Liver Of Catfish Research Articles

Nitric oxide levels in brain, liver, and gills of silver catfish (Rhamdia quelen) exposed to the antiparasitic eprinomectin.

Nitric oxide (NO) is a mediator and biomarker of pro- and anti-inflammatory processes. Excessive levels of NO for long periods have been associated with inflammation and tissue damage. The metabolism and synthesis of NO is usually measured indirectly, as metabolites and enzymes involved in reactions, often as the nitrite/nitrate (NOx) level. The aim of the present study was to measure the NOx levels in vital organs of juvenile silver catfish (Rhamdia quelen) exposed to various levels of eprinomectin in the water. The fish were exposed for 24 and 48h to start concentration (0h) of eprinomectin in water (0.0, 1.12, 1.80, and 3.97μg/L). The eprinomectin concentrations in water were lower at 24h (0.0, 0.85, 1.14, and 1.15μg/L) and 48h (0.0, 0.39, 0.69, and 1.28μg/L), due to the process of eprinomectin metabolization. Subsequently, the fish were left for 48h of recovery in eprinomectin-free water. NO levels were measured indirectly, as NOx levels in brain, liver, and gill tissue. Within 24h of exposure, there was no significant increase in NOx levels in the organs evaluated at any of the concentrations tested. However, increases in NOx levels did occur at 48h of exposure in all organs, particularly at the two highest concentrations of eprinomectin (1.80 and 3.97μg/L). The transfer of fish to eprinomectin-free water did not result in reversal of NOx levels after 48h of recovery, especially in fish that had been exposed to the two highest concentrations in the brain and liver tissues, and for the highest concentration in the gills. We conclude that silver catfish exposed to eprinomectin for up to 48h present possible cerebral, hepatic, and branchial inflammatory process associated with increased tissue NOx levels, and that recovery for 48h in water without antiparasitic is insufficient for the fish to recover from the poisoning.

FXR-mediated inhibition of autophagy contributes to FA-induced TG accumulation and accordingly reduces FA-induced lipotoxicity

BackgroundExcessive dietary fat intake induces lipid deposition and contributes to the progress of nonalcoholic fatty liver disease (NAFLD). However, the underlying mechanisms are still unclear.MethodsYellow catfish were given two experimental diets with dietary lipid levels of 11.3 and 15.4%, respectively, for 56 days, and the contents of triglyceride (TG), nonesterified free fatty acids (NEFA) and bile acid (BA), RNA-seq, enzymatic activities and mRNA expression were deteremined in the liver tissues. Hepatocytes from yellow catfish liver tissues were isolated and cultured. Fatty acids (FA) (palmitic acid: OA, oleic acid =1:1), pathway inhibitors (MA, autophagy inhibitor; guggulsterone, FXR inhibitor) and agonist (rapamyicn, autophagy agonist; GW4064, FXR agonist) were used to incubate the cells. TG and NEFA contents, ultrastructural observation, autophagic vesicles and intracellular LD,apoptosis,western blot and Co-IP, and Immunofluorescence analysis, enzymatic activities and Q-PCR were decided.ResultsUsing RNA sequencing, we found that high fat diets induced changes in expression of many genes associated with the pathways of lipid metabolism and autophagy. The mRNA profiles of the differentially expressed genes (DEG) indicated that high dietary fat-induced lipid deposition was predominantly influenced by the inhibition of autophagy. Using primary hepatocytes, we found that fatty acids (FA) suppressed autophagy, which in turn reduced cellular free FA level by decreasing triglyceride (TG) breakdown. Moreover, our study indicated that farnesoid X receptor (FXR)-cyclic AMP-responsive element-binding protein (CREB) axis was the pivotal physiological switch regulating FA-induced changes of autophagy and lipid metabolism, which represented cellular defenses against FA-induced lipotoxicity.ConclusionThis discovery may provide new targets for treating pathological changes involved in the dysfunction of autophagy and metabolism, including NAFLD.AmrG3KeYnpRNJADevGhfpFVideo Graphical abstract

Effect of stocking density on growth, hematological and biochemical parameters and antioxidant status of silver catfish (Rhamdia quelen) cultured in a biofloc system

Biofloc technology (BFT) is a technique of enhancing water quality, focused on a more efficient use of nutrients and lower water consumption. This technology may result in higher productivity with less impact to the environment. This work aimed to assess the effect of different stocking densities (SD) on growth, hematological and biochemical parameters and antioxidant status of silver catfish (Rhamdia quelen) juveniles cultured in a biofloc system. Three different SDs were used: 10, 20 and 30 g of biomass/L (designated as treatment D10, D20 and D30, respectively). After 45 days, fish from D30 group showed significantly improved growth performance (final weight and daily weight gain) and lower fat deposition in the fillet. Aspartate aminotransferase (AST) levels and superoxide dismutase (SOD) activity were significantly reduced in the liver of silver catfish reared at the higher SD. In addition, fish from D30 group showed the lower values for lipid peroxidation (TBARS) in muscle and gill tissue. These results indicate that an initial SD of 30 g of biomass/L appears appropriate for silver catfish juveniles cultured in a BFT system.

MiR-144 Mediates High Fat–Induced Changes of Cholesterol Metabolism via Direct Regulation of C/EBPα in the Liver and Isolated Hepatocytes of Yellow Catfish

Background:microRNAs (miRNAs) post-transcriptionally regulate gene expression and act as important modulators of cholesterol homeostasis. Objectives:The study explores the mechanism by which miRNAs mediate high fat–induced changes of cholesterol metabolism in yellow catfish. Methods:Yellow catfish (weight: 3.79 ± 0.16 g, 3 mo old, mixed sex) were fed 2 diets containing lipids at 11.3% [control (CON)] or 15.4% [high-fat diet (HFD)] (by weight) for 8 wk. Cholesterol content was measured; hematoxylin-eosin (H&E) staining, qPCR assays, and small RNA sequencing were conducted in the liver. Hepatocytes were isolated from separate, untreated fish and incubated for 24 h in control solution or palmitic acid (PA; 0.25 mM)/oleic acid (OA; 0.5 mM) after 4 h pretreatment with or without miR-144 inhibitor/mimic (40 nM). Cholesterol content was measured; qPCR assays and Western blotting were conducted in the hepatocytes. HEK293T cells were co-transfected with plasmids to validate miR-144 target genes. The promoter activities of miR-144 were analyzed in HEK293T cells with PA (0.25 mM) or OA (0.25 or 0.5 mM) treatment for 24 h. Luciferase activity assays, electrophoretic mobility shift assay, and Western blotting were conducted in HEK293T cells. Results:Compared with CON, HFD induced hepatic cholesterol accumulation (31.5%), and upregulated miR-144expression (8.40-fold, P < 0.05). miR-144 directly targeted hydroxymethylglutaryl-CoA reductase (hmgcr), cholesterol7á-monooxygenase A1 (cyp7a1), and adenosine triphosphate binding cassette transporter A1 (abca1) in HEK293T cells.In the hepatocytes of yellow catfish, miR-144 inversely regulated the expression of hmgcr, cyp7a1, and abca1 (30.3–78.5%, P < 0.05); loss ofmiR-144 function alleviated PA-or OA-induced cholesterol accumulation (19.5–61.1%, P <0.05).We also characterized the C/EBPá binding site in themiR-144 promoter, and found that C/EBPá positively regulated miR-144 expression through binding to the miR-144 promoter. Conclusions:miR-144 mediated HFD-induced changes in the liver and hepatocytes of yellow catfish, suggesting a possible mechanism for HFD-induced dysfunction in cholesterol metabolism.

Isolation of Chryseobacterium siluri sp. nov., from liver of diseased catfish (Silurus asotus)

Yellow-pigmented, circular bacteria (strain SNU WT7) were isolated from the liver of moribund eastern catfish (Silurus asotus). Our study focused on the taxonomic description of SNU WT7 using phylogenetic, phenotypic, and chemotaxonomic analyses. The 16S rRNA gene sequence of the SNU WT7 strain was highly similar to that of Chryseobacterium haifense H38T (97.29% similarity), followed by Chryseobacterium hominis P2K6T (97.22% similarity), while other species exhibited similarity values of less than 97.0%. The genome of strain SNU WT7 displayed average nucleotide identity and genome-to-genome distance values of 72.35% and 22.0%, respectively, which clearly indicated that the novel species was distant from the other Chryseobacterium species, with its closest relative being C. haifense H38T. Furthermore, the phenotypic characteristics, including acid production from glucose, D-fructose, lactose, and maltose, of strain SNU WT 7 differed from those of C. haifense H38T. The major polar lipid of the strain was phosphatidylethanolamine, and several unidentified aminolipids and lipids were also present. Similar to other Chryseobacterium species, the quinone system was composed mainly of MK-6. The genome of SNU WT7 is 2,690,367 bp with a G + C content of 43.6%. Taken together, our data indicate that the isolate SNU WT7 represents a novel species of the genus Chryseobacterium. Thus, we present the name Chryseobacterium siluri sp. nov. for the novel type strain SNU WT7T (KCTC 72626, JCM 33707).

Inter‐and intra-stock bioaccumulation of anionic arsenic species in an endangered catfish from South American estuaries: Risk assessment through consumption

Monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), inorganic arsenic (iAs), and non-toxic species (i.e. arsenobetaine) were determined by HPLC-ICP-MS as mg kg−1 wet weight in muscle, liver and gill of catfish (Genidens barbus) from Argentina (N = 12) and from Brazil (N = 11). Concentrations (mean ± standard deviation) of non-toxic arsenic species were 10.4 ± 2.89 and 14.9 ± 5.94 for muscle, 1.48 ± 0.58 and 2.21 ± 1.24 for liver, and 0.66 ± 0.39 and 2.44 ± 1.93 for gill, respectively, for Argentina and Brazil, and represented 95.5%–99.5% of the total arsenic for each tissue. Toxic arsenic (iAs) levels were 0.048 and 0.013 for muscle, 0.24 and 0.011 for liver, and 0.037 and 0.012 for gill and represented 0.45–4.93 % of the total arsenic for Argentina and 0.24-0.60 % for Brazil. The iAs concentrations for all tissues were below the recommended international and local legislations of 0.1-1.0. Based on iAs in muscle, target hazard quotients were 0.032 and 0.018, respectively, for Argentina and Brazil. Risks external (skin) cancer and internal (bladder/lung) cancer were 1.4 × 10-5 and 1.9 × 10-4 for Argentina and 7.3 × 10-6 and 9.9 × 10-5 for Brazil, suggesting that populations may be exposed to an internal cancer risk through chronic consumption. Risk assessments need to be based on specific fish and their iAs concentrations in muscle.

Effect of Nauclea subdita (Korth.) Steud. leaf extract on hematological and histopathological changes in liver and kidney of striped catfish infected by Aeromonas hydrophila.

Aim:The present study was conducted to investigate the efficacy of different doses of Bangkal (Nauclea subdita) leaf extract on hematological and histological changes in kidney and liver of catfish (Pangasius hypophthalmus) infected by Aeromonas hydrophila.Materials and Methods:Catfish were experimentally infected with A. hydrophila at a dose of 108 cells/mL through intraperitoneal injection, and the hematological and histological changes in the kidney and liver of catfish against the pathogen were observed.Results:Not all concentrations of N. subdita caused a toxic effect in striped catfish. The clinical symptoms of catfish after infection with A. hydrophila and treatment with N. subdita leaf extract included morphological and behavioral changes. N. subdita leaf extract reduced mortality caused by A. hydrophila. Treatment with N. subdita leaf extract was effective in reducing the inflammation by decreasing the activity of neutrophils, monocytes, and lymphocytes. The Hb and Ht levels of catfish significantly decreased after exposure to 108 cells/mL of A. hydrophila and increased significantly after N. subdita treatment. Necrosis percentages in the kidney and liver also decrease after N. subdita treatment.Conclusion:The results indicate that N. subdita leaf extract stimulates the immunity and increases the resistance of catfish to A. hydrophila. N. subdita leaf extract may be used as a potential source for future drug development and food applications.

Acrylamide-induced hematotoxicity, oxidative stress, and DNA damage in liver, kidney, and brain of catfish (Clarias gariepinus).

This study was carried out to explore the possible deleterious impacts of acrylamide (ACR) on catfish (Clarias gariepinus). The estimation of mortalities, the examination of the clinical picture, the evaluation of blood parameters, oxidative stress, DNA damage, and the histopathological picture were performed in the liver, kidney, and brain samples of the experimentally ACR-exposed catfish. The 96 hours LC50 value was estimated to be 133 mg/L by the hydrostatic method. Fish were reared in water containing four different concentrations of ACR as follows: 20%, 40%, 60%, and 80% of the estimated LC50 for 2 weeks. Abnormal behavioral, clinical, and postmortem responses were depicted. The anemic response including significant decreases in red blood cells, hemoglobin, and packed cell volume following the ascending concentrations of ACR were recorded. The malondialdehyde was significantly increased, whereas reduced glutathione level, superoxide dismutase, and total antioxidant capacity were significantly decreased. The DNA fragmentation assay illustrated a clear laddering pattern in all the tested organs. Notably, the brain was the most influenced organ. It is presumed that ACR contamination showed adverse impacts on the catfish.

MiR-489-3p Regulates the Oxidative Stress Response in the Liver and Gill Tissues of Hybrid Yellow Catfish (Pelteobagrus fulvidraco♀ × P. vachelli♂) Under Cu2+ Exposure by Targeting Cu/Zn-SOD.

Copper/zinc superoxide dismutase (Cu/Zn-SOD) plays critical roles in protecting cells and tissues against oxidative damage. Excessive copper ions (Cu2+) in water can damage the cells of aquatic organisms, leading to impaired growth and development and reduced antioxidant defenses. Many regulatory factors control the response to excess Cu2+. Among them, microRNAs (miRNAs) are important small RNAs that regulate the expression of their target genes and participate in the oxidative stress response. In the present study, we used bioinformatics and dual luciferase reporter gene analyses to demonstrate that the miR-489-3p of hybrid yellow catfish (Pelteobagrus fulvidraco♀ × P. vachelli♂) binds to the 3′-untranslated region (UTR) of its target gene, which encodes a Cu/Zn-SOD. The regulatory relationship between this miRNA and its target gene Cu/Zn-SOD was analyzed using qRT-PCR and luciferase activity assays. We also investigated the effect of the loss of miR-489-3p expression on the oxidative stress response of hybrid yellow catfish exposed to Cu2+. The Cu/Zn-SOD 3′UTR region was found to be fully complementary to positions 2–9 of the 5′-end seed region of miR-489-3p. The miR-489-3p expression levels were negatively related to Cu/Zn-SOD expression. Silencing of miR-489-3p up-regulated Cu/Zn-SOD expression in the liver and gill tissues, increased activities of SOD and catalase, and reduced the malondialdehyde content. This study is the first to demonstrate that miR-489-3p targets Cu/Zn-SOD to mediate the oxidative response to metal stress. These findings provide a theoretical basis for further studies on the response to oxidative stress caused by metals in cultured fish, and provide an experimental basis for the management of the culture environment.

Membrane associated protein flotillin in Litopenaeus vannamei plays a role in WSSV infection

Edwardsiella ictaluri causes enteric septicemia of catfish (ESC), a major disease occurring in these siluriform fish. As the liver is an important organ for defending against bacterial pathogens in fish, this study aimed to determine the liver immune response at the protein level. The differential proteomes of the darkbarbel catfish liver in response to E. ictaluri infection were identified with isobaric tags for relative and absolute quantitation (iTRAQ) labeling followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Using a 1.2-fold change in expression as a physiologically significant benchmark, a total of 819 differentially expressed proteins were reliably quantified using iTRAQ analysis, including 6 up-regulated proteins and 813 down-regulated proteins. GO enrichment analysis indicated that the “complement activation, alternative pathway” and “complement activation, classical pathway” were significantly enriched. KEGG enrichment analysis indicated the “antigen processing and presentation” and “bacterial secretion system” were significantly enriched. We selected the 6 up-regulated proteins and 10 immune-related down-regulated proteins for validation using real-time PCR. The 10 immune-related proteins included complement component C1r, C3, C5, C7, and C9 and plasma protease C1 inhibitor (C1-INH), signal recognition particle 54 kDa protein (SRP54), SRP receptor, proteasome activator complex subunit 1 (PSME1) and major histocompatibility complex class I (MHC class I) were selected from the GO clusters and KEGG pathways. The variations in mRNA expression for these genes were similar to the results of iTRAQ. This is the first report detailing the proteome response in the darkbarbel catfish liver during E. ictaluri infection and markedly contributes to our understanding of the defense mechanisms in the livers of darkbarbel catfish.

Expression of messenger RNA encoding two cellular metabolic regulators, AMP-activated protein kinase (AMPK) and O-GlcNAc transferase (OGT), in channel catfish: Their tissue distribution and relationship with changes in food intake

AMP-activated protein kinase (AMPK) is considered as the master cellular metabolism regulator that activates various proteins, including O-GlcNAc transferase (OGT). Physiological roles of AMPK and OGT, including the relationship between their mRNA expression and food intake, are poorly understood in channel catfish. This study examined the tissue distribution of AMPK and OGT mRNA and changes in their expression in response to changes in food intake in channel catfish. Expression of all AMPK subunit and OGT mRNA was detectable in the whole brain, liver, heart, spleen, white muscle, and kidney of channel catfish. The OGT mRNA was highly localized in the brain compared to other tissues. 28-day fasting increased hepatic expression of AMPK α1, β1, and OGT mRNA while refeeding fish for 14 days after the 14-day fast decreased their expression to the level similar to that of fish that were fed daily. No changes were noted in the expression of muscle and brain AMPK mRNA or OGT mRNA by fasting and refeeding. Hepatic AMPK α1, α2 and β1 mRNA decreased in response to increased feeding frequency, whereas no changes in the expression of AMPK or OGT mRNA were noted in the brain or the muscle. Results of the current study indicated that the hepatic expression of AMPK and OGT mRNA appeared to be more sensitive to changes in food intake in channel catfish. However, further studies are needed to clearly demonstrate if food intake influences the expression of AMPK and OGT mRNA in various tissues, including the hypothalamus.

Toxicity bioassay and sub-lethal effects of diazinon on blood profile and histology of liver, gills and kidney of catfish, Clarias gariepinus.

The catfish, Clarias gariepinus, was exposed to different acute concentrations (5-10 mg/l) of diazinon and the Lc50 value was recorded as high as 7.3 mg/l for 96 hours. The fishes exposed to three sub-lethal levels of diazinon (0.73, 1.095 and 1.46 mg/l) for 30 days showed that the pesticide induces changes in different blood parameters. Number of red blood cells (RBC), haemoglobin level and haematocrit values were elevated whereas white blood cells (WBC) count was reduced. Various blood indices like mean corpuscular volume (MCV), mean corpuscular haemoglobine (MCH) and mean corpuscular haemoglobine concentration (MCHC) vary insignificantly in the fish treated with diazinon. Glucose level and activity level of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was increased in Clarias gariepinus exposed to diazinon. Protein level in plasma of fish treated with pesticide was changed but the change was insignificant. Histological changes in the liver, gills and kidney of fishes exposed to diazinon were apparent when compared to control. Hepatocytes necrosis and bleeding were more distinct in the fishes exposed to pesticide. Glomerulus hypertrophy and bleeding in kidneys; and fusion and degeneration of secondary lamellae and epithelial hyperplasia in gills were also observed in the exposed fish.

The relationship between food exposure frequency and expression of AMP‐activated protein kinase (AMPK) mRNA in the brain, liver, and muscle of channel catfish

Obesity poses serious challenges to our healthcare system with serious consequences of associated diseases. Our laboratory has been examining how the expression of genes involved in food intake and tissue nutrient metabolism is associated with the development of obese‐like phenotypes in channel catfish. The objective of the study was to examine changes in expression of AMPK mRNA in response to changes in feeding frequency. Fish were fed every 12 (overfed), 24 (control), or 48 (underfed) hours (n= 4 tanks per treatment, 8 fish per tank) for 28 days. Brain, liver, and muscle tissue were collected at the end of the study. The expression of the AMPK mRNA was examined using quantitative RT‐PCR. The muscle expression of all AMPK subunit mRNA was unaffected by feeding frequency. In contrast, brain expression of alpha 1 and beta 1 subunit mRNA had a linear tendency for increase in response to increased feeding frequency. Hepatic expression of alpha 2 and beta 1 mRNA was lower in the overfeed group compared to those assigned as control or underfeed. Hepatic expression of alpha 1 mRNA decreased linearly in response to increased feeding frequency. Our results demonstrated that the hepatic and the brain expression of AMPK mRNA was influenced by increase in exposure to food in a transcript‐specific manner. Given that the AMPK serves as a regulator of tissue nutrient sensing and metabolism in mammals, it is possible that AMPK may share a similar function in the brain and liver but not in the muscle of channel catfish.Support or Funding InformationKansas IDeA Network of Biomedical Research Excellence Network (NIH/NIGMS grant number P20GM103418)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Change in Two-Spot Catfish Histopathological Liver (Mystus nigriceps) Accumulated with Heavy Metal Cadmium (Cd) in Ketingan Estuary, Sidoarjo - East Java, Indonesia

Two-spot catfish (Mystus nigriceps) is freshwater aquatic organism that can survive against the change in a polluted aquatic environment. The aim of this study is to determine the content of heavy metal cadmium (Cd) in sediment, water, and organ of two-spot catfish (Mystus nigriceps) and to examine the histopathological changes in its liver of two-spot catfish living in the waters of Ketingan Estuary river, Sidoarjo, East Java. The results showed that there were damages in liver of 9 samples of two-spot catfish taken from 3 stations. Those damages were were hepatocyte congestion and swelling on the liver. The observations on heavy metal content i.e. cadmium (Cd) in the water, sediment and the two-spot catfish liver showed that they were above the specified threshold. The water quality, i.e. temperature, pH, DO, and brightness were well within the required range.

ITRAQ analysis of liver immune-related proteins from darkbarbel catfish (Pelteobagrus vachelli) infected with Edwardsiella ictaluri

Edwardsiella ictaluri causes enteric septicemia of catfish (ESC), a major disease occurring in these siluriform fish. As the liver is an important organ for defending against bacterial pathogens in fish, this study aimed to determine the liver immune response at the protein level. The differential proteomes of the darkbarbel catfish liver in response to E. ictaluri infection were identified with isobaric tags for relative and absolute quantitation (iTRAQ) labeling followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Using a 1.2-fold change in expression as a physiologically significant benchmark, a total of 819 differentially expressed proteins were reliably quantified using iTRAQ analysis, including 6 up-regulated proteins and 813 down-regulated proteins. GO enrichment analysis indicated that the “complement activation, alternative pathway” and “complement activation, classical pathway” were significantly enriched. KEGG enrichment analysis indicated the “antigen processing and presentation” and “bacterial secretion system” were significantly enriched. We selected the 6 up-regulated proteins and 10 immune-related down-regulated proteins for validation using real-time PCR. The 10 immune-related proteins included complement component C1r, C3, C5, C7, and C9 and plasma protease C1 inhibitor (C1-INH), signal recognition particle 54 kDa protein (SRP54), SRP receptor, proteasome activator complex subunit 1 (PSME1) and major histocompatibility complex class I (MHC class I) were selected from the GO clusters and KEGG pathways. The variations in mRNA expression for these genes were similar to the results of iTRAQ. This is the first report detailing the proteome response in the darkbarbel catfish liver during E. ictaluri infection and markedly contributes to our understanding of the defense mechanisms in the livers of darkbarbel catfish.

Arsenic, selenium, and metals in a commercial and vulnerable fish from southwestern Atlantic estuaries: distribution in water and tissues and public health risk assessment.

The anadromous catfish Genidens barbus is a vulnerable and economically important species from the Southwestern Atlantic Ocean. Concentrations of As, Co, Fe, Se, and Zn were determined in water and muscle, gill, and liver of catfish from two southwestern Atlantic estuaries (Brazil and Argentina) and health risk via fish consumption was evaluated. High spatial variability was observed in the metals, As, and Se distribution for both estuaries. Considering all tissues, element concentrations (mg/kg, wet weight) were As = 0.41-23.50, Co = 0.01-2.9, Fe = 2.08-773, Se = 0.15-10.7, and Zn = 3.97-2808). Most of the trace elements tended to be higher in Brazil than in Argentina, except for Co, Fe, Se, and Zn in liver and Fe and Co in muscle and gill, respectively. Arsenic accumulation order was muscle > liver ≥ gill. Only As (muscle) was above the maximum recommended by international guidelines at both estuaries. The target hazard quotient ranged from 0.10 to 1.58, suggesting that people may experience significant health risks through catfish consumption. Supposing that the inorganic/toxic As ranged between 1 and 20% of the total, the recommended maximum intakes per capita bases were 6.1-95 and 8.4-138kg/year (wet weight) for Brazil and Argentina, respectively. Carcinogenic risk for As intake was within the acceptable range but close to the recommended limit (> 10-4). These results highlights the importance of quantifying the As species in catfish muscle in order to generate more reliable risk estimates.

Effect of Zinc on the Histopathology of Gill, Liver and Kidney of Fresh Water Catfish, Clarias batrachus (Linn.)

Effect of Zinc on the Histopathology of Gill, Liver and Kidney of Fresh Water Catfish, Clarias batrachus (Linn.)

Identification of 10 SUMOylation-Related Genes From Yellow Catfish Pelteobagrus fulvidraco, and Their Transcriptional Responses to Carbohydrate Addition in vivo and in vitro.

SUMOylation is a kind of important post-translational modification. In the present study, we identified 10 key genes involved in SUMOylation and deSUMOylation (sumo1, sumo2, sumo3, sae1, uba2, ubc9, pias1, senp1, senp2, and senp3) in yellow catfish Pelteobagrus fulvidraco, investigated their tissue expression patterns and transcriptional responses to carbohydrate addition both in vivo and in vitro. All of these members shared similar domains to their orthologous genes of other vertebrates. Their mRNAs were widely expressed in all the tested tissues, but at variable levels. Dietary carbohydrate levels differentially influenced the mRNA levels of these genes in liver, muscle, testis, and ovary of yellow catfish. Their mRNA levels in primary hepatocytes were differentially responsive to glucose addition. Our study would contribute to our understanding into the molecular basis of SUMOylation modification and into the potential SUMOylation function in the carbohydrate utilization in fish.

Concentrations of microcystins in the muscle and liver tissues of fish species from Koka reservoir, Ethiopia: A potential threat to public health

Herein, we report the presence and concentrations of three most common variants of microcystin (MC–LR, –RR and –YR) in the liver and muscle tissues of wild Nile Tilapia (Oreochromis niloticus), Common Carp (Cyprinus carpio) and African Sharp Tooth Catfish (Clarias gariepinus), which were collected from two study sites of the present study on Koka reservoir, Ethiopia. A total of 36 fish liver and 36 fish muscle samples were collected for six months. Microcystins (MCs) were quantified using LC-ESI-HRMS. The results show that MCs were found in most of the fish liver samples, while they were below the detection limit of the method of analysis used in the muscle samples. In addition to the three most common congeners of MCs, eight other microcystin variants and cylindrospermopsin were detected in the fish liver samples although further detailed study is needed. Among the three most common MC congeners, MC-LR was more prevalent than MC-RR and MC-YR in the liver samples of the three fish species. The highest MC concentration was found in Nile Tilapia collected in April (591.60 μg/g DW of MC-LR), whereas the lowest detected concentration was in Catfish collected in March (2.23 μg/g DW of MC-RR). The results of this study suggest that further intensive assessment and monitoring of the reservoir from different perspectives should be conducted in order to reduce the concentrations of the MCs and seek solutions to the potential public health risk. Moreover, this is the first study ever to report detailed quantification of MCs in fish liver and muscle samples collected from Ethiopia.

DETEKSI BAKTERI GENUS VIBRIO SEBAGAI CAUSATIVE AGENT PADA IKAN LELE SANGKURIANG (CLARIAS GARIEPINUS VAR. SANGKURIANG) DI KOTA TASIKMALAYA

Sangkuriang catfish (Clarias gariepinus var Sangkuriang) is the main commodity that widely cultivated in Tasikmalaya City. However, farmers have difficulty because of the disease which causes death in fish. High mortality is suspected as a vibriosis disease by genus Vibrio because redness wounds on dead fish. The purpose of this study is to know the genus Vibrio which causes of disease in Sangkuriang catfish. 10 samples of fish were taken from Sangkuriang catfish pond culture in Kelurahan Kersanagara Tasikmalaya City which were potentially suspected of vibriosis disease. Isolation of bacteria were done on TCBS medium. Bacterial isolates were collected from fish lesion on the body surface, liver, and kidneys of catfish. Isolation were able to gained 21 isolates and then 5 isolates (VK1, VK5, VK7, VK17, and VK21) were selected based on colony morphology and Postulates Koch’s were tested. The results showed that the clinical symptoms of catfish infected by vibriosis were redness lesions/ulcers on the body surface, hemorrhagic, fluid inside stomach, and fin eroded with redness wound. Bacterial identification through biochemical test revealed the causative agent of catfish disease at brackish pond area were bacteria of the genus Vibrio (VK 1, VK 5, and VK 7), Vibrio vulnificus (VK 17 and VK 21).