. In adults, the highest IGF-I expression was observed in the liver, followed by the brain, whereas relatively low expressions were detected in muscle and stomach. Both body weight and length increased significantly in fish fed to satiation continuously. Body weight, body length, condition factor, and hepatic IGF-I expressions were all decreased remarkably with increasing starvation times, but increased significantly after refeeding. The results showed that the expression of IGF-I was positively correlated with feed intakes and IGF-I may play a key regulatory role for somatic growth induced by compensatory growth in Yellow catfish.


Assuntos
Peixes-Gato/fisiologia , Fator de Crescimento Insulin-Like I/metabolismo , Inanição/metabolismo , Sequência de Aminoácidos , Animais , DNA Complementar , Proteínas de Peixes , Fator de Crescimento Insulin-Like I/genética , Fígado , Filogenia , Distribuição Tecidual
19.
Trop Anim Health Prod ; 52(2): 839-849, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31586318

RESUMO

Search for cost-effective, eco-friendly and sustainable plant resources as potential feedstuff to replace fishmeal in the formulation of feed for fish has been in the forefront of aquaculture researches since the last few years. In this study, experiments were conducted to evaluate if replacement of fishmeal by the fermented leaf meal of mulberry (Morus indica) was viable in the formulation of feed for carp fish Labeo rohita and catfish Heteropneustes fossilis. Four iso-proteinous, iso-lipidic and iso-energetic experimental feed were formulated by replacing 0, 25, 50 and 75% of fishmeal by the fermented mulberry leaf meal (FMLM), and both species were grown on these feeds for 8 weeks. Since the results revealed differences in response to fishmeal replacement level between parameters, we determined optimum fishmeal replacement level (OFRL) for each parameter from the polynomial curve equation. While maximum weight gain and specific growth rate and minimum feed conversion ratio was found at 30-32% OFRL for L. rohita and at 52-53% OFRL for H. fossilis, other parameters responded differently in both fish. Therefore, we applied a two-phase fuzzy goal programming technique using all parameters, which showed overall OFRL for L. rohita and H. fossilis as 30.95% and 52%, respectively. We also applied the concept of 'decision tree' to identify the key factor behind utilization of FMLM. It was concluded that activity of amylase and subsequent utilization of carbohydrate was the key factor in utilizing FMLM. Interestingly, H. fossilis was found more efficient in utilizing carbohydrate of FMLM than L. rohita.


Assuntos
Ração Animal/análise , Carpas/fisiologia , Peixes-Gato/fisiologia , Morus/química , Folhas de Planta/química , Ganho de Peso , Animais , Carpas/crescimento & desenvolvimento , Peixes-Gato/crescimento & desenvolvimento , Dieta/veterinária , Fermentação
20.
Anat Histol Embryol ; 49(1): 67-79, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31513301

RESUMO

A series of histochemical techniques have been employed to localize alkaline phosphatase, acid phosphatase, non-specific esterase, catalase and peroxidase; and to visualize and characterize glycoprotein (GPs) moieties in the epithelium of gill arch, gill filaments and secondary lamellae of an angler catfish Chaca chaca. The epithelium of gill arch and gill filament shows strong alkaline phosphatase activity in the deeper layer epithelial cells; strong non-specific esterase activities in the outer layer epithelial cells; and weak acid phosphatase activity throughout the epithelium. The activity of these enzymes in the secondary lamellae is weak. The catalase and peroxidase show strong activities in the blood cells of the secondary lamellae. Various classes of GPs have been identified and characterized in the mucous secretions of the gill epithelium of C. chaca. These include-GPs with oxidizable vicinal diols, GPs with sialic acid residues without O-acyl substitution and GPs with O-sulphate esters. The functional significance of different enzymes in gill epithelium and the GPs in the mucus secreted on the surface has been discussed with the physiology of the gills in relation to the characteristic habit and habitat of the fish.


Assuntos
Peixes-Gato , Epitélio/enzimologia , Brânquias/enzimologia , Animais , Catalase/metabolismo , Peixes-Gato/fisiologia , Brânquias/citologia , Glicoproteínas/metabolismo , Histocitoquímica , Muco/metabolismo , Peroxidase/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo
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