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Sample records for nile tilapia fed

  1. Susceptibility of Nile tilapia (Oreochromis niloticus) fed dietary sodium chloride to nitrite toxicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Juvenile Nile tilapia (Oreochromis niloticus) were fed diets supplemented with 0 or 6% NaCl for 10 weeks. Tilapia were exposed to approximately 21 mg/l nitrite-N after five and ten weeks of feeding to determine the effect of dietary NaCl supplementation on resistance to nitrite toxicity. Fish were...

  2. Nutrient retention capabilities of Nile tilapia ( Oreochromis niloticus) fed bio-regenerative life support system (BLSS) waste residues

    NASA Astrophysics Data System (ADS)

    Gonzales, John M.; Brown, Paul B.

    Nile tilapia were evaluated as a bio-regenerative sub-process for reducing solid waste potentially encountered in bio-regenerative life support systems. Ten juvenile Nile tilapia (mean weight = 2.05 g) were stocked into triplicate aquaria and fed one of seven experimental diets consisting of vegetable, bacterial, or food waste for a period of seven weeks. Weight gain (g), specific growth rate (mg/d), and daily consumption (g) was significantly higher ( p < 0.05) in the control group (13.80, 281.60, and 47.49, respectively) followed by the wheat bran/wheat germ group (4.25, 86.87, and 24.24). Carbon and crude lipid retention was significantly higher ( p < 0.001) in fish fed the control diet (37.99 and 68.54, respectively) followed by fish fed the wheat bran/wheat germ diet (23.19 and 63.67, respectively). Nitrogen, sulfur, and crude protein retention was significantly higher ( p < 0.001) in fish fed the wheat bran/wheat germ group (40.73, 98.65, and 40.75, respectively) followed by fish fed the control diet (23.68, 21.89, and 23.68, respectively). A general loss of minerals was observed among all groups. Strong associations were observed between crude lipid retention and sulfur retention ( r2 = 0.94), crude lipid retention and carbon retention ( r2 = 0.92), WG and fiber content of dietary treatments ( r2 = 0.92), WG and carbon retention and ( r2 = 0.88), WG and lysine content of waste residues ( r2 = 0.86), crude protein retention and carbon retention ( r2 = 0.84), sulfur retention and crude protein retention ( r2 = 0.84), and total sulfur amino acid (TSAA) content of residues and WG ( r2 = 0.81). Weaker associations existed between WG and crude lipid retention ( r2 = 0.77), crude fiber content and carbon retention ( r2 = 0.76), and WG and methionine content of waste residues ( r2 = 0.75). Additional research is needed to improve the nutritional quality of fibrous residues as a means to improve tilapia's ability to utilize these residues as a food source in bio

  3. Thiamin requirement of Nile tilapia (Oreochromis niloticus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Juvenile Nile tilapia were fed to apparent satiation twice daily with purified diets containing 0, 1.0, 2.0, 4.0, 8.0 and 16.0 mg/kg and 0. 2.0, 4.0, 8.0, 16.0 and 32.0 mg/kg of thiamin in separate 14-week (experiment 1) and 8-week trials (experiment 2), respectively. Fish fed the diet devoid of thi...

  4. Growth Responses and Resistance to Streptococccus iniae of Nile Tilapia, Oreochromis niloticus Fed Diets Containing Distiller's Dried Grains with Solubles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the effect of dietary levels of distiller’s dried grains with solubles (DDGS) on growth performance, body composition, hematology, immune response and resistance of Nile tilapia to Streptococcus iniae challenge. Five isocaloric diets containing DDGS at levels of ...

  5. Growth performance and metabolic efficiency in Nile tilapia (Oreochromis niloticus L.) fed on a diet containing Jatropha platyphylla kernel meal as a protein source.

    PubMed

    Kumar, V; Akinleye, A O; Makkar, H P S; Angulo-Escalante, M A; Becker, K

    2012-02-01

    Jatropha platyphylla is available on the pacific coast from Sinaloa to Michoacán including the Nayarit and Jalisco states in Mexico. The seeds of J. platyphylla are rich in oil and protein, and the kernel meal (JPKM) prepared after oil extraction contains 70-75% crude protein (CP). Contents of essential amino acids (except lysine) are higher in JPKM than in soybean meal (SBM). Phorbol-esters, the main toxin present in most Jatropha species is absent in J. platyphylla. Heat-treated JPKM (H-JPKM) was evaluated as a protein supplement in tilapia feed and compared with that of SBM and fish meal (FM). Nile tilapia (Oreochromis niloticus L.) fingerlings (15 fish; av. body mass 13.9 ± 0.17 g) were randomly distributed in three groups with five replicates each. A 12-week experiment was conducted in a respirometer system to evaluate the growth performance, nutrient utilization and energy budget. Nile tilapia fingerlings were fed three iso-nitrogenous diets (36% CP): Control containing FM, and Jatropha and Soybean diets in which 62.5% of FM protein was replaced by H-JPKM and SBM respectively. The growth performance, feed conversion ratio, protein efficiency ratio, apparent lipid conversion and energy retention did not differ significantly among the three groups. Higher protein productive value was observed in plant protein fed groups. Average metabolic rate, energy expenditure per g protein fed and retained in the body did not differ significantly among the three groups. Conclusively, Nile tilapia fed plant protein (heated JPKM and SBM) and FM protein-based diets exhibited equal average metabolic rate which indicate that JPKM can be used as a protein source in aqua feed.

  6. Control of voluntary feed intake in fish: a role for dietary oxygen demand in Nile tilapia (Oreochromis niloticus) fed diets with different macronutrient profiles.

    PubMed

    Saravanan, S; Geurden, I; Figueiredo-Silva, A C; Kaushik, S J; Haidar, M N; Verreth, J A J; Schrama, J W

    2012-10-28

    It has been hypothesised that, at non-limiting water oxygen conditions, voluntary feed intake (FI) in fish is limited by the maximal physiological capacity of oxygen use (i.e. an 'oxystatic control of FI in fish'). This implies that fish will adjust FI when fed diets differing in oxygen demand, resulting in identical oxygen consumption. Therefore, FI, digestible energy (DE) intake, energy balance and oxygen consumption were monitored at non-limiting water oxygen conditions in Nile tilapia fed diets with contrasting macronutrient composition. Diets were formulated in a 2 × 2 factorial design in order to create contrasts in oxygen demand: two ratios of digestible protein (DP):DE ('high' v. 'low'); and a contrast in the type of non-protein energy source ('starch' v. 'fat'). Triplicate groups of tilapia were fed each diet twice daily to satiation for 48 d. FI (g DM/kg(0·8) per d) was significantly lower (9·5%) in tilapia fed the starch diets relative to the fat diets. The DP:DE ratio affected DE intakes (P < 0·05), being 11% lower with 'high' than with 'low' DP:DE ratio diets, which was in line with the 11·9% higher oxygen demand of these diets. Indeed, DE intakes of fish showed an inverse linear relationship with dietary oxygen demand (DOD; R 2 0·81, P < 0·001). As hypothesised ('oxystatic' theory), oxygen consumption of fish was identical among three out of the four diets. Altogether, these results demonstrate the involvement of metabolic oxygen use and DOD in the control of FI in tilapia.

  7. Acute inflammation and hematological response in Nile tilapia fed supplemented diet with natural extracts of propolis and Aloe barbadensis.

    PubMed

    Dotta, G; Ledic-Neto, J; Gonçalves, E L T; Brum, A; Maraschin, M; Martins, M L

    2015-05-01

    This study evaluated the acute inflammatory response induced by carrageenin in the swim bladder of Nile tilapia supplemented with the mixture of natural extracts of propolis and Aloe barbadensis (1:1) at a concentration of 0.5%, 1% and 2% in diet during 15 days. Thirty-six fish were distributed into four treatments with three replicates: fish supplemented with 0.5% of admix of extracts of propolis and Aloe (1:1) injected with 500 µg carrageenin; fish supplemented with 1% of admix of extracts of propolis and Aloe (1:1) injected with 500 µg carrageenin; fish supplemented with 2% of admix of extracts of propolis and Aloe (1:1), injected with 500 µg carrageenin and unsupplemented fish injected with 500 µg carrageenin. Six hours after injection, samples of blood and exudate from the swim bladder of fish were collected. It was observed an increase in the leukocyte count in the swim bladder exudate of fish supplemented with extracts of propolis and Aloe injected with carrageenin. The most frequent cells were macrophages followed by granular leukocytes, thrombocytes and lymphocytes. Supplementation with propolis and Aloe to 0.5% caused a significant increase in the number of cells on the inflammatory focus mainly macrophages, cells responsible for the phagocytic activity in tissues, agent of innate fish immune response.

  8. Leukocyte phagocytosis and lysozyme activity in Nile tilapia fed supplemented diet with natural extracts of propolis and Aloe barbadensis.

    PubMed

    Dotta, Geovana; de Andrade, Jaqueline Inês Alves; Tavares Gonçalves, Eduardo Luiz; Brum, Aline; Mattos, Jacó Joaquim; Maraschin, Marcelo; Martins, Maurício Laterça

    2014-08-01

    Although there is evidence on the benefits in the use of immunostimulants in aquaculture, there are few commercial products being used. This study evaluated the use of natural substances as potential sources for the production of immunostimulants. Propolis and Aloe barbadensis have been widely studied and its extracts have different chemical constituents responsible for antimicrobial, anti-inflammatory and immunostimulant. Tilapia juveniles were fed for two weeks with diets supplemented mix of propolis extracts and aloe (1:1) in different concentrations: 0.5, 1 e 2%. After the experimental period, fish blood was collected for hematoimmunological as follows : hematocrit, total plasma protein, erythrocytes (RBC), leukocytes (WBC), differential leukocyte count, phagocytic activity, serum lysozyme activity, and serum antimicrobial activity, serum antimicrobial activity (evaluated against Aeromonas hydrophila, Enterococcus durans and Escherichia coli). Except for higher number of thrombocytes in 1%-supplemented fish, the rest did not show significant difference.

  9. The effect of NovaSil dietary supplementation on the growth and health performance of Nile tilapia (Oreochromis niloticus) fed aflatoxin-B1 contaminated feed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate the ability of NovaSil (NS) clay to sorb and mitigate the toxic effects of aflatoxin B1 (AFB1) in Nile tilapia (Oreochromis niloticus). Growth performance, specific innate immunological function, intestinal microbial community, and histology were evaluate...

  10. Growth Response and Resistance to Streptococcus iniae of Nile Tilapia Oreochromis niloticus Fed Diets Containing Distiller’s Dried Grains with Solubles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the effect of dietary levels of distiller’s dried grains with solubles (DDGS) on growth performance, body composition, hematology, immune response and resistance of Nile tilapia to Streptococcus iniae challenge. Five isocaloric diets containing DDGS at levels of ...

  11. Growth performance and resistance to Streptococcus iniae of juvenile Nile tilapia (Oreochromis niloticus) fed diets supplemented with GroBiotic - A and Brewtech Dried Brewers Yeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the effect of dietary levels of Brewtech® dried brewers yeast (BY) and GroBiotic®-A (GB) on growth performance, proximate body composition, immune response and resistance of juvenile Nile tilapia to Streptococcus iniae challenge. A practical basal (control) diet ...

  12. Nile tilapia and blue tilapia fry production in a subtropical climate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relationship between production in earthen ponds located in a subtropical climate of fry suitable for hormonal sex inversion and degree-days was quantified for Nile tilapia (Oreochromis niloticus; Egypt strain) and blue tilapia (O. aureus). Degree-days were calculated for each trial as the sum o...

  13. Effects of Dietary Exposure to Sulfamethazine on the Hematological Parameters and Hepatic Oxidative Stress Biomarkers in Nile Tilapia (Oreochromis niloticus).

    PubMed

    Sampaio, Fernanda Garcia; Carra, Maria Lídia; Jonsson, Claudio Martin; Gonçalves, Vitoria Teodoro; Dal'Bo, Genoefa; Nunes, Kátia Santos Damacena; Valim, José Henrique; Dallago, Bruno Stéfano Lima; do Nascimento de Queiroz, Sonia Claudia; Reyes, Felix Guillermo Reyes

    2016-10-01

    Sulfamethazine (SMZ) is one of the most commonly used sulfonamide compounds in fish farming, and its physiological effects on fish are unknown. SMZ was administered to juvenile Nile tilapia (Oreochromis niloticus) at a dose level of 422 mg kg(-1) body weight, for a period of 11 days, via medicated feed. Fish were divided into two groups, the control group (CG) and the group fed with SMZ in feed. The administration of SMZ did not alter the erythrograms and leukograms of the Nile tilapia. The SMZ-fed group showed the same hepatic lipid peroxidation (LPO) concentration as the CG. Nonetheless, the oral administration of SMZ raised the hepatic catalase (CAT) and glutathione S-transferase (GST) activities, the increase probably being sufficient to prevent hepatic LPO production. The oral administration of SMZ affects the hepatic GST and CAT activities of Nile tilapia.

  14. Effects of Dietary Exposure to Sulfamethazine on the Hematological Parameters and Hepatic Oxidative Stress Biomarkers in Nile Tilapia (Oreochromis niloticus).

    PubMed

    Sampaio, Fernanda Garcia; Carra, Maria Lídia; Jonsson, Claudio Martin; Gonçalves, Vitoria Teodoro; Dal'Bo, Genoefa; Nunes, Kátia Santos Damacena; Valim, José Henrique; Dallago, Bruno Stéfano Lima; do Nascimento de Queiroz, Sonia Claudia; Reyes, Felix Guillermo Reyes

    2016-10-01

    Sulfamethazine (SMZ) is one of the most commonly used sulfonamide compounds in fish farming, and its physiological effects on fish are unknown. SMZ was administered to juvenile Nile tilapia (Oreochromis niloticus) at a dose level of 422 mg kg(-1) body weight, for a period of 11 days, via medicated feed. Fish were divided into two groups, the control group (CG) and the group fed with SMZ in feed. The administration of SMZ did not alter the erythrograms and leukograms of the Nile tilapia. The SMZ-fed group showed the same hepatic lipid peroxidation (LPO) concentration as the CG. Nonetheless, the oral administration of SMZ raised the hepatic catalase (CAT) and glutathione S-transferase (GST) activities, the increase probably being sufficient to prevent hepatic LPO production. The oral administration of SMZ affects the hepatic GST and CAT activities of Nile tilapia. PMID:27225508

  15. Growth response and resistance to Streptococcus iniae of Nile tilapia, Oreochromis niloticus, fed diets containing different levels of wheat distiller dried grains with solubles with or without lysine supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to evaluate the effect of dietary levels of wheat distiller’s dried grains with solubles (DDGS) with or without lysine supplementation on growth, body composition, hematology, immune response, and resistance of Nile tilapia, Oreochromis niloticus, to Streptococcus iniae challen...

  16. Determination of florfenicol dose rate in feed for control of mortality in nile tilapia Oreochromis nilotica infected with streptococcus iniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A dose titration study was conducted to determine the dosage of florfenicol (FFC) in feed to control Streptococcus iniae-associated mortality in Nile tilapia Oreochromis niloticus. Six tanks were assigned to each of five treatments: (1) not challenged with S. iniae and fed unmedicated feed; (2) chal...

  17. Effects of predator odour on antipredator responses of Nile tilapia.

    PubMed

    Miyai, Caio Akira; Sanches, Fábio Henrique Carretero; Pinho-Neto, Cândido Ferreira; Barreto, Rodrigo Egydio

    2016-10-15

    Several fish species exhibit antipredator responses when exposed to chemicals which indicate risk of predation. One such substance is the scent of a predator (a kairomone) that may induce defensive responses in a potential prey. In the present study, we show that chemical cues (odour) from predator fish induce antipredator and stress responses in Nile tilapia. When exposed to predator odour, Nile tilapia decreased activity and increased ventilation rate (VR), but no increase in plasma levels of cortisol and glucose was found. Although the hypothalamic-pituitary-interrenal axis (HPI axis) was not activated, an increase in ventilation is a fast response which can provide the fish enough oxygen for a 'fight or flight' event when facing a predator. Thus, this respiratory response suggests an anticipated adjustment in order to prepare the body for a defensive response, such as escaping, irrespective of HPI axis activation.

  18. Masculinization of Nile tilapia (Oreochromis niloticus) by immersion in androgens

    USGS Publications Warehouse

    Gale, W.L.; Fitzpatrick, M.S.; Lucero, M.; Contreras-Sanchez, W.M.; Schreck, C. B.

    1999-01-01

    The use of all-male populations increases the efficiency and feasibility of tilapia aquaculture. The objective of this study was to determine the efficacy of a short-term immersion procedure for masculinizing Nile tilapia (Oreochromis niloticus). Two synthetic androgens were evaluated: 17α-methyldihydrotestosterone (MDHT) and 17α-methyltestosterone (MT). Exposure (3 h) on 10 and again on 13 days post-fertilization to MDHT at 500 μg/1 successfully masculinized fry in all experiments, resulting in 100, 94 and 83 ± 2% males in Experiments 1, 2 and 3, respectively. Immersions in MDHT or MT at 100 μg/1 resulted in significantly skewed sex ratios in Experiments 1 and 3 (MT resulted in 73 and 83 ± 3% males; and MDHT resulted in 72 and 91 ± 1% males) but not in Experiment 2. Immersion in MT at 500 μg/1 only caused masculinization in Experiment 3. Although further research and refinement is needed, immersion of Nile tilapia in MDHT may provide a practical alternative to the use of steroid-treated feed. Furthermore, when compared with current techniques for steroid-induced sex inversion of tilapia, short-term immersion reduces the period of time that workers are exposed to anabolic steroids.

  19. Identification and expression profiles of multiple genes in Nile tilapia in response to bacterial infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To understand the molecular mechanisms involved in response of Nile tilapia (Oreochromis niloticus) to bacterial infection, suppression subtractive cDNA hybridization technique was used to identify upregulated genes in the posterior kidney of Nile tilapia at 6h post infection with Aeromonas hydrophi...

  20. Complete Genome Sequence of Streptococcus agalactiae Strain S25 Isolated from Peritoneal Liquid of Nile Tilapia

    PubMed Central

    Mainardi, Rafaella Menegheti; Lima Júnior, Edson Antônio; Ribeiro Júnior, Jose Carlos; Beloti, Vanerli; Carmo, Anderson Oliveira; Kalapothakis, Evanguedes; Gonçalves, Daniela Dib; Padua, Santiago Benites

    2016-01-01

    Streptococcus agalactiae (Lancefield group B; GBS) is one of the major pathogens in fish production, especially in Nile tilapia (Oreochromis niloticus). The genomic characteristics of GBS isolated from fish must be more explored. Thus, we present here the genome of GBS S25, isolated from Nile tilapia from Brazil. PMID:27491974

  1. Complete Genome Sequence of Streptococcus agalactiae Strain S25 Isolated from Peritoneal Liquid of Nile Tilapia.

    PubMed

    Mainardi, Rafaella Menegheti; Lima Júnior, Edson Antônio; Ribeiro Júnior, Jose Carlos; Beloti, Vanerli; Carmo, Anderson Oliveira; Kalapothakis, Evanguedes; Gonçalves, Daniela Dib; Padua, Santiago Benites; Pereira, Ulisses Pádua

    2016-01-01

    Streptococcus agalactiae (Lancefield group B; GBS) is one of the major pathogens in fish production, especially in Nile tilapia (Oreochromis niloticus). The genomic characteristics of GBS isolated from fish must be more explored. Thus, we present here the genome of GBS S25, isolated from Nile tilapia from Brazil. PMID:27491974

  2. Effects of dietary genistein on GH/IGF-I axis of Nile tilapia Oreochromis niloticus

    NASA Astrophysics Data System (ADS)

    Chen, Dong; Wang, Wei; Ru, Shaoguo

    2016-09-01

    There is considerable concern that isoflavones, such as genistein in fish feed composed of soybean protein, aff ects somatic growth in fish. Our previous works demonstrated that 30 and 300 μg/g dietary genistein had no significant eff ect on growth performance in Nile tilapia ( Oreochromis niloticus), but the higher level of genistein (3 000 μg/g) significantly depressed growth. This study was conducted to further examine the eff ects of dietary genistein on the endocrine disruption on growth hormone/insulin-like growth factor-I (GH/IGF-I) axis in Nile tilapia ( O. niloticus). Juvenile fish were fed by hand twice daily to satiation with one of four isonitrogenous and isoenergetic diets, each containing either 0, 30, 300 or 3 000 μg/g genistein. Following an 8-week feeding period, plasma GH and IGF-I levels were investigated by radioimmunoassay and gene expression levels of gh, ghrelin, gnrhs, ghr, npy, npyrs, pacap, ghrs, i gf-I, igf-Ir, and igfbp3 were examined by real-time PCR. The results show that no significant change in plasma GH and IGF-I levels in fish fed with diets containing 30 μg/g and 300 μg/g genistein. mRNA expression of genes along the GH/IGF-I axis remained unaff ected, except for igf-Ir, which was stimulated by the 300 μg/g genistein diet. While in fish fed the 3 000 μg/g genistein diet, the plasma GH and IGF-I levels decreased, and mRNA expression of gh, ghr2, npyr1, igf-I, and igf-Ir were also significantly depressed. In contrast, npy and igfbp3 mRNA expression were enhanced. This study provides convincing evidence for growth impediment by genistein by disturbing the GH/IGF-I axis in Nile tilapia O. niloticus.

  3. Molecular characterization, transcriptional activity and nutritional regulation of peroxisome proliferator activated receptor gamma in Nile tilapia (Oreochromis niloticus).

    PubMed

    He, An-Yuan; Liu, Cai-Zhi; Chen, Li-Qiao; Ning, Li-Jun; Qin, Jian-Guang; Li, Jia-Ming; Zhang, Mei-Ling; Du, Zhen-Yu

    2015-11-01

    Peroxisome proliferator activated receptor gamma (PPARγ) is a master regulator in lipid metabolism and widely exists in vertebrates. However, the molecular structure and transcriptional activity of PPARγ in fish are still unclear. This study cloned PPARγ from Nile tilapia (Oreochromis niloticus) referred as NtPPARγ and transfected the NtPPARγ plasmids into HEK-293 cells to explore its mechanism of transcriptional regulation in fish. The expression of NtPPARγ was compared in fed and fasted fish. Two transcripts of NtPPARγ varied at the 5'-untranslated region and the DNA binding domain was highly conserved. Thirty-nine amino acid residues in the ligand binding domain in Nile tilapia were different from those in human. Two transcripts showed different expression profiles in 11 tissues, but both were highly expressed in liver, intestine and kidney. The transcriptional activity assay showed that NtPPARγ collaborates with retinoid X-receptor α (NtRXRα) to regulate the expression of Nile tilapia fatty acid binding protein 4 (FABP4), the compartment of which have been identified as the target gene of PPARγ in human. In the fish fasting trial, the mRNA expression of NtPPARγ1 and NtPPARγ2 in intestine and liver at 3h post-feeding (HPF) was lower than those at 8 HPF, 24 HPF and in fish fasted for 36h, but was relatively stable in kidney among different feeding treatments. In conclusion, the DNA binding domain in PPARγ was highly conserved, while the ligand binding domain was moderately conserved. In Nile tilapia, the PPARγ collaborates with RXRα to perform transcriptional regulation of FABP4 at least in vitro. The plasmid system established in this study along with a cell line from Nile tilapia will be useful tools for the further functional study of PPARγ in fish.

  4. Molecular characterization, transcriptional activity and nutritional regulation of peroxisome proliferator activated receptor gamma in Nile tilapia (Oreochromis niloticus).

    PubMed

    He, An-Yuan; Liu, Cai-Zhi; Chen, Li-Qiao; Ning, Li-Jun; Qin, Jian-Guang; Li, Jia-Ming; Zhang, Mei-Ling; Du, Zhen-Yu

    2015-11-01

    Peroxisome proliferator activated receptor gamma (PPARγ) is a master regulator in lipid metabolism and widely exists in vertebrates. However, the molecular structure and transcriptional activity of PPARγ in fish are still unclear. This study cloned PPARγ from Nile tilapia (Oreochromis niloticus) referred as NtPPARγ and transfected the NtPPARγ plasmids into HEK-293 cells to explore its mechanism of transcriptional regulation in fish. The expression of NtPPARγ was compared in fed and fasted fish. Two transcripts of NtPPARγ varied at the 5'-untranslated region and the DNA binding domain was highly conserved. Thirty-nine amino acid residues in the ligand binding domain in Nile tilapia were different from those in human. Two transcripts showed different expression profiles in 11 tissues, but both were highly expressed in liver, intestine and kidney. The transcriptional activity assay showed that NtPPARγ collaborates with retinoid X-receptor α (NtRXRα) to regulate the expression of Nile tilapia fatty acid binding protein 4 (FABP4), the compartment of which have been identified as the target gene of PPARγ in human. In the fish fasting trial, the mRNA expression of NtPPARγ1 and NtPPARγ2 in intestine and liver at 3h post-feeding (HPF) was lower than those at 8 HPF, 24 HPF and in fish fasted for 36h, but was relatively stable in kidney among different feeding treatments. In conclusion, the DNA binding domain in PPARγ was highly conserved, while the ligand binding domain was moderately conserved. In Nile tilapia, the PPARγ collaborates with RXRα to perform transcriptional regulation of FABP4 at least in vitro. The plasmid system established in this study along with a cell line from Nile tilapia will be useful tools for the further functional study of PPARγ in fish. PMID:26002036

  5. Megalocytivirus infection in cultured Nile tilapia Oreochromis niloticus.

    PubMed

    Subramaniam, Kuttichantran; Gotesman, Michael; Smith, Charlie E; Steckler, Natalie K; Kelley, Karen L; Groff, Joseph M; Waltzek, Thomas B

    2016-05-26

    Megalocytiviruses, such as infectious spleen and kidney necrosis virus (ISKNV), induce lethal systemic diseases in both ornamental and food fish species. In this study, we investigated an epizootic affecting Nile tilapia Oreochromis niloticus cultured in the US Midwest. Diseased fish displayed lethargy, gill pallor, and distension of the coelomic cavity due to ascites. Histopathological examination revealed a severe systemic abundance of intravascular megalocytes that were especially prominent in the gills, kidney, spleen, liver, and intestinal submucosa. Transmission electron microscopic examination revealed abundant intracytoplasmic polygonal virions consistent with iridovirus infection. Comparison of the full-length major capsid protein nucleotide sequences from a recent outbreak with a remarkably similar case that occurred at the same facility many years earlier revealed that both epizootics were caused by ISKNV. A comparison of this case with previous reports suggests that ISKNV may represent a greater threat to tilapia aquaculture than previously realized. PMID:27225209

  6. Megalocytivirus infection in cultured Nile tilapia Oreochromis niloticus.

    PubMed

    Subramaniam, Kuttichantran; Gotesman, Michael; Smith, Charlie E; Steckler, Natalie K; Kelley, Karen L; Groff, Joseph M; Waltzek, Thomas B

    2016-05-26

    Megalocytiviruses, such as infectious spleen and kidney necrosis virus (ISKNV), induce lethal systemic diseases in both ornamental and food fish species. In this study, we investigated an epizootic affecting Nile tilapia Oreochromis niloticus cultured in the US Midwest. Diseased fish displayed lethargy, gill pallor, and distension of the coelomic cavity due to ascites. Histopathological examination revealed a severe systemic abundance of intravascular megalocytes that were especially prominent in the gills, kidney, spleen, liver, and intestinal submucosa. Transmission electron microscopic examination revealed abundant intracytoplasmic polygonal virions consistent with iridovirus infection. Comparison of the full-length major capsid protein nucleotide sequences from a recent outbreak with a remarkably similar case that occurred at the same facility many years earlier revealed that both epizootics were caused by ISKNV. A comparison of this case with previous reports suggests that ISKNV may represent a greater threat to tilapia aquaculture than previously realized.

  7. Thermal preference predicts animal personality in Nile tilapia Oreochromis niloticus.

    PubMed

    Cerqueira, Marco; Rey, Sonia; Silva, Tome; Featherstone, Zoe; Crumlish, Margaret; MacKenzie, Simon

    2016-09-01

    Environmental temperature gradients provide habitat structure in which fish orientate and individual thermal choice may reflect an essential integrated response to the environment. The use of subtle thermal gradients likely impacts upon specific physiological and behavioural processes reflected as a suite of traits described by animal personality. In this study, we examine the relationship between thermal choice, animal personality and the impact of infection upon this interaction. We predicted that thermal choice in Nile tilapia Oreochromis niloticus reflects distinct personality traits and that under a challenge individuals exhibit differential thermal distribution. Nile tilapia were screened following two different protocols: 1) a suite of individual behavioural tests to screen for personality and 2) thermal choice in a custom-built tank with a thermal gradient (TCH tank) ranging from 21 to 33 °C. A first set of fish were screened for behaviour and then thermal preference, and a second set were tested in the opposite fashion: thermal then behaviour. The final thermal distribution of the fish after 48 h was assessed reflecting final thermal preferendum. Additionally, fish were then challenged using a bacterial Streptococcus iniae model infection to assess the behavioural fever response of proactive and reactive fish. Results showed that individuals with preference for higher temperatures were also classified as proactive with behavioural tests and reactive contemporaries chose significantly lower water temperatures. All groups exhibited behavioural fever recovering personality-specific thermal preferences after 5 days. Our results show that thermal preference can be used as a proxy to assess personality traits in Nile tilapia and it is a central factor to understand the adaptive meaning of animal personality within a population. Importantly, response to infection by expressing behavioural fever overrides personality-related thermal choice. PMID:27219014

  8. Thermal preference predicts animal personality in Nile tilapia Oreochromis niloticus.

    PubMed

    Cerqueira, Marco; Rey, Sonia; Silva, Tome; Featherstone, Zoe; Crumlish, Margaret; MacKenzie, Simon

    2016-09-01

    Environmental temperature gradients provide habitat structure in which fish orientate and individual thermal choice may reflect an essential integrated response to the environment. The use of subtle thermal gradients likely impacts upon specific physiological and behavioural processes reflected as a suite of traits described by animal personality. In this study, we examine the relationship between thermal choice, animal personality and the impact of infection upon this interaction. We predicted that thermal choice in Nile tilapia Oreochromis niloticus reflects distinct personality traits and that under a challenge individuals exhibit differential thermal distribution. Nile tilapia were screened following two different protocols: 1) a suite of individual behavioural tests to screen for personality and 2) thermal choice in a custom-built tank with a thermal gradient (TCH tank) ranging from 21 to 33 °C. A first set of fish were screened for behaviour and then thermal preference, and a second set were tested in the opposite fashion: thermal then behaviour. The final thermal distribution of the fish after 48 h was assessed reflecting final thermal preferendum. Additionally, fish were then challenged using a bacterial Streptococcus iniae model infection to assess the behavioural fever response of proactive and reactive fish. Results showed that individuals with preference for higher temperatures were also classified as proactive with behavioural tests and reactive contemporaries chose significantly lower water temperatures. All groups exhibited behavioural fever recovering personality-specific thermal preferences after 5 days. Our results show that thermal preference can be used as a proxy to assess personality traits in Nile tilapia and it is a central factor to understand the adaptive meaning of animal personality within a population. Importantly, response to infection by expressing behavioural fever overrides personality-related thermal choice.

  9. Effects of dietary levels of vitamin A on growth, hematology, immune response and resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the effect of supplemental levels of vitamin A (0, 2,500, 5,000, 10,000, and 20,000 IU/kg diet) on the growth performance, hematology, immune response and resistance of Nile tilapia, Oreochromis niloticus to Streptococcus iniae challenge. Each diet was fed to Nil...

  10. Body composition and compensatory growth in Nile tilapia Oreochromis niloticus under different feeding intervals

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Wang, Ziwei; Hur, Jun-wook; Lee, Jeong-Yeol

    2015-07-01

    We investigated the growth and body composition of Nile tilapia under five different feeding regimes. A control group was fed to satiation twice daily for 185 days; four treatment groups were fed at intervals of 2, 3, 4 or 7 days (dietary `restricted' period, days 0-80) and then fed to satiation (`refeeding' period, days 80-185). Compensatory growth in weight and length of the feed-restricted groups was observed during the refeeding period. However, the growth of none of the restricted groups caught up with that of the control group over the experimental period. Feed intake upon refeeding increased with the duration of deprivation. There were no significant differences in feed efficiency between the restricted and control groups during the refeeding stage, suggesting that hyperphagia was the mechanism responsible for the increased growth rates during this period. Tilapia preferentially used n-3 polyunsaturated fatty acids and nonessential amino acids during the restricted-feeding period. Higher production was achieved by higher feed consumption. We suggest that if attainment of market size in minimum time is required, fish should be consistently fed to satiation, while taking care to avoid the possible negative consequences of overfeeding.

  11. The effects of composting on the nutritional composition of fibrous bio-regenerative life support systems (BLSS) plant waste residues and its impact on the growth of Nile tilapia ( Oreochromis niloticus)

    NASA Astrophysics Data System (ADS)

    Gonzales, John M.; Lowry, Brett A.; Brown, Paul B.; Beyl, Caula A.; Nyochemberg, Leopold

    2009-04-01

    Utilization of bio-regenerative life support systems (BLSS) plant waste residues as a nutritional source by Nile tilapia ( Oreochromis niloticus) has proven problematic as a result of high concentrations of fibrous compounds in the plant waste residues. Nutritional improvement of plant waste residues by composting with the oyster mushroom ( Pleurotus ostreatus), and the effects on growth and nutrient utilization of Nile tilapia fed such residues were evaluated. Five Nile tilapia (mean weight = 70.9 ± 3.1 g) were stocked in triplicate aquaria and fed one of two experimental diets, cowpea (CP) and composted cowpea (CCP), twice daily for a period of 8 weeks. Composting of cowpea residue resulted in reduced concentrations of nitrogen-free extract, hemi-cellulose and trypsin inhibitor activity, though trypsin inhibitor activity remained high. Composting did not reduce crude fiber, lignin, or cellulose concentrations in the diet. No significant differences ( P < 0.05) were observed in weight gain, specific growth rate, survival rate, daily consumption, and food conversion ratio between tilapia fed CP and CCP. These results suggest that P. ostreatus is not a suitable candidate for culture in conjunction with the culture of Nile tilapia. Additional work is needed to determine what, if any, benefit can be obtained from incorporating composted residue as feed for Nile tilapia.

  12. Edwardsiella ictaluri as the causative agent of mortality in cultured Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri was consistently isolated from the spleens, livers, and head kidneys of diseased Nile tilapia Oreochromis niloticus from a farm experiencing mortality events in several culture ponds. We describe the first published outbreak of E. ictaluri–induced Edwardsiellosis in Nile tilapi...

  13. The response of New-season Nile tilapia to Aeromonas hydrophila vaccine

    PubMed Central

    Aly, Salah M; Albutti, Aqel S; Rahmani, Arshad H; Atti, Nashwa M Abdel

    2015-01-01

    The present study was conducted to recognize the response of new-season Nile tilapia to Aeromonas hydrophila vaccine. Four hundred new-season Nile tilapia were used in this study and divided into two equal groups, the first group served as control and the 2nd group was vaccinated with Aeromonas hydrophila vaccine via intraperitoneal injection. The antibody titer, Hematocrit level (HCV), Nitroblue tetrazolium activity (NBT) and lysozyme activity of new-season Nile tilapia was measured at the end of the 1st, 2nd, 3rd, 4th, 6th, 8th and 10th week post vaccination (PV). Challenge with A. hydrophila was carried out at the end of the 6th, 8th and 10th week PV. The antibody titer of vaccinated new-season tilapia showed significant higher values than unvaccinated group at all periods. The hematocrit and lysozymes activity values showed, a non significant increased in comparison with unvaccinated group at all periods PV. The NBT was significantly increased in vaccinated tilapia in comparison with unvaccinated group at all periods except one week PV. The relative level of protection of vaccinated tilapia after challenge infection was highest at 6th week PV in the new-season tilapia. We conclude that, vaccination against A. hydrophila increase the resistance of tilapia to such infection and consequently improve the survival and economic outcome. Other more applicable routes of vaccination should be investigated to be used on a large scale. PMID:26064376

  14. Identification and transcriptional profile of multiple genes in the posterior kidney of Nile tilapia at 6h post bacterial infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To understand the molecular mechanisms involved in response of Nile tilapia (Oreochromis niloticus) to bacterial infection, suppression subtractive cDNA hybridization technique was used to identify upregulated genes in the posterior kidney of Nile tilapia at 6h post infection with Aeromonas hydrophi...

  15. Systemic adaptation of lipid metabolism in response to low- and high-fat diet in Nile tilapia (Oreochromis niloticus)

    PubMed Central

    He, An-Yuan; Ning, Li-Jun; Chen, Li-Qiao; Chen, Ya-Li; Xing, Qi; Li, Jia-Min; Qiao, Fang; Li, Dong-Liang; Zhang, Mei-Ling; Du, Zhen-Yu

    2015-01-01

    Natural selection endows animals with the abilities to store lipid when food is abundant and to synthesize lipid when it is limited. However, the relevant adaptive strategy of lipid metabolism has not been clearly elucidated in fish. This study examined the systemic metabolic strategies of Nile tilapia to maintain lipid homeostasis when fed with low- or high-fat diets. Three diets with different lipid contents (1%, 7%, and 13%) were formulated and fed to tilapias for 10 weeks. At the end of the feeding trial, the growth rate, hepatic somatic index, and the triglyceride (TG) contents of serum, liver, muscle, and adipose tissue were comparable among three groups, whereas the total body lipid contents and the mass of adipose tissue increased with the increased dietary lipid levels. Overall quantitative PCR, western blotting and transcriptomic assays indicated that the liver was the primary responding organ to low-fat (LF) diet feeding, and the elevated glycolysis and accelerated biosynthesis of fatty acids (FA) in the liver is likely to be the main strategies of tilapia toward LF intake. In contrast, excess ingested lipid was preferentially stored in adipose tissue through increasing the capability of FA uptake and TG synthesis. Increasing numbers, but not enlarging size, of adipocytes may be the main strategy of Nile tilapia responding to continuous high-fat (HF) diet feeding. This is the first study illuminating the systemic adaptation of lipid metabolism responding to LF or HF diet in fish, and our results shed new light on fish physiology. PMID:26265749

  16. Effect of parasitism on vaccine efficacy against Streptococcus iniae in Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited information is available on vaccine performance in parasitized fish. The objective of this study was to determine if parasitism of fish affected vaccine efficacy. Antibody level, hematology and survival of Nile tilapia vaccinated with a modified S. iniae bacterin were compared among non-para...

  17. Bacterial distribution and tissue targets following experimental Edwardsiella ictaluri infection in nile tilapia Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri, a Gram-negative enteric bacterium, is the known etiological agent of enteric septicemia of catfish. In the last few years, different strains have been implicated as the causative agent of mortality events in cultured fish, including Nile tilapia Oreochromis niloticus L. Due to...

  18. Optimizing fish meal-free commercial diets for Nile Tilapia, Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A feeding trial was conducted in a closed recirculating aquaculture system with Nile tilapia Oreochromis niloticus juveniles (mean weight, 6.81 g) to examine the response to a practical diet containing protein primarily from menhaden fish meal (FM) and soybean meal (SBM) (control, Diet 1) or to diet...

  19. Molecular structure, distribution, and immunology function of TNFSF13B (BAFF) in Nile tilapia (Oreochromis niloticus).

    PubMed

    Liu, Hongzhen; Zhang, Jiaxin; Li, Jianfeng; Song, Jinyun; Zhang, Shuangquan

    2016-04-01

    B cell-activating factor (BAFF)is a member of the tumor necrosis factor (TNF) family and plays roles in B cell survival and maturation. In this study, the full-length cDNA of Nile tilapia (Oreochromis niloticus) BAFF (tBAFF) was amplified from the spleen by reverse transcription PCR (RT-PCR). The open reading frame of this cDNA encodes a protein of 261 amino acids containing a predicted transmembrane domain and a furin protease cleavage site, similar to mammalian, avian, and reptile BAFF. Real-time quantitative PCR (qPCR) analysis revealed that tBAFF is present in various tissues and is predominantly expressed in the spleen. The predicted three-dimensional (3D) structure of the Nile tilapia (Oreochromis niloticus) soluble BAFF (tsBAFF) monomer was determined by (3D) structure modeling monomeranalyzed by (3D) structure mouse counterpart. Both tsBAFF and EGFP/tsBAFF were efficiently expressed in Escherichia coli BL21 (DE3), as confirmed by SDS-PAGE and Western blot analysis. After purification, the EGFP/tsBAFF fusion protein showed a fluorescence spectrum similar to that of EGFP. Laser scanning confocal microscopy showed that EGFP/tsBAFF bound to its receptor. In vitro, tsBAFF promoted the proliferation of Nile tilapia and mouse splenic B cells together with/without a priming agent (Staphylococcus aureus Cowan 1, SAC) or anti-mouse IgM. Furthermore, tsBAFF showed a similar proliferation-stimulating effect on mouse B cells compared to msBAFF. These findings indicate that tsBAFF plays an important role in the proliferation of Nile tilapia B cells and has functional cross-reactivity among Nile tilapia and mammals. Therefore, BAFF may represent a useful factor for enhancing immunological efficacy in animals.

  20. Molecular structure, distribution, and immunology function of TNFSF13B (BAFF) in Nile tilapia (Oreochromis niloticus).

    PubMed

    Liu, Hongzhen; Zhang, Jiaxin; Li, Jianfeng; Song, Jinyun; Zhang, Shuangquan

    2016-04-01

    B cell-activating factor (BAFF)is a member of the tumor necrosis factor (TNF) family and plays roles in B cell survival and maturation. In this study, the full-length cDNA of Nile tilapia (Oreochromis niloticus) BAFF (tBAFF) was amplified from the spleen by reverse transcription PCR (RT-PCR). The open reading frame of this cDNA encodes a protein of 261 amino acids containing a predicted transmembrane domain and a furin protease cleavage site, similar to mammalian, avian, and reptile BAFF. Real-time quantitative PCR (qPCR) analysis revealed that tBAFF is present in various tissues and is predominantly expressed in the spleen. The predicted three-dimensional (3D) structure of the Nile tilapia (Oreochromis niloticus) soluble BAFF (tsBAFF) monomer was determined by (3D) structure modeling monomeranalyzed by (3D) structure mouse counterpart. Both tsBAFF and EGFP/tsBAFF were efficiently expressed in Escherichia coli BL21 (DE3), as confirmed by SDS-PAGE and Western blot analysis. After purification, the EGFP/tsBAFF fusion protein showed a fluorescence spectrum similar to that of EGFP. Laser scanning confocal microscopy showed that EGFP/tsBAFF bound to its receptor. In vitro, tsBAFF promoted the proliferation of Nile tilapia and mouse splenic B cells together with/without a priming agent (Staphylococcus aureus Cowan 1, SAC) or anti-mouse IgM. Furthermore, tsBAFF showed a similar proliferation-stimulating effect on mouse B cells compared to msBAFF. These findings indicate that tsBAFF plays an important role in the proliferation of Nile tilapia B cells and has functional cross-reactivity among Nile tilapia and mammals. Therefore, BAFF may represent a useful factor for enhancing immunological efficacy in animals. PMID:26915306

  1. Cinnamon (Cinnamomum sp.) inclusion in diets for Nile tilapia submitted to acute hypoxic stress.

    PubMed

    M Dos Santos, Welliene; S de Brito, Túlio; de A Prado, Samuel; G de Oliveira, Camila; C De Paula, Andréia; C de Melo, Daniela; A P Ribeiro, Paula

    2016-07-01

    The aim of this study was to evaluate the possible effects of diets supplemented with probiotics and different cinnamon levels (powder and essential oil) on immunological parameters of Nile tilapia after being subjected to acute stress by hypoxia. Three hundred and thirty juvenile male tilapia fish (66.08 ± 2.79 g) were distributed in 30 tanks of 100 L capacity (11/cage) with a water recirculation system. The animals were fed for 71 days with diets containing extruded cinnamon powder at different levels (0.5, 1, 1.5, 2%), cinnamon essential oil (0.05, 0.1, 0.15; 0.2%) and probiotics (0.4%), all in triplicate. At the end of the experiment, the fish (200.36 ± 19.88 g) of the different groups were subjected to stress by hypoxia. Hypoxia was achieved by capturing the animals with a net, keeping them out of the water for three minutes, and then sampling the blood 30 min after the procedure to determine the levels of cortisol, glucose, haematocrit, lysozyme, bactericidal index, total protein, and its fractions. The animals kept blood homeostasis after hypoxic stress. Diet supplementation with 0.5% cinnamon powder improved the fish immune response, since it resulted in an increase of 0.5% in γ-globulin level. Administration of 0.15% cinnamon essential oil resulted in an increase of α1 and α2-globulins, which may be reflected in increased lipid content of the carcass and the hepatosomatic index. More studies are necessary to better understand the effects of these additives for fish immunity.

  2. Cinnamon (Cinnamomum sp.) inclusion in diets for Nile tilapia submitted to acute hypoxic stress.

    PubMed

    M Dos Santos, Welliene; S de Brito, Túlio; de A Prado, Samuel; G de Oliveira, Camila; C De Paula, Andréia; C de Melo, Daniela; A P Ribeiro, Paula

    2016-07-01

    The aim of this study was to evaluate the possible effects of diets supplemented with probiotics and different cinnamon levels (powder and essential oil) on immunological parameters of Nile tilapia after being subjected to acute stress by hypoxia. Three hundred and thirty juvenile male tilapia fish (66.08 ± 2.79 g) were distributed in 30 tanks of 100 L capacity (11/cage) with a water recirculation system. The animals were fed for 71 days with diets containing extruded cinnamon powder at different levels (0.5, 1, 1.5, 2%), cinnamon essential oil (0.05, 0.1, 0.15; 0.2%) and probiotics (0.4%), all in triplicate. At the end of the experiment, the fish (200.36 ± 19.88 g) of the different groups were subjected to stress by hypoxia. Hypoxia was achieved by capturing the animals with a net, keeping them out of the water for three minutes, and then sampling the blood 30 min after the procedure to determine the levels of cortisol, glucose, haematocrit, lysozyme, bactericidal index, total protein, and its fractions. The animals kept blood homeostasis after hypoxic stress. Diet supplementation with 0.5% cinnamon powder improved the fish immune response, since it resulted in an increase of 0.5% in γ-globulin level. Administration of 0.15% cinnamon essential oil resulted in an increase of α1 and α2-globulins, which may be reflected in increased lipid content of the carcass and the hepatosomatic index. More studies are necessary to better understand the effects of these additives for fish immunity. PMID:27142937

  3. Antagonistic activity of dietary allicin against deltamethrin-induced oxidative damage in freshwater Nile tilapia; Oreochromis niloticus.

    PubMed

    Abdel-Daim, Mohamed M; Abdelkhalek, Nevien K M; Hassan, Ahmed M

    2015-01-01

    Allicin, the main biologically active component of garlic clove extracts, has been evaluated for its' efficacy in preventing deltamethrin-induced oxidative damage in Nile tilapia; Oreochromis niloticus. Fish were fed on 2 different doses of 0.5 g and 1 g of allicin/kg diet for 28 days. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), cholesterol, urea, uric acid, creatinine, total protein, albumin and globulin were estimated. Moreover, the level of malonaldehyde (MDA) was analyzed as a lipid peroxidation marker. In addition, reduced glutathione (GSH), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) were analyzed as antioxidant biomarkers in liver, kidney and gills. Results show that deltamethrin subacute intoxication (1.46 µg/L for 28 days) increased serum AST, ALT, ALP, cholesterol, urea, uric acid, creatinine and tissue MDA. At the same time, serum total protein and albumin as well as tissue level of GSH, GSH-Px, SOD and CAT were reduced. Allicin supplemented diets enhanced all the altered serum biochemical parameters as well as tissues' lipid peroxidation and antioxidant biomarkers in a dose-dependent manner. The results suggest that feeding allicin can ameliorate deltamethrin-induced oxidative stress and might have some therapeutic properties to protect Nile tilapia on subacute deltamethrin toxicity. PMID:25450927

  4. Parasitism affects vaccine efficacy against Streptococcus iniae in Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tilapia culture worldwide is estimated to be US$ 5 billion and is important to domestic and global food security. Parasites and bacteria co-occur in both extensive and intensive production of tilapia. The effect of parasitism on vaccine performance in fish is little studied. The objective of this ...

  5. Vitamin C modulates cadmium-induced hepatic antioxidants' gene transcripts and toxicopathic changes in Nile tilapia, Oreochromis niloticus.

    PubMed

    El-Sayed, Yasser S; El-Gazzar, Ahmed M; El-Nahas, Abeer F; Ashry, Khaled M

    2016-01-01

    Cadmium (Cd) is one of the naturally occurring heavy metals having adverse effects, while vitamin C (L-ascorbic acid) is an essential micronutrient for fish, which can attenuate tissue damage owing to its chain-breaking antioxidant and free radical scavenger properties. The adult Nile tilapia fish were exposed to Cd at 5 mg/l with and without vitamin C (500 mg/kg diet) for 45 days in addition to negative and positive controls fed with the basal diet and basal diet supplemented with vitamin C, respectively. Hepatic relative mRNA expression of genes involved in antioxidant function, metallothionein (MT), glutathione S-transferase (GST-α1), and glutathione peroxidase (GPx1), was assessed using real-time reverse transcription polymerase chain reaction (RT-PCR). Hepatic architecture was also histopathologically examined. Tilapia exposed to Cd exhibited upregulated antioxidants' gene transcript levels, GST-⍺1, GPx1, and MT by 6.10-, 4.60-, and 4.29-fold, respectively. Histopathologically, Cd caused severe hepatic changes of multifocal hepatocellular and pancreatic acinar necrosis, and lytic hepatocytes infiltrated with eosinophilic granular cells. Co-treatment of Cd-exposed fish with vitamin C overexpressed antioxidant enzyme-related genes, GST-⍺1 (16.26-fold) and GPx1 (18.68-fold), and maintained the expression of MT gene close to control (1.07-fold), averting the toxicopathic lesions induced by Cd. These results suggested that vitamin C has the potential to protect Nile tilapia from Cd hepatotoxicity via sustaining hepatic antioxidants' genes transcripts and normal histoarchitecture.

  6. Individual protein balance strongly influences δ15N and δ13C values in Nile tilapia, Oreochromis niloticus

    NASA Astrophysics Data System (ADS)

    Gaye-Siessegger, Julia; Focken, Ulfert; Abel, Hansjörg; Becker, Klaus

    Although stable isotope ratios in animals have often been used as indicators of the trophic level and for the back-calculation of diets, few experiments have been done under standardized laboratory conditions to investigate factors influencing δ15N and δ13C values. An experiment using Nile tilapia [Oreochromis niloticus (L.)] was therefore carried out to test the effect of different dietary protein contents (35.4, 42.3, and 50.9%) on δ15N and δ13C values of the whole tilapia. The fish were fed the isoenergetic and isolipidic semi-synthetic diets at a relatively low level. δ15N and δ13C values of the lipid-free body did not differ between the fish fed the diets with different protein contents, but the trophic shift for N and C isotopes decreased with increasing protein accretion in the individual fish, for N from 6.5‰ to 4‰ and for C in the lipid-free body from 4‰ to 2.5‰. This is the first study showing the strong influence of the individual protein balance to the degree to which the isotopic signature of dietary protein was modified in tissue protein of fish. The extrapolation of the trophic level or the reconstruction of the diet of an animal from stable isotope ratios without knowledge of the individual physiological condition and the feeding rate may lead to erroneous results.

  7. Does sex influence intraspecific aggression and dominance in Nile tilapia juveniles?

    PubMed

    Pinho-Neto, Cândido Ferreira; Miyai, Caio Akira; Sanches, Fabio Henrique Carretero; Giaquinto, Percília Cardoso; Delicio, Helton Carlos; Barcellos, Leonardo José Gil; Volpato, Gilson Luiz; Barreto, Rodrigo Egydio

    2014-06-01

    Although sex of mature fish is known to influence aggression, this issue has so far been neglected in juveniles. Here, we tested this sex effect and showed that it does not significantly affect intraspecific aggression in juveniles of the cichlid Nile tilapia. To reach this conclusion, we measured the latency period before onset of confrontation, the frequency and types of aggressive interactions, the duration of a dispute, and the probability of becoming dominant. This was done on pairs of Nile tilapia that varied by sex: females×females, males×males, and females×males. In a double blind approach, after pairing, the sex of each individual was histologically verified and contrasted with behavioral data.

  8. Chemical and biological evaluation of Egyptian Nile Tilapia (Oreochromis niloticas) fish scale collagen.

    PubMed

    El-Rashidy, Aiah A; Gad, Ahmed; Abu-Hussein, Abd El-Hay G; Habib, Shaymaa I; Badr, Nadia A; Hashem, Azza A

    2015-08-01

    Collagen is considered to be one of the most useful biomaterials with different medical applications. However, collagen properties differ from one source to another. The aim of this study was to extract, purify, characterize and perform preliminary biological evaluation of type I collagen from scales of Egyptian Nile Tilapia. Pepsin-solubilized collagen (PSC) was successfully prepared from Nile Tilapia fish scale waste. Lyophilized collagen was dissolved in dilute HCl to form acidic collagen solutions (ACS) which was neutralized to form gel. To confirm the biocompatibility of the produced gel, baby hamster kidney (BHK-21) fibroblast cells were seeded onto a 3D collagen gel (0.3% and 0.5%, w/v). The results of an SDS-PAGE test showed that the extracted collagens were type I collagen, with α chain composition of (α1)2α2. Thermal analysis showed that the denaturation temperature was 32 °C. X-ray diffraction (XRD) analysis and Fourier-transform infrared spectra (FTIR) showed that the extracted collagen had a triple helix structure. Active proliferation of BHK-21 cells with no signs of toxicity was evident with both collagen gel concentrations tested. The results show that Nile Tilapia scales can be an effective source of collagen extraction that could be used as a potential biomaterial in biomedical applications.

  9. Effects of exposure to pile-driving sounds on the lake sturgeon, Nile tilapia and hogchoker.

    PubMed

    Halvorsen, Michele B; Casper, Brandon M; Matthews, Frazer; Carlson, Thomas J; Popper, Arthur N

    2012-12-01

    Pile-driving and other impulsive sound sources have the potential to injure or kill fishes. One mechanism that produces injuries is the rapid motion of the walls of the swim bladder as it repeatedly contacts nearby tissues. To further understand the involvement of the swim bladder in tissue damage, a specially designed wave tube was used to expose three species to pile-driving sounds. Species included lake sturgeon (Acipenser fulvescens)--with an open (physostomous) swim bladder, Nile tilapia (Oreochromis niloticus)--with a closed (physoclistous) swim bladder and the hogchoker (Trinectes maculatus)--a flatfish without a swim bladder. There were no visible injuries in any of the exposed hogchokers, whereas a variety of injuries were observed in the lake sturgeon and Nile tilapia. At the loudest cumulative and single-strike sound exposure levels (SEL(cum) and SEL(ss) respectively), the Nile tilapia had the highest total injuries and the most severe injuries per fish. As exposure levels decreased, the number and severity of injuries were more similar between the two species. These results suggest that the presence and type of swim bladder correlated with injury at higher sound levels, while the extent of injury at lower sound levels was similar for both kinds of swim bladders.

  10. Identification and characterization of microRNAs and their target genes from Nile tilapia (Oreochromis niloticus).

    PubMed

    Huang, Yong; Ma, Xiu Ying; Yang, You Bing; Ren, Hong Tao; Sun, Xi Hong; Wang, Li Rui

    2016-01-01

    MicroRNAs (miRNAs) are a class of small single-stranded, endogenous 21-22 nt non-coding RNAs that regulate their target mRNA levels by causing either inactivation or degradation of the mRNAs. In recent years, miRNA genes have been identified from mammals, insects, worms, plants, and viruses. In this research, bioinformatics approaches were used to predict potential miRNAs and their targets in Nile tilapia from the expressed sequence tag (EST) and genomic survey sequence (GSS) database, respectively, based on the conservation of miRNAs in many animal species. A total of 19 potential miRNAs were detected following a range of strict filtering criteria. To test the validity of the bioinformatics method, seven predicted Nile tilapia miRNA genes were selected for further biological validation, and their mature miRNA transcripts were successfully detected by stem-loop RT-PCR experiments. Using these potential miRNAs, we found 56 potential targets in this species. Most of the target mRNAs appear to be involved in development, metabolism, signal transduction, transcription regulation and stress responses. Overall, our findings will provide an important foundation for further research on miRNAs function in the Nile tilapia. PMID:27305701

  11. Chemical compositions and muddy flavour/odour of protein hydrolysate from Nile tilapia and broadhead catfish mince and protein isolate.

    PubMed

    Yarnpakdee, Suthasinee; Benjakul, Soottawat; Penjamras, Pimpimol; Kristinsson, Hordur G

    2014-01-01

    Chemical compositions and muddy compounds in dorsal and ventral muscles of Nile tilapia and broadhead catfish were comparatively studied. On a dry weight basis, Nile tilapia was rich in protein (93.1-93.8%), whilst broadhead catfish contained protein (55.2-59.5%) and lipid (36.6-42.4%) as the major constituents. Ventral portion had higher lipid or phospholipid contents with coincidentally higher geosmin and/or 2-methylisoborneol (2-MIB) contents. Geosmin was found in mince of Nile tilapia and broadhead catfish at levels of 1.5 and 3.2μg/kg, respectively. Broadhead catfish mince had 2-MIB at level of 0.8μg/kg, but no 2-MIB was detected in Nile tilapia counterpart. When pre-washing and alkaline solubilisation were applied for preparing protein isolate (PI), lipid and phospholipid contents were lowered with concomitant decrease in geosmin and 2-MIB contents. Protein hydrolysate produced from PI had a lighter colour and a lower amount of muddy compounds, compared with that prepared from mince. Therefore, PI from both Nile tilapia and broadhead catfish could serve as the promising proteinaceous material, yielding protein hydrolysate with the negligible muddy odour and flavour. PMID:24001833

  12. Dietary electrolyte balance affects the nutrient digestibility and maintenance energy expenditure of Nile tilapia.

    PubMed

    Saravanan, S; Geurden, I; Orozco, Z G A; Kaushik, S J; Verreth, J A J; Schrama, J W

    2013-12-14

    Acid-base disturbances caused by environmental factors and physiological events including feeding have been well documented in several fish species, but little is known about the impact of dietary electrolyte balance (dEB). In the present study, we investigated the effect of feeding diets differing in dEB (-100, 200, 500 or 800 mEq/kg diet) on the growth, nutrient digestibility and energy balance of Nile tilapia. After 5 weeks on the test diet, the growth of the fish was linearly affected by the dEB levels (P< 0·001), with the lowest growth being observed in the fish fed the 800 dEB diet. The apparent digestibility coefficient (ADC) of fat was unaffected by dEB, whereas the ADC of DM and protein were curvilinearly related to the dEB levels, being lowest and highest in the 200 and 800 dEB diets, respectively. Stomach chyme pH at 3 h after feeding was linearly related to the dEB levels (P< 0·05). At the same time, blood pH of the heart (P< 0·05) and caudal vein (P< 0·01) was curvilinearly related to the dEB levels, suggesting the influence of dEB on postprandial metabolic alkalosis. Consequently, maintenance energy expenditure (MEm) was curvilinearly related to the dEB levels (P< 0·001), being 54 % higher in the 800 dEB group (88 kJ/kg(0·8) per d) than in the 200 dEB group (57 kJ/kg(0·8) per d). These results suggest that varying dEB levels in a diet have both positive and negative effects on fish. On the one hand, they improve nutrient digestibility; on the other hand, they challenge the acid-base homeostasis (pH) of fish, causing an increase in MEm, and thereby reduce the energy required for growth.

  13. Mechanisms and metabolic regulation of PPARα activation in Nile tilapia (Oreochromis niloticus).

    PubMed

    Ning, Li-Jun; He, An-Yuan; Li, Jia-Min; Lu, Dong-Liang; Jiao, Jian-Gang; Li, Ling-Yu; Li, Dong-Liang; Zhang, Mei-Ling; Chen, Li-Qiao; Du, Zhen-Yu

    2016-09-01

    Although the key metabolic regulatory functions of mammalian peroxisome proliferator-activated receptor α (PPARα) have been thoroughly studied, the molecular mechanisms and metabolic regulation of PPARα activation in fish are less known. In the first part of the present study, Nile tilapia (Nt)PPARα was cloned and identified, and high mRNA expression levels were detected in the brain, liver, and heart. NtPPARα was activated by an agonist (fenofibrate) and by fasting and was verified in primary hepatocytes and living fish by decreased phosphorylation of NtPPARα and/or increased NtPPARα mRNA and protein expression. In the second part of the present work, fenofibrate was fed to fish or fish were fasted for 4weeks to investigate the metabolic regulatory effects of NtPPARα. A transcriptomic study was also performed. The results indicated that fenofibrate decreased hepatic triglyceride and 18C-series fatty acid contents but increased the catabolic rate of intraperitoneally injected [1-(14)C] palmitate in vivo, hepatic mitochondrial β-oxidation efficiency, the quantity of cytochrome b DNA, and carnitine palmitoyltransferase-1a mRNA expression. Fenofibrate also increased serum glucose, insulin, and lactate concentrations. Fasting had stronger hypolipidemic and gene regulatory effects than those of fenofibrate. Taken together, we conclude that: 1) liver is one of the main target tissues of the metabolic regulation of NtPPARα activation; 2) dephosphorylation is the basal NtPPARα activation mechanism rather than enhanced mRNA and protein expression; 3) activated NtPPARα has a hypolipidemic effect by increasing activity and the number of hepatic mitochondria; and 4) PPARα activation affects carbohydrate metabolism by altering energy homeostasis among nutrients. PMID:27320014

  14. Effects of some dietary crude plant extracts on the growth and gonadal maturity of Nile tilapia (Oreochromis niloticus) and their resistance to Streptococcus agalactiae infection.

    PubMed

    Kareem, Zana H; Abdelhadi, Yasser M; Christianus, Annie; Karim, Murni; Romano, Nicholas

    2016-04-01

    A 90-day feeding trial was conducted on the growth performance, feeding efficacy, body indices, various hematological and plasma biochemical parameters, and histopathological examination of the gonads from male and female Nile tilapia fingerlings when fed different crude plant extracts from Cinnamomum camphora, Euphorbia hirta, Azadirachta indica, or Carica papaya at 2 g kg(-1) compared to a control diet. This was followed by a 14-day challenge to Streptococcus agalactiae. All treatments were triplicated, and each treatment consisted of 30 fish. Results showed that C. papaya extracts were the most effective at delaying gonadal maturation to both male and female tilapia, as well as significantly increasing (P < 0.05) growth performance compared to the control treatment. Similarly, dietary C. camphora and E. hirta extracts also significantly improved growth, while no significant growth effect was detected between the A. indica and control treatments (P > 0.05). Further, crude body lipid was lower in the C. camphora, E. hirta and C. papaya treatments, but was only significantly lower for the E. hirta treatment compared to the control. Meanwhile, none of the hematological or biochemical parameters were significantly affected, although plasma ALT was significantly lower for tilapia fed A. indica compared to the control. After the 14-day bacterial challenge, tilapia fed C. camphora supplementation had significantly higher survival, compared to the control, but was not significantly higher than the other supplemented diets. Results indicate that dietary C. papaya extract can significantly promote growth and delay gonadal maturation to both male and female tilapia, while C. camphora was the most effective prophylactic to S. agalactiae and may be a cost-effective and eco-friendly alternative to antibiotics. PMID:26643907

  15. Ameliorating effect of β-carotene on antioxidant response and hematological parameters of mercuric chloride toxicity in Nile tilapia (Oreochromis niloticus).

    PubMed

    Elseady, Y; Zahran, E

    2013-08-01

    The impact of different levels of dietary β-carotene to alleviate the effect of mercuric chloride toxicity in Nile tilapia was assessed. Semi-purified diets containing 0, 40, and 100 mg β-carotene kg(-1) dry diet were fed for 21 days, which were subjected to sublethal concentration of mercuric chloride (0.05 ppm). Hematological and biochemical parameters, lipid profile, and antioxidant response were examined. All hematological parameters of tilapia fish starting from second week of toxicity were significantly decreased. A significant increasing trend in liver enzymes (ALT and AST) were observed parallel to the time of toxicity and peroxide radicals (MDA) appearing significantly increased in toxicated group without carotene supplement, although carotene supplementation return all parameters within the control levels. Mercury accumulated significantly in fish liver and white muscles in toxicated group while it showed a significant reduction in dietary β-carotene-treated group. Overall, it can be used as immunostimulant and alleviate the suppression effect resulted from immune depressive stressful condition in farmed Nile tilapia. PMID:23475564

  16. Efficiency of eugenol as anesthetic for the early life stages of Nile tilapia (Oreochromis niloticus).

    PubMed

    Ribeiro, Paula A P; Miranda-Filho, Kleber C; Melo, Daniela C de; Luz, Ronald K

    2015-03-01

    In aquaculture, activities with anesthetic compounds are usually used in order to ensure the welfare of farmed fish, allowing handling out of water with decreased trauma by stress. Presently, there is no information about anesthetic action of eugenol in early life stages of Nile tilapia (Oreochromis niloticus). The objective of this study was to evaluate different concentrations of eugenol for larvae and juveniles of Nile tilapia. Sixty animals were used for each group of weight, group I = 0.02 g; group II = 0.08 g; group III = 0.22 g; group IV = 2.62 g; and group V = 11.64 g. The eugenol concentrations tested were 50, 75, 100, 125, 150 and 175 mg L-1. No mortality was reported during the tests with eugenol. Tilapia larvae with 0.02 g and juveniles around 11.64 g can be anesthetized with eugenol concentrations between 150 and 175 mg L-1, since they determine the shortest sedation time (23 and 72 seconds, for the group of lowest and highest weights, respectively).

  17. Successful xenogeneic germ cell transplantation from Jundia catfish (Rhamdia quelen) into adult Nile tilapia (Oreochromis niloticus) testes.

    PubMed

    Silva, M A; Costa, G M J; Lacerda, S M S N; Brandão-Dias, P F P; Kalapothakis, E; Silva Júnior, A F; Alvarenga, E R; França, L R

    2016-05-01

    Fish germ cell transplantation presents several important potential applications for aquaculture, including the preservation of germplasm from endangered fish species with high genetic and commercial values. Using this technique in studies developed in our laboratory with adult male Nile tilapias (Oreochromis niloticus), all the necessary procedures were successfully established, allowing the production of functional sperm and healthy progeny approximately 2months after allogeneic transplantation. In the present study, we evaluated the viability of the adult Nile tilapia testis to generate sperm after xenogeneic transplant of germ cells from sexually mature Jundia catfish (Rhamdia quelen) that belong to a different taxonomic order. Therefore, in order to investigate at different time-periods post-transplantation, the presence and development of donor PKH26 labeled catfish germ cells were followed in the tilapia seminiferous tubules. From 7 to 20days post-transplantation, only PKH26 labeled spermatogonia were observed, whereas spermatocytes at different stages of development were found at 70days. Germ cell transplantation success and progression of spermatogenesis were indicated by the presence of labeled PKH26 spermatids and sperm on days 90 and 120 post-transplantation, respectively. Confirming the presence of the catfish genetic material in the tilapia testis, all recipient tilapias evaluated (n=8) showed the genetic markers evaluated. Therefore, we demonstrated for the first time that the adult Nile tilapia testis offers the functional conditions for development of spermatogenesis with sperm production from a fish species belonging to a different order, which provides an important new venue for aquaculture advancement.

  18. Successful xenogeneic germ cell transplantation from Jundia catfish (Rhamdia quelen) into adult Nile tilapia (Oreochromis niloticus) testes.

    PubMed

    Silva, M A; Costa, G M J; Lacerda, S M S N; Brandão-Dias, P F P; Kalapothakis, E; Silva Júnior, A F; Alvarenga, E R; França, L R

    2016-05-01

    Fish germ cell transplantation presents several important potential applications for aquaculture, including the preservation of germplasm from endangered fish species with high genetic and commercial values. Using this technique in studies developed in our laboratory with adult male Nile tilapias (Oreochromis niloticus), all the necessary procedures were successfully established, allowing the production of functional sperm and healthy progeny approximately 2months after allogeneic transplantation. In the present study, we evaluated the viability of the adult Nile tilapia testis to generate sperm after xenogeneic transplant of germ cells from sexually mature Jundia catfish (Rhamdia quelen) that belong to a different taxonomic order. Therefore, in order to investigate at different time-periods post-transplantation, the presence and development of donor PKH26 labeled catfish germ cells were followed in the tilapia seminiferous tubules. From 7 to 20days post-transplantation, only PKH26 labeled spermatogonia were observed, whereas spermatocytes at different stages of development were found at 70days. Germ cell transplantation success and progression of spermatogenesis were indicated by the presence of labeled PKH26 spermatids and sperm on days 90 and 120 post-transplantation, respectively. Confirming the presence of the catfish genetic material in the tilapia testis, all recipient tilapias evaluated (n=8) showed the genetic markers evaluated. Therefore, we demonstrated for the first time that the adult Nile tilapia testis offers the functional conditions for development of spermatogenesis with sperm production from a fish species belonging to a different order, which provides an important new venue for aquaculture advancement. PMID:26972155

  19. Histopathological and genotoxic effects of pollution on Nile Tilapia (Oreochromis niloticus, Linnaeus, 1758) in the Billings Reservoir (Brazil).

    PubMed

    Rezende, Karina Fernandes Oliveira; Santos, Rubens Martins; Borges, João Carlos Shimada; Salvo, Lígia Maria; da Silva, José Roberto Machado Cunha

    2014-09-01

    The Billings Reservoir shows eutrophic waters due to the large amount of sewage, and consequently, the fish can be a problem for public health. Thus, this project aimed to analyze the histological gills and liver of Nile tilapia to verify morphological changes caused by environment, and the frequency of micronuclei was done, to observe the response to genotoxic activity. We observed histological alterations in gills and livers of Nile Tilapia classified as mild to severe, and the presence of micronucleus. The results enable better environmental monitoring and quality control of this species.

  20. Trace metal concentrations in Nile tilapia (Oreochromis niloticus) in three catchments, Sri Lanka.

    PubMed

    Allinson, G; Salzman, S A; Turoczy, N; Nishikawa, M; Amarasinghe, U S; Nirbadha, K G S; De Silva, S S

    2009-03-01

    Samples of the muscle and liver of the Nile tilapia (Oreochromis niloticus) were obtained from a single reservoir in each of three Sri Lankan catchments (Kaudulla, Rajanganaya, and Udawalawe reservoirs in the Mahaweli, Kala Oya, and Walawe Ganga river basins, respectively) in 2002. The concentrations of 12 elements were consistently detected in the tilapia muscle and liver (Ca, Cd, Cu, Fe, Hg, K, Mg, Mn, Na, P, Sr and Zn). However, a three factorial principal components analysis suggested that there were no differences in the metal profiles (range of elements and concentration) of the fish obtained from any of the three reservoirs, although the chemistries of each tissue (muscle and liver) were different. Metal concentrations were below WHO and Food Standards Australia and New Zealand guideline values, and substantial quantities of tilapia would need to be consumed each week on a regular basis to exceed intake limits (e.g. more than 1.5 kg to exceed intake lits for Cu), suggesting consumption of tilapia from these reservoirs poses little risk to human health. PMID:18949439

  1. Global DNA Methylation Changes in Nile Tilapia Gonads during High Temperature-Induced Masculinization

    PubMed Central

    Wang, Hui; Li, Ning

    2016-01-01

    In some fish species, high or low temperature can switch the sex determination mechanisms and induce fish sex reversal when the gonads are undifferentiated. During this high or low temperature-induced sex reversal, the expressions of many genes are altered. However, genome-wide DNA methylation changes in fish gonads after high or low temperature treatment are unclear. Herein, we compared the global DNA methylation changes in the gonads from control females (CF), control males (CM), high temperature-treated females (TF), and high temperature-induced males (IM) from the F8 family of Nile tilapia (Oreochromis niloticus) using methylated DNA immunoprecipitation sequencing. The DNA methylation level in CF was higher than that in CM for various chromosomes. Both females and males showed an increase in methylation levels on various chromosomes after high-temperature induction. We identified 64,438 (CF/CM), 63,437 (TF/IM), 98,675 (TF/CF), 235,270 (IM/CM) and 119,958 (IM/CF) differentially methylated regions (DMRs) in Nile tilapia gonads, representing approximately 0.70% (CF/CM), 0.69% (TF/IM), 1.07% (TF/CF), 2.56% (IM/CM), and 1.30% (IM/CF)of the length of the genome. A total of 89 and 65 genes that exhibited DMRs in their gene bodies and promoters were mapped to the Nile tilapia genome. Furthermore, more than half of the genes with DMRs in the gene body in CF/CM were also included in the IM/CM, TF/CF, TF/IM, and IM/CF groups. Additionally, many important pathways, including neuroactive ligand-receptor interaction, extracellular matrix-receptor interaction, and biosynthesis of unsaturated fatty acids were identified. This study provided an important foundation to investigate the molecular mechanism of high temperature-induced sex reversal in fish species. PMID:27486872

  2. Global DNA Methylation Changes in Nile Tilapia Gonads during High Temperature-Induced Masculinization.

    PubMed

    Sun, Li-Xue; Wang, Yi-Ya; Zhao, Yan; Wang, Hui; Li, Ning; Ji, Xiang Shan

    2016-01-01

    In some fish species, high or low temperature can switch the sex determination mechanisms and induce fish sex reversal when the gonads are undifferentiated. During this high or low temperature-induced sex reversal, the expressions of many genes are altered. However, genome-wide DNA methylation changes in fish gonads after high or low temperature treatment are unclear. Herein, we compared the global DNA methylation changes in the gonads from control females (CF), control males (CM), high temperature-treated females (TF), and high temperature-induced males (IM) from the F8 family of Nile tilapia (Oreochromis niloticus) using methylated DNA immunoprecipitation sequencing. The DNA methylation level in CF was higher than that in CM for various chromosomes. Both females and males showed an increase in methylation levels on various chromosomes after high-temperature induction. We identified 64,438 (CF/CM), 63,437 (TF/IM), 98,675 (TF/CF), 235,270 (IM/CM) and 119,958 (IM/CF) differentially methylated regions (DMRs) in Nile tilapia gonads, representing approximately 0.70% (CF/CM), 0.69% (TF/IM), 1.07% (TF/CF), 2.56% (IM/CM), and 1.30% (IM/CF)of the length of the genome. A total of 89 and 65 genes that exhibited DMRs in their gene bodies and promoters were mapped to the Nile tilapia genome. Furthermore, more than half of the genes with DMRs in the gene body in CF/CM were also included in the IM/CM, TF/CF, TF/IM, and IM/CF groups. Additionally, many important pathways, including neuroactive ligand-receptor interaction, extracellular matrix-receptor interaction, and biosynthesis of unsaturated fatty acids were identified. This study provided an important foundation to investigate the molecular mechanism of high temperature-induced sex reversal in fish species. PMID:27486872

  3. Sublethal ammonia exposure of Nile tilapia (Oreochromis niloticus L.): effects on gill, liver and kidney histology.

    PubMed

    Benli, Aysel Cağlan Karasu; Köksal, Gülten; Ozkul, Ayhan

    2008-07-01

    The effects of exposures to sublethal ammonia concentrations on Nile tilapia (Oreochromis niloticus L.) were determined with respect to histology. The experiments were conducted for six weeks and with four different ammonia concentrations (control, 1, 2, 5, 10 mg l(-1) TA-N). Fish exposed to different ammonia concentrations displayed histopathologic alterations in the gills, liver and kidney. Gill tissues displayed hyperemia, chloride cell proliferation, fusion in secondary lamella, telangiectasis. Liver tissue revealed cloudy swelling and hydropic degeneration, whereas in kidney tissues hyperemia and glomerulonephritis were observed.

  4. Dietary lipid levels impact lipoprotein lipase, hormone-sensitive lipase, and fatty acid synthetase gene expression in three tissues of adult GIFT strain of Nile tilapia, Oreochromis niloticus.

    PubMed

    Tian, Juan; Wu, Fan; Yang, Chang-Geng; Jiang, Ming; Liu, Wei; Wen, Hua

    2015-02-01

    The objective of this study was to assess the effects of dietary lipids on growth performance, body composition, serum parameters, and expression of genes involved in lipid metabolism in adult genetically improved farmed tilapia (GIFT strain) of Nile tilapia, Oreochromis niloticus. We randomly assigned adult male Nile tilapia (average initial body weight = 220.00 ± 9.54 g) into six groups consisting of four replicates (20 fish per replicate). Fish in each group were hand-fed a semi-purified diets containing different lipid levels [3.3 (the control group), 28.4, 51.4, 75.4, 101.9, and 124.1 g kg(-1)] for 8 weeks. The results indicated that there was no obvious effect in feeding rate among all groups (P > 0.05). The highest weight gain, specific growth rate, and protein efficiency ratio in 75.4 g kg(-1) diet group were increased by 23.31, 16.17, and 22.02 % than that of fish in the control group (P < 0.05). Protein retention ratio was highest in 51.4 g kg(-1) diet group. The results revealed that the optimum dietary lipid level for maximum growth performance is 76.6-87.9 g kg(-1). Increasing dietary lipid levels contributed to increased tissue and whole body lipid levels. Saturated and monounsaturated fatty acids (MUFAs) decreased, and polyunsaturated fatty acids increased with increasing dietary lipid levels. With the exception of MUFAs, the fatty acid profiles of liver and muscle were similar. Dietary lipid levels were negatively correlated with low-density lipoprotein- cholesterol content and positively with triacylglycerol and glucose contents. In the lipid-fed groups, there was a significant down-regulation of fatty acid synthase (FAS) mRNA in liver, muscle, and visceral adipose tissues. There was a rapid up-regulation of lipoprotein lipase (LPL) mRNA in muscle and liver with increasing dietary lipid levels. In visceral adipose tissue, LPL mRNA was significantly down-regulated in the lipid-fed groups. Dietary lipids increased hormone-sensitive lipase (HSL) m

  5. Protection induced by a CpG oligonucelotide in Nile tilapia against Streptococcus iniae infection and identification of upregulated genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At two days post treatment, a CpG oligodeoxynucleotide (CpG 120818-9A) offered Nile tilapia (Oreochromis niloticus L.) significant (P<0.05) protection against Streptococcus iniae infection, with relative percent survival up to 63%. To understand the molecular mechanisms involved in the protective im...

  6. Efficacy of QCDCR formulated CpG ODN 2007 in Nile tilapia against Streptococcus iniae and identification of upregulated genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential of using a QCDCR (quilA:cholesterol:dimethyl dioctadecyl ammonium bromide:carbopol:R1005 glycolipid) formulated CpG oligodeoxynucleotide (ODN), ODN 2007, to confer protection in Nile tilapia against Streptococcus iniae infection was evaluated in this study. At two days post treatment, ...

  7. Edwardsiella tarda and Aeromonas hydrophila isolated from diseased Southern flounder (Paralichthys lethostigma) are virulent to channel catfish and Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study is to identify bacterial pathogens isolated from diseased Southern flounder and determine their virulence to channel catfish and Nile tilapia. Twenty five Gram-negative bacteria isolates were recovered from five tissues (skin lesions, brain, liver, intestine, and posterior kidn...

  8. Development and efficacy of novobiocin and rifampicin-resistant Aeromonas hydrophila as novel vaccines in channel catfish and Nile tilapia.

    PubMed

    Pridgeon, Julia W; Klesius, Phillip H

    2011-10-19

    Three attenuated Aeromonas hydrophila vaccines were developed from the virulent 2009 West Alabama isolates through selection for resistance to both novobiocin and rifampicin. When channel catfish (Ictalurus punctatus) were IP injected with 4×105 colony-forming unit (CFU) of the mutants, no fish died. However, when the same age and size matched channel catfish were IP injected with similar amount of their virulent parents, 80-100% fish died. Similarly, when Nile tilapia (Oreochromis niloticus) were IP injected with 2×108 CFU of the mutants, no fish died. However, when Nile tilapia were IP injected with similar amount of the mutants, all fish died. Vaccination of channel catfish with the mutants at dose of 4×105 CFU/fish offered 86-100% protection against their virulent parents at 14 days post vaccination (dpv). Vaccination of Nile tilapia with the mutants at dose of 2×108 CFU/fish offered 100% protection against their virulent parents at 14, 28, and 56 dpv. Agglutination assay results suggested that protection elicited by the mutants was partially due to antibody-mediated immunity. Taken together, our results suggest that the three attenuated vaccines might be used to protect channel catfish and Nile tilapia against the highly virulent 2009 West Alabama isolates of A. hydrophila.

  9. Oxidative damage in gills and liver in Nile tilapia (Oreochromis niloticus) exposed to diazinon.

    PubMed

    Toledo-Ibarra, G A; Díaz Resendiz, K J G; Ventura-Ramón, G H; González-Jaime, F; Vega-López, A; Becerril-Villanueva, E; Pavón, L; Girón-Pérez, M I

    2016-10-01

    Agricultural activity demands the use of pesticides for plague control and extermination. In that matter, diazinon is one of the most widely used organophosphorus pesticides (OPs). Despite its benefits, the use of OPs in agricultural activities can also have negative effects since the excessive use of these substances can represent a major contamination problem for water bodies and organisms that inhabit them. The aim of this paper was to evaluate oxidative damage in lipids and proteins of Nile tilapia (Oreochromis niloticus) exposed acutely to diazinon (0.97, 1.95 and 3.95ppm) for 12 or 24h. The evaluation of oxidative damage was determined by quantifying lipid hydroperoxides (Fox method) and oxidized proteins (DNPH method). The data from this study suggest that diazinon induces a concentration-dependent oxidative damage in proteins, but not lipids, of the liver and gills of Nile tilapia. Furthermore, the treatment leads to a decrease in the concentration of total proteins, which can have serious consequences in cell physiology and fish development.

  10. Oxidative damage in gills and liver in Nile tilapia (Oreochromis niloticus) exposed to diazinon.

    PubMed

    Toledo-Ibarra, G A; Díaz Resendiz, K J G; Ventura-Ramón, G H; González-Jaime, F; Vega-López, A; Becerril-Villanueva, E; Pavón, L; Girón-Pérez, M I

    2016-10-01

    Agricultural activity demands the use of pesticides for plague control and extermination. In that matter, diazinon is one of the most widely used organophosphorus pesticides (OPs). Despite its benefits, the use of OPs in agricultural activities can also have negative effects since the excessive use of these substances can represent a major contamination problem for water bodies and organisms that inhabit them. The aim of this paper was to evaluate oxidative damage in lipids and proteins of Nile tilapia (Oreochromis niloticus) exposed acutely to diazinon (0.97, 1.95 and 3.95ppm) for 12 or 24h. The evaluation of oxidative damage was determined by quantifying lipid hydroperoxides (Fox method) and oxidized proteins (DNPH method). The data from this study suggest that diazinon induces a concentration-dependent oxidative damage in proteins, but not lipids, of the liver and gills of Nile tilapia. Furthermore, the treatment leads to a decrease in the concentration of total proteins, which can have serious consequences in cell physiology and fish development. PMID:27174646

  11. Arsenic-induced genotoxicity in Nile tilapia (Orechromis niloticus); the role of Spirulina platensis extract.

    PubMed

    Sayed, Alaa El-Din H; Elbaghdady, Heba Allah M; Zahran, Eman

    2015-12-01

    Arsenic (As) is one of the most relevant environmental global single substance toxicants that have long been regarded as a carcinogenic and genotoxic potential. In this respect, we evaluated the cytogenetic effect of arsenic exposure in Nile tilapia (Oreochromis niloticus), in terms of erythrocyte alteration, apoptosis, and induction of micronuclei. Spirulina platensis (SP) is a filamentous cyanobacterium microalgae with potent dietary phytoantioxidant, anti-inflammatory, and anti-cancerous properties supplementation. The protective role of Spirulina as supplementary feeds was studied in Nile tilapia (O. niloticus) against arsenic-induced cytogenotoxicity. Four groups were assigned as control group (no SP or As), As group (exposed to water-born As in the form of NaAsO2 at 7 ppm), SP1 (SP at 7.5% + As at the same level of exposure), and SP2 (SP at 10% + As at the same level of exposure). As-treated group had a significant increase in all cytogenetic analyses including erythrocyte alteration, apoptosis, and induction of micronuclei after 2 weeks with continuous increase in response after 3 weeks. The combined treatment of Spirulina at two different concentrations of 7.5 and 10% had significantly declined the induction of erythrocyte alteration, apoptosis, and micronuclei formation induced by arsenic intoxication. PMID:26573688

  12. Effect of different stress factors on some physiological parameters of Nile tilapia (Oreochromis niloticus)

    PubMed Central

    EL-Khaldi, Aziza T.F.

    2010-01-01

    This study was conducted to determine the effect of different stress factors on some physiological measurements of Nile tilapia (Oreochromis niloticus). A total number of 160 Nile tilapia, the body weight ranging between 100 and 120 g, were exposed to three stress factors of hypoxia, overcrowding and starvation for different periods 24, 72 and 144 h. The results of cortisol level were 134.15, 144.27, 154.12 ng/ml and 140.18 ng/ml for control, hypoxia, overcrowding and starvation, respectively, while after 144 h did not show significant difference among treatments compared with control group. In contrast, the values of T3 and T4 observed reduction with significant difference that T3 ranged between the highest value 122.12 ng/ml for control group to lowest value of starvation group 94.35, 93.81 and 88.46 ng/ml after 24, 72 and 144 h. Also, similar trend of results observed in T4 and blood glucose among treatments. And the enzymatic activity of lactate dehydrogenise (LDH) increased in hypoxic group, while a significant reduction appeared in overcrowding and starved fish compared to control group. The pyruvate kinase (PK) activity decreased in hypoxic group but increased in other group. PMID:23961085

  13. Arsenic-induced genotoxicity in Nile tilapia (Orechromis niloticus); the role of Spirulina platensis extract.

    PubMed

    Sayed, Alaa El-Din H; Elbaghdady, Heba Allah M; Zahran, Eman

    2015-12-01

    Arsenic (As) is one of the most relevant environmental global single substance toxicants that have long been regarded as a carcinogenic and genotoxic potential. In this respect, we evaluated the cytogenetic effect of arsenic exposure in Nile tilapia (Oreochromis niloticus), in terms of erythrocyte alteration, apoptosis, and induction of micronuclei. Spirulina platensis (SP) is a filamentous cyanobacterium microalgae with potent dietary phytoantioxidant, anti-inflammatory, and anti-cancerous properties supplementation. The protective role of Spirulina as supplementary feeds was studied in Nile tilapia (O. niloticus) against arsenic-induced cytogenotoxicity. Four groups were assigned as control group (no SP or As), As group (exposed to water-born As in the form of NaAsO2 at 7 ppm), SP1 (SP at 7.5% + As at the same level of exposure), and SP2 (SP at 10% + As at the same level of exposure). As-treated group had a significant increase in all cytogenetic analyses including erythrocyte alteration, apoptosis, and induction of micronuclei after 2 weeks with continuous increase in response after 3 weeks. The combined treatment of Spirulina at two different concentrations of 7.5 and 10% had significantly declined the induction of erythrocyte alteration, apoptosis, and micronuclei formation induced by arsenic intoxication.

  14. MicroRNA-10 modulates Hox genes expression during Nile tilapia embryonic development.

    PubMed

    Giusti, Juliana; Pinhal, Danillo; Moxon, Simon; Campos, Camila Lovaglio; Münsterberg, Andrea; Martins, Cesar

    2016-05-01

    Hox gene clusters encode a family of transcription factors that govern anterior-posterior axis patterning during embryogenesis in all bilaterian animals. The time and place of Hox gene expression are largely determined by the relative position of each gene within its cluster. Furthermore, Hox genes were shown to have their expression fine-tuned by regulatory microRNAs (miRNAs). However, the mechanisms of miRNA-mediated regulation of these transcription factors during fish early development remain largely unknown. Here we have profiled three highly expressed miR-10 family members of Nile tilapia at early embryonic development, determined their genomic organization as well as performed functional experiments for validation of target genes. Quantitative analysis during developmental stages showed miR-10 family expression negatively correlates with the expression of HoxA3a, HoxB3a and HoxD10a genes, as expected for bona fide miRNA-mRNA interactions. Moreover, luciferase assays demonstrated that HoxB3a and HoxD10a are targeted by miR-10b-5p. Overall, our data indicate that the miR-10 family directly regulates members of the Hox gene family during Nile tilapia embryogenesis. PMID:26980108

  15. Genotoxicity of sub-lethal di-n-butyl phthalate (DBP) in Nile tilapia (Oreochromis niloticus).

    PubMed

    Benli, Aysel Çağlan Karasu; Erkmen, Belda; Erkoç, Figen

    2016-03-01

    This study aimed to assess genotoxicity in Nile tilapia (Oreochromis niloticus) erythrocytes after exposure to a sub-lethal concentration of 10 mg L(-1) di-n-butyl phthalate (DBP) for 24 and 96 h. The results showed that mean MN frequencies in both DBP and ethyl methane-sulfonate (EMS, positive control for MN bioassay) groups were significantly different (p<0.01) with respect to control and solvent control groups, in both exposure scenarios. When analysing nuclear abnormalities, the frequency of notched nuclei was significantly different (p<0.05) but the frequencies of other subtypes did not change. The 96-h exposure led to an increase in the mean frequencies of notched nuclei, and also caused significant differences between MN frequencies in all groups (p<0.01). Our findings indicate that sub-lethal DBP concentrations when tested in controlled laboratory conditions have genotoxic potential towards Nile tilapia. Further detailed studies should be done for the determination of the environmental risk assessment for aquatic life since DBP is a high risk contaminant of freshwater and marine ecosystems. PMID:27092636

  16. Metacercarial Infection of Wild Nile Tilapia (Oreochromis niloticus) from Brazil

    PubMed Central

    Pinto, Hudson A.; Mati, Vitor L. T.; Melo, Alan L.

    2014-01-01

    Fingerlings of Oreochromis niloticus collected in an artificial urban lake from Belo Horizonte, Minas Gerais, Brazil, were evaluated for natural infection with trematodes. Morphological taxonomic identification of four fluke species was performed in O. niloticus examined, and the total prevalence of metacercariae was 60.7% (37/61). Centrocestus formosanus, a heterophyid found in the gills, was the species with the highest prevalence and mean intensity of infection (31.1% and 3.42 (1–42), resp.), followed by the diplostomid Austrodiplostomum compactum (29.5% and 1.27 (1-2)) recovered from the eyes. Metacercariae of Drepanocephalus sp. and Ribeiroia sp., both found in the oral cavity of the fish, were verified at low prevalences (8.2% and 1.6%, resp.) and intensities of infection (only one metacercaria of each of these species per fish). These species of trematodes are reported for the first time in O. niloticus from South America. The potential of occurrence of these parasites in tilapia farming and the control strategies are briefly discussed. PMID:25485302

  17. Genetic differentiation among natural populations of the Nile tilapia Oreochromis niloticus (Teleostei, cichlidae).

    PubMed

    Agnèse, J F; Adépo-Gourène, B; Abban, E K; Fermon, Y

    1997-07-01

    We analysed the genetic differentiation among 17 natural populations of the Nile tilapia Oreochromis niloticus (Linnaeus, 1758) using allozymes and restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA). The populations studied, from the River Senegal to Lake Tana and from Lake Manzalla to Lake Baringo, represent all subspecies which have been previously described. Sixteen variable nuclear loci showed that these populations can be clustered in three groups: (1) West African populations (Senegal, Niger, Volta and Chad drainages), (2) Ethiopian Rift Valley populations (Lakes Awasa, Ziway, Koka and the Awash River) and (3) Nile drainage (Manzalla, Cairo, Lake Edward) and Kenyan Rift Valley populations (Lakes Turkana, Baringo and River Suguta). Nine different mtDNA haplotypes were found in the RFLP analysis of a 1 kb portion of the D-loop region. The network obtained showed that there are three geographically distinct groups; all West African populations and O. aureus are clustered, the two Ethiopian Rift Valley populations are distinct and between these two groups are the Kenyan and Ugandan Rift Valley populations. Nile populations show affinities both with West African populations and with specimens from Lakes Tana and Turkana. Taxonomic and biogeographical implications of these results are discussed. PMID:9253615

  18. Genetic differentiation among natural populations of the Nile tilapia Oreochromis niloticus (Teleostei, cichlidae).

    PubMed

    Agnèse, J F; Adépo-Gourène, B; Abban, E K; Fermon, Y

    1997-07-01

    We analysed the genetic differentiation among 17 natural populations of the Nile tilapia Oreochromis niloticus (Linnaeus, 1758) using allozymes and restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA). The populations studied, from the River Senegal to Lake Tana and from Lake Manzalla to Lake Baringo, represent all subspecies which have been previously described. Sixteen variable nuclear loci showed that these populations can be clustered in three groups: (1) West African populations (Senegal, Niger, Volta and Chad drainages), (2) Ethiopian Rift Valley populations (Lakes Awasa, Ziway, Koka and the Awash River) and (3) Nile drainage (Manzalla, Cairo, Lake Edward) and Kenyan Rift Valley populations (Lakes Turkana, Baringo and River Suguta). Nine different mtDNA haplotypes were found in the RFLP analysis of a 1 kb portion of the D-loop region. The network obtained showed that there are three geographically distinct groups; all West African populations and O. aureus are clustered, the two Ethiopian Rift Valley populations are distinct and between these two groups are the Kenyan and Ugandan Rift Valley populations. Nile populations show affinities both with West African populations and with specimens from Lakes Tana and Turkana. Taxonomic and biogeographical implications of these results are discussed.

  19. Isolation and characterization of bacteria with antibacterial properties from Nile tilapia (Oreochromis niloticus).

    PubMed

    Etyemez, Miray; Balcazar, Jose Luis

    2016-04-01

    One hundred and twenty bacterial isolates were obtained from the intestinal mucus of Nile tilapia (Oreochromis niloticus) and screened for antagonistic activity and adherence abilities. Based on in vitro antagonism against two pathogens (Streptococcus iniae and Edwardsiella piscicida), five isolates were selected and identified by 16S rRNA gene sequence analysis. All antagonistic isolates were affiliated to the genus Bacillus, which showed inhibitory activity against S. iniae. Only the isolate B191 (closely related to Bacillus mojavensis) inhibited the growth of both pathogens. Moreover, isolate B191 adhered significantly better to fish intestinal mucus than other antagonistic isolates. According to our results, these bacterial isolates, particularly isolate B191, should be further studied to explore their probiotic effects under in vivo conditions. PMID:27033910

  20. Paratrichodina africana (Ciliophora): a pathogenic gill parasite in farmed Nile tilapia.

    PubMed

    Valladão, G M R; Pádua, S B; Gallani, S U; Menezes-Filho, R N; Dias-Neto, J; Martins, M L; Ishikawa, M M; Pilarski, F

    2013-11-01

    Trichodinids are ciliated protozoa that are widely known as one of the main groups of fish parasites. The genus Trichodina presents the greatest species diversity. However, records of Paratrichodina species are scarce, and little is known about their pathogenicity in hosts. The present study provides new records of Paratrichodina africana Kazubski and El-Tantawy (1986) in Nile tilapia from South America and descriptions of pathological changes and seasonality. A total of 304 farmed fish were examined. From gill scraping, parasites were identified using Klein's nitrate impregnation method. Gill samples were fixed for histopathological analysis. Small trichodinid found in this study have a prominent blade apophysis and narrow central part and blade shape that corresponds to the characteristics of P. africana Kazubski and El-Tantawy (1986). Gill lesions were proportional to parasite intensity, in which the gill tissue was compromised in heavy infestation. Proliferative disturbances were found, including epithelial hyperplasia, desquamation, and mononuclear and eosinophilic infiltrate that culminated in necrosis. We did not observe a seasonality effect on the occurrence of P. africana. This ciliated protozoan causes compromised respiratory capacity that leads to severe gill lesions and currently is an important pathogen that afflicts intensive tilapia cultures in Brazil.

  1. Figla Favors Ovarian Differentiation by Antagonizing Spermatogenesis in a Teleosts, Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Sun, Lina; Wei, Jing; Nagahama, Yoshitaka; Wang, Deshou; Zhou, Linyan

    2015-01-01

    Figla (factor in the germ line, alpha), a female germ cell-specific transcription factor, had been shown to activate genetic hierarchies in oocytes. The ectopic expression of Figla was known to repress spermatogenesis-associated genes in male mice. However, the potential role of Figla in other vertebrates remains elusive. The present work was aimed to identify and characterize the functional relevance of Figla in the ovarian development of Nile tilapia (Oreochromis niloticus). Tissue distribution and ontogeny analysis revealed that tilapia Figla gene was dominantly expressed in the ovary from 30 days after hatching. Immunohistochemistry analysis also demonstrated that Figla was expressed in the cytoplasm of early primary oocytes. Intriguingly, over-expression of Figla in XY fish resulted in the disruption of spermatogenesis along with the depletion of meiotic spermatocytes and spermatids in testis. Dramatic decline of sycp3 (synaptonemal complex protein 3) and prm (protamine) expression indicates that meiotic spermatocytes and mature sperm production are impaired. Even though Sertoli cell (dmrt1) and Leydig cell (star and cyp17a1) marker genes remained unaffected, hsd3b1 expression and 11-KT production were enhanced in Figla-transgene testis. Taken together, our data suggest that fish Figla might play an essential role in the ovarian development by antagonizing spermatogenesis. PMID:25894586

  2. Estrogenic activities of diuron metabolites in female Nile tilapia (Oreochromis niloticus).

    PubMed

    Pereira, Thiago Scremin Boscolo; Boscolo, Camila Nomura Pereira; Felício, Andreia Arantes; Batlouni, Sergio Ricardo; Schlenk, Daniel; de Almeida, Eduardo Alves

    2016-03-01

    Some endocrine disrupting chemicals (EDCs) can alter the estrogenic activities of the organism by directly interacting with estrogen receptors (ER) or indirectly through the hypothalamus-pituitary-gonadal axis. Recent studies in male Nile tilapia (Oreochromis niloticus) indicated that diuron may have anti-androgenic activity augmented by biotransformation. In this study, the effects of diuron and three of its metabolites were evaluated in female tilapia. Sexually mature female fish were exposed for 25 days to diuron, as well as to its metabolites 3,4-dichloroaniline (DCA), 3,4-dichlorophenylurea (DCPU) and 3,4-dichlorophenyl-N-methylurea (DCPMU), at concentrations of 100 ng/L. Diuron metabolites caused increases in E2 plasma levels, gonadosomatic indices and in the percentage of final vitellogenic oocytes. Moreover, diuron and its metabolites caused a decrease in germinative cells. Significant differences in plasma concentrations of the estrogen precursor and gonadal regulator17α-hydroxyprogesterone (17α-OHP) were not observed. These results show that diuron metabolites had estrogenic effects potentially mediated through enhanced estradiol biosynthesis and accelerated the ovarian development of O. niloticus females.

  3. Blockage of progestin physiology disrupts ovarian differentiation in XX Nile tilapia (Oreochromis niloticus).

    PubMed

    Zhou, Linyan; Luo, Feng; Fang, Xuelian; Charkraborty, Tapas; Wu, Limin; Wei, Jing; Wang, Deshou

    2016-04-22

    Previous studies indicated that maturation inducing hormone, 17α, 20β-Dihydroxy-4-pregnen-3-one (DHP), probably through nuclear progestin receptor (Pgr), might be involved in spermatogenesis and oogenesis in fish. To further elucidate DHP actions in teleostean ovarian differentiation, we analyzed the expression of pgr in the ovary of Nile tilapia (Oreochromis niloticus), and performed RU486 (a synthetic Pgr antagonist) treatment in XX fish from 5 days after hatching (dah) to 120 dah. Tilapia Pgr was abundantly expressed in the follicular cells surrounding oocytes at 30 and 90 dah. Continuous RU486 treatment led to the blockage of oogenesis and masculinization of somatic cells in XX fish. Termination of RU486 treatment and maintenance in normal condition resulted in testicular differentiation, and estrogen compensation in RU486-treated XX fish successfully restored oogenesis. In RU486-treated XX fish, transcript levels of female dominant genes were significantly reduced, while male-biased genes were evidently augmented. Meanwhile, both germ cell mitotic and meiotic markers were substantially reduced. Consistently, estrogen production levels were significantly declined in RU486-treated XX fish. Taken together, our data further proved that DHP, possibly through Pgr, might be essential in the ovarian differentiation and estrogen production in fish.

  4. Blockage of progestin physiology disrupts ovarian differentiation in XX Nile tilapia (Oreochromis niloticus).

    PubMed

    Zhou, Linyan; Luo, Feng; Fang, Xuelian; Charkraborty, Tapas; Wu, Limin; Wei, Jing; Wang, Deshou

    2016-04-22

    Previous studies indicated that maturation inducing hormone, 17α, 20β-Dihydroxy-4-pregnen-3-one (DHP), probably through nuclear progestin receptor (Pgr), might be involved in spermatogenesis and oogenesis in fish. To further elucidate DHP actions in teleostean ovarian differentiation, we analyzed the expression of pgr in the ovary of Nile tilapia (Oreochromis niloticus), and performed RU486 (a synthetic Pgr antagonist) treatment in XX fish from 5 days after hatching (dah) to 120 dah. Tilapia Pgr was abundantly expressed in the follicular cells surrounding oocytes at 30 and 90 dah. Continuous RU486 treatment led to the blockage of oogenesis and masculinization of somatic cells in XX fish. Termination of RU486 treatment and maintenance in normal condition resulted in testicular differentiation, and estrogen compensation in RU486-treated XX fish successfully restored oogenesis. In RU486-treated XX fish, transcript levels of female dominant genes were significantly reduced, while male-biased genes were evidently augmented. Meanwhile, both germ cell mitotic and meiotic markers were substantially reduced. Consistently, estrogen production levels were significantly declined in RU486-treated XX fish. Taken together, our data further proved that DHP, possibly through Pgr, might be essential in the ovarian differentiation and estrogen production in fish. PMID:26993165

  5. Antimicrobial Susceptibility of Escherichia coli Isolated from Fresh-Marketed Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Rocha, Rafael dos Santos; Leite, Lana Oliveira; de Sousa, Oscarina Viana; Vieira, Regine Helena Silva dos Fernandes

    2014-01-01

    The contamination of seafood by bacteria of fecal origin, especially Escherichia coli, is a widely documented sanitary problem. The objective of the present study was to isolate E. coli strains from the gills, muscle, and body surface of farmed Nile tilapias (Oreochromis niloticus) fresh-marketed in supermarkets in Fortaleza (Ceará, Brazil), to determine their susceptibility to antibiotics of different families (amikacin, gentamicin, imipenem, cephalothin, cefotaxime, ciprofloxacin, aztreonam, ampicillin, nalidixic acid, tetracycline, and sulfametoxazol-trimetoprim), and to determine the nature of resistance by plasmid curing. Forty-four strains (body surface = 25, gills = 15, muscle = 4) were isolated, all of which were susceptible to amikacin, aztreonam, cefotaxime, ciprofloxacin, gentamicin, and imipenem. Gill and body surface samples yielded 11 isolates resistant to ampicillin, tetracycline, and sulfametoxazol-trimetoprim, 4 of which of plasmidial nature. The multiple antibiotic resistance index was higher for strains isolated from body surface than from gills. The overall high antibiotic susceptibility of E. coli strains isolated from fresh-marketed tilapia was satisfactory, although the occasional finding of plasmidial resistance points to the need for close microbiological surveillance of the farming, handling, and marketing conditions of aquaculture products. PMID:24808957

  6. The aggressive behavior of Nile tilapia introduced into novel environments with variation in enrichment.

    PubMed

    Barreto, Rodrigo E; Carvalho, Graziele G Arantes; Volpato, Gilson L

    2011-02-01

    Many studies show environmental enrichment is correlated with benefits to captive animals; however, one should not always assume this positive relationship given that enrichment increases the amount of resources that a territorial animal must defend and possibly affects its aggressive dynamics. In this study, we tested if environmental enrichment affects aggressive interactions in the aggressive fish Nile tilapia (Oreochromis niloticus). We compared fights staged between pairs of male tilapia of similar size (= matched in resource holding potential) in a novel arena that was either barren or enriched, to examine whether enrichment enhances territory value in line with theoretical predictions, with the potential for compromised welfare. We evaluated time elapsed until the first attack (latency), frequency of aggressive interactions and fight duration. We detected fight dynamic differences at the pair level. Higher resource value generated increased aggression but had no effect on fight duration or latency. This conclusion is in line with game theory predictions concerning resource value and contradicts the theory that enrichment of the environment will serve welfare purposes.

  7. Role of catalase on the hypoxia/reoxygenation stress in the hypoxia-tolerant Nile tilapia.

    PubMed

    Welker, Alexis F; Campos, Elida G; Cardoso, Luciano A; Hermes-Lima, Marcelo

    2012-05-01

    The specific contribution of each antioxidant enzyme to protection against the reoxygenation-associated oxidative stress after periods of hypoxia is not well understood. We assessed the physiological role of catalase during posthypoxic reoxygenation by the combination of two approaches. First, catalase activity of Nile tilapias (Oreochromis niloticus) was 90% suppressed by intraperitoneal injection of 3-amino-1,2,4-triazole (ATZ, 1g/kg). In ATZ-injected fish, liver GSH levels, oxidative stress markers, and activities of other antioxidant enzymes remained unchanged. Second, animals with depleted catalase activity (or those saline-injected) were subjected to a cycle of severe hypoxia (dissolved O(2) = 0.28 mg/l for 3 h) followed by reoxygenation (0.5 to 24 h). Hypoxia did not induce changes in the above-mentioned parameters, either in saline- or in ATZ-injected animals. Reoxygenation increased superoxide dismutase activity in saline-injected fish, whose levels were similar to ATZ-injected animals. The activities of glutathione S-transferase, selenium-dependent glutathione peroxidase, and total-GPX and the levels of GSH-eq, GSSG, and thiobarbituric acid reactive substances remained unchanged during reoxygenation in both saline- and ATZ-injected fish. The GSSG/GSH-eq ratio in ATZ-injected fish increased at 30 min of reoxygenation compared with saline-injected ones. Reoxygenation also increased carbonyl protein levels in saline-injected fish, whose levels were similar to the ATZ-injected group. Our work shows that inhibition of liver tilapia catalase causes a redox imbalance during reoxygenation, which is insufficient to induce further oxidative stress. This indicates the relevance of hepatic catalase for hypoxia/reoxygenation stress in tilapia fish. PMID:22378777

  8. Blocking of progestin action disrupts spermatogenesis in Nile tilapia (Oreochromis niloticus).

    PubMed

    Liu, Gang; Luo, Feng; Song, Qiang; Wu, Limin; Qiu, Yongxiu; Shi, Hongjuan; Wang, Deshou; Zhou, Linyan

    2014-08-01

    In vitro studies have indicated that the maturation-inducing hormone 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-DP, DHP), probably through nuclear progestin receptor (Pgr), might be involved in the proliferation of spermatogonial cells and the initiation of meiosis in several fish species. However, further in vivo evidence is required to elucidate the role of DHP in spermatogenesis during sexual differentiation in teleosts. In this study, we cloned pgr and analyzed its expression in Nile tilapia (Oreochromis niloticus) and treated XY fish with RU486 (a synthetic Pgr antagonist) from 5 days after hatching (dah) to determine the role of DHP in spermatogenesis. Sequence and phylogenetic analyses revealed that the Pgr identified in tilapia is a genuine Pgr. Pgr was found to be expressed in the Sertoli cells surrounding spermatogonia and spermatids in the testis of tilapia. Real-time PCR analysis revealed that the expression of pgr in the testis was significantly upregulated from 10 dah, further increased at 50 dah, and persisted until adulthood in fish. In the testis of RU486-treated fish, the transcript levels of germ cell markers and a meiotic marker were substantially reduced. However, the expression of markers in Sertoli cells remained unchanged. Moreover, the production of 11-ketotestosterone and the expression of genes encoding various steroidogenic enzymes were also not altered. In contrast, the expression of cyp17a2, encoding one of the critical steroidogenic enzymes involved in DHP biosynthesis, declined significantly, possibly indicating the inhibition of DHP production by RU486. RU486 treatment given for 2 months did not affect spermatogenesis; however, treatment given for more than 3 months resulted in a decrease in spermatogonial cell numbers and depletion of later-phase spermatogenic cells. Simultaneous excessive DHP supplementation restored spermatogenesis in RU486-treated XY fish. Taken together, our data further indicated that DHP, possibly through

  9. Effect of N-acetyl cysteine and glycine supplementation on growth performance, glutathione synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus.

    PubMed

    Xie, Shiwei; Zhou, Weiwen; Tian, Lixia; Niu, Jin; Liu, Yongjian

    2016-08-01

    An 8-week feeding trial was conducted to evaluate the effect of N-acetyl cysteine (NAC) and glycine supplementation on growth performance, glutathione (GSH) synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus. Four practical diets were formulated, control, control +0.2% NAC, control +0.5% glycine, control +0.2% NAC +0.5% glycine. Each diet was randomly assigned to quadruplicate groups of 30 fish (approximately 9.5 g). The weight gain and specific growth rate were significantly increased with the supplementation of NAC and glycine. While they had no effect on feed efficiency feed intake and survival. Glutathion peroxidase (GPx) was increased by NAC and γ-glutamine cysteine synthase (γ-GCS) in plasma were increased by glycine. After the feeding trail, fish were challenged by Streptococcus iniae, fish fed the diet supplemented with NAC obtained significantly higher survival rate after 72 h challenge test. NAC also decreased malonaldehyde (MDA) in liver, increased glutathione S-transferase (GST) activity in plasma, up-regulated mRNA expression of Superoxide dismutase (SOD) and GPx in liver and headkidney. Dietary supplementation of glycine increased the anti-oxidative ability of tilapia through increase anti-oxidative enzyme activity (SOD, glutathione reductase, myeloperoxidase) and up-regulate anti-oxidative gene expression (SOD). Immune ability only enhanced by the supplementation of NAC through increased interleukin-1β (IL-1β) mRNA expression. These results clearly indicated that the supplementation of NAC and glycine can significantly improve the growth performance of tilapia, and NAC also enhance the anti-oxidative and immune capacity of tilapia, glycine could only enhance the anti-oxidative ability.

  10. Effect of N-acetyl cysteine and glycine supplementation on growth performance, glutathione synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus.

    PubMed

    Xie, Shiwei; Zhou, Weiwen; Tian, Lixia; Niu, Jin; Liu, Yongjian

    2016-08-01

    An 8-week feeding trial was conducted to evaluate the effect of N-acetyl cysteine (NAC) and glycine supplementation on growth performance, glutathione (GSH) synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus. Four practical diets were formulated, control, control +0.2% NAC, control +0.5% glycine, control +0.2% NAC +0.5% glycine. Each diet was randomly assigned to quadruplicate groups of 30 fish (approximately 9.5 g). The weight gain and specific growth rate were significantly increased with the supplementation of NAC and glycine. While they had no effect on feed efficiency feed intake and survival. Glutathion peroxidase (GPx) was increased by NAC and γ-glutamine cysteine synthase (γ-GCS) in plasma were increased by glycine. After the feeding trail, fish were challenged by Streptococcus iniae, fish fed the diet supplemented with NAC obtained significantly higher survival rate after 72 h challenge test. NAC also decreased malonaldehyde (MDA) in liver, increased glutathione S-transferase (GST) activity in plasma, up-regulated mRNA expression of Superoxide dismutase (SOD) and GPx in liver and headkidney. Dietary supplementation of glycine increased the anti-oxidative ability of tilapia through increase anti-oxidative enzyme activity (SOD, glutathione reductase, myeloperoxidase) and up-regulate anti-oxidative gene expression (SOD). Immune ability only enhanced by the supplementation of NAC through increased interleukin-1β (IL-1β) mRNA expression. These results clearly indicated that the supplementation of NAC and glycine can significantly improve the growth performance of tilapia, and NAC also enhance the anti-oxidative and immune capacity of tilapia, glycine could only enhance the anti-oxidative ability. PMID:27235905

  11. Effects of dietary levels of carbohydrate, lipid, phosphorus and zinc on the growth, feed conversion and protein efficiency ratio of Nile tilapia ( Oreochromis niloticus)

    NASA Astrophysics Data System (ADS)

    Li, Zhongjie; Lei, Wu; Yang, Yunxia; Ye, Jun

    1993-09-01

    A 54-day feeding experiment was conducted on juvenile Nile tilapia using isonitrogenous, isocaloric semipurified diets. The carbohydrate content in the diet was 9%, 32% and 50%; the corresponding lipid content was 22.2%, 12%, and 4%. The diets were supplemented with 0.85% or 1.5% phosphorus and 40 mg/kg or 100 mg/kg zinc. The experiment was carried out in flow-through aquaria using dechlorinated tap water at 23 26°C. The experiment showed that the increase of the carbohydrate content in the diets resulted in a 43 249% increase in weight gain, a 27 59% decrease in feed conversion ratio, and a 65 121% increase in protein efficiency ratio. In fish fed diets containing 36 50% carbohydrate, an increase in supplemented phosphorus to 1.5% greatly increased the weight gain. On the contrary, a high content of supplemented zinc (100 mg/kg) inhibited growth and increased feed conversion ratio.

  12. The potential effects of Spirulina platensis (Arthrospira platensis) on tissue protection of Nile tilapia (Oreochromis niloticus) through estimation of P53 level.

    PubMed

    Ibrahem, Mai D; Ibrahim, Marwa A

    2014-01-01

    The current study was designed to investigate the potential effect of Spirulina platensis, Arthrospira platensis, (SP) on tissue protection of Nile tilapia (Oreochromis niloticus) through estimation of P53 level. Five isonitrogenous and isocaloric rations containing graded levels of dried SP 5, 7.5,10, 15, and 20 g/kg diet were fed separately to five equal groups of O. niloticus fingerlings, additional control group was assigned for 3 months. Liver samples were separately collected from each group by the end of each month. The expression level of P53 showed a substantial decrease among the treated groups in a time-dependent manner. It is therefore advisable to incorporate SP in diets for tissue protection and antioxidant effects in cultured O. niloticus. PMID:25685480

  13. The potential effects of Spirulina platensis (Arthrospira platensis) on tissue protection of Nile tilapia (Oreochromis niloticus) through estimation of P53 level

    PubMed Central

    Ibrahem, Mai D.; Ibrahim, Marwa A.

    2013-01-01

    The current study was designed to investigate the potential effect of Spirulina platensis, Arthrospira platensis, (SP) on tissue protection of Nile tilapia (Oreochromis niloticus) through estimation of P53 level. Five isonitrogenous and isocaloric rations containing graded levels of dried SP 5, 7.5,10, 15, and 20 g/kg diet were fed separately to five equal groups of O. niloticus fingerlings, additional control group was assigned for 3 months. Liver samples were separately collected from each group by the end of each month. The expression level of P53 showed a substantial decrease among the treated groups in a time-dependent manner. It is therefore advisable to incorporate SP in diets for tissue protection and antioxidant effects in cultured O. niloticus. PMID:25685480

  14. Fish-borne trematodes in cultured Nile tilapia (Oreochromis niloticus) and wild-caught fish from Thailand.

    PubMed

    Wiriya, Benjamaporn; Clausen, Jesper Hedegaard; Inpankaew, Tawin; Thaenkham, Urusa; Jittapalapong, Sathaporn; Satapornvanit, Kriengkrai; Dalsgaard, Anders

    2013-11-15

    Fish-borne zoonotic trematode (FZT) infections affect the health of more than 18 million people around the world, particularly in Asian countries. Nile tilapia (Oreochromis niloticus) is a white meat fish that has an increasing national and international market. The objective of this study was to determine the prevalence of FZT metacercarial infections in Nile tilapia from cage and pond aquaculture systems and in wild-caught fish from Suphan Buri, Nakhon Pathom and Chachoengsao provinces, Thailand. Fish were collected from four cages in Suphan Buri and four ponds in Nakhon Pathom provinces between September-October 2011 and April-May 2012 and wild-caught fish were collected in May 2012. All fish were examined for metacercariae by a pepsin digestion and metacercariae identified using morphological and molecular methods. During the first sampling of tilapia the prevalence of metacercariae in cage culture fish were 2.5% and 10% in pond culture fish. During the second sampling, metacercariae was found in 2.0% of tilapia from cage and none from the ponds. Of the 150 wild-caught fish, a total of 80 (53.3%) were found to be infected with metacercariae, mostly the zoonotic species Stellantchasmus falcatus, Haplorchis pumilio and Procerovum varium. The results revealed a low risk for FZT in Nile tilapia cultured in cage and pond aquaculture systems. However, the high prevalence of FZT in wild-caught fish indicates a high potential for spillover from wild reservoir hosts and underscores the need for vigilance and good management practices by the aquaculture sector.

  15. A new record of Myxobolus brachysporus and M. israelensis in the tilapia (Oreochromis niloticus) collected from the Nile River, Egypt

    PubMed Central

    Abdel-Baki, Abdel-Azeem S.; Zayed, Eman; Sakran, Thabet; Al-Quraishy, Saleh

    2015-01-01

    The present study was carried out as part of an ongoing general survey for myxosporean parasites infecting tilapias in the River Nile, Egypt. In the present study, 77 Nile tilapia (Oreochromis niloticus) were collected from boat landing sites at Beni-Suef governorate, Egypt and examined for the myxosporean infection. The infection was encountered as a huge number of free spores in the kidney and the spleen. The infection showed a prevalence of 51.9% (40/77) for Myxobolus brachysporus while it was 25.9% (20/77) for Myxobolus israelensis. Mature spores of M. brachysporus were ellipsoidal and measured 8.6 × 13.2 μm. The polar capsules were subcircular with 5–6 filament turns and measured 4.7 × 3.6 μm. Spores of M. israelensis were ellipsoidal in the frontal view and fusiform in the lateral view. Spore measurements were 13.4 μm long and 8.7 μm wide. The polar capsules were elongated with 6–7 filament coils and measured 8.6 × 3.1 μm. The findings presented here proved that tilapia fishes in the Nile River are still suffering from infections with Myxobolus species. Therefore, further studies should be carried out to survey the Myxobolus infection among tilapias under culture conditions to clarify the pathological impacts of this parasite in tilapias aquaculture. PMID:26286347

  16. Ecotoxicological effects of carbofuran and oxidised multiwalled carbon nanotubes on the freshwater fish Nile tilapia: nanotubes enhance pesticide ecotoxicity.

    PubMed

    Campos-Garcia, Janaína; Martinez, Diego Stéfani T; Alves, Oswaldo L; Leonardo, Antônio Fernando Gervásio; Barbieri, Edison

    2015-01-01

    The interactions of carbon nanotubes with pesticides, such as carbofuran, classical contaminants (e.g., pesticides, polyaromatic hydrocarbons, heavy metals, and dyes) and emerging contaminants, including endocrine disruptors, are critical components of the environmental risks of this important class of carbon-based nanomaterials. In this work, we studied the modulation of acute carbofuran toxicity to the freshwater fish Nile tilapia (Oreochromis niloticus) by nitric acid treated multiwalled carbon nanotubes, termed HNO3-MWCNT. Nitric acid oxidation is a common chemical method employed for the purification, functionalisation and aqueous dispersion of carbon nanotubes. HNO3-MWCNT were not toxic to Nile tilapia at concentrations ranging from 0.1 to 3.0 mg/L for exposure times of up to 96 h. After 24, 48, 72 and 96 h, the LC50 values of carbofuran were 4.0, 3.2, 3.0 and 2.4 mg/mL, respectively. To evaluate the influence of carbofuran-nanotube interactions on ecotoxicity, we exposed the Nile tilapia to different concentrations of carbofuran mixed together with a non-toxic concentration of HNO3-MWCNT (1.0 mg/L). After 24, 48, 72, and 96 h of exposure, the LC50 values of carbofuran plus nanotubes were 3.7, 1.6, 0.7 and 0.5 mg/L, respectively. These results demonstrate that HNO3-MWCNT potentiate the acute toxicity of carbofuran, leading to a more than five-fold increase in the LC50 values. Furthermore, the exposure of Nile tilapia to carbofuran plus nanotubes led to decreases in both oxygen consumption and swimming capacity compared to the control. These findings indicate that carbon nanotubes could act as pesticide carriers affecting fish survival, metabolism and behaviour.

  17. Non-lethal detection of DNA from Cichlidogyrus spp. (Monogenea, Ancyrocephalinae) in gill mucus of the Nile tilapia Oreochromis niloticus.

    PubMed

    Ek-Huchim, Juan Pablo; Jimenez-Garcia, Isabel; Pérez-Vega, Juan Antonio; Rodríguez-Canul, Rossanna

    2012-03-20

    Infection of Nile tilapia Oreochromis niloticus by monogeneans of the genus Cichlidogyrus is harmful. Currently, diagnosis of this infection is based on invasive techniques and the identification of isolated parasites by their morphology. To facilitate diagnosis, we have developed a non-lethal polymerase chain reaction (PCR) test for detection of Cichlidogyrus spp. DNA in the gill mucus of O. niloticus, using 5 pairs of specific primers based on Cichlidogyrus sclerosus 28S rRNA (Cicly 1 to Cicly 5) which generate fragments of approximately 188, 180, 150, 159 and 189 bp, respectively. PCR specificity was tested using genomic DNA extracted individually from 175 isolated Cichlidogyrus spp., 75 Gyrodactylus cichlidarum and 75 endopararasitic Enterogyrus spp., as well as from 75 protozoans Trichodina spp. The Cicly primers were used to detect Cichlidogyrus spp. DNA in mucus from the gills of 23 Nile tilapia confirmed to be infected with the parasite. Negative controls consisted of 45 uninfected Nile tilapia. The limit of sensitivity of the assay was 1.2 ng of purified parasite DNA. The Cicly primers did not amplify DNA from the mucus of non-infected Nile tilapia, G. cichlidarum, Trichodina spp. or Enterogyrus spp. In all cases, the sensitivity and specificity of the test were 100%. The sequences of all the amplified fragments showed a high similarity to that of the 28S rRNA region of C. sclerosus (93 to 100% identical to GenBank Accession No. DQ157660.1). We provide evidence for a safe and non-invasive DNA-based diagnostic method for the presence of Cichlidogyrus in the gill mucus of O. niloticus. PMID:22436463

  18. Nile tilapia Oreochromis niloticus as a food source in advanced life support systems: Initial considerations

    NASA Astrophysics Data System (ADS)

    Gonzales, John M.; Brown, Paul B.

    2006-01-01

    Maintenance of crew health is of paramount importance for long duration space missions. Weight loss, bone and calcium loss, increased exposure to radiation and oxidative stress are critical concerns that need to be alleviated. Tilapia are currently under evaluation as a source of food and their contribution to reducing waste in advanced life support systems (ALSS). The nutritional composition of tilapia whole bodies, fillet, and carcass residues were quantitatively determined. Carbon and nitrogen free-extract percentages were similar among whole body (53.76% and 6.96%, respectively), fillets (47.06% and 6.75%, respectively), and carcass (56.36% and 7.04%, respectively) whereas percentages of N, S, and protein were highest in fillet (13.34, 1.34, and 83.37%, respectively) than whole body (9.27, 0.62, and 57.97%, respectively) and carcass (7.70, 0.39, and 48.15%, respectively). Whole body and fillet meet and/or exceeded current nutritional recommendations for protein, vitamin D, ascorbic acid, and selenium for international space station missions. Whole body appears to be a better source of lipids and n-3 fatty acids, calcium, and phosphorous than fillet. Consuming whole fish appears to optimize equivalent system mass compared to consumption of fillets. Additional research is needed to determine nutritional composition of tilapia whole body, fillet, and carcass when fed waste residues possibly encountered in an ALSS.

  19. Dietary nutrient composition affects digestible energy utilisation for growth: a study on Nile tilapia (Oreochromis niloticus) and a literature comparison across fish species.

    PubMed

    Schrama, J W; Saravanan, S; Geurden, I; Heinsbroek, L T N; Kaushik, S J; Verreth, J A J

    2012-07-01

    The effect of the type of non-protein energy (NPE) on energy utilisation in Nile tilapia was studied, focusing on digestible energy utilisation for growth (k(gDE)). Furthermore, literature data on k(gDE) across fish species were analysed in order to evaluate the effect of dietary macronutrient composition. A total of twelve groups of fish were assigned in a 2 × 2 factorial design: two diets ('fat' v. 'starch') and two feeding levels ('low' v. 'high'). In the 'fat'-diet, 125 g fish oil and in the 'starch'-diet 300 g maize starch were added to 875 g of an identical basal mixture. Fish were fed restrictively one of two ration levels ('low' or 'high') for estimating k(gDE). Nutrient digestibility, N and energy balances were measured. For estimating k(gDE), data of the present study were combined with previous data of Nile tilapia fed similar diets to satiation. The type of NPE affected k(gDE) (0.561 and 0.663 with the 'starch' and 'fat'-diets, respectively; P < 0.001). Across fish species, literature values of k(gDE) range from 0.31 to 0.82. Variability in k(gDE) was related to dietary macronutrient composition, the trophic level of the fish species and the composition of growth (fat:protein gain ratio). The across-species comparison suggested that the relationships of k(gDE) with trophic level and with growth composition were predominantly induced by dietary macronutrient composition. Reported k(gDE) values increased linearly with increasing dietary fat content and decreasing dietary carbohydrate content. In contrast, k(gDE) related curvilinearly to dietary crude protein content. In conclusion, energy utilisation for growth is influenced by dietary macronutrient composition.

  20. Defining a breeding objective for Nile tilapia that takes into account the diversity of smallholder production systems.

    PubMed

    Omasaki, S K; van Arendonk, J A M; Kahi, A K; Komen, H

    2016-10-01

    In general, livestock and fish farming systems in developing countries tend to be highly diverse in terms of agro-ecological conditions and market orientation. There are no studies that have investigated if and how this diversity translates to varying preferences for breeding objective traits. This is particularly important for breeding programmes that are organized on a national level (e.g. government-supported nucleus breeding programmes). The aim of this study was to investigate whether Nile tilapia farmers with diverse production systems and economic constraints have different preferences for breeding objective traits. The second objective was to derive a consensus breeding goal, using weighted goal programming that could be used for a national breeding programme for Nile tilapia. A survey was conducted among 100 smallholder Nile tilapia farmers in Kenya to obtain preference values for traits of economic importance, by using multiple pairwise comparisons. Individual and group preference values were estimated using analytical hierarchy process. Low-income farmers preferred harvest weight, while medium- and high-income farmers preferred growth rate and survival. Grouping farmers according to market objective (fingerling production or fattening) showed that fingerling producers preferred growth rate and survival, while fattening farmers preferred harvest weight, height and thickness. Weighted goal programming was used to obtain consensus preference values, and these were used to derive desired gains for a breeding goal of a national breeding programme that takes into account the diversity of smallholder production systems. PMID:26996153

  1. Defining a breeding objective for Nile tilapia that takes into account the diversity of smallholder production systems.

    PubMed

    Omasaki, S K; van Arendonk, J A M; Kahi, A K; Komen, H

    2016-10-01

    In general, livestock and fish farming systems in developing countries tend to be highly diverse in terms of agro-ecological conditions and market orientation. There are no studies that have investigated if and how this diversity translates to varying preferences for breeding objective traits. This is particularly important for breeding programmes that are organized on a national level (e.g. government-supported nucleus breeding programmes). The aim of this study was to investigate whether Nile tilapia farmers with diverse production systems and economic constraints have different preferences for breeding objective traits. The second objective was to derive a consensus breeding goal, using weighted goal programming that could be used for a national breeding programme for Nile tilapia. A survey was conducted among 100 smallholder Nile tilapia farmers in Kenya to obtain preference values for traits of economic importance, by using multiple pairwise comparisons. Individual and group preference values were estimated using analytical hierarchy process. Low-income farmers preferred harvest weight, while medium- and high-income farmers preferred growth rate and survival. Grouping farmers according to market objective (fingerling production or fattening) showed that fingerling producers preferred growth rate and survival, while fattening farmers preferred harvest weight, height and thickness. Weighted goal programming was used to obtain consensus preference values, and these were used to derive desired gains for a breeding goal of a national breeding programme that takes into account the diversity of smallholder production systems.

  2. Molecular Cloning and Expression Analysis of IgD in Nile Tilapia (Oreochromis niloticus) in Response to Streptococcus agalactiae Stimulus.

    PubMed

    Wang, Bei; Wang, Pei; Wu, Zao-He; Lu, Yi-Shan; Wang, Zhong-Liang; Jian, Ji-Chang

    2016-01-01

    IgD is considered to be a recently-evolved Ig and a puzzling molecule, being previously found in all vertebrate taxa, except for birds. Although IgD likely plays an important role in vertebrate immune responses, the function of IgD in Nile tilapia (Oreochromis niloticus) is virtually unknown. In the present study, a membrane form of IgD (mIgD) heavy chains were cloned from the GIFT strain of Nile tilapia (designated On-mIgD). The On-mIgD heavy chain's cDNA is composed of 3347 bp with a 31 bp of 5'-UTR, 3015 bp open reading frame (ORF) and 301 bp 3'-UTR, encoding a polypeptide of 1004 amino acids (GenBank accession no: KF530821). Phylogenetic analysis revealed that On-mIgD heavy chains showed the highest similarity to Siniperca chuatsi. Quantitative real-time PCR (qRT-PCR) analysis showed that On-mIgD expression occurred predominately in head kidney, thymus, spleen, and kidney. After Streptococcus agalactiae infection, transcripts of On-mIgD increased and reached its peak at 48 h in the head kidney and thymus, and 72 h in the spleen, respectively. Taken together, these results collectively indicated that IgD could possibly have a key role to play in the immune response when bacterial infections in Nile tilapia.

  3. Molecular Cloning and Expression Analysis of IgD in Nile Tilapia (Oreochromis niloticus) in Response to Streptococcus agalactiae Stimulus.

    PubMed

    Wang, Bei; Wang, Pei; Wu, Zao-He; Lu, Yi-Shan; Wang, Zhong-Liang; Jian, Ji-Chang

    2016-01-01

    IgD is considered to be a recently-evolved Ig and a puzzling molecule, being previously found in all vertebrate taxa, except for birds. Although IgD likely plays an important role in vertebrate immune responses, the function of IgD in Nile tilapia (Oreochromis niloticus) is virtually unknown. In the present study, a membrane form of IgD (mIgD) heavy chains were cloned from the GIFT strain of Nile tilapia (designated On-mIgD). The On-mIgD heavy chain's cDNA is composed of 3347 bp with a 31 bp of 5'-UTR, 3015 bp open reading frame (ORF) and 301 bp 3'-UTR, encoding a polypeptide of 1004 amino acids (GenBank accession no: KF530821). Phylogenetic analysis revealed that On-mIgD heavy chains showed the highest similarity to Siniperca chuatsi. Quantitative real-time PCR (qRT-PCR) analysis showed that On-mIgD expression occurred predominately in head kidney, thymus, spleen, and kidney. After Streptococcus agalactiae infection, transcripts of On-mIgD increased and reached its peak at 48 h in the head kidney and thymus, and 72 h in the spleen, respectively. Taken together, these results collectively indicated that IgD could possibly have a key role to play in the immune response when bacterial infections in Nile tilapia. PMID:27005611

  4. Molecular Cloning and Expression Analysis of IgD in Nile Tilapia (Oreochromis niloticus) in Response to Streptococcus agalactiae Stimulus

    PubMed Central

    Wang, Bei; Wang, Pei; Wu, Zao-He; Lu, Yi-Shan; Wang, Zhong-Liang; Jian, Ji-Chang

    2016-01-01

    IgD is considered to be a recently-evolved Ig and a puzzling molecule, being previously found in all vertebrate taxa, except for birds. Although IgD likely plays an important role in vertebrate immune responses, the function of IgD in Nile tilapia (Oreochromis niloticus) is virtually unknown. In the present study, a membrane form of IgD (mIgD) heavy chains were cloned from the GIFT strain of Nile tilapia (designated On-mIgD). The On-mIgD heavy chain’s cDNA is composed of 3347 bp with a 31 bp of 5′-UTR, 3015 bp open reading frame (ORF) and 301 bp 3′-UTR, encoding a polypeptide of 1004 amino acids (GenBank accession no: KF530821). Phylogenetic analysis revealed that On-mIgD heavy chains showed the highest similarity to Siniperca chuatsi. Quantitative real-time PCR (qRT-PCR) analysis showed that On-mIgD expression occurred predominately in head kidney, thymus, spleen, and kidney. After Streptococcus agalactiae infection, transcripts of On-mIgD increased and reached its peak at 48 h in the head kidney and thymus, and 72 h in the spleen, respectively. Taken together, these results collectively indicated that IgD could possibly have a key role to play in the immune response when bacterial infections in Nile tilapia. PMID:27005611

  5. Effects of dietary live and heat-inactive baker's yeast on growth, gut health, and disease resistance of Nile tilapia under high rearing density.

    PubMed

    Ran, Chao; Huang, Lu; Hu, Jun; Tacon, Philippe; He, Suxu; Li, Zhimin; Wang, Yibing; Liu, Zhi; Xu, Li; Yang, Yalin; Zhou, Zhigang

    2016-09-01

    In this study, the effects of baker's yeast as probiotics was evaluated in Nile tilapia reared at high density. Juvenile tilapia were distributed to tanks at high density (436 fish/m(3)) and fed with basal diet (CK) or diets supplemented with live (LY) or heat-inactivated yeast (HIY). Another group of fish reared at low density (218 fish/m(3)) and fed with basal diet was also included (LowCK). After 8 weeks of feeding, growth, feed utilization, gut microvilli morphology, digestive enzymes, and expressions of hsp70 and inflammation-related cytokines in the intestine were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Fish were challenged with Aeromonas hydrophila to evaluate disease resistance. High rearing density significantly decreased the growth, feed utilization, microvilli length, and disease resistance of fish (CK versus LowCK). Moreover, the intestinal hsp70 expression was increased in fish reared at high density, supporting a stress condition. Compared to CK group, supplementation of live yeast significantly increased gut microvilli length and trypsin activity, decreased intestinal hsp70 expression, and enhanced resistance of fish against A. hydrophila (reflected by reduced intestinal alkaline phosphatase activity 24 h post infection). The gut microbiota was not markedly influenced by either rearing density or yeast supplementation. Heat-inactivated yeast (HIY) didn't display the beneficial effects observed in LY except an increase in gut trypsin activity, suggesting the importance of yeast viability and thus secretory metabolites of yeast. In conclusion, live baker's yeast may alleviate the negative effects induced by crowding stress, and has the potential to be used as probiotics for tilapia reared at high density. PMID:27393237

  6. Effects of dietary live and heat-inactive baker's yeast on growth, gut health, and disease resistance of Nile tilapia under high rearing density.

    PubMed

    Ran, Chao; Huang, Lu; Hu, Jun; Tacon, Philippe; He, Suxu; Li, Zhimin; Wang, Yibing; Liu, Zhi; Xu, Li; Yang, Yalin; Zhou, Zhigang

    2016-09-01

    In this study, the effects of baker's yeast as probiotics was evaluated in Nile tilapia reared at high density. Juvenile tilapia were distributed to tanks at high density (436 fish/m(3)) and fed with basal diet (CK) or diets supplemented with live (LY) or heat-inactivated yeast (HIY). Another group of fish reared at low density (218 fish/m(3)) and fed with basal diet was also included (LowCK). After 8 weeks of feeding, growth, feed utilization, gut microvilli morphology, digestive enzymes, and expressions of hsp70 and inflammation-related cytokines in the intestine were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Fish were challenged with Aeromonas hydrophila to evaluate disease resistance. High rearing density significantly decreased the growth, feed utilization, microvilli length, and disease resistance of fish (CK versus LowCK). Moreover, the intestinal hsp70 expression was increased in fish reared at high density, supporting a stress condition. Compared to CK group, supplementation of live yeast significantly increased gut microvilli length and trypsin activity, decreased intestinal hsp70 expression, and enhanced resistance of fish against A. hydrophila (reflected by reduced intestinal alkaline phosphatase activity 24 h post infection). The gut microbiota was not markedly influenced by either rearing density or yeast supplementation. Heat-inactivated yeast (HIY) didn't display the beneficial effects observed in LY except an increase in gut trypsin activity, suggesting the importance of yeast viability and thus secretory metabolites of yeast. In conclusion, live baker's yeast may alleviate the negative effects induced by crowding stress, and has the potential to be used as probiotics for tilapia reared at high density.

  7. Immunoproteomic analysis of the antibody response obtained in Nile tilapia following vaccination with a Streptococcus iniae vaccine.

    PubMed

    LaFrentz, Benjamin R; Shoemaker, Craig A; Klesius, Phillip H

    2011-09-28

    Streptococcus iniae is one of the most economically important Gram-positive pathogens in cultured fish species worldwide. The USDA-ARS Aquatic Animal Health Research Unit developed a modified (contains concentrated culture supernatant) S. iniae bacterin that has been demonstrated to be efficacious, and protection is mediated by specific anti-S. iniae antibodies. Although effective, the specific vaccine components important for efficacy are not known. In the present study, an immunoproteomic approach was utilized to identify whole-cell lysate proteins of S. iniae that stimulated specific antibody production in Nile tilapia (Oreochromis niloticus) following vaccination. Groups of tilapia were vaccinated by intraperitoneal injection with the modified S. iniae bacterin or were mock-vaccinated, and at 30 d post-vaccination sera samples were obtained from individual fish. Vaccination of tilapia with the S. iniae vaccine stimulated significantly elevated specific antibody responses against proteins of the bacterium and passive immunization of tilapia with this serum demonstrated the antibodies were highly protective. Whole-cell lysate proteins of S. iniae were separated by 2D-PAGE and were probed with a pooled serum sample from vaccinated tilapia. A total of eleven unique immunogenic proteins were positively identified by mass spectrometry. Based on research conducted on homologous proteins in other Streptococcus spp., antibodies specific for three of the identified proteins, enolase, glyceraldehyde-3-phosphate dehydrogenase, and fructose-bisphosphate aldolase, are likely involved in protection from streptococcosis caused by S. iniae. PMID:21601381

  8. Effect of dietary genistein on growth performance, digestive enzyme activity, and body composition of Nile tilapia Oreochromis niloticus

    NASA Astrophysics Data System (ADS)

    Chen, Dong; Wang, Wei; Ru, Shaoguo

    2015-01-01

    An 8-week feeding experiment was performed to evaluate the effect of dietary genistein on growth performance, body composition, and digestive enzymes activity of juvenile Nile tilapia ( Oreochromis niloticus). Four isonitrogenous and isoenergetic diets were formulated containing four graded supplements of genistein: 0, 30, 300, and 3 000 μg/g. Each diet was randomly assigned in triplicate to tanks stocked with 15 juvenile tilapia (10.47±1.24 g). The results show that 30 and 300 μg/g dietary genistein had no significant effect on growth performance of Nile tilapia, but the higher level of genistein (3 000 μg/g) significantly depressed the final body weight and specific growth rate. There was no significant difference in survival rate, feed intake, feed efficiency ratio or whole body composition among all dietary treatments. An assay of digestive enzymes showed that the diet containing 3 000 μg/ggenistein decreased stomach and hepatopancreas protease activity, and amylase activity in the liver and intestine, while a dietary level of 300 μg/g genistein depressed stomach protease and intestine amylase activities. However, no significant difference in stomach amylase activity was found among dietary treatments. Overall, the results of the present study indicate that a high level of dietary genistein (3 000 μg/g, or above) would significantly reduce the growth of Nile tilapia, partly because of its inhibitory effect on the activity of major digestive enzymes. Accordingly, the detrimental effects of genistein, as found in soybean products, should not be ignored when applied as an alternative ingredient source in aquaculture.

  9. Characterization of gonadal transcriptomes from Nile tilapia (Oreochromis niloticus) reveals differentially expressed genes.

    PubMed

    Tao, Wenjing; Yuan, Jing; Zhou, Linyan; Sun, Lina; Sun, Yunlv; Yang, Shijie; Li, Minghui; Zeng, Sheng; Huang, Baofeng; Wang, Deshou

    2013-01-01

    Four pairs of XX and XY gonads from Nile tilapia were sequenced at four developmental stages, 5, 30, 90, and 180 days after hatching (dah) using Illumina Hiseq(TM) technology. This produced 28 Gb sequences, which were mapped to 21,334 genes. Of these, 259 genes were found to be specifically expressed in XY gonads, and 69 were found to be specific to XX gonads. Totally, 187 XX- and 1,358 XY-enhanced genes were identified, and 2,978 genes were found to be co-expressed in XX and XY gonads. Almost all steroidogenic enzymes, including cyp19a1a, were up-regulated in XX gonads at 5 dah; but in XY gonads these enzymes, including cyp11b2, were significantly up-regulated at 90 dah, indicating that, at a time critical to sex determination, the XX fish produced estrogen and the XY fish did not produce androgens. The most pronounced expression of steroidogenic enzyme genes was observed at 30 and 90 dah for XX and XY gonads, corresponding to the initiation of germ cell meiosis in the female and male gonads, respectively. Both estrogen and androgen receptors were found to be expressed in XX gonads, but only estrogen receptors were expressed in XY gonads at 5 dah. This could explain why exogenous steroid treatment induced XX and XY sex reversal. The XX-enhanced expression of cyp19a1a and cyp19a1b at all stages suggests an important role for estrogen in female sex determination and maintenance of phenotypic sex. This work is the largest collection of gonadal transcriptome data in tilapia and lays the foundation for future studies into the molecular mechanisms of sex determination and maintenance of phenotypic sex in non-model teleosts.

  10. Effects of plasma total ammonia content and pH on urea excretion in Nile tilapia.

    PubMed

    McKenzie, D J; Piraccini, G; Felskie, A; Romano, P; Bronzi, P; Bolis, C L

    1999-01-01

    Nile tilapia (Oreochromis niloticus) were infused with ammonium salts, acid, and base to investigate the effects of changes in arterial plasma total ammonia content (Tamm) and pH (pHa) on plasma urea-nitrogen (urea-N) levels and urea-N excretory fluxes (Jurea-N). The tilapia did not possess a functional hepatic ornithine urea-cycle (no significant carbamyl phosphate synthetase III activity). Infused substances were dissolved in a saline vehicle and injected twice (5 mL kg-1), the first infusion to "prime" the animal and promote a more marked response to the second infusion, given 2.5 h later. The results reported are those of the second infusion. Infusion of 200 mM NH4Cl increased Tamm, reduced pHa, and increased plasma urea-N and Jurea-N. Two hundred mM NH4HCO3 increased Tamm and arterial plasma total CO2 content (TaCO2), reduced pHa, and increased Jurea-N. Fifty mM HCl reduced pHa but had no effects on urea dynamics. Fifty mM NaOH increased pHa, plasma urea-N levels, and Jurea-N. Two hundred mM NaHCO3 increased pHa, TaCO2, plasma urea-N levels, and Jurea-N. Infusion of the saline vehicle was without effect. The results indicate that ammonia loading and plasma alkalosis both stimulate urea excretion in uricolytic fish. The responses to hyperammonemia or alkalosis were not modified when combined with elevated plasma bicarbonate levels.

  11. Micrococcus luteus and Pseudomonas species as probiotics for promoting the growth performance and health of Nile tilapia, Oreochromis niloticus.

    PubMed

    Abd El-Rhman, Azza M; Khattab, Yassir A E; Shalaby, Adel M E

    2009-08-01

    Micrococcus luteus and Pseudomonas species were isolated from the gonads and intestine of Nile tilapia, Oreochromis niloticus. M. luteus and Ps. species antagonized Aeromonas hydrophila with inhibition zone of 4 and 9 cm diameter, respectively. Both microorganisms were added to artificial basal diet with 30% crude protein to evaluate their efficacy on the growth-performance and survival rate, besides some blood-parameters and chemistry. Two hundred and forty O. niloticus with average body-weight of 2.35 +/- 0.1 g/fish were equally divided into four treatments of triplet replicates. T(1) was given basal diet (control), T(2) was given basal diet with M. luteus, T(3) was given basal diet with Ps. species, T(4) was given basal diet with both M. luteus and Ps. Species. Fishes were fed twice daily at the rate of 3% of their live body-weight, for six days a week during the experimental periods (90 day). Fish were challenged by A. hydrophila (0.3 x 10(7) cells ml(-1)) via intra-peritoneal injection and kept for 14 more days. The best growth rate, feed utilization and survival rate were noticed with T(2). The erythrocyte-count was significantly higher with T(2) than T(3) than the control T(1). The hematocrit-values (HCT) and hemoglobin-content (Hb) were significantly decreased with T(3) and T(4). The highest glucose-level was recorded with T(3). The challenged fish of T(2) showed 25% mortality, while T(1), T(3) and T(4) showed 80-90% mortality. M. luteus enhanced the fish growth and health. It is recommended to use M. luteus as a probiotic in vivo, while Pseudomonas species showed probiotic effects in vitro only.

  12. Effects of dietary acidifiers on growth, hematology, immune response and disease resistance of Nile tilapia, Oreochromis niloticus.

    PubMed

    Reda, Rasha M; Mahmoud, Rania; Selim, Khaled M; El-Araby, Iman E

    2016-03-01

    between G1 and G2 after 30 d. The lowest immune parameters were recorded in G4. After 30 d, the highest expression of interleukin-1β and tumor necrosis factor-alpha in the liver and kidney were found in G3. The best protection against challenged Aeromonas sobria was in G3, followed by G2 and G4. Dietary supplementation with a combination of formic acid, propionic acid and calcium propionate improves the performance of Nile tilapia.

  13. Effects of dietary acidifiers on growth, hematology, immune response and disease resistance of Nile tilapia, Oreochromis niloticus.

    PubMed

    Reda, Rasha M; Mahmoud, Rania; Selim, Khaled M; El-Araby, Iman E

    2016-03-01

    between G1 and G2 after 30 d. The lowest immune parameters were recorded in G4. After 30 d, the highest expression of interleukin-1β and tumor necrosis factor-alpha in the liver and kidney were found in G3. The best protection against challenged Aeromonas sobria was in G3, followed by G2 and G4. Dietary supplementation with a combination of formic acid, propionic acid and calcium propionate improves the performance of Nile tilapia. PMID:26860238

  14. Molecular characterization and expression of CD2 in Nile tilapia (Oreochromis niloticus) in response to Streptococcus agalactiae stimulus.

    PubMed

    Gan, Zhen; Wang, Bei; Tang, Jufen; Lu, Yishan; Jian, JiChang; Wu, Zaohe; Nie, Pin

    2016-03-01

    The cluster of differentiation 2 (CD2), functioning as a cell adhesion and costimulatory molecule, plays a crucial role in T-cell activation. In this paper, the CD2 gene of Nile tilapia, Oreochromis niloticus (designated as On-CD2) was cloned and its expression pattern under the stimulation of Streptococcus agalactiae was investigated. Sequence analysis showed On-CD2 protein consists of two extracellular Ig-like domains, a transmembrane region, and a long proline-rich cytoplasmic tail, which is a hallmark of CD2, and several important structural characteristics required for T-cell activation were detected in the deduced amino acid sequence of On-CD2. In healthy tilapia, the On-CD2 transcripts were mainly detected in the head kidney, spleen, blood and thymus. Moreover, there was a clear time-dependent expression pattern of On-CD2 after immunized by formalin-inactivated S. agalactiae and the expression reached the highest level at 12 h in the brain and head kidney, 48 h in the spleen, and 72 h in the thymus, respectively. This is the first report on the expression of CD2 induced by bacteria vaccination in teleosts. These findings indicated that On-CD2 may play an important role in the immune response to intracellular bacteria in Nile tilapia.

  15. Molecular characterization and expression of CD2 in Nile tilapia (Oreochromis niloticus) in response to Streptococcus agalactiae stimulus.

    PubMed

    Gan, Zhen; Wang, Bei; Tang, Jufen; Lu, Yishan; Jian, JiChang; Wu, Zaohe; Nie, Pin

    2016-03-01

    The cluster of differentiation 2 (CD2), functioning as a cell adhesion and costimulatory molecule, plays a crucial role in T-cell activation. In this paper, the CD2 gene of Nile tilapia, Oreochromis niloticus (designated as On-CD2) was cloned and its expression pattern under the stimulation of Streptococcus agalactiae was investigated. Sequence analysis showed On-CD2 protein consists of two extracellular Ig-like domains, a transmembrane region, and a long proline-rich cytoplasmic tail, which is a hallmark of CD2, and several important structural characteristics required for T-cell activation were detected in the deduced amino acid sequence of On-CD2. In healthy tilapia, the On-CD2 transcripts were mainly detected in the head kidney, spleen, blood and thymus. Moreover, there was a clear time-dependent expression pattern of On-CD2 after immunized by formalin-inactivated S. agalactiae and the expression reached the highest level at 12 h in the brain and head kidney, 48 h in the spleen, and 72 h in the thymus, respectively. This is the first report on the expression of CD2 induced by bacteria vaccination in teleosts. These findings indicated that On-CD2 may play an important role in the immune response to intracellular bacteria in Nile tilapia. PMID:26804651

  16. Two Myxobolus spp. infecting the kidney of Nile tilapia (Oreochromis niloticus) in the River Nile at Beni-Suef governorate, Egypt, and the associated renal changes.

    PubMed

    Abdel-Baki, Abdel-Azeem S; Abdel-Haleem, Heba M; Sakran, Thabet; Zayed, Eman; Ibrahim, Khalid E; Al-Quraishy, Saleh

    2015-03-01

    Two Myxobolus spp. are described from the kidney of the Nile tilapia (Oreochromis niloticus) collected from the River Nile, Egypt. The prevalence of infection was 61 % (47/77), with the infected fish in each case parasitized by the two Myxobolus species simultaneously. The infection was exhibited as free spores in Bowman capsules and renal glomeruli, which makes their original structures difficult to discern. In some cases, the infection appeared as a fibrous plasmodia-like structure containing degenerated developmental stages and spores in the interstitium. The paper identifies each species based on the morphological characteristics of its spores and identifies the histological impacts of Myxobolus infection in this species of fish. PMID:25566769

  17. Oxidative stress in tissues of Nile Tilapia (Oreochromis niloticus) from a polluted site

    SciTech Connect

    Bainy, A.C.D.; Carvalho, P.S.M.; Saito, E.; Leitao, M.A.S.; Junqueira, V.B.C.

    1995-12-31

    Pro and antioxidant parameters were compared in the erythrocytes, gill, liver and kidney of Nile Tilapia from a fish farm (Reference group) and from a polluted site at Billings Reservoir (Reservoir group). The erythrocyte oxidative stress was characterized by the increased oxygen uptake and decreased time induction (induced by t-butyl hydroperoxide, t-BHP) evidencing a higher susceptibility to oxidative damage. Moreover, a decrease in both catalase (CAT) activity and total glutathione content (GSH) in erythrocytes of Reservoir fish were observed. The higher gill cytochrome b{sub 5} levels is probably related to the enhanced oxyradical production. This fact associated to the diminished CAT and G6PDH activities establish a gill oxidative stress of Reservoir fish. The liver pro-oxidant parameters were greatly increased in the Reservoir fish. These results together with the increase in SOD activity and decrease in CAT, glutathione reductase (GR) and G6PDH activities indicate a liver oxidative stress condition. The observed increase in kidney NADH cytochrome c reductase and in both P-450 and b{sub 5} contents did not reflect in enhanced oxyradical production. The decrease in GSH observed in this tissue is probably associated to the conjugation reactions for ulterior excretion. These results furnish useful data for prospections of polluted aquatic sites in order to correlate the presence of pollutants to associated biological effects.

  18. Organochlorine pesticides residues in feed and muscle of farmed Nile tilapia from Brazilian fish farms.

    PubMed

    Botaro, Daniele; Torres, João Paulo Machado; Malm, Olaf; Rebelo, Mauro Freitas; Henkelmann, Bernhard; Schramm, Karl-Werner

    2011-09-01

    Organochlorine pesticide (OCP) concentrations were determined in fish muscle and feed collected from four different fish farms in Brazil. Nile tilapia from two growth stages, juveniles and adults, collected at two intensive tanks farms (IT1 and IT2) and two net cage farms (NC1 and NC2), were analyzed by High Resolution Gas Chromatography/High Resolution Mass Spectrometry. Pesticides were detected in almost all samples, but no samples exceeded international maximum limits for safe fish consumption. ΣDDT was the predominant pesticide in fish muscle, found in all fish samples, and endosulfan was the most predominant pesticide in feed, found in all feed samples. No significant correlation (p>0.05) was observed between the different growth stages and OCP concentrations, although slightly higher OCP concentrations were observed in adults. Among the rearing systems, NC farmed fish presented higher lipid levels and, consequently, higher OCP concentrations than fish from IT farms. Some OCPs (ΣHCH, aldrin, dieldrin and endrin) presented strong positive correlations (p<0.05) between feed and fish muscle concentrations, while others (ΣDDT, mirex, chlordane, ΣHCB and endosulfan) presented no correlation. However, the low levels of the sum of contaminants found in most of the feed samples may explain the low contaminant levels in fish tissue.

  19. Copper sulfate affects Nile tilapia (Oreochromis niloticus) cardiomyocytes structure and contractile function.

    PubMed

    de Andrade Waldemarin, Kátia Cristina; Alves, Rosiane Nascimento; Beletti, Marcelo Emílio; Rantin, Francisco Tadeu; Kalinin, Ana Lúcia

    2012-04-01

    Copper sulfate (CuSO(4))is an inorganic chemical product worldwide used as an algaecide and a fungicide in aquaculture and agriculture and being discharged into freshwater environments where it can affect the freshwater fauna, especially fishes. The impact of copper on fish cardiac function was analyzed in two groups of Nile tilapias, Oreochromis niloticus (control group and group exposed to 1 mg l(-1) of CuSO(4) for 96 h). Structural and ultra-structural changes were studied and related to perturbations of the inotropic and chronotropic responses of ventricle strips. Fish of Cu exposed group did not show significant alterations in the medium diameter and in the percentage of collagen in the cardiac myocytes when evaluated through the light microscope. However, the ultrastructural analysis revealed cellular swelling followed by mitochondrial swelling. The myofibrils did not show significant variations among groups. Force contraction was significantly decreased, and rates of time to tension increase (contraction) and decrease (relaxation) were significantly augmented after copper exposure. The results suggest that the copper sulfate impairs the oxidative mitochondrial function and consequently alters the cardiac performance of this species.

  20. Effects of diazinon on the lymphocytic cholinergic system of Nile tilapia fish (Oreochromis niloticus).

    PubMed

    Toledo-Ibarra, G A; Díaz-Resendiz, K J G; Pavón-Romero, L; Rojas-García, A E; Medina-Díaz, I M; Girón-Pérez, M I

    2016-08-01

    Fish rearing under intensive farming conditions can be easily disturbed by pesticides, substances that have immunotoxic properties and may predispose to infections. Organophosphorus pesticides (OPs) are widely used in agricultural activities; however, the mechanism of immunotoxicity of these substances is unclear. The aim of this study was to evaluate the effect of diazinon pesticides (OPs) on the cholinergic system of immune cells as a possible target of OP immunotoxicity. We evaluated ACh levels and cholinergic (nicotinic and muscarinic) receptor concentration. Additionally, AChE activity was evaluated in mononuclear cells of Nile tilapia (Oreochromis niloticus), a freshwater fish mostly cultivated in tropical regions around the world. The obtained results indicate that acute exposure to diazinon induces an increase in ACh concentration and a decrease in nAChR and mAChR concentrations and AChE activity in fish immune cells, This suggests that the non-neuronal lymphocytic cholinergic system may be the main target in the mechanism of OP immunotoxicity. This study contributes to the understanding of the mechanisms of immunotoxicity of pollutants and may help to take actions for animal health improvement. PMID:27260186

  1. Assessment of benthic macroinvertebrates at Nile tilapia production using artificial substrate samplers.

    PubMed

    Moura E Silva, M S G; Graciano, T S; Losekann, M E; Luiz, A J B

    2016-05-17

    Biomonitoring is a cheap and effective tool for evaluation of water quality, and infer on the balance of aquatic ecosystems. The benthic macroinvertebrates are bioindicators sensitive to environmental changes, and can assist in detecting and preventing impacts such as organic enrichment and imbalance in the food chain. We compared the structure of benthic communities on artificial substrate samplers located in places near and far from net cages for production of Nile tilapia (Oreochromis niloticus). Samplers were manufactured with nylon net, using substrates such as crushed stone, gravel, loofah and cattail leaves. Samples were collected after 30 days of colonization, rinsed and then the specimens were identified and quantified. The following metrics were calculated: richness of Operational Taxonomic Units, Margalef richness, abundance of individuals, Shannon index and evenness index. The macrobenthic community structure was strongly modified according to the proximity of the net cages. Metrics showed significant differences (p < 0.05) between near and distant sites, for both periods (dry and rainy seasons). The position of the samplers significantly affected the structure of macroinvertebrate community, as near sites showed higher values for the community metrics, such as richness and diversity. Near sites presented a larger number of individuals, observed both in the dry and rainy seasons, with a predominance of Chironomidae (Diptera) in the dry season and Tubificidae (Oligochaeta) in the rainy season. PMID:27191461

  2. Integrated cytogenetics and genomics analysis of transposable elements in the Nile tilapia, Oreochromis niloticus.

    PubMed

    Valente, Guilherme; Kocher, Thomas; Eickbush, Thomas; Simões, Rafael P; Martins, Cesar

    2016-06-01

    Integration of cytogenetics and genomics has become essential to a better view of architecture and function of genomes. Although the advances on genomic sequencing have contributed to study genes and genomes, the repetitive DNA fraction of the genome is still enigmatic and poorly understood. Among repeated DNAs, transposable elements (TEs) are major components of eukaryotic chromatin and their investigation has been hindered even after the availability of whole sequenced genomes. The cytogenetic mapping of TEs in chromosomes has proved to be of high value to integrate information from the micro level of nucleotide sequence to a cytological view of chromosomes. Different TEs have been cytogenetically mapped in cichlids; however, neither details about their genomic arrangement nor appropriated copy number are well defined by these approaches. The current study integrates TEs distribution in Nile tilapia Oreochromis niloticus genome based on cytogenetic and genomics/bioinformatics approach. The results showed that some elements are not randomly distributed and that some are genomic dependent on each other. Moreover, we found extensive overlap between genomics and cytogenetics data and that tandem duplication may be the major mechanism responsible for the genomic dynamics of TEs here analyzed. This paper provides insights in the genomic organization of TEs under an integrated view based on cytogenetics and genomics. PMID:26860923

  3. Ectoparasites of Nile tilapia (Oreochromis niloticus) in cage farming in a hydroelectric reservoir in Brazil.

    PubMed

    Zago, Aline Cristina; Franceschini, Lidiane; Garcia, Fabiana; Schalch, Sérgio Henrique Canello; Gozi, Kátia Suemi; Silva, Reinaldo José da

    2014-01-01

    For this study, we performed a parasitological analysis of cage-cultured Nile tilapia (Oreochromis niloticus) from the Água Vermelha Reservoir, Southeastern Brazil, and verified relationships with limnological data, seasonality, and fish growth phase. From March 2010 to March 2011, sixty-three specimens of O. niloticus in three growth phases (i.e., initial, intermediate, and final) were collected. All fish specimens were infested with at least one ectoparasite species (prevalence = 100%). Five species of protozoans (Trichodina compacta, Trichodina magna, Ichthyophthirius multifiliis, Piscinoodinium pillulare, and Epistylis sp.) and five species of monogenoids (Cichlidogyrus halli, Cichlidogyrus thurstonae, Cichlidogyrus sp. 1, Scutogyrus longicornis, and Gyrodactylus sp.) were observed. The abundance of Trichodina spp. and the prevalence of Epistylis sp. were higher in the dry season, and the prevalence of C. halli was higher in the rainy season. For the majority of ectoparasites found in this study, fish in the intermediate and final phases had higher parasitism rates than those in the initial phase. The data presented may help fish farmers to understand the parasite dynamics of the fish species studied in cage-farming systems. PMID:25054495

  4. Identification of (L)-fucose-binding proteins from the Nile tilapia (Oreochromis niloticus L.) serum.

    PubMed

    Argayosa, Anacleto M; Lee, Yuan C

    2009-09-01

    Lectins are carbohydrate-binding proteins with many biological functions including cellular recognition and innate immunity. In this study, a major l-fucose-binding lectin from the serum of Nile tilapia (Oreochromis niloticus L.), designated as TFBP, was isolated by l-fucose-BSA Sepharose CL6B affinity chromatography. The SDS-PAGE (10%) analysis of TFBP revealed a major band of approximately 23 kDa with an N-terminal amino acid sequence of DQTETAGQQSXPQDIHAVLREL which did not give significant similarities to the protein databases using BLASTp searches. Ruthenium red staining indicate positive calcium-binding property of TFBP. The purified TFBP agglutinated human type O erythrocytes but not the type A and B fresh erythrocytes. Live Aeromonas hydrophila and Enterococcus faecalis cells were also agglutinated by the lectin. The fucose-binding proteins were detected in the soluble protein extracts from the gills, gut, head kidneys, liver, serum and spleen using a fucose-binding protein probe (l-fucose-BSA-horseradish peroxidase). The binding of TFBP with the l-fucose-BSA probe was inhibited by l-fucose but not by alpha-methyl-d-mannose.

  5. Induction of triploidy and tetraploidy in Nile tilapia, Oreochromis niloticus (L.)

    USGS Publications Warehouse

    El Gamal, A.-R.A.; Davis, K.B.; Jenkins, J.A.; Les, Torrans E.

    1999-01-01

    Induction of triploidy and tetraploidy in Nile tilapia, Oreochromis niloticus, was investigated by heat shock, cold shock, hydrostatic pressure, and/ or chemicals (cytochalasin A, B, and D). Additionally, efficacy of combined protocols was determined. Heat shock 10 min after fertilization induced triploidy when incubation temperature was 24 C but not when incubation temperature was 31 C. Heat shock of 40-41 C at 4-6 min after fertilization was effective in inducing up to 100% triploidy with hatchability similar to controls. Cold shock at 13 C for 45 min five min after fertilization induced 85-100% triploids. Heat shock and multiple heat shocking were the most effective treatments for the induction of tetraploidy. Two heat treatments of 41 C applied at 65 and 80 min after fertilization for 5 min each produced approximately 80% tetraploidy in hatched fry. Immersion of fertilized eggs in cytochalasin A, B, or D at concentrations up to 10 ??g/L applied at various times and durations was ineffective in inducing triploidy or tetraploidy.

  6. Eutrophication, Ammonia Intoxication, and Infectious Diseases: Interdisciplinary Factors of Mass Mortalities in Cultured Nile Tilapia.

    PubMed

    Abu-Elala, Nermeen M; Abd-Elsalam, Reham M; Marouf, Sherif; Abdelaziz, Mohamed; Moustafa, Mohamed

    2016-09-01

    The present study was designed to assess the possible causes of the mass mortalities of Nile Tilapia Oreochromis niloticus at El-Behera Governorate, Egypt, in relationship to environmental and microbiotic factors. Water samples were collected from fish farms at different locations and from Lake Edku to analyze water temperature, water pH, salinity, biological oxygen demand, dissolved oxygen, total ammonia nitrogen, and un-ionized ammonia. A number of moribund and freshly dead fish were sampled and submitted to our laboratory for microbiological, molecular, and histopathological examination. Water analysis of the fish farms revealed noticeable increases in the previously mentioned physicochemical parameters. Clinical examinations of moribund fish showed severe gill rot and massive external and internal hemorrhages. Ordinary and molecular laboratory findings confirmed the presence of Branchiomyces sp. in gill tissue and mixed bacterial fish pathogens (Streptococcus agalactiae, Vibrio alginolyticus, V. parahaemolyticus, Pseudomonas anguilliseptica, and P. aeruginosa) in visceral organs. The histopathological and transmission electron microscopic examinations revealed severe necrosis of gill filaments and blockage of branchial blood vessels and lamellar capillaries with Branchiomyces sp. hyphae and spores mixed with different shapes of bacteria. Severe inflammations were detected in liver, kidney, heart, and brain tissues. Ultimately, we can conclude that the syndrome of mass fish kills in this area is a consequence of ecological damage to the aquatic environment, which is mainly related to natural and anthropogenic factors, as well as to the presence of infectious agents. Received September 30, 2015; accepted April 12, 2016. PMID:27484819

  7. Effects of diazinon on the lymphocytic cholinergic system of Nile tilapia fish (Oreochromis niloticus).

    PubMed

    Toledo-Ibarra, G A; Díaz-Resendiz, K J G; Pavón-Romero, L; Rojas-García, A E; Medina-Díaz, I M; Girón-Pérez, M I

    2016-08-01

    Fish rearing under intensive farming conditions can be easily disturbed by pesticides, substances that have immunotoxic properties and may predispose to infections. Organophosphorus pesticides (OPs) are widely used in agricultural activities; however, the mechanism of immunotoxicity of these substances is unclear. The aim of this study was to evaluate the effect of diazinon pesticides (OPs) on the cholinergic system of immune cells as a possible target of OP immunotoxicity. We evaluated ACh levels and cholinergic (nicotinic and muscarinic) receptor concentration. Additionally, AChE activity was evaluated in mononuclear cells of Nile tilapia (Oreochromis niloticus), a freshwater fish mostly cultivated in tropical regions around the world. The obtained results indicate that acute exposure to diazinon induces an increase in ACh concentration and a decrease in nAChR and mAChR concentrations and AChE activity in fish immune cells, This suggests that the non-neuronal lymphocytic cholinergic system may be the main target in the mechanism of OP immunotoxicity. This study contributes to the understanding of the mechanisms of immunotoxicity of pollutants and may help to take actions for animal health improvement.

  8. Assessment of benthic macroinvertebrates at Nile tilapia production using artificial substrate samplers.

    PubMed

    Moura E Silva, M S G; Graciano, T S; Losekann, M E; Luiz, A J B

    2016-05-17

    Biomonitoring is a cheap and effective tool for evaluation of water quality, and infer on the balance of aquatic ecosystems. The benthic macroinvertebrates are bioindicators sensitive to environmental changes, and can assist in detecting and preventing impacts such as organic enrichment and imbalance in the food chain. We compared the structure of benthic communities on artificial substrate samplers located in places near and far from net cages for production of Nile tilapia (Oreochromis niloticus). Samplers were manufactured with nylon net, using substrates such as crushed stone, gravel, loofah and cattail leaves. Samples were collected after 30 days of colonization, rinsed and then the specimens were identified and quantified. The following metrics were calculated: richness of Operational Taxonomic Units, Margalef richness, abundance of individuals, Shannon index and evenness index. The macrobenthic community structure was strongly modified according to the proximity of the net cages. Metrics showed significant differences (p < 0.05) between near and distant sites, for both periods (dry and rainy seasons). The position of the samplers significantly affected the structure of macroinvertebrate community, as near sites showed higher values for the community metrics, such as richness and diversity. Near sites presented a larger number of individuals, observed both in the dry and rainy seasons, with a predominance of Chironomidae (Diptera) in the dry season and Tubificidae (Oligochaeta) in the rainy season.

  9. Competitive Interactions between Invasive Nile Tilapia and Native Fish: The Potential for Altered Trophic Exchange and Modification of Food Webs

    PubMed Central

    Martin, Charles W.; Valentine, Marla M.; Valentine, John F.

    2010-01-01

    Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus), in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus). Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass) was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes) will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important. PMID:21200433

  10. A piscirickettsiosis-like syndrome in cultured Nile tilapia in Latin America with Francisella spp. as the pathogenic agent.

    PubMed

    Mauel, M J; Soto, E; Moralis, J A; Hawke, J

    2007-03-01

    In 2004, cultured Nile tilapia Oreochromis niloticus in several Latin America farms began to succumb to a disease similar to the piscirickettsiosis-like syndrome previously reported in tilapia in Taiwan and the United States. Mortality increased during 2005; reductions in tilapia biomass ranged from 5% to 80% in individual ponds and averaged 50% overall. All ages of fish have been involved. Clinical signs include lethargy, loss of appetite, petechia, exophthalmia, and abnormal swimming behavior. Gross lesions have included splenomegaly, renomegaly, and numerous white nodules observed in the spleen, kidney, testes, heart, ovaries, and occasionally the liver. A previously unreported black granulomatous lesion was reported in up to 30% of the fillets. Histologically, granulomatous infiltrates were observed in the kidney, spleen, liver, testes, ovary, and choroid gland, and rarely in the brain and heart. A small pleomorphic bacterium was observed in Giemsa-stained blood smears and spleen imprints. The bacterium did not grow on standard microbiological media and has not been isolated in cell culture. We obtained a near-complete 16S ribosomal DNA sequence with high similarity to Francisella spp. sequences previously identified in tilapias Oreochromis spp. (Taiwan), Atlantic cod Gadus morhua (Norway), and three-line grunts Parapristipoma trilineatum (Japan). PMID:18236629

  11. Competitive interactions between invasive Nile tilapia and native fish: the potential for altered trophic exchange and modification of food webs.

    PubMed

    Martin, Charles W; Valentine, Marla M; Valentine, John F

    2010-12-21

    Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus), in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus). Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass) was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes) will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important.

  12. Digestive enzyme activity in the intestine of Nile tilapia (Oreochromis niloticus L.) under pond and cage farming systems.

    PubMed

    Santos, Juliana Ferreira; Soares, Karollina Lopes Siqueira; Assis, Caio Rodrigo Dias; Guerra, Carlos Augusto Martins; Lemos, Daniel; Carvalho, Luiz Bezerra; Bezerra, Ranilson Souza

    2016-10-01

    The effect of different farming systems (cage, pond) upon digestive enzyme activities of Nile tilapia was evaluated. Juvenile Nile tilapia (87.61 ± 1.52 g) were simultaneously cultured in pond and cage systems during 90 days. Cages used nutritional biphasic plan (35 and 32 % crude protein-CP feeds) and ponds used nutritional triphasic plan (35, 32 and 28 % CP feeds). Biometric measurements were monthly performed for adjustments in feeding regimes and removal of intestine tissues to evaluate the performance of enzyme activities. Total proteolytic, amylase and lipase activities were not statistically different between the treatments throughout the periods analyzed (31, 63 and 94 days of culture). However, trypsin and chymotrypsin activities were higher with 31 and 63 days of culture in fish from pond system, suggesting that natural food may have influenced these activities. A positive correlation was observed between the recommended concentration of essential amino acids for Nile tilapia and specific aminopeptidases activity in fish cage system. Substrate-SDS-PAGE revealed 12 active proteolytic bands in both systems. However, integrated density (ID) values were higher in the bands of ponds. Specimens of either cage or pond exhibited five bands of amylolytic activity. Fish from cage and pond systems showed the highest values of ID within 31 days of cultivation. In this study, the complexity of digestive functions could be verified for animals maintained under commercial conditions. Some of the assessed enzymes may show adaptations of their activities and/or expression that allow the fish to achieve a more efficient nutrient assimilation. PMID:27021899

  13. Effect of poly-β-hydroxybutyrate on growth and disease resistance of Nile tilapia Oreochromis niloticus juveniles.

    PubMed

    Situmorang, Magdalena Lenny; De Schryver, Peter; Dierckens, Kristof; Bossier, Peter

    2016-01-01

    The growth promoting effect of the bacterial storage compound poly-β-hydroxybutyrate (PHB) has been studied for young fish of high trophic level (European sea bass) and intermediate trophic level (Siberian sturgeon). Here, the effect of PHB on growth, digestive enzyme activities, body composition and diseases resistance of juvenile Nile tilapia (Oreochromis niloticus) of low trophic level was investigated. Although dietary PHB supplementation (5, 25 and 50 g PHB kg(-1) formulated semi-purified diet) during 28 days resulted in a trend of increased weight gain, there was no significant difference in the mean final body weight (258-284 mg) when compared to the fish from the control group (on average 218 mg). Lipase activity increased significantly with about 20-40% by the supplementation of PHB in the diet, which may have led to the significant increase in total lipid content with about 10% in the PHB treatment groups. However, the profile of total (n-6) fatty acids (FAs), total monounsaturated FAs and total saturated FAs relative to the total lipid was similar among various PHB treatments. An additional challenge test on gnotobiotic Nile tilapia larvae using the pathogen Edwardsiella ictaluri gly09R showed that feeding challenged larvae with PHB-enriched Artemia nauplii resulted in a 20% higher survival as compared to the challenged control larvae. Overall, it is suggested that the trend of increased body weight gain resulted from intestinal lipid digestion, absorption and deposition and that PHB is effective as an antimicrobial agent for application in Nile tilapia larviculture.

  14. The Expression Pattern of Melatonin Receptor 1a Gene during Early Life Stages in the Nile tilapia (Oreochromis niloticus)

    PubMed Central

    Jin, Ye Hwa; Park, Jin Woo; Kim, Jung-Hyun; Kwon, Joon Yeong

    2013-01-01

    The action of melatonin within the body of animals is known to be mediated by melatonin receptors. Three different types of melatonin receptors have been identified so far in fish. However, which of these are specifically involved in puberty onset is not known in fish. We cloned and analyzed the sequence of melatonin receptor 1a (mel 1a) gene in Nile tilapia Oreochromis niloticus. In addition, we examined the tissue distribution of gene expressions for three types of receptors, mel 1a, 1b and lc and investigated which of them is involved in the onset of puberty by comparing their expression with that of gonadotropin-releasing hormone receptor I (GnRHr I) gene using quantitative real-time PCR from 1 week post hatch (wph) to 24 wph. The mel 1a gene of Nile tilapia consisted of two exons and one bulky intron between them. Mel 1a gene was found to be highly conserved gene showing high homology with the corresponding genes from different teleost. All three types of melatonin receptor genes were expressed in the brain, eyes and ovary in common. Expression of mel 1a gene was the most abundant and ubiquitous among 3 receptors in the brain, liver, gill, ovary, muscle, eye, heart, intestine, spleen and kidney. Mel 1b and mel 1c genes were, however, expressed in fewer tissues at low level. During the development post hatch, expressions of both mel 1a and GnRHr I genes significantly increased at 13 wph which was close to the putative timing of puberty onset in this species. These results suggest that among three types of receptors mel 1a is most likely associated with the action of melatonin in the onset of puberty in Nile tilapia. PMID:25949120

  15. Effect of poly-β-hydroxybutyrate on growth and disease resistance of Nile tilapia Oreochromis niloticus juveniles.

    PubMed

    Situmorang, Magdalena Lenny; De Schryver, Peter; Dierckens, Kristof; Bossier, Peter

    2016-01-15

    The growth promoting effect of the bacterial storage compound poly-β-hydroxybutyrate (PHB) has been studied for young fish of high trophic level (European sea bass) and intermediate trophic level (Siberian sturgeon). Here, the effect of PHB on growth, digestive enzyme activities, body composition and diseases resistance of juvenile Nile tilapia (Oreochromis niloticus) of low trophic level was investigated. Although dietary PHB supplementation (5, 25 and 50 g PHB kg(-1) formulated semi-purified diet) during 28 days resulted in a trend of increased weight gain, there was no significant difference in the mean final body weight (258-284 mg) when compared to the fish from the control group (on average 218 mg). Lipase activity increased significantly with about 20-40% by the supplementation of PHB in the diet, which may have led to the significant increase in total lipid content with about 10% in the PHB treatment groups. However, the profile of total (n-6) fatty acids (FAs), total monounsaturated FAs and total saturated FAs relative to the total lipid was similar among various PHB treatments. An additional challenge test on gnotobiotic Nile tilapia larvae using the pathogen Edwardsiella ictaluri gly09R showed that feeding challenged larvae with PHB-enriched Artemia nauplii resulted in a 20% higher survival as compared to the challenged control larvae. Overall, it is suggested that the trend of increased body weight gain resulted from intestinal lipid digestion, absorption and deposition and that PHB is effective as an antimicrobial agent for application in Nile tilapia larviculture. PMID:26711027

  16. Expression patterns of gonadotropin hormones and their receptors during early sexual differentiation in Nile tilapia Oreochromis niloticus.

    PubMed

    Yan, Hongwei; Ijiri, Shigeho; Wu, Quan; Kobayashi, Tohru; Li, Shuang; Nakaseko, Taro; Adachi, Shinji; Nagahama, Yoshitaka

    2012-11-01

    In Nile tilapia, sex-specific expression of foxl2 and cyp19a1a in XX gonads and dmrt1 in XY gonads at 5-6 days after hatching (dah) is critical for differentiation of the gonads into either ovaries or testes. The factors triggering sexually dimorphic expression of these genes are unknown, and whether the gonadotropin hormones are involved in early gonadal sex differentiation of the Nile tilapia has been unclear. In the present study, we determined the precise timing of expression of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the pituitary and that of their receptors (fshra and lhcgrbb) in the undifferentiated gonad in both XX and XY tilapia fry by quantitative RT-PCR and immunohistochemical analysis. Expression of fshb mRNA and Fsh protein in the pituitary was detected from the first sampling day (3 dah) to 25 dah in both XX and XY tilapia larvae without sexual dimorphism and increased gradually after 25 dah in the pituitary. fshra mRNA was expressed beginning 5 dah and was present at significantly higher levels in XX gonads than in the XY gonads at 6-25 dah. These results indicate that the level of Fsh protein in the pituitary was not critical for differentiation of gonads into ovaries or testes, but the expression level of its receptor, fshra, in undifferentiated gonads appeared to be involved in determining gonadal sexual differentiation. Based on these observations, it is likely that in XX gonads, up-regulation of fshra may be necessary to induce cyp19a1a expression, which stimulates estradiol-17beta (E(2)) production and subsequent ovarian differentiation. On the other hand, lhb mRNA was not detected until 25 dah in the pituitaries of both sexes, and sexual dimorphism in lhcgrbb mRNA levels appeared later (10-25 dah) than that of fshra in the gonads, indicating the limited role of LH and lhcgrbb in gonadal differentiation of the Nile tilapia.

  17. Molecular characterization, functional analysis, and defense mechanisms of two CC chemokines in Nile tilapia (Oreochromis niloticus) in response to severely pathogenic bacteria.

    PubMed

    Nakharuthai, Chatsirin; Areechon, Nontawith; Srisapoome, Prapansak

    2016-06-01

    Two full-length cDNAs encoding CC chemokine genes in Nile tilapia (Oreochromis niloticus) (On-CC1 and On-CC2) were cloned and characterized. On-CC1 and On-CC2 showed signature cysteine motifs consisting of four cysteines. The expression levels of On-CC1 and On-CC2 were analyzed by RT-PCR, which showed that low expression of these two genes was only observed in the peripheral blood leukocytes (PBLs) and spleen of normal fish. Expression levels of these two molecules were quantified in 13 tissues of fish infected with virulent strains of Streptococcus agalactiae and Flavobacterium columnare. Most tissues, especially PBLs, the spleen and the liver, expressed significantly higher mRNA levels than the controls, particularly at 12 and 24 h after infection (P < 0.05). The current study strongly indicates that CC chemokine genes in Nile tilapia are crucially involved in the early immune responses to pathogens. Functional analyses clearly demonstrated that 10 and 100 μg/ml of recombinant rOn-CC1 and rOn-CC2 proteins efficiently enhanced the phagocytic activity (in vitro) of Nile tilapia phagocytes. Finally, Southern blot analysis and searching in Ensembl databases demonstrated that two different functional CC chemokine genes and other pseudogene fragments were discovered in the Nile tilapia genome.

  18. Cloning and molecular characterization of complement component 1 inhibitor (C1INH) and complement component 8β (C8β) in Nile tilapia (Oreochromis niloticus).

    PubMed

    He, Anyuan; Yang, Jie; Tang, Shoujie; Wang, Chenghui

    2013-09-01

    Nile tilapia (Oreochromis niloticus), one of the most important groups of food fishes in the world, has frequently suffered from serious challenge from pathogens in recent years. Immune responses of Nile tilapia should be understood to protect the aquaculture industry of this fish. The complement system has an important function in recognizing bacteria, opsonizing these pathogens by phagocytes, or killing them by direct lysis. In this study, two Nile tilapia complement component genes, complement component 1 inhibitor (C1INH) and complement component 8β subunit (C8β), were cloned and their expression characteristics were analyzed. C1INH cDNA was found containing a 1791 bp open reading frame (ORF) encoding a putative protein with 597 amino acids, a 101 bp 5'-untranslated region (UTR) and a 236 bp 3'-UTR. The predicted protein structure for this gene consisted of two Ig-like domains and glycosyl hydrolase family-9 active site signature 2. The C8β cDNA consisted of a 1761 bp ORF encoding 587 amino acids, a 15 bp 5'-UTR and a 170 bp 3'-UTR. The predicted protein of C8β contained three motifs, thrombospondin type-1 repeat, membrane attack complex/perforin domain, and LDL-receptor class A. Expression analysis revealed that these two complement genes were highly expressed in the liver, however, were weakly expressed in the gill, heart, brain, kidney, intestine, spleen and dorsal muscle tissues. The present study provided insights into the complement system and immune functions of Nile tilapia.

  19. Molecular characterization, functional analysis, and defense mechanisms of two CC chemokines in Nile tilapia (Oreochromis niloticus) in response to severely pathogenic bacteria.

    PubMed

    Nakharuthai, Chatsirin; Areechon, Nontawith; Srisapoome, Prapansak

    2016-06-01

    Two full-length cDNAs encoding CC chemokine genes in Nile tilapia (Oreochromis niloticus) (On-CC1 and On-CC2) were cloned and characterized. On-CC1 and On-CC2 showed signature cysteine motifs consisting of four cysteines. The expression levels of On-CC1 and On-CC2 were analyzed by RT-PCR, which showed that low expression of these two genes was only observed in the peripheral blood leukocytes (PBLs) and spleen of normal fish. Expression levels of these two molecules were quantified in 13 tissues of fish infected with virulent strains of Streptococcus agalactiae and Flavobacterium columnare. Most tissues, especially PBLs, the spleen and the liver, expressed significantly higher mRNA levels than the controls, particularly at 12 and 24 h after infection (P < 0.05). The current study strongly indicates that CC chemokine genes in Nile tilapia are crucially involved in the early immune responses to pathogens. Functional analyses clearly demonstrated that 10 and 100 μg/ml of recombinant rOn-CC1 and rOn-CC2 proteins efficiently enhanced the phagocytic activity (in vitro) of Nile tilapia phagocytes. Finally, Southern blot analysis and searching in Ensembl databases demonstrated that two different functional CC chemokine genes and other pseudogene fragments were discovered in the Nile tilapia genome. PMID:26853931

  20. Evaluation of plant and animal protein sources as partial or total replacement of fish meal in diets for juvenile Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A feeding trial was conducted in a closed system with Nile tilapia (Oreochromis niloticus) juveniles (mean weight, 2.84 g) to examine the effects of total replacement of fish meal (FM), with and without supplementation of DL-methionine (Met) and L-lysine (Lys), by plant protein sources. Fish were f...

  1. Use of biofuel by-product from the green algae Desmochloris sp. and diatom Nanofrustulum sp. meal in diets for nile tilapia Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Algal by-product meals from the Hawaiian biofuels industry were evaluated as protein ingredients in diets for juveniles of Nile tilapia (Oreochromis niloticus). Four experimental diets were formulated to contain 40% protein and were made with fish meal, soybean meal, whole diatom (Nanofrustulum sp.)...

  2. Histopathological alterations in the gills of Nile tilapia exposed to carbofuran and multiwalled carbon nanotubes.

    PubMed

    Campos-Garcia, Janaína; Martinez, Diego Stéfani Teodoro; Rezende, Karina Fernandes Oliveira; da Silva, José Roberto Machado Cunha; Alves, Oswaldo Luiz; Barbieri, Edison

    2016-11-01

    Carbofuran is a nematicide insecticide with a broad spectrum of action. Carbofuran has noxious effects in several species and has been banned in the USA and Europe; however, it is still used in Brazil. Aquatic organisms are not only exposed to pesticides but also to manufactured nanoparticles, and the potential interaction of these compounds therefore requires investigation. The aim of this study was to examine the histopathological alterations in the gills of Nile tilapia (Oreochromis niloticus) to determine possible effects of exposure to carbofuran, nitric acid-treated multiwalled carbon nanotubes (HNO3-MWCNTs) and the combination of carbofuran with nanotubes. Juvenile fish were exposed to different concentrations of carbofuran (0.1, 0.5, 2.0, 4.0 and 8.0mg/L), different concentrations of HNO3-MWCNTs (0.5, 1.0 and 2.0mg/L) or different concentrations of carbofuran (0.1, 0.5, 2.0, 4.0 and 8.0mg/L) with 1.0mg/L of HNO3-MWCNTs. After 24h of exposure, the animals were removed from the aquarium, the spinal cord was transversely sectioned, and the second gill arch was removed for histological evaluation. Common histological changes included dislocation of the epithelial cells, hyperplasia of the epithelial cells along the secondary lamellae, aneurism, and dilation and disarrangement of the capillaries. All the groups exposed to carbofuran demonstrated a dose-dependent correlation in the Histological Alteration Index; the values found for carbofuran and carbon nanotubes were up to 25% greater than for carbofuran alone. This result indicates an interaction between these toxicants, with enhanced ecotoxic effects. This work contributes to the understanding of the environmental impacts of nanomaterials on aquatic organisms, which is necessary for the sustainable development of nanotechnologies.

  3. Histopathological alterations in the gills of Nile tilapia exposed to carbofuran and multiwalled carbon nanotubes.

    PubMed

    Campos-Garcia, Janaína; Martinez, Diego Stéfani Teodoro; Rezende, Karina Fernandes Oliveira; da Silva, José Roberto Machado Cunha; Alves, Oswaldo Luiz; Barbieri, Edison

    2016-11-01

    Carbofuran is a nematicide insecticide with a broad spectrum of action. Carbofuran has noxious effects in several species and has been banned in the USA and Europe; however, it is still used in Brazil. Aquatic organisms are not only exposed to pesticides but also to manufactured nanoparticles, and the potential interaction of these compounds therefore requires investigation. The aim of this study was to examine the histopathological alterations in the gills of Nile tilapia (Oreochromis niloticus) to determine possible effects of exposure to carbofuran, nitric acid-treated multiwalled carbon nanotubes (HNO3-MWCNTs) and the combination of carbofuran with nanotubes. Juvenile fish were exposed to different concentrations of carbofuran (0.1, 0.5, 2.0, 4.0 and 8.0mg/L), different concentrations of HNO3-MWCNTs (0.5, 1.0 and 2.0mg/L) or different concentrations of carbofuran (0.1, 0.5, 2.0, 4.0 and 8.0mg/L) with 1.0mg/L of HNO3-MWCNTs. After 24h of exposure, the animals were removed from the aquarium, the spinal cord was transversely sectioned, and the second gill arch was removed for histological evaluation. Common histological changes included dislocation of the epithelial cells, hyperplasia of the epithelial cells along the secondary lamellae, aneurism, and dilation and disarrangement of the capillaries. All the groups exposed to carbofuran demonstrated a dose-dependent correlation in the Histological Alteration Index; the values found for carbofuran and carbon nanotubes were up to 25% greater than for carbofuran alone. This result indicates an interaction between these toxicants, with enhanced ecotoxic effects. This work contributes to the understanding of the environmental impacts of nanomaterials on aquatic organisms, which is necessary for the sustainable development of nanotechnologies. PMID:27543744

  4. Haploinsufficiency of SF-1 Causes Female to Male Sex Reversal in Nile Tilapia, Oreochromis niloticus.

    PubMed

    Xie, Qing-Ping; He, Xue; Sui, Yi-Ning; Chen, Li-Li; Sun, Li-Na; Wang, De-Shou

    2016-06-01

    Steroidogenic factor-1 (Sf-1) (officially designated nuclear receptor subfamily 5 group A member 1 [NR5A1]) is a master regulator of steroidogenesis and reproduction in mammals. However, its function remains unclear in nonmammalian vertebrates. In the present study, we used immunohistochemistry to detect expression of Sf-1 in the steroidogenic cells, the interstitial, granulosa, and theca cells of the ovary, and the Leydig cells of the testis, in Nile tilapia. Clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9 (Cas9) cleavage of sf-1 resulted in a high mutation rate in the F0 generation and a phenotype of gonadal dysgenesis and reduced steroidogenic cells in XX and XY fish. Sf-1 deficiency also resulted in decreased cytochrome P450, family 19, subfamily A, polypeptide 1a, forkhead box L2 expression, and serum estradiol-17β in XX fish. In XY fish, Sf-1 deficiency increased cytochrome P450, family 19, subfamily A, polypeptide 1a and forkhead box L2 expression but decreased cytochrome P450, family 11, subfamily B, polypeptide 2 expression and serum 11-ketotestosterone levels. 17α-methyltestosterone treatment successfully rescued the gonadal phenotype of Sf-1-deficient XY fish, as demonstrated by normal spermatogenesis and production of F1 mutants. In contrast, estradiol-17β treatment only partially rescued the gonadal phenotype of Sf-1-deficient XX fish, as demonstrated by the appearance of phase II oocytes. Furthermore, both sf-1(+/-) F1 XX and XY mutants developed as fertile males, although spermatogenesis was delayed and efferent duct formation was disordered. Our data suggest that Sf-1 is a major regulator of steroidogenesis and reproduction in fish, as it is in mammals. Sf-1 deficiency resulted in gonadal dysgenesis and feminization of XY gonads. However, unlike in mammals, Sf-1 deficiency also resulted in female to male sex reversal in 8.1% of F0 and 92.1% of sf-1(+/-) F1 in XX fish. PMID:27046435

  5. Ecological Risk Assessment of Metal Pollution along Greater Cairo Sector of the River Nile, Egypt, Using Nile Tilapia, Oreochromis niloticus, as Bioindicator

    PubMed Central

    Omar, Wael A.; Mikhail, Wafai Z. A.; Abdo, Hanaa M.; Abou El Defan, Tarek A.; Poraas, Mamdouh M.

    2015-01-01

    The present work aims to evaluate seasonal metal pollution along Greater Cairo sector of the River Nile, Egypt, using wild Nile tilapia, Oreochromis niloticus, as bioindicator and to conduct a risk assessment for human consumers. Greater Cairo is the largest populated area along the whole course of River Nile with a wide range of anthropogenic activities. Effects of metal pollution on fish body indices were studied using condition factor (CF) and scaled mass index (SMI). Metal pollution index (MPI) showed that the total metal load in fish organs followed the follwoing order: kidney > liver > gill > muscle which gives a better idea about the target organs for metal accumulation. Metal concentrations in fish muscle (edible tissue) showed the following arrangement: Fe > Zn > Cu > Mn > Pb > Cd. Metal's bioaccumulation factor (BAF) in fish muscle showed the following arrangement: Zn > Cu > Fe > Mn > Cd and Pb. The hazard index (HI) as an indicator of human health risks associated with fish consumption showed that adverse health effects are not expected to occur in most cases. However, the metals' cumulative risk effects gave an alarming sign specifically at high fish consumption rates. PMID:26617637

  6. Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Sarker, Pallab K.; Kapuscinski, Anne R.; Lanois, Alison J.; Livesey, Erin D.; Bernhard, Katie P.; Coley, Mariah L.

    2016-01-01

    We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds. PMID:27258552

  7. Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus).

    PubMed

    Sarker, Pallab K; Kapuscinski, Anne R; Lanois, Alison J; Livesey, Erin D; Bernhard, Katie P; Coley, Mariah L

    2016-01-01

    We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds.

  8. Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus).

    PubMed

    Sarker, Pallab K; Kapuscinski, Anne R; Lanois, Alison J; Livesey, Erin D; Bernhard, Katie P; Coley, Mariah L

    2016-01-01

    We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds. PMID:27258552

  9. Efficacy of florfenicol for control of mortality associated with Francisella noatunensis subsp. orientalis in Nile tilapia, Oreochromis niloticus (L.).

    PubMed

    Soto, E; Kidd, S; Gaunt, P S; Endris, R

    2013-04-01

    Francisella noatunensis subsp. orientalis (Fno) (syn. F. asiatica) is an emergent Gram-negative facultative intracellular bacterium. Although it is considered one of the most pathogenic bacteria in fish, there are no commercially available treatments or vaccines. The objective of this project was to determine the most efficacious concentration of florfenicol (FFC) [10, 15 or 20 mg FFC kg(-1) body weight (bw) per days for 10 days] administered in feed to control experimentally induced infections of Fno in Nile tilapia, Oreochromis niloticus (L.), reared in a recirculating aquaculture system. The cumulative mortality of fish that received 0, 10, 15 or 20 mg FFC kg(-1)  bw per day was 60, 37, 14 and 16%, respectively. Francisella noatunensis subsp. orientalis genome equivalents were detected in water from all challenged groups with slight reduction in the concentration in the florfenicol-treated groups 4 days after treatment. The mean LOG of CFU Fno mg(-1) spleen was 3-5 and was present in all challenged groups at necropsy 11 days after treatment (21 days after challenge). Results show that florfenicol administered at doses of 15 and 20 mg FFC kg(-1)  bw per days for 10 days significantly reduced mortality associated with francisellosis in Nile tilapia. PMID:23134104

  10. Survival, Growth and Reproduction of Non-Native Nile Tilapia II: Fundamental Niche Projections and Invasion Potential in the Northern Gulf of Mexico

    PubMed Central

    Lowe, Michael R.; Wu, Wei; Peterson, Mark S.; Brown-Peterson, Nancy J.; Slack, William T.; Schofield, Pamela J.

    2012-01-01

    Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity (0–60, by increments of 10). These predictive models were combined with kriged seasonal salinity data derived from multiple long-term data sets to project the species' fundamental niche in Mississippi coastal waters during normal salinity years (averaged across all years) and salinity patterns in extremely wet and dry years (which might emerge more frequently under scenarios of climate change). The derived fundamental niche projections showed that during the summer, Nile tilapia is capable of surviving throughout Mississippi's coastal waters but growth and reproduction were limited to river mouths (or upriver). Overwinter survival was also limited to river mouths. The areas where Nile tilapia could survive, grow, and reproduce increased during extremely wet years (2–368%) and decreased during extremely dry years (86–92%) in the summer with a similar pattern holding for overwinter survival. These results indicate that Nile tilapia is capable of 1) using saline waters to gain access to other watersheds throughout the region and 2) establishing populations in nearshore, low-salinity waters, particularly in the western portion of coastal Mississippi. PMID:22848533

  11. Survival, growth and reproduction of non-native Nile tilapia II: fundamental niche projections and invasion potential in the northern Gulf of Mexico

    USGS Publications Warehouse

    Lowe, Michael R.; Wu, Wei; Peterson, Mark S.; Brown-Peterson, Nancy J.; Slack, William T.; Schofield, Pamela J.

    2012-01-01

    Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity (0–60, by increments of 10). These predictive models were combined with kriged seasonal salinity data derived from multiple long-term data sets to project the species' fundamental niche in Mississippi coastal waters during normal salinity years (averaged across all years) and salinity patterns in extremely wet and dry years (which might emerge more frequently under scenarios of climate change). The derived fundamental niche projections showed that during the summer, Nile tilapia is capable of surviving throughout Mississippi's coastal waters but growth and reproduction were limited to river mouths (or upriver). Overwinter survival was also limited to river mouths. The areas where Nile tilapia could survive, grow, and reproduce increased during extremely wet years (2–368%) and decreased during extremely dry years (86–92%) in the summer with a similar pattern holding for overwinter survival. These results indicate that Nile tilapia is capable of 1) using saline waters to gain access to other watersheds throughout the region and 2) establishing populations in nearshore, low-salinity waters, particularly in the western portion of coastal Mississippi.

  12. Controlled laboratory challenge demonstrates substantial additive genetic variation in resistance to Streptococcus iniae in Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is an etiologic agent of streptococcal disease in tilapia and is one of several Streptococcus spp. that negatively impact worldwide tilapia production. Methods for the prevention and control of S. iniae include vaccines, management strategies, and antibiotics. An alternative and ...

  13. Neurokinin B-related Peptide Suppresses the Expression of GnRH I, Kiss2 and tac3 in the Brain of Mature Female Nile tilapia Oreochromis niloticus.

    PubMed

    Jin, Ye Hwa; Park, Jin Woo; Kim, Jung-Hyun; Kwon, Joon Yeong

    2016-03-01

    Neurokinin B (NKB) and neurokinin B related peptide (NKBRP) belong to tachykinin peptide family. Theyact as a neurotransmitter and/or neuromodulator. Mutation of NKB and/or its cognate receptor, NK3R resulted in hypogonadotropic hypogonadism in mammals, implying a strong involvement of NKB/NK3R system in controlling mammalian reproduction. Teleosts possess NKBRP as well as NKB, but their roles in fish reproduction need to be clarified. In this study, NKB and NKBRP coding gene (tac3) was cloned from Nile tilapia and sequenced. Based on the sequence, Nile tilapia NKB and NKBRP peptide were synthesized and their biological potencies were tested in vitro pituitary culture. The synthetic NKBRP showed direct inhibitory effect on the expression of GTH subunits at the pituitary level. This inhibitory effect was confirmed in vivo by means of intraperitoneal (ip) injection of synthetic NKB and NKBRP to mature female tilapia (20 pmol/g body weight [BW]). Both NKB and NKBRP had no effect on the plasma level of sex steroids, E2 and 11-KT. However, NKBRP caused declines of expression level of GnRH I, Kiss2 and tac3 mRNAs in the brain while NKB seemed to have no distinct effect. These results indicate some inhibitory roles of NKBRP in reproduction of mature female Nile tilapia, although their exact functions are not clear at the moment. PMID:27294210

  14. Characterization of two paralogous StAR genes in a teleost, Nile tilapia (Oreochromis niloticus).

    PubMed

    Yu, Xiangguo; Wu, Limin; Xie, Lang; Yang, Shijie; Charkraborty, Tapas; Shi, Hongjuan; Wang, Deshou; Zhou, Linyan

    2014-07-01

    Steroidogenic acute regulatory protein (StAR) transports cholesterol, the substrate for steroid synthesis, to the inner membranes of mitochondria. It is well known that estrogen is essential for female sex determination/differentiation in fish. However, no reports showed that the conventional StAR, which was supposed to be essential for estrogen production, was expressed in female gonads during the critical timing of sex determination/differentiation. In this study, two different StAR isoforms, named as StAR1 and StAR2, were characterized from the gonads of Nile tilapia (Oreochromis niloticus). Phylogenetic and synteny analysis revealed that two StAR genes existed in teleosts, Xenopus and chicken indicating that the duplication event occurred before the divergence of teleosts and tetrapods. Real-time PCR revealed that StAR1 was dominantly expressed in the testis, head kidney and kidney; while StAR2 was expressed exclusively in the gonads. In situ hybridization and immunohistochemistry demonstrated that StAR1 was expressed in the interrenal cells of the head kidney and Leydig cells of the testis; while StAR2 was expressed in the Leydig cells of the testis and the interstitial cells of the ovary. Ontogenic analysis demonstrated that StAR2 was expressed abundantly from 5 days after hatching (dah) in the somatic cells in XX gonads, whereas in XY gonads, both StARs could be detected from 30 dah until adulthood. Intraperitoneal injection of human chorionic gonadotropin experiments showed that expression of StAR1 and 2 was significantly elevated at 8h and persisted until 24h after injection in the testis. Taken together, our data suggested that StAR1 is likely to be required for cortisol production in the head kidney, and StAR2 is probably involved in estrogen production during early sex differentiation in XX gonads. In contrast, both StARs might be required for androgen production in testes. For the first time, our data demonstrated that two fish StARs might be involved

  15. Ceftiofur pharmacokinetics in Nile tilapia Oreochromis niloticus after intracardiac and intramuscular administrations.

    PubMed

    Khalil, Waleed F; Shaheen, Hazem M; Abdou, Rania H

    2016-08-31

    Ceftiofur is a broad-spectrum third generation cephalosporin, which acts by inhibiting bacterial cell wall synthesis. It is active against Gram-positive and Gram-negative bacteria such as Aeromonas hydrophila and β-lactamase-producing strains, which are common pathogens in freshwater fish. Ceftiofur pharmacokinetics in Nile tilapia Oreochromis niloticus were studied following single intracardiac (i.c.) or intramuscular (i.m.) administration of ceftiofur sodium (NAXCEL®) in a dose of 5 mg ceftiofur kg-1 body weight. After i.c. injection, ceftiofur plasma concentrations decreased biexponentially, suggesting a 2-compartmental open model. Distribution and elimination half-lives (t0.5(α) and t0.5(β)) were 0.61 ± 0.22 and 0.14 ± 0.03 h mean ±SD, respectively. Elimination constant (Kel) and total body clearances (Cltot) were 3.22 ± 0.48 h-1 and 1.64 ± 0.47 l h-1 kg-1, respectively. Volume of distribution (Vss) and areas under curves (AUC) were 0.12 ± 0.03 l kg-1 and 24.18 ± 8.81 µg ml-1 h, respectively. Following i.m. injection of ceftiofur, plasma concentrations were best described by a 1-compartment open model with a first order absorption; bioavailability was quite high (96.85 ± 23.74%). Plasma maximum concentration (Cmax) was 12.32 ± 6.53 µg ml-1; achieved at time of maximum concentration (Tmax) of 0.74 ± 0.04 h. Absorption and elimination half-lives (t0.5ab and t0.5β) were 0.49 ± 0.06 and 0.53 ± 0.03 h, respectively. In conclusion, i.m. injection of ceftiofur sodium produced extremely high bioavailability with high plasma concentrations that persisted up to 6 h post injection, which may make ceftiofur a useful alternative antibiotic for treatment of brood stock or important ornamental fishes. PMID:27596857

  16. Supplemental effects of mixed ingredients and rice bran on the growth performance, survival and yield of Nile tilapia, Oreochromis niloticus reared in fertilized earthen ponds.

    PubMed

    Limbu, S M; Shoko, A P; Lamtane, H A; Kishe-Machumu, M A; Joram, M C; Mbonde, A S; Mgana, H F; Mgaya, Y D

    2016-01-01

    Unaffordability of commercial feeds to semi-intensive Nile tilapia, Oreochromis niloticus farmers has led to reliance on supplemental feeding and fertilization for nutrition of their fish without a scientific basis. This study compared the growth, survival, condition factor and yield performance of O. niloticus fed on mixed ingredients (MI) and rice bran alone (RB) diets reared in fertilized earthen ponds in small scale farmers' ponds. The study also determined phytoplankton composition, biomass and abundance in the experimental ponds. Quadruplicate ponds were stocked with O. niloticus and African sharptooth catfish, Clarias gariepinus at a stocking ratio of 1:3. The initial mean weights of O. niloticus and C. gariepinus were 14.62 ± 0.61 and 20.34 ± 1.44 g respectively. The fish were fed on MI and RB diets with protein content of 184.74 and 126.06 g kg(-1) respectively for 270 days. The results showed that growth performance, survival rate and condition factor of O. niloticus were not affected by either feeding with MI or RB diet (p > 0.05). Moreover, there were no significant differences obtained in phytoplankton biomass and abundance in O. niloticus ponds fed on the two diets (p > 0.05). Furthermore, feeding O. niloticus either on MI or RB diet did not affect the net and gross fish yields (p > 0.05). The study revealed that the use of either MI or RB diet does not significantly affect the performance of O. niloticus cultured in semi-intensive earthen ponds where natural food organisms are an integral part of the culture system. Rice bran could be used for semi-intensive culture of O. niloticus in fertilized ponds to boost the production based on its availability and low cost.

  17. E2 potentializes benzo(a)pyrene-induced hepatic cytochrome P450 enzyme activities in Nile tilapia at high concentrations.

    PubMed

    Rodrigues, Aline Cristina Ferreira; Moneró, Tatiana de Oliveira; Frighetto, Rosa Toyoko Shiraishi; de Almeida, Eduardo Alves

    2015-11-01

    In the aquatic environment, biotransformation enzymes are established biomarkers for assessing PAH exposure in fish, but little is known about the effect of 17β-estradiol (E2) on these enzymes during exposure to benzo(a)pyrene (BaP). In this study, Nile tilapia (Oreochromis niloticus) were exposed for 3, 5, and 10 days to BaP (300 μg L(-1)) and E2 (5 μg L(-1)). These substances were applied isolated or mixed. In the mixture experiment, fish were analyzed pre- and postexposure in order to better understand whether preexposure to the hormone masks the responses activated by PAH or vice versa. Phase I enzymes ethoxyresorufin-O-deethylase (EROD), pentoxyresorufin-O-depenthylase (PROD), and benzyloxyresorufin-O-debenzylase (BROD) activities as well as the phase II enzyme glutathione S-transferase (GST) were analyzed. Isolated E2 treatment decreased EROD activity after 3 days, but this enzyme activity returned to control values after 5 and 10 days of exposure. Isolated BaP treatment significantly induced EROD activity after 3 and 5 days, and the activity returned to control levels after ten exposure days. Combined treatment (E2 + Bap) significantly increased EROD activity, both in the pre- and postexposure. This increase was even higher than in the isolated BaP treatment, suggesting a synergism between these two compounds. When E2 and BaP were used singly, they did not change BROD and PROD activities. However, combined treatment (E2 + Bap) significantly increased PROD activity. Isolated BaP treatment increased GST activity after 10 days. However, this response was not observed in the mixture treatment, suggesting that E2 suppressed the GST induction modulated by BaP. The results put together indicated that E2 altered the biotransformation pathway regarding enzymes activated by BaP in Nile tilapia.

  18. Biodegradation of 17alpha-methyltestosterone and isolation of MT-degrading bacterium from sediment of Nile tilapia masculinization pond.

    PubMed

    Homklin, Supreeda; Wattanodorn, Theerachit; Ong, Say Kee; Limpiyakorn, Tawan

    2009-01-01

    The fast growing and highly tolerant fish Nile tilapia is one of the most commonly raised fish in the aquaculture industry. To produce an all-male population, a common practice is to feed the Nile tilapia fry with 17alpha-methyltestosterone (MT)-impregnated food. Uneaten fish food with MT may accumulate in the masculinization ponds and be released into the receiving waters. Not much is known about the fate of MT in the fish farms and in the receiving streams. The objective of this study is to investigate the biodegradation of MT under aerobic condition and to isolate responsible microorganisms. Aerobic biodegradation tests were conducted with MT concentrations of 0.3, 1.0, 5.0, 7.0, and 10.0 mg/L using sediment from the masculinization pond as microbial seed. The results suggested that MT is biodegradable. Lag phase was not observed in all cases. With initial concentrations of 0.3, 1.0, 5.0, 7.0, and 10.0 mg/l, the first-order degradation rates were 0.52, 0.23, 0.17, 0.13 and 0.10 day(-1), respectively. Degradation rates were found to decrease with an increase in the initial MT concentration. Analysis of 16S rRNA gene sequences of a strain isolated from the sediment indicated that the strain was highly similar to Pimelobacter simplex strain S151 (100%) which is in the genus Nocardioidaceae. Using this strain, MT is degraded with a first-order degradation rate of 0.044 h(-1) excluding the lag phase. This is the first work reporting biodegradation of MT and isolation of MT-degrading bacterium from environment.

  19. Molecular characterization of Galectin-8 from Nile tilapia (Oreochromis niloticus Linn.) and its response to bacterial infection.

    PubMed

    Unajak, Sasimanas; Pholmanee, Nutthida; Songtawee, Napat; Srikulnath, Kornsorn; Srisapoome, Prapansak; Kiataramkul, Asama; Kondo, Hidehiro; Hirono, Ikuo; Areechon, Nontawith

    2015-12-01

    Galectins belong to the family of galactoside-binding proteins and play a major role in the immune and inflammatory responses of vertebrates and invertebrates. The galectin family is divided into three subtypes based on molecular structure; prototypes, chimera types, and tandem-repeated types. We isolated and characterized the cDNA of galectin-8 (OnGal-8) in Nile tilapia (Oreochromis niloticus). OnGal-8 consisted of a 966 bp open reading frame (ORF) that encoded a 321 amino acid protein (43.47 kDa). Homology and phylogenetic tree analysis suggested the protein was clustered with galectin-8s from other animal species and shared at least 56.8% identity with salmon galectin-8. Structurally, the amino acid sequence included two distinct N- and C- terminus carbohydrate recognition domains (CRDs) of 135 and 133 amino acids, respectively, that were connected by a 39 amino acid polypeptide linker. The N- and C-CRDs contained two conserved WG-E-I and WG-E-T motifs, suggesting they have an important role in mediating the specific interactions between OnGal-8 and saccharide moieties such as β-galactoside. The structure of OnGal-8 was characterized by a two-fold symmetric pattern of 10-and 12-stranded antiparallel ß-sheets of both N- and C-CRDs, and the peptide linker presumably formed a random coil similar to the characteristic tandem-repeat type galectin. The expression of OnGal-8 in healthy fish was highest in the skin, intestine, and brain. Experimental challenge of Nile tilapia with S. agalactiae resulted in significant up-regulation of OnGal-8in the spleen after 5 d. Our results suggest that OnGal-8 is involved in the immune response to bacterial infection.

  20. Biochemical biomarkers in Nile tilapia (Oreochromis niloticus) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends.

    PubMed

    Nogueira, Lílian; Sanches, Ana Letícia Madeira; da Silva, Danilo Grünig Humberto; Ferrizi, Vítor Cid; Moreira, Altair Benedito; de Almeida, Eduardo Alves

    2011-09-01

    Fossil fuels such as diesel are being gradually replaced by biodiesel, a renewable energy source, cheaper and less polluting. However, little is known about the toxic effects of this new energy source on aquatic organisms. Thus, we evaluated biochemical biomarkers related to oxidative stress in Nile tilapia (Oreochromis niloticus) after two and seven exposure days to diesel and pure biodiesel (B100) and blends B5 and B20 at concentrations of 0.01 and 0.1 mL L(-1). The hepatic ethoxyresorufin-O-deethylase activity was highly induced in all groups, except for those animals exposed to B100. There was an increase in lipid peroxidation in liver and gills in the group exposed to the higher concentration of B5. All treatments caused a significant increase in the levels of 1-hydroxypyrene excreted in the bile after 2 and 7d, except for those fish exposed to B100. The hepatic glutathione-S-transferase increased after 7d in animals exposed to the higher concentration of diesel and in the gill of fish exposed to the higher concentration of pure diesel and B5, but decreased for the two tested concentrations of B100. Superoxide dismutase, catalase and glutathione peroxidase also presented significant changes according to the treatments for all groups, including B100. Biodiesel B20 in the conditions tested had fewer adverse effects than diesel and B5 for the Nile tilapia, and can be suggested as a less harmful fuel in substitution to diesel. However, even B100 could activate biochemical responses in fish, at the experimental conditions tested, indicating that this fuel can also represent a risk to the aquatic biota.

  1. Inactivation kinetics of formaldehyde on N-acetyl-β-D-glucosaminidase from Nile tilapia (Oreochromis niloticus).

    PubMed

    Zhang, Wei-Ni; Bai, Ding-Ping; Lin, Xin-Yu; Chen, Qing-Xi; Huang, Xiao-Hong; Huang, Yi-Fan

    2014-04-01

    Formaldehyde is a widely used sanitizer in aquaculture in China, while the appropriate concentration is not available to be used effectively and without damage to tilapia much less to its reproductive function. N-acetyl-β-D-glucosaminidase (EC 3.2.1.52, NAGase), hydrolyzing the oligomers of N-acetyl-β-D-glucosamine into monomer, is proved to be correlated with reproduction of male animals. In this paper, NAGase from spermary of tilapia was chosen as the material to study the effects of formaldehyde on its activity in order to further investigate the effects of formaldehyde use on tilapia reproduction. The results showed the relationship between the residual enzyme activity and the concentration of formaldehyde was concentration dependent, and the IC50 value was estimated to be 3.2 ± 0.1 %. Appropriate concentration of formaldehyde leaded to competitive reversible inhibition on tilapia NAGase. Moreover, formaldehyde could reduce the thermal and pH stability of the enzyme. The inactivation kinetics of formaldehyde on the enzyme was studied using the kinetic method of substrate reaction. The inactivation model was setup, and the rate constants were determined. The results showed that the inactivation of formaldehyde on tilapia NAGase was a slow, reversible reaction with partially residual activity. The results will give some basis to determine the concentration of formaldehyde used in tilapia culture.

  2. Does selection in a challenging environment produce Nile tilapia genotypes that can thrive in a range of production systems?

    PubMed Central

    Thoa, Ngo Phu; Ninh, Nguyen Huu; Knibb, Wayne; Nguyen, Nguyen Hong

    2016-01-01

    This study assessed whether selection for high growth in a challenging environment of medium salinity produces tilapia genotypes that perform well across different production environments. We estimated the genetic correlations between trait expressions in saline and freshwater using a strain of Nile tilapia selected for fast growth under salinity water of 15–20 ppt. We also estimated the heritability and genetic correlations for new traits of commercial importance (sexual maturity, feed conversion ratio, deformity and gill condition) in a full pedigree comprising 36,145 fish. The genetic correlations for the novel characters between the two environments were 0.78–0.99, suggesting that the effect of genotype by environment interaction was not biologically important. Across the environments, the heritability for body weight was moderate to high (0.32–0.62), indicating that this population will continue responding to future selection. The estimates of heritability for sexual maturity and survival were low but significant. The additive genetic components also exist for FCR, gill condition and deformity. Genetic correlations of harvest body weight with sexual maturity were positive and those between harvest body weight with FCR were negative. Our results indicate that the genetic line selected under a moderate saline water environment can be cultured successfully in freshwater systems. PMID:26892814

  3. Flow cytometric evaluation of antibiotic effects on viability and mitochondrial function of refrigerated spermatozoa of Nile tilapia

    USGS Publications Warehouse

    Segovia, M.; Jenkins, J.A.; Paniagua-Chavez, C.; Tiersch, T.R.

    2000-01-01

    Improved techniques for storage and evaluation of fish sperm would enhance breeding programs around the world. The goal of this study was to test the effect of antibiotics on refrigerated sperm from Nile tilapia (Oreochromis niloticus) by use of flow cytometry with 2 dual-staining protocols for objective assessment of sperm quality. Concentrations of 1 x 109 sperm/mL were suspended in Ringer's buffer at 318 mOsmol/kg (pH 8.0). The fluorescent stains Sybr 14 (10 ??M), propidium iodide (2.4 mM), and rhodamine 123 (0.13 ??M) were used to assess cell viability and mitochondrial function. Three concentrations of ampicillin, gentamicin, and an antibiotic/antimycotic solution were added to fresh spermatozoa. Motility estimates and flow cytometry measurements were made daily during 7 d of refrigerated storage (4 ??C). The highest concentrations of gentamicin and antibiotic/antimycotic and all 3 concentrations of ampicillin significantly reduced sperm viability. The highest of each of the 3 antibiotic concentrations significantly reduced mitochondrial function. This study demonstrates that objective sperm quality assessments can be made using flow cytometry and that addition of antibiotics at appropriate concentrations can lengthen refrigerated storage time for tilapia spermatozoa. With minor modifications, these protocols can be adapted for use with sperm from other species and with other tissue types.

  4. Hydroyeast Aquaculture® as a reproductive enhancer agent for the adult Nile tilapia (Oreochromis niloticus Linnaeus, 1758).

    PubMed

    Mehrim, Ahmed I; Khalil, Fathy F; Hassan, Montaha E

    2015-04-01

    Tilapias are becoming increasingly popular culture fish because of their superior culture adaptability. In recent years, there has been a great interest in the use of probiotics in fish aquaculture. The objectives of the present study were to evaluate the effect of dietary graded levels (0, 5, 10, and 15 g/kg commercial diet, referred to treatments numbers T1, T2, T3, and T4, for males and T5, T6, T7, and T8 treatments for females) of a new probiotic Hydroyeast Aquaculture(®) on hematological and biochemical parameters, serum sex hormones, and the reproductive efficiency parameters of the adult Nile tilapia Oreochromis niloticus for 8 weeks. Results revealed that high levels of probiotics diet, 15 g (T4, ♂) and 10 g (T7, ♀) probiotic/kg diet, significantly (P ≤ 0.05) enhanced the physiological responses (hematological as well as serum biochemical parameters) together with, reproductive performances (sex hormones, testes and sperm quality parameters, absolute and relative fecundity, and ovarian measurements). Therefore, it could be conclude that Hydroyeast Aquaculture(®) is useful at levels of 15 g (T4) and 10 g (T7)/kg diet in improving the reproductive efficiency of adult O. niloticus males and females, respectively. Thus, the use of Hydroyeast Aquaculture(®) may be economically important for fish hatcheries.

  5. Seabream GnRH immunoreactivity in brain and pituitary of XX and XY Nile tilapia, Oreochromis niloticus during early development.

    PubMed

    Swapna, I; Sudhakumari, C C; Sakai, F; Sreenivasulu, G; Kobayashi, T; Kagawa, H; Nagahama, Y; Senthilkumaran, B

    2008-08-01

    Seabream gonadotropin-releasing hormone (sbGnRH)-the chief preoptic area-hypothalamus (POA-H) form of GnRH in tilapia is involved in sexual maturation. In this study, we investigated the qualitative changes in ontogeny of sbGnRH immunoreactivity (ir-), between sexes to understand its impending role during sex differentiation. For this, the differences in immunocytochemical localization of sbGnRH in genetically male (XY) and female (XX) fish were studied from 1 day after hatching (dah), through the critical period of sex differentiation (7-21 dah) to 40 dah and mature Nile tilapia. Specific antisera against sbGnRH were used for immunolocalization. SbGnRH ir- neurons were observed in POA-H as early as 5 and 15 dah in XY fish and XX fish, respectively. Higher ir- was detected in the POA-H of XY tilapia compared with XX population till 10 dah. There was a qualitative drop in sbGnRH ir- neurons/cell bodies in POA-H around 20 dah till 30 dah in XY population compared with other durations. SbGnRH ir- cells were detected in pituitary of XX fish by 15 dah and in XY fish around 10 dah but seemed to drop down by 20 dah in XY whereas it continued to remain steady in XX fish. The sbGnRH ir- in XY fish showed a rise from 35 dah and thence till 40 dah. This study revealed subtle differences in POA-H and pituitary sbGnRH ir- during early development between genetic male and female fish with possible implications in sex differentiation.

  6. Assessment of bile fluorescence patterns in a tropical fish, Nile tilapia (Oreochromis niloticus) exposed to naphthalene, phenanthrene, pyrene and chrysene using fixed wavelength fluorescence and synchronous fluorescence spectrometry.

    PubMed

    Pathiratne, A; Hemachandra, C K; Pathiratne, K A S

    2010-05-01

    Bile fluorescence patterns in Nile tilapia, a potential fish for biomonitoring tropical water pollution were assessed following exposure to selected polycyclic aromatic hydrocarbons (PAHs): naphthalene, phenanthrene, pyrene and chrysene. Non-normalized fixed wavelength fluorescence signals in the fish exposed to these PAHs reflected dose and/or time response relationships of their metabolism. Normalizing signals to biliverdin introduced deviations to these response patterns. The optimal wavelength pairs (excitation/emission) for synchronous fluorescence scanning measurements of bile metabolites of naphthalene, phenanthrene, pyrene and chrysene were identified as 284/326, 252/357, 340/382 and 273/382 respectively. This study supports the use of bile fluorescence in Nile tilapia by fixed wavelength fluorescence and synchronous fluorescence spectrometry with non-normalized data as a simple method for screening bioavailability of these PAHs.

  7. Identification and characterization of microRNAs in ovary and testis of Nile tilapia (Oreochromis niloticus) by using solexa sequencing technology.

    PubMed

    Xiao, Jun; Zhong, Huan; Zhou, Yi; Yu, Fan; Gao, Yun; Luo, Yongju; Tang, Zhanyang; Guo, Zhongbao; Guo, Enyan; Gan, Xi; Zhang, Ming; Zhang, Yaping

    2014-01-01

    MicroRNAs (miRNAs) are endogenous non-coding small RNAs which play important roles in the regulation of gene expression by cleaving or inhibiting the translation of target gene transcripts. Thereinto, some specific miRNAs show regulatory activities in gonad development via translational control. In order to further understand the role of miRNA-mediated posttranscriptional regulation in Nile tilapia (Oreochromis niloticus) ovary and testis, two small RNA libraries of Nile tilapia were sequenced by Solexa small RNA deep sequencing methods. A total of 9,731,431 and 8,880,497 raw reads, representing 5,407,800 and 4,396,281 unique sequences were obtained from the sexually mature ovaries and testes, respectively. After comparing the small RNA sequences with the Rfam database, 1,432,210 reads in ovaries and 984,146 reads in testes were matched to the genome sequence of Nile tilapia. Bioinformatic analysis identified 764 mature miRNA, 209 miRNA-5p and 202 miRNA-3p were found in the two libraries, of which 525 known miRNAs are both expressed in the ovary and testis of Nile tilapia. Comparison of expression profiles of the testis, miR-727, miR-129 and miR-29 families were highly expressed in tilapia ovary. Additionally, miR-132, miR-212, miR-33a and miR-135b families, showed significant higher expression in testis compared with that in ovary. Furthermore, the expression patterns of the miRNAs were analyzed in different developmental stages of gonad. The result showed different expression patterns were observed during development of testis and ovary. In addition, the identification and characterization of differentially expressed miRNAs in the ovaries and testis of Nile tilapia provides important information on the role of miRNA in the regulation of the ovarian and testicular development and function. This data will be helpful to facilitate studies on the regulation of miRNAs during teleosts reproduction.

  8. Isolation and molecular identification of the etiological agents of streptococcosis in Nile tilapia (Oreochromis niloticus) cultured in net cages in Lake Sentani, Papua, Indonesia.

    PubMed

    Anshary, Hilal; Kurniawan, Rio A; Sriwulan, Sriwulan; Ramli, Ramli; Baxa, Dolores V

    2014-01-01

    Infections with Streptococcus spp. were observed in Nile tilapia cultured in net cages in Lake Sentani, Papua, Indonesia. Clinical signs included exophthalmia, erratic swimming, ascites in abdominal cavity, and external hemorrhages. Four types of bacterial colonies (SK, K10, P20, and M12) were isolated from the brain, kidney, and eyes. Based on phenotypic and genetic (16S rDNA sequencing) characteristics, the isolates were identified as Streptococcus iniae (SK), Streptococcus agalactiae (K10 and P20) and Lactococcus garvieae (M12). The latter species has not been previously isolated or reported from fish streptococcosis in Indonesia. Intraperitoneal injection of healthy tilapia with the bacterial species caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post injection. Experimental infections and reisolation of the bacteria from morbid and dead fish suggest they are the causative agents of streptococcosis, which rendered high mortality among cage cultured Nile tilapia in Lake Sentani. Our results suggest the need for developing diagnostic tools for accurate identification of the agents of streptococcosis. As tilapia aquaculture continues to expand as a means of food production and livelihood in Indonesia, it becomes crucial to ensure that fish resources are monitored and protected from the adverse effects of infectious diseases. PMID:25392797

  9. Infection dynamics of Cichlidogyrus tilapiae and C. sclerosus (Monogenea, Ancyrocephalinae) in Nile tilapia (Oreochromis niloticus L.) from Uganda.

    PubMed

    Akoll, P; Fioravanti, M L; Konecny, R; Schiemer, F

    2012-09-01

    The infection dynamics of the gill monogeneans Cichlidogyrus tilapiae and C. sclerosus on Oreochromis niloticus with respect to habitat type (reservoir, stream, ponds and cages), host sex, size and seasons was determined between January and November 2008. During the study period, 45.2% of the 650 fish examined were infected with Cichlidogyrus spp. The infected hosts harboured an average of 8.6 ± 3.4 parasites/fish. Across habitat types, the proportion of infected fish was not statistically different. In contrast, the number of parasites recorded on infected fish from different habitat types differed significantly. The highest parasite number was recorded in reservoir-dwelling fish and lowest in stream-dwelling hosts. Concerning sex, more female O. niloticus were infected and harboured a high number of parasites than male and sexually undifferentiated fish. A weak negative relationship was found between rainfall and monthly parasite infections. However, a higher number of parasites and proportion of infected hosts were found during dry than in wet seasons, except in ponds. Results of this study show that differential exposure due to changes in fish behaviour associated with habitat modification and sex may account for the infection difference across the sampled sites. Meanwhile, rainfall and the associated hydrological events are important factors regulating monogenean infections in tropical aquatic environments. The continuous presence of Cichlidogyrus spp. in fish provides evidence of possible parasite outbreaks, indicating the application of biosecurity measures as crucial for the success of intensive fish farming. PMID:21791155

  10. Genome-Wide Identification and Transcriptome-Based Expression Profiling of the Sox Gene Family in the Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Wei, Ling; Yang, Chao; Tao, Wenjing; Wang, Deshou

    2016-01-01

    The Sox transcription factor family is characterized with the presence of a Sry-related high-mobility group (HMG) box and plays important roles in various biological processes in animals, including sex determination and differentiation, and the development of multiple organs. In this study, 27 Sox genes were identified in the genome of the Nile tilapia (Oreochromis niloticus), and were classified into seven groups. The members of each group of the tilapia Sox genes exhibited a relatively conserved exon-intron structure. Comparative analysis showed that the Sox gene family has undergone an expansion in tilapia and other teleost fishes following their whole genome duplication, and group K only exists in teleosts. Transcriptome-based analysis demonstrated that most of the tilapia Sox genes presented stage-specific and/or sex-dimorphic expressions during gonadal development, and six of the group B Sox genes were specifically expressed in the adult brain. Our results provide a better understanding of gene structure and spatio-temporal expression of the Sox gene family in tilapia, and will be useful for further deciphering the roles of the Sox genes during sex determination and gonadal development in teleosts. PMID:26907269

  11. Genome-Wide Identification and Transcriptome-Based Expression Profiling of the Sox Gene Family in the Nile Tilapia (Oreochromis niloticus).

    PubMed

    Wei, Ling; Yang, Chao; Tao, Wenjing; Wang, Deshou

    2016-01-01

    The Sox transcription factor family is characterized with the presence of a Sry-related high-mobility group (HMG) box and plays important roles in various biological processes in animals, including sex determination and differentiation, and the development of multiple organs. In this study, 27 Sox genes were identified in the genome of the Nile tilapia (Oreochromis niloticus), and were classified into seven groups. The members of each group of the tilapia Sox genes exhibited a relatively conserved exon-intron structure. Comparative analysis showed that the Sox gene family has undergone an expansion in tilapia and other teleost fishes following their whole genome duplication, and group K only exists in teleosts. Transcriptome-based analysis demonstrated that most of the tilapia Sox genes presented stage-specific and/or sex-dimorphic expressions during gonadal development, and six of the group B Sox genes were specifically expressed in the adult brain. Our results provide a better understanding of gene structure and spatio-temporal expression of the Sox gene family in tilapia, and will be useful for further deciphering the roles of the Sox genes during sex determination and gonadal development in teleosts. PMID:26907269

  12. The use of nile tilapia (Oreochromis niloticus) cultivation wastewater for the production of romaine lettuce (Lactuca sativa L. var. longifolia) in water recirculation system

    NASA Astrophysics Data System (ADS)

    Effendi, Hefni; Wahyuningsih, Sri; Wardiatno, Yusli

    2016-05-01

    In the recirculation aquaponic system (RAS), fish farming waste was utilized as a nutrient for plant, minimizing the water need, reducing the waste disposal into the environment, and producing the fish and plant as well. The study aimed to examine the growth of romaine lettuce (Lactuca sativa L. var. Longifolia) in aquaponic system without the addition of artificial nutrient. The nutrient relies solely on wastewater of nile tilapia (Oreochromis niloticus) cultivation circulated continuously on the aquaponic system. The results showed that tilapia weight reached 48.49 ± 3.92 g of T3 (tilapia, romaine lettuce, and inoculated bacteria), followed by T2 (tilapia and romaine lettuce) and T1 (tilapia) of 47.80 ± 1.97 and 45.89 ± 1.10 g after 35 days of experiment. Tilapia best performance in terms of growth and production occurred at T3 of 3.96 ± 0.44 g/day, 12.10 ± 0.63 %/day, 96.11 ± 1.44 % and 1.60 ± 0.07 for GR, SGR, SR, and FCR, respectively. It is also indicated by better water quality characteristic in this treatment. Romaine lettuce harvests of T2 and T3 showed no significant difference, with the final weight of 61.87 ± 5.59 and 57.74 ± 4.35 g. Overall, the integration of tilapia fish farming and romaine lettuce is potentially a promising aquaponic system for sustainable fish and horticulture plant production.

  13. Allelic variant in the anti-Müllerian hormone gene leads to autosomal and temperature-dependent sex reversal in a selected Nile tilapia line.

    PubMed

    Wessels, Stephan; Sharifi, Reza Ahmad; Luehmann, Liane Magdalena; Rueangsri, Sawichaya; Krause, Ina; Pach, Sabrina; Hoerstgen-Schwark, Gabriele; Knorr, Christoph

    2014-01-01

    Owing to the demand for sustainable sex-control protocols in aquaculture, research in tilapia sex determination is gaining momentum. The mutual influence of environmental and genetic factors hampers disentangling the complex sex determination mechanism in Nile tilapia (Oreochromis niloticus). Previous linkage analyses have demonstrated quantitative trait loci for the phenotypic sex on linkage groups 1, 3, and 23. Quantitative trait loci for temperature-dependent sex reversal similarly reside on linkage group 23. The anti-Müllerian hormone gene (amh), located in this genomic region, is important for sexual fate in higher vertebrates, and shows sexually dimorphic expression in Nile tilapia. Therefore this study aimed at detecting allelic variants and marker-sex associations in the amh gene. Sequencing identified six allelic variants. A significant effect on the phenotypic sex for SNP ss831884014 (p<0.0017) was found by stepwise logistic regression. The remaining variants were not significantly associated. Functional annotation of SNP ss831884014 revealed a non-synonymous amino acid substitution in the amh protein. Consequently, a fluorescence resonance energy transfer (FRET) based genotyping assay was developed and validated with a representative sample of fish. A logistic linear model confirmed a highly significant effect of the treatment and genotype on the phenotypic sex, but not for the interaction term (treatment: p<0.0001; genotype: p<0.0025). An additive genetic model proved a linear allele substitution effect of 12% in individuals from controls and groups treated at high temperature, respectively. Moreover, the effect of the genotype on the male proportion was significantly higher in groups treated at high temperature, giving 31% more males on average of the three genotypes. In addition, the groups treated at high temperature showed a positive dominance deviation (+11.4% males). In summary, marker-assisted selection for amh variant ss831884014 seems to be

  14. Allelic Variant in the Anti-Müllerian Hormone Gene Leads to Autosomal and Temperature-Dependent Sex Reversal in a Selected Nile Tilapia Line

    PubMed Central

    Wessels, Stephan; Sharifi, Reza Ahmad; Luehmann, Liane Magdalena; Rueangsri, Sawichaya; Krause, Ina; Pach, Sabrina; Hoerstgen-Schwark, Gabriele; Knorr, Christoph

    2014-01-01

    Owing to the demand for sustainable sex-control protocols in aquaculture, research in tilapia sex determination is gaining momentum. The mutual influence of environmental and genetic factors hampers disentangling the complex sex determination mechanism in Nile tilapia (Oreochromis niloticus). Previous linkage analyses have demonstrated quantitative trait loci for the phenotypic sex on linkage groups 1, 3, and 23. Quantitative trait loci for temperature-dependent sex reversal similarly reside on linkage group 23. The anti-Müllerian hormone gene (amh), located in this genomic region, is important for sexual fate in higher vertebrates, and shows sexually dimorphic expression in Nile tilapia. Therefore this study aimed at detecting allelic variants and marker-sex associations in the amh gene. Sequencing identified six allelic variants. A significant effect on the phenotypic sex for SNP ss831884014 (p<0.0017) was found by stepwise logistic regression. The remaining variants were not significantly associated. Functional annotation of SNP ss831884014 revealed a non-synonymous amino acid substitution in the amh protein. Consequently, a fluorescence resonance energy transfer (FRET) based genotyping assay was developed and validated with a representative sample of fish. A logistic linear model confirmed a highly significant effect of the treatment and genotype on the phenotypic sex, but not for the interaction term (treatment: p<0.0001; genotype: p<0.0025). An additive genetic model proved a linear allele substitution effect of 12% in individuals from controls and groups treated at high temperature, respectively. Moreover, the effect of the genotype on the male proportion was significantly higher in groups treated at high temperature, giving 31% more males on average of the three genotypes. In addition, the groups treated at high temperature showed a positive dominance deviation (+11.4% males). In summary, marker-assisted selection for amh variant ss831884014 seems to be

  15. Β-defensin in Nile tilapia (Oreochromis niloticus): Sequence, tissue expression, and anti-bacterial activity of synthetic peptides.

    PubMed

    Dong, Jun-Jian; Wu, Fang; Ye, Xing; Sun, Cheng-Fei; Tian, Yuan-Yuan; Lu, Mai-Xin; Zhang, Rui; Chen, Zhi-Hang

    2015-07-15

    Beta-defensins (β-defensins) are small cationic amphiphilic peptides that are widely distributed in plants, insects, and vertebrates, and are important for their antimicrobial properties. In this study, the β-defensin (Onβ-defensin) gene of the Nile tilapia (Oreochromis niloticus) was cloned from spleen tissue. Onβ-defensin has a genomic DNA sequence of 674 bp and produces a cDNA of 454 bp. Sequence alignments showed that Onβ-defensin contains three exons and two introns. Sequence analysis of the cDNA identified an open reading frame of 201 bp, encoding 66 amino acids. Bioinformatic analysis showed that Onβ-defensin encodes a cytoplasmic protein molecule containing a signal peptide. The deduced amino acid sequence of this peptide contains six conserved cysteine residues and two conserved glycine residues, and shows 81.82% and 78.33% sequence similarities with β-defensin-1 of fugu (Takifugu rubripes) and rainbow trout (Oncorhynchus mykiss), respectively. Real-time quantitative PCR showed that the level of Onβ-defensin expression was highest in the skin (307.1-fold), followed by the spleen (77.3-fold), kidney (17.8-fold), and muscle (16.5-fold) compared to controls. By contrast, low levels of expression were found in the liver, heart, intestine, stomach, and gill (<3.0-fold). Artificial infection of tilapia with Streptococcus agalactiae (group B streptococcus [GBS] strain) resulted in a significantly upregulated expression of Onβ-defensin in the skin, muscle, kidney, and gill. In vitro antimicrobial experiments showed that a synthetic Onβ-defensin polypeptide had a certain degree of inhibitory effect on the growth of Escherichia coli DH5α and S. agalactiae. The results indicate that Onβ-defensin plays a role in immune responses that suppress or kill pathogens.

  16. Pharmacokinetic study of enrofloxacin in Nile tilapia (Oreochromis niloticus) after a single oral administration in medicated feed.

    PubMed

    Teles, J A; Castello Branco, L C; Del Bianchi, M; Pilarski, F; Reyes, F G R

    2016-04-01

    The objective of this study was to evaluate the disposition kinetics of enrofloxacin (ENR) in the plasma and its distribution in the muscle tissue of Nile tilapia (Oreochromis niloticus) after a single oral dose of 10 mg/kg body weight via medicated feed. The fish were kept at a temperature between 28 and 30 °C. The collection period was between 30 min and 120 h after administration of the drug. The samples were analyzed by high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). The ENR was slowly absorbed and eliminated from the plasma (Cmax = 1.24 ± 0.37 μg/mL; Tmax = 8 h; T1/2Ke  = 19.36 h). ENR was efficiently distributed in the muscle tissue and reached maximum values (2.17 ± 0.74 μg/g) after 8 h. Its metabolite, ciprofloxacin (CIP), was detected and quantified in the plasma (0.004 ± 0.005 μg/mL) and muscle (0.01 ± 0.011 μg/g) for up to 48 h. After oral administration, the mean concentration of ENR in the plasma was well above the minimum inhibitory concentrations (MIC50 ) for most bacteria already isolated from fish except for Streptococcus spp. This way the dose used in this study allowed for concentrations in the blood to treat the diseases of tilapia. PMID:26270353

  17. Survival, growth and reproduction of non-indigenous Nile tilapia, Oreochromis niloticus (Linnaeus 1758). I. Physiological capabilities in various temperatures and salinities

    USGS Publications Warehouse

    Schofield, Pamela J.; Peterson, Mark S.; Lowe, Michael R.; Brown-Peterson, Nancy J.; Slack, William T.

    2011-01-01

    The physiological tolerances of non-native fishes is an integral component of assessing potential invasive risk. Salinity and temperature are environmental variables that limit the spread of many non-native fishes. We hypothesised that combinations of temperature and salinity will interact to affect survival, growth, and reproduction of Nile tilapia, Oreochromis niloticus, introduced into Mississippi, USA. Tilapia withstood acute transfer from fresh water up to a salinity of 20 and survived gradual transfer up to 60 at typical summertime (30°C) temperatures. However, cold temperature (14°C) reduced survival of fish in saline waters ≥10 and increased the incidence of disease in freshwater controls. Although fish were able to equilibrate to saline waters in warm temperatures, reproductive parameters were reduced at salinities ≥30. These integrated responses suggest that Nile tilapia can invade coastal areas beyond their point of introduction. However, successful invasion is subject to two caveats: (1) wintertime survival depends on finding thermal refugia, and (2) reproduction is hampered in regions where salinities are ≥30. These data are vital to predicting the invasion of non-native fishes into coastal watersheds. This is particularly important given the predicted changes in coastal landscapes due to global climate change and sea-level rise.

  18. Molecular and functional characterization of peptidoglycan-recognition protein SC2 (PGRP-SC2) from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.

    PubMed

    Gan, Zhen; Chen, Shannan; Hou, Jing; Huo, Huijun; Zhang, Xiaolin; Ruan, Baiye; Laghari, Zubair Ahmed; Li, Li; Lu, Yishan; Nie, Pin

    2016-07-01

    PGRP-SC2, the member of PGRP family, plays an important role in regulation of innate immune response. In this paper, a PGRP-SC2 gene of Nile tilapia, Oreochromis niloticus (designated as On-PGRP-SC2) was cloned and its expression pattern under the infection of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for amidase activity were detected in the deduced amino acid sequence of On-PGRP-SC2. In healthy tilapia, the On-PGRP-SC2 transcripts could be detected in all the examined tissues, with the most abundant expression in the muscle. When infected with S. agalactiae, there was a clear time-dependent expression pattern of On-PGRP-SC2 in the spleen, head kidney and brain. The assays for the amidase activity suggested that recombinant On-PGRP-SC2 protein had a Zn(2+)-dependent PGN-degrading activity. Moreover, our works showed that recombinant On-PGRP-SC2 protein could significantly reduce bacterial load in target organs attacked by S. agalactiae. These findings indicated that On-PGRP-SC2 may play important roles in the immune response to S. agalactiae in Nile tilapia.

  19. Molecular and functional characterization of peptidoglycan-recognition protein SC2 (PGRP-SC2) from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.

    PubMed

    Gan, Zhen; Chen, Shannan; Hou, Jing; Huo, Huijun; Zhang, Xiaolin; Ruan, Baiye; Laghari, Zubair Ahmed; Li, Li; Lu, Yishan; Nie, Pin

    2016-07-01

    PGRP-SC2, the member of PGRP family, plays an important role in regulation of innate immune response. In this paper, a PGRP-SC2 gene of Nile tilapia, Oreochromis niloticus (designated as On-PGRP-SC2) was cloned and its expression pattern under the infection of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for amidase activity were detected in the deduced amino acid sequence of On-PGRP-SC2. In healthy tilapia, the On-PGRP-SC2 transcripts could be detected in all the examined tissues, with the most abundant expression in the muscle. When infected with S. agalactiae, there was a clear time-dependent expression pattern of On-PGRP-SC2 in the spleen, head kidney and brain. The assays for the amidase activity suggested that recombinant On-PGRP-SC2 protein had a Zn(2+)-dependent PGN-degrading activity. Moreover, our works showed that recombinant On-PGRP-SC2 protein could significantly reduce bacterial load in target organs attacked by S. agalactiae. These findings indicated that On-PGRP-SC2 may play important roles in the immune response to S. agalactiae in Nile tilapia. PMID:27033804

  20. Tilapia show immunization response against Ich

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compares the immune response of Nile tilapia and red tilapia against parasite Ichthyophthirius multifiliis (Ich) using a cohabitation challenge model. Both Nile and red tilapia showed strong immune response post immunization with live Ich theronts by IP injection or immersion. Blood serum...

  1. Transcriptome Profiling and Molecular Pathway Analysis of Genes in Association with Salinity Adaptation in Nile Tilapia Oreochromis niloticus

    PubMed Central

    Xu, Zhixin; Gan, Lei; Li, Tongyu; Xu, Chang; Chen, Ke; Wang, Xiaodan; Qin, Jian G.; Chen, Liqiao; Li, Erchao

    2015-01-01

    Nile tilapia Oreochromis niloticus is a freshwater fish but can tolerate a wide range of salinities. The mechanism of salinity adaptation at the molecular level was studied using RNA-Seq to explore the molecular pathways in fish exposed to 0, 8, or 16 (practical salinity unit, psu). Based on the change of gene expressions, the differential genes unions from freshwater to saline water were classified into three categories. In the constant change category (1), steroid biosynthesis, steroid hormone biosynthesis, fat digestion and absorption, complement and coagulation cascades were significantly affected by salinity indicating the pivotal roles of sterol-related pathways in response to salinity stress. In the change-then-stable category (2), ribosomes, oxidative phosphorylation, signaling pathways for peroxisome proliferator activated receptors, and fat digestion and absorption changed significantly with increasing salinity, showing sensitivity to salinity variation in the environment and a responding threshold to salinity change. In the stable-then-change category (3), protein export, protein processing in endoplasmic reticulum, tight junction, thyroid hormone synthesis, antigen processing and presentation, glycolysis/gluconeogenesis and glycosaminoglycan biosynthesis—keratan sulfate were the significantly changed pathways, suggesting that these pathways were less sensitive to salinity variation. This study reveals fundamental mechanism of the molecular response to salinity adaptation in O. niloticus, and provides a general guidance to understand saline acclimation in O. niloticus. PMID:26305564

  2. Acanthocephalan Parasites (Acanthogyrus sp.) of Nile Tilapia (Oreochromis niloticus) as Biosink of Lead (Pb) Contamination in a Philippine Freshwater Lake.

    PubMed

    Paller, Vachel Gay V; Resurreccion, Dan Jacob B; de la Cruz, Christian Paul P; Bandal, Modesto Z

    2016-06-01

    The potential use of acanthocephalans as bioindicators of Lead (Pb) pollution in Sampaloc Lake, Laguna, Philippines was investigated. Nile tilapias (Oreochromis niloticus) were collected and Pb concentrations were determined in fish tissues and in their acanthocephalan parasites, Acanthogyrus sp. Significantly higher levels of Pb were detected in the parasites relative to the fish host tissues (p = 0.001). Bioaccumulation capacity of the parasites against fish tissues were 102, 119, and 147 times higher than the fish intestine, liver, and muscles, respectively. Pb sensitivity of the parasites was quantified by exact logistic analysis showing higher odds of Pb detection ranging from 18 to 45 folds (p = 0.001-0.009). Interestingly, infected fish showed significantly lower Pb concentration in their tissues compared to uninfected fish (p = 0.001), suggesting parasites were able to sequester Pb and served as active biosinks. The Pb levels in the parasites were also hundred folds higher (988 times) relative to the ambient waters, indicating a potential role of fish parasites as metal biosinks in aquatic ecosystems. PMID:27052033

  3. A high molecular weight glycoprotein in seminal plasma is a sperm immobilizing factor in the teleost Nile tilapia, Oreochromis niloticus.

    PubMed

    Mochida, K; Kondo, T; Matsubara, T; Adachi, S; Yamauchi, K

    1999-10-01

    Sperm that have acquired potential for motility are kept immotile in seminal plasma in the teleost, Nile tilapia. In order to investigate the mechanism of immobilization, several experiments were performed using a previously characterized monoclonal antibody (TAT-30) against a molecular weight (Mr) = 120,000 protein that is secreted by Sertoli cells and epithelial cells of the sperm duct, and is also bound to the head of the spermatozoon. First, we assessed sperm motility in the seminal plasma protein fraction (SPP), and demonstrated that the sperm motility is inhibited by SPP in a concentration-dependent manner. Furthermore, sperm motility was recovered if SPP was pretreated with TAT-30, suggesting that the TAT-30 antigen is one of the components of the sperm immobilizing factor. Calibration by gel filtration followed by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting with TAT-30 demonstrated that the sperm immobilizing factor was more than Mr = 1,000,000 in seminal plasma, suggesting that it is a homopolymer of the Mr = 120,000-TAT-30 positive protein. Additionally, lectin blot analysis showed that the TAT-30 antigen was reactive with Lens culinarin agglutinin (LCA) and Conavalia ensiformis agglutinin (ConA), indicating that it is a glycoprotein. Immunohistochemical studies showed that the TAT-30 antigen was localized specifically on the heads of spermatozoa and on the apical surface, lysosomes and rough endoplasmic reticulum of Sertoli cells. PMID:10545034

  4. First evidence for family-specific QTL for temperature-dependent sex reversal in Nile tilapia (Oreochromis niloticus).

    PubMed

    Lühmann, L M; Knorr, C; Hörstgen-Schwark, G; Wessels, S

    2012-01-01

    This study for the first time screens microsatellite markers for associations with the temperature-dependent sex of Oreochromis niloticus. Previous studies revealed markers on linkage groups (LG) 1, 3, and 23 to be linked to the phenotypic sex of Oreochromis spp. at normal rearing temperatures. Moreover, candidate genes for sex determination and differentiation have been mapped to these linkage groups. Here, 6 families of a temperature-treated genetically all-female (XX) F(1)-population were genotyped for 21 microsatellites on the 3 LGs. No population-wide QTL (quantitative trait loci) or marker trait associations could be detected. However, family-specific QTL were found on LG 1 flanked by UNH995 and UNH104, on LG 3 at the position of GM213, and on LG 23 next to GM283. Moreover, family-specific single marker associations for UNH995 and UNH104 on LG 1, GM213 on LG 3, as well as for UNH898 and GM283 on LG 23 were detected. Yet, marker trait associations could not explain the temperature-dependent sex of all fish in the respective families. The molecular cue for the temperature-dependent sex in Nile tilapia might partially coincide with allelic variants at major and minor genetic sex determining factors. Moreover, additional QTL contributing to variable liabilities towards temperature might persist on other LGs. PMID:22797471

  5. Transcriptome Profiling and Molecular Pathway Analysis of Genes in Association with Salinity Adaptation in Nile Tilapia Oreochromis niloticus.

    PubMed

    Xu, Zhixin; Gan, Lei; Li, Tongyu; Xu, Chang; Chen, Ke; Wang, Xiaodan; Qin, Jian G; Chen, Liqiao; Li, Erchao

    2015-01-01

    Nile tilapia Oreochromis niloticus is a freshwater fish but can tolerate a wide range of salinities. The mechanism of salinity adaptation at the molecular level was studied using RNA-Seq to explore the molecular pathways in fish exposed to 0, 8, or 16 (practical salinity unit, psu). Based on the change of gene expressions, the differential genes unions from freshwater to saline water were classified into three categories. In the constant change category (1), steroid biosynthesis, steroid hormone biosynthesis, fat digestion and absorption, complement and coagulation cascades were significantly affected by salinity indicating the pivotal roles of sterol-related pathways in response to salinity stress. In the change-then-stable category (2), ribosomes, oxidative phosphorylation, signaling pathways for peroxisome proliferator activated receptors, and fat digestion and absorption changed significantly with increasing salinity, showing sensitivity to salinity variation in the environment and a responding threshold to salinity change. In the stable-then-change category (3), protein export, protein processing in endoplasmic reticulum, tight junction, thyroid hormone synthesis, antigen processing and presentation, glycolysis/gluconeogenesis and glycosaminoglycan biosynthesis-keratan sulfate were the significantly changed pathways, suggesting that these pathways were less sensitive to salinity variation. This study reveals fundamental mechanism of the molecular response to salinity adaptation in O. niloticus, and provides a general guidance to understand saline acclimation in O. niloticus.

  6. Gill monogeneans of Nile tilapia (Oreochromis niloticus) and red hybrid tilapia (Oreochromis spp.) from the wild and fish farms in Perak, Malaysia: infection dynamics and spatial distribution.

    PubMed

    Lim, Shen-Yin; Ooi, Ai-Lin; Wong, Wey-Lim

    2016-01-01

    Tilapia is one of the commercially important fish in Malaysia as well as in other parts of the world. An understanding of monogenean infection dynamics in tilapia fish may assist us in searching for some intervention measures in reducing the loss of fish caused by parasitic diseases. The present study aimed (1) to compare infection level of monogeneans between the wild and cultured Oreochromis niloticus, and between the cultured O. niloticus and cultured red hybrid tilapia, and (2) to examine the spatial distribution of monogenean species over the gills of the different host species. From a total of 75 fish specimens, six species of monogeneans from two genera: Cichlidogyrus (C. halli, C. mbirizei, C. sclerosus, C. thurstonae, C. tilapiae) and Scutogyrus (S. longicornis) were identified. Data showed that the infection level of cultured O. niloticus was higher than that of the wild O. niloticus, however, the former was lower than that of the cultured red hybrid tilapia. Higher species richness of monogeneans was observed in the cultured red hybrid tilapia as compared to the others. Results for spatial distribution showed that the monogeneans have no preference on the left or right sides of the gills. However, C. halli, C. mbirizei, and C. tilapiae showed preferences on specific gill arches in the cultured O. niloticus and red hybrid tilapia. In general, the gill arch IV harboured the least number of monogeneans. The susceptibility of monogenean infection between the different types of tilapia is discussed. PMID:27652182

  7. Gill monogeneans of Nile tilapia (Oreochromis niloticus) and red hybrid tilapia (Oreochromis spp.) from the wild and fish farms in Perak, Malaysia: infection dynamics and spatial distribution.

    PubMed

    Lim, Shen-Yin; Ooi, Ai-Lin; Wong, Wey-Lim

    2016-01-01

    Tilapia is one of the commercially important fish in Malaysia as well as in other parts of the world. An understanding of monogenean infection dynamics in tilapia fish may assist us in searching for some intervention measures in reducing the loss of fish caused by parasitic diseases. The present study aimed (1) to compare infection level of monogeneans between the wild and cultured Oreochromis niloticus, and between the cultured O. niloticus and cultured red hybrid tilapia, and (2) to examine the spatial distribution of monogenean species over the gills of the different host species. From a total of 75 fish specimens, six species of monogeneans from two genera: Cichlidogyrus (C. halli, C. mbirizei, C. sclerosus, C. thurstonae, C. tilapiae) and Scutogyrus (S. longicornis) were identified. Data showed that the infection level of cultured O. niloticus was higher than that of the wild O. niloticus, however, the former was lower than that of the cultured red hybrid tilapia. Higher species richness of monogeneans was observed in the cultured red hybrid tilapia as compared to the others. Results for spatial distribution showed that the monogeneans have no preference on the left or right sides of the gills. However, C. halli, C. mbirizei, and C. tilapiae showed preferences on specific gill arches in the cultured O. niloticus and red hybrid tilapia. In general, the gill arch IV harboured the least number of monogeneans. The susceptibility of monogenean infection between the different types of tilapia is discussed.

  8. Pre-Slaughter Stress Affects Ryanodine Receptor Protein Gene Expression and the Water-Holding Capacity in Fillets of the Nile Tilapia

    PubMed Central

    Lara, Jorge A. F.; Gasparino, Eliane; Del Vesco, Ana P.; Goes, Marcio D.; Alexandre Filho, Luiz

    2015-01-01

    Current study evaluated the effect of pre-slaughter stress on serum cortisol levels, pH, colorimetry, water-holding capacity (WHC) and gene expression of ryanodine receptors (RyR1 and RyR3) in the Nile tilapia. A 3x4 factorial scheme experiment was conducted comprising three densities (100, 200, 400 kg/m³) with four transportation times (60, 120, 180, and 240 minutes).Transportation times alone reduced cortisol levels up to 180 minutes, followed by increased WHC and mRNA expression, RyR1 and RyR3 (200 kg/m³ density). No effect of density x transportation time interacted on the evaluated parameters. Results provided the first evidence that pre-slaughter stress affected ryanodine gene expression receptors and, consequently, the water-holding capacity in tilapia fillets. PMID:26053858

  9. Effects of dietary Astragalus polysaccharides (APS) on growth performance, immunological parameters, digestive enzymes, and intestinal morphology of Nile tilapia (Oreochromis niloticus).

    PubMed

    Zahran, Eman; Risha, Engy; Abdelhamid, Fatma; Mahgoub, Hebata Allah; Ibrahim, Tarek

    2014-05-01

    This work investigated the potential immunomodulatory and growth-promoting effects of Astragalus polysaccharides (APS) in Nile tilapia (Oreochromis niloticus). The dietary supplementation with APS (1500 mg/kg of diet) caused a significant increase in growth parameters (initial and final weight, weight gain (WG), specific growth rate (SGR), feed conversion ratio (FCR) and feed intake (FI), when compared to non-supplemented control basal diet. In addition, APS upregulated the phagocytic activity, the respiratory burst activity, plasma lysozyme, the bactericidal activity, superoxide dismutase (SOD), glutathione peroxidase (GPx), and amylase activity. However, it had no effect on serum nitric oxide (NO) or Malondialdehyde (MDA) levels. While APS had no effect of intestinal histology, a slight increase in the villi length was recorded. Collectively, our results indicate that dietary APS supplementation could improve the growth performance and the immune parameters of cultured tilapia fish.

  10. Effects of malachite green on the mRNA expression of detoxification-related genes in Nile tilapia (Oreochromis niloticus) and other major Chinese freshwater fishes.

    PubMed

    Li, Guangyu; Shen, Dan; Liang, Xu-Fang; He, Yan; He, Shan

    2013-03-01

    The use of malachite green (MG) in fish farming is prohibited in China due to its potentially toxicological and carcinogenic nature, but it is still illegally used in some places. The aim of this study was to investigate the time and concentration-dependent responses of xenobiotic metabolizing and detoxification-related genes in diverse fishes exposed to MG both in vivo and in vitro. Experimental fish were administered to two exposure groups of malachite green (MG) (0.10 and 0.50 mg L⁻¹) for 8 h. The hepatocytes isolated from Nile tilapia were incubated with MG (0.5, 1.0, and 2.0 mg L⁻¹) for 8 and 24 h, respectively. In vivo, exposure to 0.10 and 0.50 mg L⁻¹ MG for 8 h caused significant changes of the detoxification-related genes on the mRNA expression levels. Low-concentration (0.10 mg L⁻¹) level of MG induced significant increase on the mRNA expression level of GSTR gene in Nile tilapia and other fishes. The mRNA expression of grass carp UCP2 was significantly induced when exposed to 0.5 mg L⁻¹ MG. However, the mRNA expression levels of GSTA, CYP1A, and GPX were inhibited significantly by 0.5 mg L⁻¹ MG in Nile tilapia, grass carp, and Taiwan snakehead. In vitro, the significant increase of mRNA expression of these genes was detected after exposure to 0.5 mg L⁻¹ MG (UCP2), and 1.0 mg L⁻¹ MG (CYP1A1, GSTA, GSTR, and UCP2). The induction of hepatic CYP1A1, GSTA, GSTR, and UCP2 in response to MG suggested a potential role of fish CYP1A1, GSTA, GSTR, and UCP2 in MG metabolism.

  11. Neuropeptide B in Nile tilapia Oreochromis niloticus: molecular cloning and its effects on the regulation of food intake and mRNA expression of growth hormone and prolactin.

    PubMed

    Yang, Lu; Sun, Caiyun; Li, Wensheng

    2014-05-01

    Neuropeptide B (NPB) regulates food intake, energy homeostasis and hormone secretion in mammals via two G-protein coupled receptors, termed as GPR 7 and GPR 8. However, there is no study that reports the function of NPB in teleosts. In this study, the full-length cDNA of prepro-NPB with the size of 663bp was cloned from the hypothalamus of Nile tilapia. The CDS of the prepro-NPB is 387bp which encodes a precursor protein with the size of 128a.a. This precursor contains a mature peptide with the size of 29a.a, and it was named as NPB29. Tissue distribution study showed that this gene was mainly expressed in different parts of brain, especially in the diencephalon as well as hypothalamus, and the spinal cord in Nile tilapia. Fasting significantly stimulated the mRNA expression of NPB in the brain area without hypothalamus, and refeeding after fasting for 3 and 14days also showed similar effects on NPB expression. While, only short-term fasting (3days) and refeeding after fasting for 7 and 14days induced mRNA expression of NPB in the hypothalamus. Intraperitoneal (i.p.) injection of NPB remarkably elevated the mRNA expression of hypothalamic neuropeptide Y (NPY), cholecystokinin 1 (CCK1) and pituitary prolactin (PRL), whereas significantly inhibited growth hormone (GH) expression in pituitary. These observations in the present study suggested that NPB may participate in the regulation of feeding and gene expression of pituitary GH and PRL in Nile tilapia.

  12. Effect of repeated application of fenthion as a mosquito larvicide on Nile tilapia (Oreochromis niloticus) inhabiting selected water canals in Sri Lanka.

    PubMed

    Jayasundara, Viranga K; Pathiratne, Asoka

    2008-04-01

    Health status of feral Nile tilapia following repeated applications of fenthion as a mosquito larvicide to selected water canals in Sri Lanka was assessed. With three spray applications of fenthion to the study sites at weekly intervals at the concentration recommended for mosquito control, condition factor and brain acetylcholinesterase activity of the fish were depressed in a time dependent manner. Prominent histopathological alterations displayed were gill hyperplasia and telangiectasis and vacoulation of hepatocytes. Observed ill health effects of fenthion on the fish demonstrate probable ecological risk to the fish populations inhabiting the water canals which receive repeated inputs of fenthion.

  13. Innate immune defenses exhibit circadian rhythmicity and differential temporal sensitivity to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus).

    PubMed

    Lazado, Carlo C; Skov, Peter Vilhelm; Pedersen, Per Bovbjerg

    2016-08-01

    The present study investigated the daily dynamics of humoral immune defenses and the temporal influence in the sensitivity of these responses to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus). The first experiment subjected the fish to two photoperiod conditions, 12L:12D (LD) and 0L:24D (DD), for 20 days to characterize the rhythms of humoral immunity. Serum alkaline phosphatase (ALP), lysozyme (LYZ), peroxidase (PER) and protease (PRO) exhibited significant rhythmicity under LD but not in DD. No significant rhythms were observed in esterase (ESA) and anti-protease (ANTI) in both photoperiod conditions. Fish reared under LD were subsequently subjected to DD while the group previously under DD was exposed to LD, and this carried on for 3 days before another set of samples was collected. Results revealed that the rhythms of LYZ, PER and PRO but not ALP persisted when photoperiod was changed from LD to DD. Nonetheless, immune parameters remained arrhythmic in the group subjected from DD to LD. Cluster analysis of the humoral immune responses under various light conditions revealed that each photic environment had distinct daily immunological profile. In the second experiment, fish were injected with bacterial endotoxin lipopolysaccharide (LPS) either at ZT3 (day) or at ZT15 (night) to evaluate the temporal sensitivity of humoral immunity to a pathogen-associated molecular pattern. The results demonstrated that responses to LPS were gated by the time of day. LPS significantly modulated serum ALP and ANTI activities but only when the endotoxin was administered at ZT3. Serum LYZ and PER were stimulated at both injection times but with differing response profiles. Modulated LYZ activity was persistent when injected at ZT3 but transient when LPS was applied at ZT15. The magnitude of LPS-induced PER activity was higher when the endotoxin was delivered at ZT3 versus ZT15. It was further shown that plasma cortisol was significantly elevated but only when LPS

  14. Innate immune defenses exhibit circadian rhythmicity and differential temporal sensitivity to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus).

    PubMed

    Lazado, Carlo C; Skov, Peter Vilhelm; Pedersen, Per Bovbjerg

    2016-08-01

    The present study investigated the daily dynamics of humoral immune defenses and the temporal influence in the sensitivity of these responses to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus). The first experiment subjected the fish to two photoperiod conditions, 12L:12D (LD) and 0L:24D (DD), for 20 days to characterize the rhythms of humoral immunity. Serum alkaline phosphatase (ALP), lysozyme (LYZ), peroxidase (PER) and protease (PRO) exhibited significant rhythmicity under LD but not in DD. No significant rhythms were observed in esterase (ESA) and anti-protease (ANTI) in both photoperiod conditions. Fish reared under LD were subsequently subjected to DD while the group previously under DD was exposed to LD, and this carried on for 3 days before another set of samples was collected. Results revealed that the rhythms of LYZ, PER and PRO but not ALP persisted when photoperiod was changed from LD to DD. Nonetheless, immune parameters remained arrhythmic in the group subjected from DD to LD. Cluster analysis of the humoral immune responses under various light conditions revealed that each photic environment had distinct daily immunological profile. In the second experiment, fish were injected with bacterial endotoxin lipopolysaccharide (LPS) either at ZT3 (day) or at ZT15 (night) to evaluate the temporal sensitivity of humoral immunity to a pathogen-associated molecular pattern. The results demonstrated that responses to LPS were gated by the time of day. LPS significantly modulated serum ALP and ANTI activities but only when the endotoxin was administered at ZT3. Serum LYZ and PER were stimulated at both injection times but with differing response profiles. Modulated LYZ activity was persistent when injected at ZT3 but transient when LPS was applied at ZT15. The magnitude of LPS-induced PER activity was higher when the endotoxin was delivered at ZT3 versus ZT15. It was further shown that plasma cortisol was significantly elevated but only when LPS

  15. Salmon testes meal as a functional feed additive in fish meal and plant-protein based diets for rainbow trout(Oncorhynchus mykiss walbaum)and nile tilapia(Oreochromis niloticus L.) fry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report that salmon testes meal (TM) produced from Alaskan seafood processing byproducts is a potential protein source for aquafeed formulations. A series of feeding trials was conducted using three different fish species; including Nile tilapia, rainbow trout, and white sturgeon at their early gr...

  16. Antioxidant and sensory properties of protein hydrolysate derived from Nile tilapia (Oreochromis niloticus) by one- and two-step hydrolysis.

    PubMed

    Yarnpakdee, Suthasinee; Benjakul, Soottawat; Kristinsson, Hordur G; Kishimura, Hideki

    2015-06-01

    Antioxidant and sensory properties of Nile tilapia protein hydrolysates prepared by one- and two-step hydrolysis using commercial proteases were investigated. Hydrolysates prepared using single protease including Alcalase (HA), Flavourzyme (HF), Protamex (HPr) and papain (HPa) had increases in antioxidant activities as the degree of hydrolysis (DH) increased up to 40 % (P < 0.05). Amongst all hydrolysates, HA having 40 % DH showed the highest antioxidant activities. When HA was further hydrolysed by papain, the resulting hydrolysate (HAPa) exhibited the highest antioxidant activities for all assays tested (P < 0.05). ABTS radical scavenging activity and metal chelating of HAPa generally remained constant in a wide pH range (1-11) and during heating at 30-100 °C. Both activities increased in the simulated gastrointestinal tract model system, especially in intestine condition. HAPa (100-1,000 ppm) could retard lipid oxidation in β-carotene-linoleate and lecithin-liposome model systems in a dose dependent manner. Peptides in both HA and HAPa with molecular weight of 513 Da and 1,484 Da possessed the strongest ABTS radical scavenging activity and metal chelating activity, respectively. The amino acid profile of both HA and HAPa contained a high amount of hydrophobic amino acids (38.26-38.85 %) and had glutamic acid/glutamine, lysine and aspartic acid/asparagine as the dominant amino acids. However, HAPa showed a higher acceptability than did HA, owing to the lower bitterness. Therefore, the use of Alcalase in combination with papain for hydrolysis of protein isolate rendered the hydrolysate with antioxidant properties and reduced bitterness, which could serve as the functional supplement. PMID:26028714

  17. Characterization of the POU5F1 Homologue in Nile Tilapia: From Expression Pattern to Biological Activity.

    PubMed

    Xiaohuan, Huang; Yang, Zhao; Linyan, Liu; Zhenhua, Fan; Linyan, Zhou; Zhijian, Wang; Ling, Wei; Deshou, Wang; Jing, Wei

    2016-09-15

    POU5F1 (OCT4) is a crucial transcription factor for induction and maintenance of cellular pluripotency, as well as survival of germ cells in mammals. However, the homologues of POU5F1 in teleost fish, including zebrafish and medaka, now named Pou5f3, exhibit considerable differences in expression pattern and pluripotency-maintaining activity. To what extent the POU5F1 homologues are conserved in vertebrates has been unclear. In this study, we report that the POU5F1 homologue from the Nile tilapia (Oreochromis niloticus), OnPou5f3, displays an expression pattern and biological activity somewhat different from those in zebrafish or medaka. The expression of Onpou5f3 at both mRNA and protein levels was abundant in early development embryos until blastula stages, barely detectable as proceeding, and then displayed a transiently strong expression domain in the brain region during neurula stages similar to zebrafish but not medaka. Afterward, OnPou5f3 appeared as germline-restricted (including primordial germ cells and female and male gonad germ cells) expression just like medaka. Notably, OnPou5f3 depletion through morpholino oligos caused blastula blockage or lethality and failure of survival and proliferation of blastula cell-derived cells. These findings indicate that equivalent POU5F1-like expression and activity of Pou5f3 might be conserved accompanying with species-specific expression pattern during evolution. Our study provides insight into the evolutionary conservation of the POU5F1 homologues across vertebrates. PMID:27473876

  18. Sublethal concentrations of di-n-butyl phthalate promote biochemical changes and DNA damage in juvenile Nile tilapia (Oreochromis niloticus).

    PubMed

    Khalil, Samah R; Abd Elhakim, Yasser; El-Murr, Abd Elhakeem

    2016-02-01

    Increase in consumption of consumer items such as plasticizers have resulted in a sharp rise in the presence of xenobiotics like phthalic acid esters (PEs) in freshwater and marine environments due to contaminated runoff and improper release of effluents. The sublethal toxicity of Di-n-butyl phthalate (DBP) was investigated in juvenile Nile tilapia, Oreochromis niloticus, in an attempt to determine the biological effect of exposure to 1/2 and 1/3 median lethal concentration (96-h LC50) which, in our study was experimentally determined to be 11.8 mg/l. Following four days of exposure, indices of the oxidative potential [Malondialdehyde content (MDA)], antioxidant parameters [superoxide dismutase activity (SOD) and reduced glutathione level (GSH)] and DNA damage were evaluated by single-cell gel electrophoresis (Comet assay). Hepato-renal markers [alanine aminotransferase activity (ALT), creatinine and urea level] and cortisol levels were also quantified in serum. Additionally, histopathological investigations of liver, kidney and gill tissues were conducted. Comparative results between the 1/2 96-h LC50 group and the 1/3 96-h LC50 group clearly showed that there was a significant elevation in MDA levels and a marked increase in DNA damage in addition to inhibition of antioxidant barriers as represented by attenuation of SOD activity and GSH level in the group that was exposed to higher concentration of DBP (1/2 96-h LC50). The hepatorenal markers and cortisol levels were also observed to be elevated. Histopathological examination of the liver, kidney and gills showed pathological alterations that could be correlated with changes in the biochemical profile of the exposed fish. Additionally, anomalous clinical signs were noted. Based on these findings, we conclude from our study that exposure of juvenile O. niloticus to DBP has the potential to induce biochemical as well as tissue morphological alterations associated with oxidative injury and DNA damage. PMID:27348890

  19. Morphological and quantitative evaluation of the ovarian recrudescence in Nile tilapia (Oreochromis niloticus) after spawning in captivity.

    PubMed

    Melo, Rafael Magno Costa; Martins, Yuri Simões; Teixeira, Edgar de Alencar; Luz, Ronald Kennedy; Rizzo, Elizete; Bazzoli, Nilo

    2014-03-01

    The Nile tilapia is one of the most important fish species for aquaculture worldwide. Understanding their reproductive biology is essential for improving their aquaculture methods. The morphological and quantitative dynamics of ovarian recrudescence of Oreochromis niloticus was studied for 21 days postspawning. To accomplish this, breeding females were kept in controlled conditions and ovarian samples were collected weekly for histological, ultrastructural and morphometric analyses. Ovarian follicle morphology revealed an intense synthesis activity of the follicular cells, which actively contributed to formation of the zona radiata and oocyte development following spawning. Recently spawned ovaries contained follicles at all developmental stages, but they were predominantly early primary growth (∼ 42%) and full-grown follicles (∼ 20%). Remnants of spawning, postovulatory follicle complexes represented approximately 5% of the former ovarian follicles immediately after spawning, and less than 1% after 7 days. Atretic follicles accounted for approximately 2% of the follicles studied during the period. The stock of primary growth follicles was stable during ovarian recrudescence, indicating their availability for continuous recruitment. Only the frequency of full-grown follicles significantly increased in the ovaries during recrudescence, representing approximately 35% of the follicles 21 days postspawning. The diameters of all follicles were significantly different between the periods analyzed. The ovaries' morphological characteristics, the maintenance of young follicles stocks and the gradual and significant increase in the proportion and diameter of full-grown follicles showed a rapid ovarian recovery and follicular growth of O. niloticus, in 21 days at 29.5°C, necessary for the next spawning.

  20. Degradation of 17α-methyltestosterone by Rhodococcus sp. and Nocardioides sp. isolated from a masculinizing pond of Nile tilapia fry.

    PubMed

    Homklin, Supreeda; Ong, Say Kee; Limpiyakorn, Tawan

    2012-06-30

    17α-Methyltestosterone (MT), a synthetic anabolic androgenic steroid, is widely used in aquafarming for the production of an all male fish population such as Nile tilapia. This study isolated, identified and characterized MT-degrading bacteria in the sediment and water from a masculinizing pond of Nile tilapia fry. Based on the phylogeny, physiological properties and cell morphology, the three isolated MT-degrading bacteria were related closely to Rhodococcus equi, Nocardioides aromaticivorans, and Nocardioides nitrophenolicus. Growth of the three isolated strains was found to be inhibited for MT concentrations in the range of 1.0-10mg/L. The inhibition of cell growth was found to be modeled using the Haldane's substrate inhibition model. The kinetic constants ranged from 0.13 to 0.19h(-1) for μ(max), 0.7-24.8mg/L for K(s) and 19.6-76.2mg/L for K(i). Androgenic activity using β-galactosidase assay showed that all strains degraded MT to the products with no androgenic potency.

  1. P-glycoprotein and CYP1A protein expression patterns in Nile tilapia (Oreochromis niloticus) tissues after waterborne exposure to benzo(a)pyrene (BaP).

    PubMed

    Costa, Joana; Reis-Henriques, Maria Armanda; Wilson, Jonathan M; Ferreira, Marta

    2013-09-01

    The protein levels and tissue distribution patterns of P-glycoprotein (Pgp) and cytochrome P450 (CYP1A) were investigated in Nile tilapia (Oreochromis niloticus) after waterborne exposure to different benzo(a)pyrene (BaP) concentrations, using immunochemical approaches. The Pgp mammalian monoclonal antibody (mAb) C219 cross reacted with a ∼170kDa protein, almost exclusively localized to the bile canaliculi, while probing with the Pgp mammalian mAb C494, resulted in a positive reaction in liver, gills and intestine of Nile tilapia and covered a wider set of cell types. Levels of Pgp expression were not altered after in vivo exposure to BaP. CYP1A, detected with the mAb C10-7, reacted positively in liver, gills and intestine and followed a BaP dose-dependent fold induction. Taken together, these results indicate that CYP1A is involved in BaP metabolism in liver, gills and intestine, however, further studies are needed to elucidate the possible interaction of the efflux protein Pgp with BaP and/or its metabolites.

  2. A Comparison of the Beneficial Effects of Live and Heat-Inactivated Baker's Yeast on Nile Tilapia: Suggestions on the Role and Function of the Secretory Metabolites Released from the Yeast.

    PubMed

    Ran, Chao; Huang, Lu; Liu, Zhi; Xu, Li; Yang, Yalin; Tacon, Philippe; Auclair, Eric; Zhou, Zhigang

    2015-01-01

    Yeast is frequently used as a probiotic in aquaculture with the potential to substitute for antibiotics. In this study, the involvement and extent to which the viability of yeast cells and thus the secretory metabolites released from the yeast contribute to effects of baker's yeast was investigated in Nile tilapia. No yeast, live yeast or heat-inactivated baker's yeast were added to basal diets high in fishmeal and low in soybean (diet A) or low in fishmeal and high in soybean (diet B), which were fed to fish for 8 weeks. Growth, feed utilization, gut microvilli morphology, and expressions of hsp70 and inflammation-related cytokines in the intestine and head kidney were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Gut alkaline phosphatase (AKP) activity was measured after challenging the fish with Aeromonas hydrophila. Results showed that live yeast significantly improved FBW and WG (P < 0.05), and tended to improve FCR (P = 0.06) of fish compared to the control (no yeast). No significant differences were observed between inactivated yeast and control. Live yeast improved gut microvilli length (P < 0.001) and density (P < 0.05) while inactivated yeast did not. The hsp70 expression level in both the intestine and head kidney of fish was significantly reduced by live yeast (P < 0.05) but not inactivated yeast. Live yeast but not inactivated yeast reduced intestinal expression of tnfα (P < 0.05), tgfβ (P < 0.05 under diet A) and il1β (P = 0.08). Intestinal Lactococcus spp. numbers were enriched by both live and inactivated yeast. Lastly, both live and inactivated yeast reduced the gut AKP activity compared to the control (P < 0.001), indicating protection of the host against infection by A. hydrophila. In conclusion, secretory metabolites did not play major roles in the growth promotion and disease protection effects of yeast. Nevertheless, secretory metabolites were the major contributing factor towards improved gut

  3. A Comparison of the Beneficial Effects of Live and Heat-Inactivated Baker’s Yeast on Nile Tilapia: Suggestions on the Role and Function of the Secretory Metabolites Released from the Yeast

    PubMed Central

    Liu, Zhi; Xu, Li; Yang, Yalin; Tacon, Philippe; Auclair, Eric; Zhou, Zhigang

    2015-01-01

    Yeast is frequently used as a probiotic in aquaculture with the potential to substitute for antibiotics. In this study, the involvement and extent to which the viability of yeast cells and thus the secretory metabolites released from the yeast contribute to effects of baker’s yeast was investigated in Nile tilapia. No yeast, live yeast or heat-inactivated baker’s yeast were added to basal diets high in fishmeal and low in soybean (diet A) or low in fishmeal and high in soybean (diet B), which were fed to fish for 8 weeks. Growth, feed utilization, gut microvilli morphology, and expressions of hsp70 and inflammation-related cytokines in the intestine and head kidney were assessed. Intestinal microbiota was investigated using 16S rRNA gene pyrosequencing. Gut alkaline phosphatase (AKP) activity was measured after challenging the fish with Aeromonas hydrophila. Results showed that live yeast significantly improved FBW and WG (P < 0.05), and tended to improve FCR (P = 0.06) of fish compared to the control (no yeast). No significant differences were observed between inactivated yeast and control. Live yeast improved gut microvilli length (P < 0.001) and density (P < 0.05) while inactivated yeast did not. The hsp70 expression level in both the intestine and head kidney of fish was significantly reduced by live yeast (P < 0.05) but not inactivated yeast. Live yeast but not inactivated yeast reduced intestinal expression of tnfα (P < 0.05), tgfβ (P < 0.05 under diet A) and il1β (P = 0.08). Intestinal Lactococcus spp. numbers were enriched by both live and inactivated yeast. Lastly, both live and inactivated yeast reduced the gut AKP activity compared to the control (P < 0.001), indicating protection of the host against infection by A. hydrophila. In conclusion, secretory metabolites did not play major roles in the growth promotion and disease protection effects of yeast. Nevertheless, secretory metabolites were the major contributing factor towards improved gut

  4. Oxidative stress in Nile tilapia (Oreochromis niloticus) and armored catfish (Pterygoplichthys anisitsi) exposed to diesel oil.

    PubMed

    Nogueira, Lílian; Rodrigues, Aline Cristina Ferreira; Trídico, Camila Pereira; Fossa, Carlos Eduardo; de Almeida, Eduardo Alves

    2011-09-01

    Considering that diesel oil is one of the most common aquatic contaminants, we compare the oxidative stress between two species of fish with different habitats (Pterygoplichthys anisitsi, benthic and Oreochromis niloticus, nektonic) exposed to diesel oil. Malondialdehyde concentrations (MDA) and the activities of ethoxyresorufin-O-deethylase (EROD), glutathione S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase were all analyzed in the fishes' livers and gills after 2 and 7 days of exposure to different concentrations of diesel (0.1 and 0.5 mL/L). In the tilapia, MDA levels and the activities of EROD and GST activity in the liver, as well as MDA levels and the activities of GST and SOD in the gill had statistically significant differences between the treatments and between the times of exposure. For the catfish, the same occurred in the case of MDA, EROD, and SOD in the liver and in CAT and SOD in the gills. There were significant differences in the enzyme activity and lipid peroxidation between the species. Although the activity of most enzymes seemed to be more expressive and responsive to diesel in O. niloticus, diesel oil also caused significant effects on oxidative stress parameters in P. anisitsi, even though this species is benthic and thus has less access to insoluble fractions of diesel oil. Therefore, both species can be used as sentinel organisms in environmental biomonitoring of diesel contamination.

  5. Characterization of four heat-shock protein genes from Nile tilapia (Oreochromis niloticus) and demonstration of the inducible transcriptional activity of Hsp70 promoter.

    PubMed

    Zhang, Lili; Sun, Chengfei; Ye, Xing; Zou, Shuming; Lu, Maixin; Liu, Zhigang; Tian, Yuanyuan

    2014-02-01

    Heat-shock proteins (Hsps), known as stress proteins and extrinsic chaperones, play important roles in the folding, translocation, and refolding/degradation of proteins. In this study, we identified four Hsps in Nile tilapia (Oreochromis niloticus), which display conserved Hsp characteristics in their predicted amino acid sequences. Further analyses on the structures, homology, and phylogenetics revealed that the four Hsps belong to Hsp70 family. One of them does not contain introns and is named Hsp70, while all the other three contain introns and are named Hsc70-1, Hsc70-2, and Hsc70-3. Expressions of the four Hsp proteins were observed in all examined tissues. Six hours after infection of Streptococcus agalactiae in Nile tilapia, the expression of Hsp70 was significantly increased in the liver, head kidney, spleen and gill, while Hsc70s' expression was unchanged in all examined tissues except the head kidney that showed significantly reduced expression of both Hsc70-2 and Hsc70-3. These results suggest that Hsp70 may participate in the defense against S. agalactiae infection. We then isolated the promoter of Hsp70 gene and inserted it into the donor plasmid of Tgf2 transposon system containing green fluorescent protein (GFP) gene. The plasmid was microinjected into zebrafish embryos, where the expression of GFP was induced by heat shock, S. agalactiae immersion challenge, indicating that the isolated Hsp70 promoter has transcriptional activity and is inducible by both heat shock and bacterial challenge. This promoter may facilitate the future construction of disease-resistant transgenic fish. The work also contributes to the further study of immune response of tilapia after bacterial infection.

  6. Controlled challenge experiment demonstrates substantial additive genetic variation in resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus iniae is an etiologic agent of streptococcal disease in tilapia and is one of several Streptococcus spp. that negatively impact worldwide tilapia production. Methods for the prevention and control of S. iniae include vaccines, management strategies, and antibiotics. A complimentary pre...

  7. Influence of water temperature and waterborne cadmium toxicity on growth performance and metallothionein-cadmium distribution in different organs of Nile tilapia, Oreochromis niloticus (L.).

    PubMed

    Abdel-Tawwab, Mohsen; Wafeek, Mohammed

    2014-10-01

    Cadmium (Cd) is believed to be one of the most abundant and ubiquitously distributed toxins in the aquatic system. This metal is released to the aquatic environment from both anthropogenic sources, such as industrial, agricultural and urban effluents as well as natural sources, such as rocks and soils. Otherwise, the temperature increase of water bodies, which has been observed due to global climatic changes, has been shown to increase Cd toxicity for several aquatic animal species including fish. In the present study, Nile tilapia, Oreochromis niloticus (L.), (26.0 ± 0.38 g) were reared at 20, 24, 28, or 32 °C and exposed to 0.0 or 0.5mg Cd/L for 8 weeks to investigate effects of water temperature, Cd toxicity and their interaction on fish performance as well as metallothionein (MT) and Cd distribution in different fish organs. It was found that fish reared in Cd-free group at 28 °C showed the optimum growth and feed intake, while Cd-exposed fish showed low growth and feed intake irrespective to water temperature. A synergetic relationship between water temperature and Cd toxicity was observed where Cd toxicity increased as water temperature increased and the worse growth was obtained in Cd-exposed fish reared at 32 °C. Additionally, the highest Cd residues in different fish organs were detected in Cd-exposed fish reared at 32 °C. Similarly, MT concentrations in different fish organs increased as water temperature increased especially in Cd-exposed fish groups. A high positive correlation between MT and Cd concentrations in fish organs was detected. The distribution of MT and Cd levels was in the order of liver>kidney>gills>muscles. The present study revealed that the optimum water temperature suitable for Nile tilapia growth is 28 °C. Additionally, Cd exposure had a deteriorate effect on the growth and health of Nile tilapia. This hazardous effect increased as water temperature increased. Further, liver and kidney were the prime sites of Cd accumulation

  8. Production and characterization of crude and refined oils obtained from the co-products of Nile tilapia and hybrid sorubim processing.

    PubMed

    Menegazzo, Mariana Lara; Petenuci, Maria Eugenia; Fonseca, Gustavo Graciano

    2014-08-15

    In this study, crude oil was extracted by heating and filtering of the residual fat obtained from the processing of mechanically separated meats of Nile tilapia (Oreochromis niloticus) and hybrid sorubim (Pseudoplatystoma corruscans×P. fasciatum) for protein concentrate obtaining. The crude oil was refined by the following steps: degumming with 85% phosphoric acid, neutralization with 20% NaOH, washing with hot water at 85 °C, drying at 90 °C, clarification with activated charcoal and filtration with diatomaceous earth and anhydrous sodium sulfate. The quality of crude and refined oils was verified by acidity, peroxide, iodine, refractive, and saponification indexes, beyond moisture, lipid and free fatty acids contents, and density. The results show that the refining reduced the acidity index of the crude oil, however, favored the oil oxidation, as demonstrated by the increase in peroxide index. In most of the cases there was no change in the identity of the fish oils.

  9. Assessment and control of an invasive aquaculture species: An update on Nile tilapia (Oreochromis niloticus) in coastal Mississippi after Hurricane Katrina

    USGS Publications Warehouse

    Schofield, Pamela J.; Slack, W. Todd; Peterson, Mark S.; Gregoire, Denise R.

    2007-01-01

    We provide information about the effects of Hurricane Katrina on populations of an invasive fish, the Nile tilapia (Oreochromis niloticus) in southern Mississippi. By resampling areas surveyed before the storm, we attempted to determine whether the species expanded its range by moving with storm-related floods. Additionally, we used rotenone to eradicate individuals of this species at a hurricane-damaged aquaculture facility on the Mississippi coast. Although our survey was limited geographically, we did not find the species to occur beyond the aquaculture facility, other than in an adjacent bayou. Our rotenone treatment of the facility appeared effective with only a single O. niloticus being collected six weeks after the treatment. To reduce the spread of O. niloticus in the southeastern U.S., it is important to continue to control feral populations, work to eliminate vectors for dispersal, and continue monitoring their distribution.

  10. Production and characterization of crude and refined oils obtained from the co-products of Nile tilapia and hybrid sorubim processing.

    PubMed

    Menegazzo, Mariana Lara; Petenuci, Maria Eugenia; Fonseca, Gustavo Graciano

    2014-08-15

    In this study, crude oil was extracted by heating and filtering of the residual fat obtained from the processing of mechanically separated meats of Nile tilapia (Oreochromis niloticus) and hybrid sorubim (Pseudoplatystoma corruscans×P. fasciatum) for protein concentrate obtaining. The crude oil was refined by the following steps: degumming with 85% phosphoric acid, neutralization with 20% NaOH, washing with hot water at 85 °C, drying at 90 °C, clarification with activated charcoal and filtration with diatomaceous earth and anhydrous sodium sulfate. The quality of crude and refined oils was verified by acidity, peroxide, iodine, refractive, and saponification indexes, beyond moisture, lipid and free fatty acids contents, and density. The results show that the refining reduced the acidity index of the crude oil, however, favored the oil oxidation, as demonstrated by the increase in peroxide index. In most of the cases there was no change in the identity of the fish oils. PMID:24679757

  11. Lead poisoning in Nile tilapia (Oreochromis niloticus): oxidant and antioxidant relationship.

    PubMed

    Tanekhy, Mahmoud

    2015-04-01

    Selenium and vitamin E are very effective antioxidant agents which play important roles in improving and development of aquaculture sector. This study was conducted to determine the protective and treatment effects of vitamin E and selenium against lead toxicity. Administration of both vitamin E and selenium ameliorated the adverse effects of lead acetate toxicity through significant increase in hemoglobin, packed cell volume, RBC count, WBC count, and lymphocytes compared to lead acetate-exposed groups especially after the 10th week. Also, it is revealed that severe decrease of total protein, calcium, phosphorous, and magnesium in lead acetate intoxicated group. On contrary, significant increase of blood parameters upon addition of vitamin E and selenium combined with/without lead. On the other hand, insignificant decreases of sAST, sALT, urea, and creatinine in group fed on vitamin E and selenium, while increase in lead acetate intoxicated group. Lead acetate caused increasing of lipid peroxidation level (malondialdehyde) and decreasing of superoxide dismutase activity and reduced glutathione level. From these results, it is concluded that exposure to lead acetate is considered as hepatotoxic environmental pollutant. Exposure to lead acetate induced significant effects on antioxidant status. Antioxidants (vitamin E and selenium) showed important roles to protect body against lipid peroxidation, which considered as the first step of cell membrane damage, in addition to the improvement of the endogenous antioxidant enzyme activities.

  12. Lead poisoning in Nile tilapia (Oreochromis niloticus): oxidant and antioxidant relationship.

    PubMed

    Tanekhy, Mahmoud

    2015-04-01

    Selenium and vitamin E are very effective antioxidant agents which play important roles in improving and development of aquaculture sector. This study was conducted to determine the protective and treatment effects of vitamin E and selenium against lead toxicity. Administration of both vitamin E and selenium ameliorated the adverse effects of lead acetate toxicity through significant increase in hemoglobin, packed cell volume, RBC count, WBC count, and lymphocytes compared to lead acetate-exposed groups especially after the 10th week. Also, it is revealed that severe decrease of total protein, calcium, phosphorous, and magnesium in lead acetate intoxicated group. On contrary, significant increase of blood parameters upon addition of vitamin E and selenium combined with/without lead. On the other hand, insignificant decreases of sAST, sALT, urea, and creatinine in group fed on vitamin E and selenium, while increase in lead acetate intoxicated group. Lead acetate caused increasing of lipid peroxidation level (malondialdehyde) and decreasing of superoxide dismutase activity and reduced glutathione level. From these results, it is concluded that exposure to lead acetate is considered as hepatotoxic environmental pollutant. Exposure to lead acetate induced significant effects on antioxidant status. Antioxidants (vitamin E and selenium) showed important roles to protect body against lipid peroxidation, which considered as the first step of cell membrane damage, in addition to the improvement of the endogenous antioxidant enzyme activities. PMID:25732982

  13. Cross-sectional study of hepatic CYP1A and CYP3A enzymes in hybrid striped bass, channel catfish and Nile tilapia following oxytetracycline treatment.

    PubMed

    Topic Popovic, N; Howell, T; Babish, J G; Bowser, P R

    2012-04-01

    Terramycin for Fish® (oxytetracycline, OTC) is one of three approved drugs for therapeutic treatment of fish in the United States. Nothing is known, however, of the effects of this therapeutic on drug metabolizing enzymes in fish post-treatment. The main purpose of the study was to examine whether the fish CYP1A and CYP3A enzymes would cross-react with antibodies to known mammalian cytochrome P-450 forms (CYP1A1 and CYP3A). Observational feeding studies of OTC effects were conducted in hybrid striped bass, channel catfish and Nile tilapia. Oxytetracycline was mixed into the feed to achieve a daily dose of 82.8 mg per kg body weight at a feeding rate of 1% body weight per day. Hepatic microsomes of each fish were prepared and Western blotting of CYP1A1 and CYP3A4 and enzyme assays of CYP1A2 and CYP3A4 were performed prior to OTC treatment and on post-treatment days 1, 6, 11 and 21. Both goat anti-rat CYP1A1 and rabbit anti-human CYP3A4 showed good cross-reactivity with all three species in this study. All three species exhibited distinct perturbations in one or more of the variables examined on day 1 post-treatment. Immediately following the 10-day medication period, relative liver weight (RLW) of hybrid striped bass was increased 44% and remained elevated through post-treatment day 21. Increased CYP3A4 enzyme activity and protein abundance were noted in channel catfish and Nile tilapia, respectively. This observational approach demonstrated species differences both in control activities and in the timing and extent of hepatic responses to OTC. The unique perturbations of hepatic CYP450 enzymes in different fish species to OTC treatment observed in this study may have relevance for the use of additional antibiotics or other therapeutics used in aquaculture. PMID:21458012

  14. Ontogenic expression patterns of several nuclear receptors and cytochrome P450 aromatases in brain and gonads of the Nile tilapia Oreochromis niloticus suggests their involvement in sex differentiation.

    PubMed

    Sudhakumari, C C; Senthilkumaran, B; Kobayashi, T; Kajiura-Kobayashi, H; Wang, D S; Yoshikuni, M; Nagahama, Y

    2005-04-01

    Using semi-quantitative reverse transcriptase polymerase chain reaction we analyzed the ontogenic expression patterns of several nuclear receptors (estrogen receptors [ERalpha and beta], androgen receptors [ARalpha and beta], Ad4BP/SF-1 and Dax-1) and cytochrome P450 aromatases (brain and ovarian types) in whole brain and gonads of the Nile tilapia. ERalpha and beta transcripts were evident in both sexes with a high expression of ERalpha in females at 0 day after hatching (0 dah). ARalpha appeared early (0 dah) in males and while in females at 25 dah. Among the two types of cytochrome P450 aromatases, the expression of the brain type (bP450arom) but not the ovarian type (oP450arom) was evident from 0 to 90 dah in the whole brain of both males and females. Expression of Ad4BP/SF-1 in female brain began from 0 dah but in male brain at 5 dah. Expression of Dax-1 began at 0 dah and it was higher throughout in male brain than that of the female brain. In gonads, ERalpha and beta transcripts were evident in both sexes with slight variation. In females, both oP450arom and Ad4BP/SF-1 amplicons were evident at 15 dah. In males, although faint expressions of Ad4BP/SF-1 amplicons were evident at early duration of development, oP450arom did not appear until 90 dah. Conversely, expression of bP450arom was observed throughout in the developing testis with varied pattern while in developing ovary it was evident till 15 dah and reappeared only after 90 dah. Taken together, present results suggest that brain acts merely as a synchronizer in the sex differentiation process initiated by gonadal cues/factors in the Nile tilapia.

  15. Cross-sectional study of hepatic CYP1A and CYP3A enzymes in hybrid striped bass, channel catfish and Nile tilapia following oxytetracycline treatment.

    PubMed

    Topic Popovic, N; Howell, T; Babish, J G; Bowser, P R

    2012-04-01

    Terramycin for Fish® (oxytetracycline, OTC) is one of three approved drugs for therapeutic treatment of fish in the United States. Nothing is known, however, of the effects of this therapeutic on drug metabolizing enzymes in fish post-treatment. The main purpose of the study was to examine whether the fish CYP1A and CYP3A enzymes would cross-react with antibodies to known mammalian cytochrome P-450 forms (CYP1A1 and CYP3A). Observational feeding studies of OTC effects were conducted in hybrid striped bass, channel catfish and Nile tilapia. Oxytetracycline was mixed into the feed to achieve a daily dose of 82.8 mg per kg body weight at a feeding rate of 1% body weight per day. Hepatic microsomes of each fish were prepared and Western blotting of CYP1A1 and CYP3A4 and enzyme assays of CYP1A2 and CYP3A4 were performed prior to OTC treatment and on post-treatment days 1, 6, 11 and 21. Both goat anti-rat CYP1A1 and rabbit anti-human CYP3A4 showed good cross-reactivity with all three species in this study. All three species exhibited distinct perturbations in one or more of the variables examined on day 1 post-treatment. Immediately following the 10-day medication period, relative liver weight (RLW) of hybrid striped bass was increased 44% and remained elevated through post-treatment day 21. Increased CYP3A4 enzyme activity and protein abundance were noted in channel catfish and Nile tilapia, respectively. This observational approach demonstrated species differences both in control activities and in the timing and extent of hepatic responses to OTC. The unique perturbations of hepatic CYP450 enzymes in different fish species to OTC treatment observed in this study may have relevance for the use of additional antibiotics or other therapeutics used in aquaculture.

  16. Construction of a Streptococcus iniae sortase A mutant and evaluation of its potential as an attenuated modified live vaccine in Nile tilapia (Oreochromis niloticus).

    PubMed

    Wang, J; Zou, L L; Li, A X

    2014-10-01

    Streptococcus iniae is a major Gram-positive aquatic pathogen, which causes invasive diseases in cultured fish worldwide. The identification of potential virulence determinants of streptococcal infections will help to understand and control this disease, but only a few have been confirmed in S. iniae. Sortase A (srtA) is the key enzyme that anchors pre-mature cell wall-attached proteins to peptidoglycan and it can affect the correct positioning of surface proteins, as well as the course of Gram-positive bacterial infection, thereby making it a potential target in the study of virulence factors and disease control. In this study, the 759 bp srtA gene was cloned from pathogenic S. iniae TBY-1 strain and the mutant strain TBY-1ΔsrtA was constructed via allelic exchange mutagenesis. We found that srtA shares high similarities with sortase A from other Streptococcus spp. Direct survival rate assay and challenge experiments were performed, which showed that the mutant strain TBY-1ΔsrtA had a lower survival capacity in healthy tilapia blood and it was less virulent than the wild type strain in tilapia, thereby indicating that the deletion of sortase A affects the virulence and infectious capacity of S. iniae. The mutant strain TBY-1ΔsrtA was used as a live vaccine, which was administered via intraperitoneal injection, and it provided the relative percent survival value of 95.5% in Nile tilapia, thereby demonstrating its high potential as an effective attenuated live vaccine candidate.

  17. R-spondin1 signaling pathway is required for both the ovarian and testicular development in a teleosts, Nile tilapia (Oreochromis niloticus).

    PubMed

    Wu, Limin; Yang, Peng; Luo, Feng; Wang, Deshou; Zhou, Linyan

    2016-05-01

    The furin-domain-containing peptide R-spondin 1 (RSPO1) has recently emerged as an important regulator of ovarian development, upregulating the WNT/β-catenin pathway to oppose testis formation in mammals. However, little information has been reported on the Rspo1 signaling pathway in teleosts. In this study, Rspo1 was isolated from the gonads of the Nile tilapia, Oreochromis niloticus. An in situ hybridization analysis demonstrated that Rspo1 is expressed in the germ cells of the ovary and the testis. An ontogenic analysis demonstrated that Rspo1 expression is upregulated just before meiotic initiation in both the ovary and testis during the early developmental stages of the tilapia. The expression pattern is sexually dimorphic from 20days after hatching, with higher expression in the ovary. The reduction of Rspo1 expression by transcription activator-like (TAL) effector nuclease (TALEN) caused retarded ovarian development, the ectopic expression of male-dominant genes, and increased serum 11-ketotestosterone. Intriguingly, a deficiency of Rspo1 in XY fish caused a delay in spermatogenesis, the inhibition of igf3 and amh expression and a reduction in serum 11-ketotestosterone. Furthermore, incubation with FH535, an inhibitor of the Rspo1/Wnt pathway, decreased β-catenin, while increased cyp11c1 and dmrt1 expression in the in vitro cultured ovaries; decreased cyp11c1, amh and igf3 expression in the in vitro cultured testes. Taken together, our data suggest that the Rspo1 signaling pathway might be involved in both ovarian and testicular development in the tilapia. PMID:27044511

  18. Construction of a Streptococcus iniae sortase A mutant and evaluation of its potential as an attenuated modified live vaccine in Nile tilapia (Oreochromis niloticus).

    PubMed

    Wang, J; Zou, L L; Li, A X

    2014-10-01

    Streptococcus iniae is a major Gram-positive aquatic pathogen, which causes invasive diseases in cultured fish worldwide. The identification of potential virulence determinants of streptococcal infections will help to understand and control this disease, but only a few have been confirmed in S. iniae. Sortase A (srtA) is the key enzyme that anchors pre-mature cell wall-attached proteins to peptidoglycan and it can affect the correct positioning of surface proteins, as well as the course of Gram-positive bacterial infection, thereby making it a potential target in the study of virulence factors and disease control. In this study, the 759 bp srtA gene was cloned from pathogenic S. iniae TBY-1 strain and the mutant strain TBY-1ΔsrtA was constructed via allelic exchange mutagenesis. We found that srtA shares high similarities with sortase A from other Streptococcus spp. Direct survival rate assay and challenge experiments were performed, which showed that the mutant strain TBY-1ΔsrtA had a lower survival capacity in healthy tilapia blood and it was less virulent than the wild type strain in tilapia, thereby indicating that the deletion of sortase A affects the virulence and infectious capacity of S. iniae. The mutant strain TBY-1ΔsrtA was used as a live vaccine, which was administered via intraperitoneal injection, and it provided the relative percent survival value of 95.5% in Nile tilapia, thereby demonstrating its high potential as an effective attenuated live vaccine candidate. PMID:25090938

  19. Effects of dietary Bacillus licheniformis on growth performance, immunological parameters, intestinal morphology and resistance of juvenile Nile tilapia (Oreochromis niloticus) to challenge infections.

    PubMed

    Han, Biao; Long, Wei-Qing; He, Ju-Yun; Liu, Yong-Jian; Si, Yu-Qi; Tian, Li-Xia

    2015-10-01

    The effects of oral administration of Bacillus licheniformis on growth performance, immunity, intestinal morphology and disease resistance of juvenile tilapia were investigated. Six experimental diets supplemented with different concentrations of B. licheniformis (0%, 0.02%, 0.04%, 0.06%, 0.08% and 0.1% of AlCare(®), containing live germ 2 × 10(10) CFU/g) were formulated, viz. control, T1, T2, T3, T4 and T5. Each diet was randomly assigned to triplicate groups of 30 fishes (3.83 ± 0.03 g). After 10 weeks of feeding trial, weight gain (WG), final body wet weight (FBW) and specific growth rate (SGR) increased significantly in groups T2, T3, T4 and T5 compared with control and T1 (p < 0.05). However, survival rate and feed conversion ratio (FCR) were not found to be significantly affected (P > 0.05). Compared with control, dietary B. licheniformis supplementation increased the content of complement C3 in serum significantly (P < 0.05). The lysozyme activity was observed to be highest in T2 (P < 0.05) without differences among other groups. However, SOD activity was not affected by B. licheniformis supplementation (P > 0.05). When tilapia were challenged against Streptococcus iniae, survival rate improved significantly when tilapia fed with T2, T3, T4 and T5 (P < 0.05). Although there was no significant differences in villi length and muscular layer thickness of anterior intestinal among the treatments, intestinal villi of fish fed with higher concentrations of B. licheniformis (T2, T3, T4, T5) tended to be regularly arranged and exhibited less exfoliation, twist and fusion. These results indicated that dietary supplementation of B. licheniformis not only increased the growth, immune response and disease resistance of juvenile tilapia, but also influenced anterior intestinal development and integrity. Furthermore, in our study, the optimal concentration of B. licheniformis in diets for tilapia was greater than or equal to 4.4 × 10(6) CFU/g.

  20. The study on the candidate probiotic properties of encapsulated yeast, Saccharomyces cerevisiae JCM 7255, in Nile Tilapia (Oreochromis niloticus).

    PubMed

    Pinpimai, Komkiew; Rodkhum, Channarong; Chansue, Nantarika; Katagiri, Takayuki; Maita, Masashi; Pirarat, Nopadon

    2015-10-01

    Saccharomyces cerevisiae JCM 7255 was tested as a probiotic candidate in tilapia after encapsulating and freeze drying. Viability and morphology during storage and during transit through simulated gut and bile conditions were determined. Growth performance, anti-streptococcal activity and gut mucosal immune parameters were also tested. The viability of encapsulated yeasts was significantly high in simulated gastric and bile conditions and remained high after storage at room temperature for 14 days. The morphology of free S. cerevisiae revealed rough, bumpy, ruptured surface during incubation in gut and bile conditions. Agar spot anti-streptococcal activity showed inhibition of 20 out of 30 strains of Streptococcus agalactiae. Supplementation improved the intestinal structure and growth performance in tilapias. Intraepithelial lymphocytes in the proximal intestine were significantly observed. Lower cumulative mortality after the oral streptococcal challenge was also seen. The results suggest that encapsulated S. cerevisiae JCM 2755 could be a potential probiotic strain in tilapia culture.

  1. Evaluation and Selection of Appropriate Reference Genes for Real-Time Quantitative PCR Analysis of Gene Expression in Nile Tilapia (Oreochromis niloticus) during Vaccination and Infection.

    PubMed

    Wang, Erlong; Wang, Kaiyu; Chen, Defang; Wang, Jun; He, Yang; Long, Bo; Yang, Lei; Yang, Qian; Geng, Yi; Huang, Xiaoli; Ouyang, Ping; Lai, Weimin

    2015-04-30

    qPCR as a powerful and attractive methodology has been widely applied to aquaculture researches for gene expression analyses. However, the suitable reference selection is critical for normalizing target genes expression in qPCR. In the present study, six commonly used endogenous controls were selected as candidate reference genes to evaluate and analyze their expression levels, stabilities and normalization to immune-related gene IgM expression during vaccination and infection in spleen of tilapia with RefFinder and GeNorm programs. The results showed that all of these candidate reference genes exhibited transcriptional variations to some extent at different periods. Among them, EF1A was the most stable reference with RefFinder, followed by 18S rRNA, ACTB, UBCE, TUBA and GAPDH respectively and the optimal number of reference genes for IgM normalization under different experiment sets was two with GeNorm. Meanwhile, combination the Cq (quantification cycle) value and the recommended comprehensive ranking of reference genes, EF1A and ACTB, the two optimal reference genes, were used together as reference genes for accurate analysis of immune-related gene expression during vaccination and infection in Nile tilapia with qPCR. Moreover, the highest IgM expression level was at two weeks post-vaccination when normalized to EF1A, 18S rRNA, ACTB, and EF1A together with ACTB compared to one week post-vaccination before normalizing, which was also consistent with the IgM antibody titers detection by ELISA.

  2. Evaluation of reference genes for quantitative real-time RT-PCR analysis of gene expression in Nile tilapia (Oreochromis niloticus).

    PubMed

    Yang, Chang Geng; Wang, Xian Li; Tian, Juan; Liu, Wei; Wu, Fan; Jiang, Ming; Wen, Hua

    2013-09-15

    Quantitative real-time reverse-transcriptase polymerase chain reaction (RT-qPCR) has been used frequently to study gene expression related to fish immunology. In such studies, a stable reference gene should be selected to correct the expression of the target gene. In this study, seven candidate reference genes (glyceraldehyde-3-phosphate dehydrogenase (GADPH), ubiquitin-conjugating enzyme (UBCE), 18S ribosomal RNA (18S rRNA), beta-2-microglobulin (B2M), elongation factor 1 alpha (EF1A), tubulin alpha chain-like (TUBA) and beta actin (ACTB)), were selected to analyze their stability and normalization in seven tissues (liver, spleen, kidney, brain, heart, muscle and intestine) of Nile tilapia (Oreochromis niloticus) challenged with Streptococcus agalactiae or Streptococcus iniae, respectively. The results showed that all the candidate reference genes exhibited tissue-dependent transcriptional variations. With PBS injection as a control, UBCE was the most stable and suitable single reference gene in the intestine, liver, brain, kidney, and spleen after S. iniae infection, and in the liver, kidney, and spleen after S. agalactiae infection. EF1A was the most suitable in heart and muscle after S. iniae or S. agalactiae infection. GADPH was the most suitable gene in intestine and brain after S. agalactiae infection. In normal conditions, UBCE and 18S rRNA were the most stably expressed genes across the various tissues. These results showed that for RT-qPCR analysis of tilapia, selecting two or more reference genes may be more suitable for cross-tissue analysis of gene expression.

  3. Dispersion of the Vancomycin Resistance Genes vanA and vanC of Enterococcus Isolated from Nile Tilapia on Retail Sale: A Public Health Hazard

    PubMed Central

    Osman, Kamelia M.; Ali, Mohamed N.; Radwan, Ismail; ElHofy, Fatma; Abed, Ahmed H.; Orabi, Ahmed; Fawzy, Nehal M.

    2016-01-01

    Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE) has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to van-mediated glycopeptide (vanA and vanC) as well as the presence of enterococcal surface protein (esp) using conventional and molecular methods. The cultural, biochemical (Vitek 2 system) and polymerase chain reaction results revealed eight Enterococcus isolates from the 80 fish samples (10%) to be further identified as E. faecalis (6/8, 75%) and E gallinarum (2/8, 25%). Intraperitoneal injection of healthy Nile tilapia with the eight Enterococcus isolates caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post-injection with general signs of septicemia. All of the eight Enterococcus isolates were found to be resistant to tetracycline. The 6/6 E. faecalis isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol, and ciprofloxacin. The two isolates of E. gallinarum were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol, and erythromycin. Molecular characterization proved that they all presented the prototypic vanC element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the esp virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasize the

  4. Dispersion of the Vancomycin Resistance Genes vanA and vanC of Enterococcus Isolated from Nile Tilapia on Retail Sale: A Public Health Hazard

    PubMed Central

    Osman, Kamelia M.; Ali, Mohamed N.; Radwan, Ismail; ElHofy, Fatma; Abed, Ahmed H.; Orabi, Ahmed; Fawzy, Nehal M.

    2016-01-01

    Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE) has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to van-mediated glycopeptide (vanA and vanC) as well as the presence of enterococcal surface protein (esp) using conventional and molecular methods. The cultural, biochemical (Vitek 2 system) and polymerase chain reaction results revealed eight Enterococcus isolates from the 80 fish samples (10%) to be further identified as E. faecalis (6/8, 75%) and E gallinarum (2/8, 25%). Intraperitoneal injection of healthy Nile tilapia with the eight Enterococcus isolates caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post-injection with general signs of septicemia. All of the eight Enterococcus isolates were found to be resistant to tetracycline. The 6/6 E. faecalis isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol, and ciprofloxacin. The two isolates of E. gallinarum were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol, and erythromycin. Molecular characterization proved that they all presented the prototypic vanC element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the esp virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasize the

  5. A Tandem Duplicate of Anti-Müllerian Hormone with a Missense SNP on the Y Chromosome Is Essential for Male Sex Determination in Nile Tilapia, Oreochromis niloticus

    PubMed Central

    Li, Minghui; Sun, Yunlv; Zhao, Jiue; Shi, Hongjuan; Zeng, Sheng; Ye, Kai; Jiang, Dongneng; Zhou, Linyan; Sun, Lina; Tao, Wenjing; Nagahama, Yoshitaka; Kocher, Thomas D.; Wang, Deshou

    2015-01-01

    Variation in the TGF-β signaling pathway is emerging as an important mechanism by which gonadal sex determination is controlled in teleosts. Here we show that amhy, a Y-specific duplicate of the anti-Müllerian hormone (amh) gene, induces male sex determination in Nile tilapia. amhy is a tandem duplicate located immediately downstream of amhΔ-y on the Y chromosome. The coding sequence of amhy was identical to the X-linked amh (amh) except a missense SNP (C/T) which changes an amino acid (Ser/Leu92) in the N-terminal region. amhy lacks 5608 bp of promoter sequence that is found in the X-linked amh homolog. The amhΔ-y contains several insertions and deletions in the promoter region, and even a 5 bp insertion in exonVI that results in a premature stop codon and thus a truncated protein product lacking the TGF-β binding domain. Both amhy and amhΔ-y expression is restricted to XY gonads from 5 days after hatching (dah) onwards. CRISPR/Cas9 knockout of amhy in XY fish resulted in male to female sex reversal, while mutation of amhΔ-y alone could not. In contrast, overexpression of Amhy in XX fish, using a fosmid transgene that carries the amhy/amhΔ-y haplotype or a vector containing amhy ORF under the control of CMV promoter, resulted in female to male sex reversal, while overexpression of AmhΔ-y alone in XX fish could not. Knockout of the anti-Müllerian hormone receptor type II (amhrII) in XY fish also resulted in 100% complete male to female sex reversal. Taken together, these results strongly suggest that the duplicated amhy with a missense SNP is the candidate sex determining gene and amhy/amhrII signal is essential for male sex determination in Nile tilapia. These findings highlight the conserved roles of TGF-β signaling pathway in fish sex determination. PMID:26588702

  6. Dispersion of the Vancomycin Resistance Genes vanA and vanC of Enterococcus Isolated from Nile Tilapia on Retail Sale: A Public Health Hazard.

    PubMed

    Osman, Kamelia M; Ali, Mohamed N; Radwan, Ismail; ElHofy, Fatma; Abed, Ahmed H; Orabi, Ahmed; Fawzy, Nehal M

    2016-01-01

    Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE) has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to van-mediated glycopeptide (vanA and vanC) as well as the presence of enterococcal surface protein (esp) using conventional and molecular methods. The cultural, biochemical (Vitek 2 system) and polymerase chain reaction results revealed eight Enterococcus isolates from the 80 fish samples (10%) to be further identified as E. faecalis (6/8, 75%) and E gallinarum (2/8, 25%). Intraperitoneal injection of healthy Nile tilapia with the eight Enterococcus isolates caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post-injection with general signs of septicemia. All of the eight Enterococcus isolates were found to be resistant to tetracycline. The 6/6 E. faecalis isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol, and ciprofloxacin. The two isolates of E. gallinarum were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol, and erythromycin. Molecular characterization proved that they all presented the prototypic vanC element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the esp virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasize the

  7. A Tandem Duplicate of Anti-Müllerian Hormone with a Missense SNP on the Y Chromosome Is Essential for Male Sex Determination in Nile Tilapia, Oreochromis niloticus.

    PubMed

    Li, Minghui; Sun, Yunlv; Zhao, Jiue; Shi, Hongjuan; Zeng, Sheng; Ye, Kai; Jiang, Dongneng; Zhou, Linyan; Sun, Lina; Tao, Wenjing; Nagahama, Yoshitaka; Kocher, Thomas D; Wang, Deshou

    2015-11-01

    Variation in the TGF-β signaling pathway is emerging as an important mechanism by which gonadal sex determination is controlled in teleosts. Here we show that amhy, a Y-specific duplicate of the anti-Müllerian hormone (amh) gene, induces male sex determination in Nile tilapia. amhy is a tandem duplicate located immediately downstream of amhΔ-y on the Y chromosome. The coding sequence of amhy was identical to the X-linked amh (amh) except a missense SNP (C/T) which changes an amino acid (Ser/Leu92) in the N-terminal region. amhy lacks 5608 bp of promoter sequence that is found in the X-linked amh homolog. The amhΔ-y contains several insertions and deletions in the promoter region, and even a 5 bp insertion in exonVI that results in a premature stop codon and thus a truncated protein product lacking the TGF-β binding domain. Both amhy and amhΔ-y expression is restricted to XY gonads from 5 days after hatching (dah) onwards. CRISPR/Cas9 knockout of amhy in XY fish resulted in male to female sex reversal, while mutation of amhΔ-y alone could not. In contrast, overexpression of Amhy in XX fish, using a fosmid transgene that carries the amhy/amhΔ-y haplotype or a vector containing amhy ORF under the control of CMV promoter, resulted in female to male sex reversal, while overexpression of AmhΔ-y alone in XX fish could not. Knockout of the anti-Müllerian hormone receptor type II (amhrII) in XY fish also resulted in 100% complete male to female sex reversal. Taken together, these results strongly suggest that the duplicated amhy with a missense SNP is the candidate sex determining gene and amhy/amhrII signal is essential for male sex determination in Nile tilapia. These findings highlight the conserved roles of TGF-β signaling pathway in fish sex determination. PMID:26588702

  8. Effect of acute exposure to nonylphenol on biochemical, hormonal, and hematological parameters and muscle tissues residues of Nile tilapia; Oreochromis niloticus

    PubMed Central

    Ismail, Hager Tarek H.; Mahboub, Heba Hassan H.

    2016-01-01

    Aim: This study was aimed to evaluate some biochemical, hormonal, hematological, and histopathological changes in Nile tilapia, Oreochromis niloticus, after acute exposure to nonylphenol (NP). In addition to detection of NP residues in the fish, muscle tissues for human health concern. Materials and Methods: A total of 90 apparently healthy Nile tilapia, O. niloticus, were randomly divided into three equal groups; each containing 30 fish (three replicates). Groups 1 and 2 kept as a control and solvent control (acetone), respectively, and Group 3 exposed to NP at a dose level of 500 µg/L water for 7 successive days. Blood and tissue samples were collected 2 times randomly from each group after 7 days from fish exposure to NP and 10 days from exposure stopping. Results: Fish exposed to NP Group 3 showed anorexia, sluggish movement, erythema of the skin, areas of scales loss, and hemorrhagic ulcers in some areas of body region leading to exposing the viscera. Biochemical results revealed a significant increase in serum total proteins and globulins levels, a highly significant increase in serum alanine aminotransferase and aspartate aminotransferase activities, triglycerides, cholesterol, and creatinine levels, insignificant increase in serum uric acid level, and a highly significant decrease in serum testosterone and estradiol-β17 levels in Group 3 in compare with the control group. Histopathological finding confirms these results. While hematological results of the same group revealed a significant increase in red blood cells count and packed cell volume value, insignificant increase in hemoglobin concentration, leukopenia, lymphopenia, and monocytopenia in compared with the control group. All of these changes appeared after 7 days from fish exposure to NP. Most of these alterations returned toward the normal level after 10 days from stopping exposure to NP. NP residues detected in fish muscle tissues of Group 3 during exposure and after stopping exposure to it

  9. Retinoic acid homeostasis through aldh1a2 and cyp26a1 mediates meiotic entry in Nile tilapia (Oreochromis niloticus).

    PubMed

    Feng, Ruijuan; Fang, Lingling; Cheng, Yunying; He, Xue; Jiang, Wentao; Dong, Ranran; Shi, Hongjuan; Jiang, Dongneng; Sun, Lina; Wang, Deshou

    2015-01-01

    Meiosis is a process unique to the differentiation of germ cells. Retinoic acid (RA) is the key factor controlling the sex-specific timing of meiotic initiation in tetrapods; however, the role of RA in meiotic initiation in teleosts has remained unclear. In this study, the genes encoding RA synthase aldh1a2, and catabolic enzyme cyp26a1 were isolated from Nile tilapia (Oreochromis niloticus), a species without stra8. The expression of aldh1a2 was up-regulated and expression of cyp26a1 was down-regulated before the meiotic initiation in ovaries and in testes. Treatment with RA synthase inhibitor or disruption of Aldh1a2 by CRISPR/Cas9 resulted in delayed meiotic initiation, with simultaneous down-regulation of cyp26a1 and up-regulation of sycp3. By contrast, treatment with an inhibitor of RA catabolic enzyme and disruption of cyp26a1 resulted in earlier meiotic initiation, with increased expression of aldh1a2 and sycp3. Additionally, treatment of XY fish with estrogen (E2) and XX fish with fadrozole led to sex reversal and reversion of meiotic initiation. These results indicate that RA is indispensable for meiotic initiation in teleosts via a stra8 independent signaling pathway where both aldh1a2 and cyp26a1 are critical. In contrast to mammals, E2 is a major regulator of sex determination and meiotic initiation in teleosts. PMID:25976364

  10. Histopathological alterations in the liver and intestine of Nile tilapia Oreochromis niloticus exposed to long-term sublethal concentrations of cadmium chloride

    NASA Astrophysics Data System (ADS)

    Younis, Elsayed; Abdel-Warith, Abdel-Wahab; Al-Asgah, Nasser; Ebaid, Hossam

    2015-07-01

    Fingerlings of Nile tilapia Oreochromis niloticus were exposed to 1.68, 3.36, and 5.04 mg/L cadmium (as CdCl2), which represent 10%, 20%, and 30% of their previously determined 96-h LC50. After exposure for 20 days, sections of the liver and intestine of treated fish were examined histologically. Histopathological changes varied from slight to severe structural modification, depending on the exposure concentration. The hepatic tissues of fish exposed to 10% LC50 showed markedly increased vacuolation of the hepatocytes and coarse granulation of their cytoplasm. Abundant erythrocytic infiltration among the hepatocytes was observed in fish exposed to 20% LC50. In the intestinal tissues of fish exposed to all doses, goblet cells proliferated and were greatly increased in size, the longitudinal muscularis mucosa was disturbed and, in the crypts of the sub-mucosal layer, apoptosis increased, indicated by large numbers of degenerated nuclei. Large numbers of inflammatory cells and dilated blood vessels were observed in the intestine of the group treated with 30% LC50.

  11. Retinoic acid homeostasis through aldh1a2 and cyp26a1 mediates meiotic entry in Nile tilapia (Oreochromis niloticus)

    PubMed Central

    Feng, Ruijuan; Fang, Lingling; Cheng, Yunying; He, Xue; Jiang, Wentao; Dong, Ranran; Shi, Hongjuan; Jiang, Dongneng; Sun, Lina; Wang, Deshou

    2015-01-01

    Meiosis is a process unique to the differentiation of germ cells. Retinoic acid (RA) is the key factor controlling the sex-specific timing of meiotic initiation in tetrapods; however, the role of RA in meiotic initiation in teleosts has remained unclear. In this study, the genes encoding RA synthase aldh1a2, and catabolic enzyme cyp26a1 were isolated from Nile tilapia (Oreochromis niloticus), a species without stra8. The expression of aldh1a2 was up-regulated and expression of cyp26a1 was down-regulated before the meiotic initiation in ovaries and in testes. Treatment with RA synthase inhibitor or disruption of Aldh1a2 by CRISPR/Cas9 resulted in delayed meiotic initiation, with simultaneous down-regulation of cyp26a1 and up-regulation of sycp3. By contrast, treatment with an inhibitor of RA catabolic enzyme and disruption of cyp26a1 resulted in earlier meiotic initiation, with increased expression of aldh1a2 and sycp3. Additionally, treatment of XY fish with estrogen (E2) and XX fish with fadrozole led to sex reversal and reversion of meiotic initiation. These results indicate that RA is indispensable for meiotic initiation in teleosts via a stra8 independent signaling pathway where both aldh1a2 and cyp26a1 are critical. In contrast to mammals, E2 is a major regulator of sex determination and meiotic initiation in teleosts. PMID:25976364

  12. Pharmacodynamic interaction of Spirulina platensis and deltamethrin in freshwater fish Nile tilapia, Oreochromis niloticus: impact on lipid peroxidation and oxidative stress.

    PubMed

    Abdelkhalek, Nevien K M; Ghazy, Emad W; Abdel-Daim, Mohamed M

    2015-02-01

    Spirulina platensis (SP) is one of the most commonly used dietary supplements in human and many animal species, including fish. Recently, it has gained more attention in fish not only for its growth-promoting and immunomodulatory effects but also for its antioxidant potential. The present study was conducted to investigate the protective role of two different dietary levels of SP on freshwater Nile tilapia; Oreochromis niloticus exposed to subacute deltamethrin (DLM) intoxication. Spirulina was supplemented at levels of 0.5 and 1 % in the diet along with DLM at a concentration of 1.46 μg/l for 28 days. Serum biochemical parameters, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total protein, albumin, cholesterol, urea, uric acid and creatinine, were estimated. In addition, the level of malondialdehyde (MDA) was analysed as a lipid peroxidation marker. Reduced glutathione (GSH) content and glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activities were analysed as antioxidant biomarkers in liver, kidney and gills. The results revealed that DLM intoxication increased serum AST, ALT, ALP, cholesterol, urea, uric acid, creatinine and tissue MDA, while decreased serum total protein and albumin as well as tissue GSH level and GSH-Px, SOD and CAT activities. SP supplementation at the two tested levels enhanced all altered serum biochemical parameters as well as tissue lipid peroxidation and antioxidant biomarkers. Therefore, it could be concluded that SP administration could minimize DLM-induced toxic effects by its free radical scavenging and potent antioxidant activity. PMID:25231739

  13. Phenological and liver antioxidant profiles of adult Nile tilapia (Oreochromis niloticus) exposed to toxic live cyanobacterium (Microcystis aeruginosa Kützing) cells.

    PubMed

    Khairy, Hanan M; Ibrahim, Marwa A; Ibrahem, Mai D

    2012-01-01

    Blue-green algae (cyanobacteria) constitute the greater part of the phytoplankton. Microcystis aeruginosa is amongst the most ubiquitously distributed cyanobacterial species, and almost invariably produces cyclic heptapeptide toxins called microcystins (MCs). The present study was designed to investigate the phenological and liver antioxidant profiles of the Nile tilapia Oreochromis niloticus chronically exposed to toxic live M. aeruginosa cells. Fish were grown in the absence and presence of M. aeruginosa in three different concentrations for seven days, and subsequently reared for another 30 days in the absence of the cyanobacteria. While cyanobacteria did not cause any fish mortality, there was a progressive development of yellowish discolouration in the livers of exposed fish. In the livers, the activities and levels of superoxide dismutase (SOD), lactate dehydrogenase (LDH), glutathione (GSH), and lipid peroxidation products like malondialdehyde (MDA) were elevated in response to the concentration of M. aeruginosa. Moreover, DNA fragmentation and DNA-protein crosslinks were measured. These parameters can thus be considered potential biomarkers for the fish exposure to M. aeruginosa. The present study sheds light on cyanobacterial blooms like health, environmental, and economic problem, respectively. PMID:23413757

  14. Circadian rhythms of clock gene expression in Nile tilapia (Oreochromis niloticus) central and peripheral tissues: influence of different lighting and feeding conditions.

    PubMed

    Costa, Leandro S; Serrano, Ignacio; Sánchez-Vázquez, Francisco J; López-Olmeda, Jose F

    2016-08-01

    The present research aimed to investigate the existence of clock gene expression rhythms in tilapia, their endogenous origin, and how light and feeding cycles synchronize these rhythms. In the first experiment, two groups of fish were kept under an LD cycle and fed at two different time points: in the middle of the light (ML) or in the middle of the dark (MD) phase. In the second experiment, fish fed at ML was fasted and kept under constant lighting (LL) conditions for 1 day. In both experiments, the samples from central (optic tectum and hypothalamus) and peripheral (liver) tissues were collected every 3 h throughout a 24 h cycle. The expression levels of clock genes bmal1a, clock1, per1b, cry2a, and cry5 were analyzed by quantitative PCR. All the clock genes analyzed in brain regions showed daily rhythms: clock1, bmal1a, and cry2a showed the acrophase approximately at the end of the light phase (ZT 8:43-11:22 h), whereas per1b and cry5 did so between the end of the dark phase and the beginning of the light phase, respectively (ZT 21:16-4:00 h). These rhythms persisted under constant conditions. No effect of the feeding time was observed in the brain. In the liver, however, the rhythms of clock1 and cry5 were influenced by feeding, and a shift was observed in the MD fish group (ZT 3:58 h for clock1 and 11:20 h for cry5). This study provides the first insights into the molecular clock of tilapia, a very important fish species for aquaculture. It also reveals the endogenous origin of clock gene rhythms and the ability of feeding time to shift the phase in some clock genes in the peripheral, but not the central, oscillator. PMID:27085855

  15. First description of the adult stage of Clinostomum cutaneum Paperna, 1964 (Digenea: Clinostomidae) from grey herons Ardea cinerea L. and a redescription of the metacercaria from the Nile tilapia Oreochromis niloticus niloticus (L.) in Kenya.

    PubMed

    Gustinelli, Andrea; Caffara, Monica; Florio, Daniela; Otachi, Elick O; Wathuta, Euty M; Fioravanti, Maria L

    2010-05-01

    The combined use of morphological and molecular studies allowed for the first time the recognition and description of the adult stage of Clinostomum cutaneum Paperna, 1964 from the grey heron Ardea cinerea L. in Kenya. A redescription of the metacercaria that infect Nile tilapia Oreochromis niloticus niloticus (L.) from the same aquatic environment is also presented. C. cutaneum differs from all other species of Clinostomum Leidy, 1856 in the shape of its uterus. Sequencing the rRNA confirmed the morphological similarity between adults from the grey heron and the metacercarial stage from tilapia, and a level of genetic similarity with the other previously sequenced Clinostomum spp. was observed. The need for a reorganisation of Clinostomum using both morphological and molecular methods is highlighted.

  16. First description of the adult stage of Clinostomum cutaneum Paperna, 1964 (Digenea: Clinostomidae) from grey herons Ardea cinerea L. and a redescription of the metacercaria from the Nile tilapia Oreochromis niloticus niloticus (L.) in Kenya.

    PubMed

    Gustinelli, Andrea; Caffara, Monica; Florio, Daniela; Otachi, Elick O; Wathuta, Euty M; Fioravanti, Maria L

    2010-05-01

    The combined use of morphological and molecular studies allowed for the first time the recognition and description of the adult stage of Clinostomum cutaneum Paperna, 1964 from the grey heron Ardea cinerea L. in Kenya. A redescription of the metacercaria that infect Nile tilapia Oreochromis niloticus niloticus (L.) from the same aquatic environment is also presented. C. cutaneum differs from all other species of Clinostomum Leidy, 1856 in the shape of its uterus. Sequencing the rRNA confirmed the morphological similarity between adults from the grey heron and the metacercarial stage from tilapia, and a level of genetic similarity with the other previously sequenced Clinostomum spp. was observed. The need for a reorganisation of Clinostomum using both morphological and molecular methods is highlighted. PMID:20401577

  17. Additive genetic variation in resistance of Nile tilapia (Oreochromis niloticus) to Streptococcus iniae and S. agalactiae capsular type Ib: is genetic resistance correlated?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus (S.) iniae and S. agalactiae are both economically important Gram positive bacterial pathogens affecting the globally farmed tilapia (Oreochromis spp.). Historically control of these bacteria in tilapia culture has included biosecurity, therapeutants and vaccination strategies. Genet...

  18. Comparison of adhesive gut bacteria composition, immunity, and disease resistance in juvenile hybrid tilapia fed two different Lactobacillus strains.

    PubMed

    Liu, Wenshu; Ren, Pengfei; He, Suxu; Xu, Li; Yang, Yaling; Gu, Zemao; Zhou, Zhigang

    2013-07-01

    This study compares the effects of two Lactobacillus strains, highly adhesive Lactobacillus brevis JCM 1170 (HALB) and less-adhesive Lactobacillus acidophilus JCM 1132 (LALB), on the survival and growth, adhesive gut bacterial communities, immunity, and protection against pathogenic bacterial infection in juvenile hybrid tilapia. During a 5-week feeding trial the fish were fed a diet containing 0 to 10(9) cells/g feed of the two Lactobacillus strains. Samples of intestine, kidney, and spleen were taken at the start and at 10, 20, and 35 days for analysis of stress tolerance and cytokine gene mRNA levels and to assess the diversity of adhesive gut bacterial communities. A 14-day immersion challenge with Aeromonas hydrophila NJ-1 was also performed following the feeding trial. The results showed no significant differences in survival rate, weight gain, or feed conversion in the different dietary treatments. The adhesive gut bacterial communities were strikingly altered in the fish fed either the HALB or the LALB, but the response was more rapid and substantial with the adhesive strain. The two strains induced similar changes in the patterns (upregulation or downregulation) of intestinal, splenic or kidney cytokine expression, but they differed in the degree of response for these genes. Changes in intestinal HSP70 expression levels coincided with changes in the similarity coefficient of the adhesive gut bacterial communities between the probiotic treatments. The highest dose of the HALB appeared to protect against the toxic effects of immersion in A. hydrophila (P < 0.05). In conclusion, the degree to which Lactobacillus strains adhere to the gut may be a favorable criterion in selecting probiotic strain for aquaculture.

  19. Growth and production performance of monosex tilapia (Oreochromis niloticus) fed with homemade feed in earthen mini ponds.

    PubMed

    Ahmed, G U; Sultana, N; Shamsuddin, M; Hossain, M Belal

    2013-12-01

    Field experiment was conducted to evaluate the growth performance of monosex tilapia using homemade feed with Peninsula Group fish meal and commercially available feed with local fish meal in earthen mini ponds from June-September 2010. Three ponds (T1) were supplied with prepared feed and the other three ponds (T2) with commercially available fish feed. Fish were fed at the rate of 10% of their body weight for the first thirty days then gradually reduced to 6% for the next ten days, 2% for the next ten days and 3% for remaining days. The temperature were ranged from 31.5-33.0 degrees C, DO from 5.5-15 mg L(-1) in T1 and 6.5-14 mg L(-1) in T2, pH from 7.1-8.0 in T1 and 7.1-7.7 in T2, alkalinity from 105-160 mg L(-1) inT1 and 100-145 mg L(-1) in T2, nitrate was 0.06 mg L(-1) in both treatments and ammonia from 0.02 and 0.04 mg L(-1) in T1 and T2, respectively. The results of the present study showed that the best weight gain was observed as 123.48 g in T1 than T2 (111.82 g). The Specific Growth Rate (SGR) was recorded 3.09 and 2.97 and the Food Conversion Ratio (FCR) was 1.51 and 1.40 in T1 and T2, respectively. There was significant (p < 0.05) variation among the survival rate (%) of fishes which were 75.55 and 90.37% in T1 and T2, respectively. The fish productions were 19076 and 16312.11 kg ha(-1) in T1 and T2. The highest net profit (Taka/ha/70 days) of Tk. 15, 83,213 was obtained with T1 So, the prepared feed showed better performance with monosex tilapia in compared with commercial fish feed with local fish meal.

  20. Genome-wide identification, evolution and expression analysis of nuclear receptor superfamily in Nile tilapia, Oreochromis niloticus.

    PubMed

    Cheng, Yun-Ying; Tao, Wen-Jing; Chen, Jin-Lin; Sun, Li-Na; Zhou, Lin-Yan; Song, Qiang; Wang, De-Shou

    2015-09-10

    The nuclear receptor (NR) superfamily, which is divided into 7 subfamilies, constitutes one of the largest classes of transcription factors. In this study, through comprehensive database search, we identified all NRs (including 4 novel members) from the tilapia (75), common carp (137), zebrafish (73), fugu (73), tetraodon (72), stickleback (70), medaka (69), coelacanth (55), spotted gar (51) and elephant shark (50). For 21 NRs, two duplicates were found in teleosts, while only one in tetrapods. These duplicates, except those of DAX1, SHP and GCNF found in the elephant shark, were derived from 3R (third round of genome duplication). The linkage duplication of 5 syntenic blocks (comprising 14 duplicated NR couples) in teleosts further supported their 3R origin. Based on transcriptome data from adult tilapia, 53 NRs were found to be expressed in more than one tissue (brain, head kidney, heart, liver, kidney, muscle, ovary and testis), and 4 were tissue-specific, indicating their essential roles in the corresponding tissue. Based on the XX and XY gonadal transcriptome data from four developmental stages, 65 NRs were detected in gonads, with 21, 31, 11 and 29 expressed sexual dimorphically at 5, 30, 90 and 180days after hatching, respectively. The expression of four selected genes was examined by in situ hybridization (ISH) and quantitative PCR (qPCR) to validate the spatial and temporal expression profiles of NRs. Comparative analyses of the expression profiles of duplicated NRs revealed divergence in gene expression as well as gene function. Our results demonstrated that NRs may play important roles in sex determination and gonadal development in teleosts.

  1. Major surfome and secretome profile of Streptococcus agalactiae from Nile tilapia (Oreochromis niloticus): Insight into vaccine development.

    PubMed

    Li, Wei; Wang, Hai-Qing; He, Run-Zhen; Li, Yan-Wei; Su, You-Lu; Li, An-Xing

    2016-08-01

    Streptococcus agalactiae is a major piscine pathogen that is responsible for huge economic losses to the aquaculture industry. Safe recombinant vaccines, based on a small number of antigenic proteins, are emerging as the most attractive, cost-effective solution against S. agalactiae. The proteins of S. agalactiae exposed to the environment, including surface proteins and secretory proteins, are important targets for the immune system and they are likely to be good vaccine candidates. To obtain a precise profile of its surface proteins, S. agalactiae strain THN0901, which was isolated from tilapia (Oreochromis niloticus), was treated with proteinase K to cleave surface-exposed proteins, which were identified by liquid chromatography-tandem spectrometry (LC-MS/MS). Forty surface-associated proteins were identified, including ten proteins containing cell wall-anchoring motifs, eight lipoproteins, eleven membrane proteins, seven secretory proteins, three cytoplasmic proteins, and one unknown protein. In addition, culture supernatant proteins of S. agalactiae were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and all of the Coomassie-stained bands were subsequently identified by LC-MS/MS. A total of twenty-six extracellular proteins were identified, including eleven secretory proteins, seven cell wall proteins, three membrane proteins, two cytoplasmic proteins and three unknown proteins. Of these, six highly expressed surface-associated and secretory proteins are putative to be vaccine candidate of piscine S. agalactiae. Moreover, immunogenic secreted protein, a highly expressed protein screened from the secretome in the present study, was demonstrated to induce high antibody titer in tilapia, and it conferred protection against S. agalactiae, as evidenced by the relative percent survival (RPS) 48.61± 8.45%. The data reported here narrow the scope of screening protective antigens, and provide guidance in the development of a novel

  2. Major surfome and secretome profile of Streptococcus agalactiae from Nile tilapia (Oreochromis niloticus): Insight into vaccine development.

    PubMed

    Li, Wei; Wang, Hai-Qing; He, Run-Zhen; Li, Yan-Wei; Su, You-Lu; Li, An-Xing

    2016-08-01

    Streptococcus agalactiae is a major piscine pathogen that is responsible for huge economic losses to the aquaculture industry. Safe recombinant vaccines, based on a small number of antigenic proteins, are emerging as the most attractive, cost-effective solution against S. agalactiae. The proteins of S. agalactiae exposed to the environment, including surface proteins and secretory proteins, are important targets for the immune system and they are likely to be good vaccine candidates. To obtain a precise profile of its surface proteins, S. agalactiae strain THN0901, which was isolated from tilapia (Oreochromis niloticus), was treated with proteinase K to cleave surface-exposed proteins, which were identified by liquid chromatography-tandem spectrometry (LC-MS/MS). Forty surface-associated proteins were identified, including ten proteins containing cell wall-anchoring motifs, eight lipoproteins, eleven membrane proteins, seven secretory proteins, three cytoplasmic proteins, and one unknown protein. In addition, culture supernatant proteins of S. agalactiae were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and all of the Coomassie-stained bands were subsequently identified by LC-MS/MS. A total of twenty-six extracellular proteins were identified, including eleven secretory proteins, seven cell wall proteins, three membrane proteins, two cytoplasmic proteins and three unknown proteins. Of these, six highly expressed surface-associated and secretory proteins are putative to be vaccine candidate of piscine S. agalactiae. Moreover, immunogenic secreted protein, a highly expressed protein screened from the secretome in the present study, was demonstrated to induce high antibody titer in tilapia, and it conferred protection against S. agalactiae, as evidenced by the relative percent survival (RPS) 48.61± 8.45%. The data reported here narrow the scope of screening protective antigens, and provide guidance in the development of a novel

  3. Molecular characterization and immune response to lipopolysaccharide (LPS) of the suppressor of cytokine signaling (SOCS)-1, 2 and 3 genes in Nile tilapia (Oreochromis niloticus).

    PubMed

    Liu, Cai-Zhi; He, An-Yuan; Chen, Li-Qiao; Limbu, Samwel Mchele; Wang, Ya-Wen; Zhang, Mei-Ling; Du, Zhen-Yu

    2016-03-01

    Suppressor of cytokine signaling (SOCS) proteins are inverse feedback regulators of cytokine and hormone signaling mediated by the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway that are involved in immunity, growth and development of organisms. In the present study, three SOCS genes, SOCS-1, SOCS-2 and SOCS-3, were identified in an economically important fish, Nile tilapia (Oreochromis niloticus) referred to as NtSOCS-1, NtSOCS-2 and NtSOCS-3. Multiple alignments showed that, the three SOCS molecules share highly conserved functional domains, including the SRC homology 2 (SH2) domain, the extended SH2 subdomain (ESS) and the SOCS box with others vertebrate counterparts. Phylogenetic analysis indicated that NtSOCS-1, 2 and 3 belong to the SOCS type II subfamily. Whereas NtSOCS-1 and 3 showed close evolutionary relationship with Perciformes, NtSOCS-2 was more related to Salmoniformes. Tissue specific expression results showed that, NtSOCS-1, 2 and 3 were constitutively expressed in all nine tissues examined. NtSOCS-1 and 3 were highly expressed in immune-related tissues, such as gills, foregut and head kidney. However, NtSOCS-2 was superlatively expressed in liver, brain and heart. In vivo, NtSOCS-1 and 3 mRNA levels were up-regulated after lipopolysaccharide (LPS) challenge while NtSOCS-2 was down-regulated. In vitro, LPS stimulation increased NtSOCS-3 mRNA expression, however it inhibited the transcription of NtSOCS-1 and 2. Collectively, our findings suggest that, the NtSOCS-1 and 3 might play significant role(s) in innate immune response, while NtSOCS-2 may be more involved in metabolic regulation.

  4. Seasonal variations in the body composition and bioaccumulation of heavy metals in Nile tilapia collected from drainage canals in Al-Ahsa, Saudi Arabia

    PubMed Central

    Younis, Elsayed M.; Al-Asgah, Nasser A.; Abdel-Warith, Abdel-Wahab A.; Al-Mutairi, Abdullah A.

    2014-01-01

    The body composition of Nile tilapia (Oreochromis niloticus) collected from drainage canals in Al-Ahsa, Saudi Arabia and the concentration of four heavy metals; zinc (Zn), cadmium (Cd), cobalt (Co) and lead (Pb) in both fish muscles and the water collected from this environment were assessed across the four seasons. The body composition was found to change with the seasons, with the best body composition being recorded in autumn and winter, where higher levels of protein (17.24, 17.65%), and fat (0.58, 0.71%) and lower water content (80.15, 79.86%) respectively were noted. The concentration of heavy metals in both fish muscles and the water body also varied significantly with the seasons. In the fish muscles, the highest content of Zn (0.409 mg/kg dry weight) and Cd (4.140 mg/kg dry weight) was recorded in winter, however, the highest concentration of Co (0.318 mg/kg dry weight) and Pb (1.96 mg/kg dry weight) was observed in spring and summer respectively. On the other hand, the water samples collected in autumn showed the maximum concentration of Cd (1.385 mg/L), Co (0.762 mg/L) and Pb (0.18 mg/L) however, the maximum concentration of Zn (0.0041 mg/L) was recorded in winter. With the exception of Cd, the accumulation of the studied heavy metals in fish muscles was within the safe limits for seafood recommended by various organizations. PMID:26150751

  5. Effects of sub-lethal and chronic lead concentrations on blood and liver ALA-D activity and hematological parameters in Nile tilapia.

    PubMed

    Dos Santos, Carlucio Rocha; Cavalcante, Ana Luiza Michel; Hauser-Davis, Rachel Ann; Lopes, Renato Matos; Mattos, Rita De Cássia Oliveira Da Costa

    2016-07-01

    Liver and blood δ-aminolevulinic acid dehydratase (ALA-D) inhibition by exposure to sub-lethal lead concentrations over time in Nile tilapia (Oreochromis niloticus) were investigated. All three lead concentrations (1mgkg(-1), 10mgkg(-1) and 100mgkg(-1)) significantly inhibited ALA-D activity in blood (319±29.2; 180±14.6 and 172±19µmols(-1)h(-1)L(-1) respectively) and liver (302±5.84; 201±41.4 and 93±22.1µmols(-1)h(-1)L(-1)) 24h after injection relative to controls (blood: 597±37.0µmols(-1)h(-1)L(-1); liver: 376±23.1µmols(-1)h(-1)L(-1)). Blood ALA-D was greatly inhibited in all but the highest lead dose. Fish were then exposed to 1mgkg(-1) lead for 9 days, and presented short-term hyperglycemia, decreased hemoglobin and hematocrit values and time-dependent blood ALA-D activity inhibition, corroborating blood ALA-D activity as being more suitable for investigating lead effects, showing dose and time-dependent ALA-D inhibition after lead exposure. The results of the present study also demonstrated that fish size affects blood ALA-D activity, as fish from the 24-h assay, which were slightly smaller (approximately 200g), showed higher ALA-D inhibition in response to lead exposure when compared to the fish from the 9-day assay (approximately 500g). Thus, fish size should always be taken into account both in the field and in laboratory settings, and efforts should be made to obtain uniform fish size samples for biomarker studies.

  6. Effects of sub-lethal and chronic lead concentrations on blood and liver ALA-D activity and hematological parameters in Nile tilapia.

    PubMed

    Dos Santos, Carlucio Rocha; Cavalcante, Ana Luiza Michel; Hauser-Davis, Rachel Ann; Lopes, Renato Matos; Mattos, Rita De Cássia Oliveira Da Costa

    2016-07-01

    Liver and blood δ-aminolevulinic acid dehydratase (ALA-D) inhibition by exposure to sub-lethal lead concentrations over time in Nile tilapia (Oreochromis niloticus) were investigated. All three lead concentrations (1mgkg(-1), 10mgkg(-1) and 100mgkg(-1)) significantly inhibited ALA-D activity in blood (319±29.2; 180±14.6 and 172±19µmols(-1)h(-1)L(-1) respectively) and liver (302±5.84; 201±41.4 and 93±22.1µmols(-1)h(-1)L(-1)) 24h after injection relative to controls (blood: 597±37.0µmols(-1)h(-1)L(-1); liver: 376±23.1µmols(-1)h(-1)L(-1)). Blood ALA-D was greatly inhibited in all but the highest lead dose. Fish were then exposed to 1mgkg(-1) lead for 9 days, and presented short-term hyperglycemia, decreased hemoglobin and hematocrit values and time-dependent blood ALA-D activity inhibition, corroborating blood ALA-D activity as being more suitable for investigating lead effects, showing dose and time-dependent ALA-D inhibition after lead exposure. The results of the present study also demonstrated that fish size affects blood ALA-D activity, as fish from the 24-h assay, which were slightly smaller (approximately 200g), showed higher ALA-D inhibition in response to lead exposure when compared to the fish from the 9-day assay (approximately 500g). Thus, fish size should always be taken into account both in the field and in laboratory settings, and efforts should be made to obtain uniform fish size samples for biomarker studies. PMID:27054706

  7. Molecular characterization and immune response to lipopolysaccharide (LPS) of the suppressor of cytokine signaling (SOCS)-1, 2 and 3 genes in Nile tilapia (Oreochromis niloticus).

    PubMed

    Liu, Cai-Zhi; He, An-Yuan; Chen, Li-Qiao; Limbu, Samwel Mchele; Wang, Ya-Wen; Zhang, Mei-Ling; Du, Zhen-Yu

    2016-03-01

    Suppressor of cytokine signaling (SOCS) proteins are inverse feedback regulators of cytokine and hormone signaling mediated by the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway that are involved in immunity, growth and development of organisms. In the present study, three SOCS genes, SOCS-1, SOCS-2 and SOCS-3, were identified in an economically important fish, Nile tilapia (Oreochromis niloticus) referred to as NtSOCS-1, NtSOCS-2 and NtSOCS-3. Multiple alignments showed that, the three SOCS molecules share highly conserved functional domains, including the SRC homology 2 (SH2) domain, the extended SH2 subdomain (ESS) and the SOCS box with others vertebrate counterparts. Phylogenetic analysis indicated that NtSOCS-1, 2 and 3 belong to the SOCS type II subfamily. Whereas NtSOCS-1 and 3 showed close evolutionary relationship with Perciformes, NtSOCS-2 was more related to Salmoniformes. Tissue specific expression results showed that, NtSOCS-1, 2 and 3 were constitutively expressed in all nine tissues examined. NtSOCS-1 and 3 were highly expressed in immune-related tissues, such as gills, foregut and head kidney. However, NtSOCS-2 was superlatively expressed in liver, brain and heart. In vivo, NtSOCS-1 and 3 mRNA levels were up-regulated after lipopolysaccharide (LPS) challenge while NtSOCS-2 was down-regulated. In vitro, LPS stimulation increased NtSOCS-3 mRNA expression, however it inhibited the transcription of NtSOCS-1 and 2. Collectively, our findings suggest that, the NtSOCS-1 and 3 might play significant role(s) in innate immune response, while NtSOCS-2 may be more involved in metabolic regulation. PMID:26820103

  8. gsdf is a downstream gene of dmrt1 that functions in the male sex determination pathway of the Nile tilapia.

    PubMed

    Jiang, Dong-Neng; Yang, Hui-Hui; Li, Ming-Hui; Shi, Hong-Juan; Zhang, Xian-Bo; Wang, De-Shou

    2016-06-01

    Gonadal soma-derived factor (gsdf) is critical for testicular differentiation in teleosts, yet detailed analysis of Gsdf on testicular differentiation is lacking. In the present study, we knocked out tilapia gsdf using CRISPR/Cas9. F0 gsdf-deficient XY fish with high mutation rate (≥58%) developed as intersex, with ovotestes 90 days after hatching (dah), and become completely sex-reversed with ovaries at 180 and 240 dah. Those individuals with a low mutation rate (<58%) and XY gsdf(+/-) fish developed as males with normal testes. In F2 XY gsdf(-/-) fish, the gonads first expressed Dmrt1, which initiated the male pathway at 10 dah, then both male and female pathways were activated, as reflected by the simultaneous expression of Dmrt1 and Cyp19a1a in different cell populations at 18 dah, shifted to the female pathway expressing only Cyp19a1a at 36 dah, and finally developed into functional ovaries as adults. The male pathway and Dmrt1 expression was initiated, but failed to be maintained, in the absence of Gsdf. Aromatase-inhibitor treatment from 10 to 35 dah, however, rescued the phenotype, resulting in XY gsdf(-/-) with normal testes that expressed Dmrt1 and Cyp11b2. In vitro promoter analyses demonstrated that Dmrt1 activated gsdf expression in a dose-dependent manner in the presence of Sf1, even though Dmrt1 alone could not. Taken together, our results demonstrated that gsdf is a downstream gene of dmrt1. Gsdf probably inhibits estrogen production to trigger testicular differentiation. Mol. Reprod. Dev. 83: 497-508, 2016. © 2016 Wiley Periodicals, Inc.

  9. Somatic growth effects of intramuscular injection of growth hormone in androgen-treated juvenile Nile tilapia, Oreochromis niloticus (Perciformes: Cichlidae).

    PubMed

    Liñán-Cabello, Marco A; Robles-Basto, Cindy M; Mena-herrera, Alfredo

    2013-03-01

    Little is known about the effects of the interaction of growth hormone (GH) with 17 alpha-methyltestosterone (17-MT) during fish growth. We evaluated this in the present study to assess the effect on fish growth. Fish in two batches of juvenile tilapia (Oreochromis niloticus) (approximately 5.0cm in length) were randomly assigned in triplicate to three treatments and a control group, distributed among 12 fiberglass tanks of 1 000L capacity (50 fish per tank) in an experiment covering a period of six weeks. The experimental groups were: a) fish treated with 17-MT and GH in mineral oil (RGH); b) fish treated with 17-MT and mineral oil without the addition of GH (R); c) fish treated with GH in mineral oil but not 17-MT (NGH); and d) fish of the control group, which were treated with mineral oil but not 17-MT or GH (N). The GH was injected into the fish at a rate of 0.625mg/g body weight. Morphometric data were recorded at the beginning of the experiment (T0) and at 15, 30 and 45 days (T15, T30 and T45), and various indicators of growth were assessed: condition factor (K); survival percentage (S), feed conversion rate (FCR), percentage weight gain (WG) and (v) daily weight gain. The optimum dietary level was calculated assuming 5% food conversion to total weight in each group. During the experiment, the fish were provided with a commercial food containing 45% protein. The data showed that GH injection resulted in a greater weight gain in fish treated with 17-MT (the RGH treatment group), being particularly significant increase in weight during T15 and T30 (p<0.05). High values of K were found in the R and RGH treatments during the initial days of the experiment, which may have been a consequence of the better nutritional status affecting both weight gain and growth in body length, as a result of the additive effects of 17-MT and GH. The fish in groups not treated with 17-MT and treated with 17-MT and added GH showed greater increases in WG per day, higher K values and

  10. Deposition of tocopherol and tocotrienol in the tissues of red hybrid tilapia, Oreochromis sp., fed vitamin E-free diets supplemented with different plant oils.

    PubMed

    Lee, Kuan-Shern; Yuen, Kah-Hay; Ng, Wing-Keong

    2013-12-01

    Vitamin E, a potent antioxidant consisting of four isomers each (α, β, γ, δ) of tocopherol (T) and tocotrienol (T3), is found naturally in plant oils at different concentrations. In this study, four semi-purified isonitrogenous and isolipidic (10 %) diets containing canola oil, cold-pressed soybean oil, wheat germ oil, or palm fatty acid distillates (PFAD) as the sole vitamin E source were fed to triplicate groups of red hybrid tilapia (Oreochromis sp.) fingerlings (14.82 ± 0.05 g) for 45 days. Vitamin E concentrations and composition were measured in the muscle, liver, skin, and adipose tissue. Deposition of α-T (53.4-93.1 % of total vitamin E) predominated over deposition of other isomers, except in the liver of fish fed the SBO diet, where α-T and γ-T deposition was in the ratio 40:60. T3 deposition (2.6-29.4 %) was only detected in tissues of fish fed the PFAD diet; adipose tissue was the major storage depot. Fish fed the SBO diet contained significantly more (P < 0.05) muscle thiobarbituric acid-reactive substances. Muscle fatty acid composition reflected dietary fatty acid profile. This is the first study to compare the deposition in fish tissues of the naturally occurring vitamin E isomers present in plant oils. The type and concentration of endogenous vitamin E and the fatty acid composition of plant oils can affect the oxidative stability of tilapia tissues.

  11. The role of vitamins A, C, E and selenium as antioxidants against genotoxicity and cytotoxicity of cadmium, copper, lead and zinc on erythrocytes of Nile tilapia, Oreochromis niloticus.

    PubMed

    Harabawy, Ahmed S A; Mosleh, Yahia Y I

    2014-06-01

    This study was carried out to investigate the genotoxic and cytotoxic potentials of sublethal concentration (5mg L(-1)) of combined metals including Cd, Cu, Pb and Zn (1.25mg L(-1) of each) on erythrocytes of Nile tilapia, Oreochromis niloticus after exposure for five and seven days; and to evaluate the protective role of vitamin E alone and a combination of selenium (Se) with vitamins A, C and E which was added to the diet as antioxidants against the genotoxicity and cytotoxicity of these metals. This was accomplished by application of micronuclei (MN), binuclei (BN), nuclear abnormalities (NAs) assays in addition to morphological erythrocyte alteration (MAEs) assay. The results revealed that, exposure of O. niloticus to Cd, Cu, Pb and Zn induced the formation of nine genotoxic endpoints including MN, BN and seven patterns of NAs, kidney-shaped nuclei, blebbed nuclei, lobed nuclei, bilobed nuclei, notched nuclei, hook-shaped nuclei and vacuolated nuclei; and five patterns of morphological malformations were recorded as cytotoxic endpoints including echinocytes, acanthocytes, teardrop-like erythrocytes, microcytes and fused erythrocytes. Frequencies of these abnormalities were significantly different (p<0.05) in comparison to control group. The maximum number of MN, BN and most of NAs and MAEs were recorded in the 5th day of exposure and then start to decrease as recorded in the 7th day. Addition of the vitamin E alone to the diet significantly (p<0.05) decreased the frequencies of MN, BN, and most of NAs and MAEs to become less than those recorded in metals-treated fish. But, addition of a combination of Se with vitamins A, C and E in the diet resulted in more significant decrease (p<0.05) in frequencies of MN, BN, NAs and most MAEs to become less than those recorded in both, fish treated with metals only and fish treated with metals and supplied with vitamin E alone in the diet. Therefore, this study confirms the powerful protective potential of the vitamin E

  12. The effects of rearing density on growth, size heterogeneity and inter-individual variation of feed intake in monosex male Nile tilapia Oreochromis niloticus L.

    PubMed

    Azaza, M S; Assad, A; Maghrbi, W; El-Cafsi, M

    2013-11-01

    The growth dispersion of farmed fish is a subject of increasing interest and one of the most important factors in stocking density. On a duration of 60 days, the effect of stocking density on the growth, coefficient of variation and inter-individual variation of feed intake (CVFI) of juvenile Nile tilapia Oreochromis niloticus L. (14.9 ± 1.2 g) were studied in an experimental tank-based flow-through system. Groups of fish were stocked at four stocking densities: 200, 400, 600 and 800 fish/m3, corresponding to a density of ∼3, 6, 9 and 12 kg/m3 and referred to as D1, D2, D3 and D4, respectively. Each treatment was applied to triplicate groups in a completely randomized design. No treatment-related mortality was observed. The fish densities increased throughout the experiment from 3 to 23.5, 6 to 43.6, 9 to 56.6 and 12 to 69 kg/m3. Results show that mass gain and specific growth rate (SGR, %M/day) were negatively correlated with increased stocking density. Groups of the D1 treatment reached a mean final body mass (FBM) of 119.3 g v. 88.9 g for the D4 groups. Feed conversion ratios (FCRs) were 1.38, 1.54, 1.62 and 1.91 at D1, D2, D3 and D4 treatments, respectively. Growth heterogeneity, expressed by the inter-individual variations of fish mass (CVM), was significantly affected by time (P < 0.001), stocking density (P < 0.001) and their interaction (P < 0.05). The difference in CVM was particularly conspicuous towards the end of the experiment and was positively correlated with stocking density. Similarly, radiographic study shows that CVFI was also found to be significantly greater for groups reared at high stocking densities (D3 and D4) than the other treatments (D1 and D2). These differences in both CVM and CVFI related to the stocking density need to be taken into account by husbandry practices to assure the production of more homogeneous fish size. A simple economic analysis indicates a parabolic relationship between profit and density with optimal final

  13. Growth, body fatty acid composition, immune response and resistance to Streptococcus iniae of hybrid tilapia, Oreochromis niloticus X O. aureus, fed diets containing various levels of linoleic and linolenic acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of dietary linoleic (LA) and linolenic acids (LN) on growth and immunity of all-male hybrid tilapia, Oreochromis niloticus × O. aureus, were evaluated for 10 weeks. Fish fed 0.12% LA + 0% LN had the lowest weight gain (WG) but was not significantly different from diets containing 0.5% LA...

  14. Growth Performance and Resistance to Streptococcus iniae of Nile Tilapia, Oreochromis niloticus Fed Various Dietary Levels of Thiamin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thiamin or vitamin B1 functions in all cells as the coenzyme thiamin pyrophosphate that involves in the oxidative decarboxylation of an alpha-keto acids and the transketolase reactions in the pentose phosphate pathway. Thiamin has been demonstrated to be essential in diets of fish, and quantitative ...

  15. First records of Ambiphrya and Vorticella spp. (Protozoa, Ciliophora) in cultured Nile tilapia (Oreochromis niloticus) in the central region of Saudi Arabia.

    PubMed

    Abdel-Baki, Abdel-Azeem S; Gewik, Mohamed M; Al-Quraishy, Saleh

    2014-12-01

    The present study was carried out as part of an ongoing general survey seeking to uncover protozoan parasites infecting cultured tilapia in the central region of Saudi Arabia. In the sample of 400 specimens of tilapia (Oreochromis niloticus) 30 were infested with Ambiphrya ameiuri simultaneously with Vorticella sp. Morphometric criteria were used to describe and identify these species and this study presents the first records of these species among cultured fish in Saudi Arabia. PMID:25473359

  16. Temperature modulates hepatic carbohydrate metabolic enzyme activity and gene expression in juvenile GIFT tilapia (Oreochromis niloticus) fed a carbohydrate-enriched diet.

    PubMed

    Qiang, J; He, J; Yang, H; Wang, H; Kpundeh, M D; Xu, P; Zhu, Z X

    2014-02-01

    The effects of rearing temperature on hepatic glucokinase (GK), glucose-6-phosphatase (G6Pase) and Glucose-6-phosphate dehydrogenase (G6PD) activity and gene expression were studied in GIFT (genetically improved farmed tilapia) tilapia fed a high carbohydrate diet containing 28% crude protein, 5% crude lipid and 40% wheat starch. Triplicate groups of fish (11.28 g initial body weight) were fed the diet for 45 days at 22 °C, 28 °C or 34 °C. At the end of the trial, final body weight of juvenile at 28 °C (59.12 g) was higher than that of the fish reared at 22 °C (27.13 g) and 34 °C (43.17 g). Feed intake, feed efficiency and protein efficiency ratio were also better at 28 °C. Liver glycogen levels were higher at 28 °C, while plasma glucose levels were higher in the 22 °C group. Significant (P<0.05) effects of water temperature on enzymes activities and gene expression were observed. Hepatic GK activity and mRNA level were higher at 28 °C than at 34 °C. Higher G6Pase and G6PD activity and gene expression were observed at 22 °C. Overall, the data show that juveniles reared at 28 °C exhibited enhanced liver glycolytic capacity. In contrast, hepatic gluconeogenesis and lipogenesis were increased by low temperature (22 °C).

  17. Myo-inositol phosphate synthase expression in the European eel (Anguilla anguilla) and Nile tilapia (Oreochromis niloticus): effect of seawater acclimation.

    PubMed

    Kalujnaia, Svetlana; Hazon, Neil; Cramb, Gordon

    2016-08-01

    A single MIPS gene (Isyna1/Ino1) exists in eel and tilapia genomes with a single myo-d-inositol 3-phosphate synthase (MIPS) transcript identified in all eel tissues, although two MIPS spliced variants [termed MIPS(s) and MIPS(l)] are found in all tilapia tissues. The larger tilapia transcript [MIPS(l)] results from the inclusion of the 87-nucleotide intron between exons 5 and 6 in the genomic sequence. In most tilapia tissues, the MIPS(s) transcript exhibits much higher abundance (generally >10-fold) with the exception of white skeletal muscle and oocytes, in which the MIPS(l) transcript predominates. SW acclimation resulted in large (6- to 32-fold) increases in mRNA expression for both MIPS(s) and MIPS(l) in all tilapia tissues tested, whereas in the eel, changes in expression were limited to a more modest 2.5-fold increase and only in the kidney. Western blots identified a number of species- and tissue-specific immunoreactive MIPS proteins ranging from 40 to 67 kDa molecular weight. SW acclimation failed to affect the abundance of any immunoreactive protein in any tissue tested from the eel. However, a major 67-kDa immunoreactive protein (presumed to be MIPS) found in tilapia tissues exhibited 11- and 54-fold increases in expression in gill and fin samples from SW-acclimated fish. Immunohistochemical investigations revealed specific immunoreactivity in the gill, fin, skin, and intestine taken from only SW-acclimated tilapia. Immunofluorescence indicated that MIPS was expressed within gill chondrocytes and epithelial cells of the primary filaments, basal epithelial cell layers of the skin and fin, the cytosol of columnar intestinal epithelial and mucous cells, as well as unknown entero-endocrine-like cells.

  18. Comprehensive identification and profiling of Nile tilapia (Oreochromis niloticus) microRNAs response to Streptococcus agalactiae infection through high-throughput sequencing.

    PubMed

    Wang, Bei; Gan, Zhen; Cai, Shuanghu; Wang, Zhongliang; Yu, Dapeng; Lin, Ziwei; Lu, Yishan; Wu, Zaohe; Jian, Jichang

    2016-07-01

    MicroRNAs are a kind of small non-coding RNAs that participate in various biological processes. Deregulated microRNA expression is associated with several types of diseases. Tilapia (Oreochromis niloticus) is an important commercial fish species in China. To identify miRNAs and investigate immune-related miRNAs of O. niloticus, we applied high-throughput sequencing technology to identify and analyze miRNAs from tilapia infected with Streptococcus agalactiae at a timescale of 72 h divided into six different time points. The results showed that a total of 3009 tilapia miRNAs were identified, including in 1121 miRNAs which have homologues in the currently available databases and 1878 novel miRNAs. The expression levels of 218 tilapia miRNAs were significantly altered at 6 h-72 h post-bacterial infection (pi), and these miRNAs were therefore classified as differentially expressed tilapia miRNAs. For the 1121 differentially expressed tilapia miRNAs target 41961 genes. GO and KEGG enrichment analysis revealed that some target genes of tilapia miRNAs were grouped mainly into the categories of apoptotic process, signal pathway, and immune response. This is the first report of comprehensive identification of O. niloticus miRNAs being differentially regulated in spleen in normal conditions relating to S. agalactiae infection. This work provides an opportunity for further understanding of the molecular mechanisms of miRNA regulation in O. niloticus host-pathogen interactions.

  19. Myo-inositol phosphate synthase expression in the European eel (Anguilla anguilla) and Nile tilapia (Oreochromis niloticus): effect of seawater acclimation

    PubMed Central

    Kalujnaia, Svetlana; Hazon, Neil

    2016-01-01

    A single MIPS gene (Isyna1/Ino1) exists in eel and tilapia genomes with a single myo-d-inositol 3-phosphate synthase (MIPS) transcript identified in all eel tissues, although two MIPS spliced variants [termed MIPS(s) and MIPS(l)] are found in all tilapia tissues. The larger tilapia transcript [MIPS(l)] results from the inclusion of the 87-nucleotide intron between exons 5 and 6 in the genomic sequence. In most tilapia tissues, the MIPS(s) transcript exhibits much higher abundance (generally >10-fold) with the exception of white skeletal muscle and oocytes, in which the MIPS(l) transcript predominates. SW acclimation resulted in large (6- to 32-fold) increases in mRNA expression for both MIPS(s) and MIPS(l) in all tilapia tissues tested, whereas in the eel, changes in expression were limited to a more modest 2.5-fold increase and only in the kidney. Western blots identified a number of species- and tissue-specific immunoreactive MIPS proteins ranging from 40 to 67 kDa molecular weight. SW acclimation failed to affect the abundance of any immunoreactive protein in any tissue tested from the eel. However, a major 67-kDa immunoreactive protein (presumed to be MIPS) found in tilapia tissues exhibited 11- and 54-fold increases in expression in gill and fin samples from SW-acclimated fish. Immunohistochemical investigations revealed specific immunoreactivity in the gill, fin, skin, and intestine taken from only SW-acclimated tilapia. Immunofluorescence indicated that MIPS was expressed within gill chondrocytes and epithelial cells of the primary filaments, basal epithelial cell layers of the skin and fin, the cytosol of columnar intestinal epithelial and mucous cells, as well as unknown entero-endocrine-like cells. PMID:27252471

  20. Comprehensive identification and profiling of Nile tilapia (Oreochromis niloticus) microRNAs response to Streptococcus agalactiae infection through high-throughput sequencing.

    PubMed

    Wang, Bei; Gan, Zhen; Cai, Shuanghu; Wang, Zhongliang; Yu, Dapeng; Lin, Ziwei; Lu, Yishan; Wu, Zaohe; Jian, Jichang

    2016-07-01

    MicroRNAs are a kind of small non-coding RNAs that participate in various biological processes. Deregulated microRNA expression is associated with several types of diseases. Tilapia (Oreochromis niloticus) is an important commercial fish species in China. To identify miRNAs and investigate immune-related miRNAs of O. niloticus, we applied high-throughput sequencing technology to identify and analyze miRNAs from tilapia infected with Streptococcus agalactiae at a timescale of 72 h divided into six different time points. The results showed that a total of 3009 tilapia miRNAs were identified, including in 1121 miRNAs which have homologues in the currently available databases and 1878 novel miRNAs. The expression levels of 218 tilapia miRNAs were significantly altered at 6 h-72 h post-bacterial infection (pi), and these miRNAs were therefore classified as differentially expressed tilapia miRNAs. For the 1121 differentially expressed tilapia miRNAs target 41961 genes. GO and KEGG enrichment analysis revealed that some target genes of tilapia miRNAs were grouped mainly into the categories of apoptotic process, signal pathway, and immune response. This is the first report of comprehensive identification of O. niloticus miRNAs being differentially regulated in spleen in normal conditions relating to S. agalactiae infection. This work provides an opportunity for further understanding of the molecular mechanisms of miRNA regulation in O. niloticus host-pathogen interactions. PMID:27050313

  1. Myo-inositol phosphate synthase expression in the European eel (Anguilla anguilla) and Nile tilapia (Oreochromis niloticus): effect of seawater acclimation.

    PubMed

    Kalujnaia, Svetlana; Hazon, Neil; Cramb, Gordon

    2016-08-01

    A single MIPS gene (Isyna1/Ino1) exists in eel and tilapia genomes with a single myo-d-inositol 3-phosphate synthase (MIPS) transcript identified in all eel tissues, although two MIPS spliced variants [termed MIPS(s) and MIPS(l)] are found in all tilapia tissues. The larger tilapia transcript [MIPS(l)] results from the inclusion of the 87-nucleotide intron between exons 5 and 6 in the genomic sequence. In most tilapia tissues, the MIPS(s) transcript exhibits much higher abundance (generally >10-fold) with the exception of white skeletal muscle and oocytes, in which the MIPS(l) transcript predominates. SW acclimation resulted in large (6- to 32-fold) increases in mRNA expression for both MIPS(s) and MIPS(l) in all tilapia tissues tested, whereas in the eel, changes in expression were limited to a more modest 2.5-fold increase and only in the kidney. Western blots identified a number of species- and tissue-specific immunoreactive MIPS proteins ranging from 40 to 67 kDa molecular weight. SW acclimation failed to affect the abundance of any immunoreactive protein in any tissue tested from the eel. However, a major 67-kDa immunoreactive protein (presumed to be MIPS) found in tilapia tissues exhibited 11- and 54-fold increases in expression in gill and fin samples from SW-acclimated fish. Immunohistochemical investigations revealed specific immunoreactivity in the gill, fin, skin, and intestine taken from only SW-acclimated tilapia. Immunofluorescence indicated that MIPS was expressed within gill chondrocytes and epithelial cells of the primary filaments, basal epithelial cell layers of the skin and fin, the cytosol of columnar intestinal epithelial and mucous cells, as well as unknown entero-endocrine-like cells. PMID:27252471

  2. An outbreak of disease caused by Francisella sp. in Nile tilapia Oreochromis niloticus at a recirculation fish farm in the UK.

    PubMed

    Jeffery, Keith R; Stone, David; Feist, Stephen W; Verner-Jeffreys, David W

    2010-09-01

    This study details the first diagnosis of Francisella sp. in tilapia in the United Kingdom. Losses of tilapia fry at a recirculation fish farm in England were investigated, giving a presumptive positive diagnosis of infection with Francisella sp. by histopathological examination. Most fish sampled showed moderate to marked pathology of the major organs, with lesions being present in most tissues. The most obvious host response was granuloma formulation. A subsequent follow-up visit provided further evidence for the presence of a Francisella species. PCR amplicons were obtained using Francisella spp.-specific primers that shared 100% sequence identity with the 16S rRNA gene of the type strain of the species F. asiatica previously described as the cause of disease in tilapia in Southeast Asia and Central America. This outbreak and the subsequent investigation emphasise the importance of strict biosecurity at fish farms and the care that needs to be taken when using a new supplier of fish. PMID:21387995

  3. Successful production of Nile and blue tilapia fry - findings based on degree days and demonstrated for earthen ponds in subtropical climates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Degree-days can be used to adjust for seasonal variation in water temperature when planning tilapia fingerling production strategies and are calculated by subtracting a threshold temperature ("biological zero") from the mean daily water temperature; the threshold temperature is the temperature below...

  4. Dietary supplementation with Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus oryzae enhance immunity and disease resistance against Aeromonas hydrophila and Streptococcus iniae infection in juvenile tilapia Oreochromis niloticus.

    PubMed

    Iwashita, Marina Keiko P; Nakandakare, Ivan B; Terhune, Jeffery S; Wood, Theresa; Ranzani-Paiva, Maria José T

    2015-03-01

    A feeding trial was conducted to investigate the effects of dietary administration of probiotic with Bacillus subtilis, Aspergillus oryzae and Saccharomyces cerevisiae on growth, innate immune response, Hemato-immunological parameters and disease resistance of Nile tilapia, Oreochromis niloticus. Animals were distributed in three equal groups, each of five replicates and received one of the following experimental diets for four weeks: Control, non-supplemented diet; 5 g kg(-1) probiotic mixture (B. subtilis 1.5 × 10(9) CFU g(-1), S. cerevisiae 10(9) CFU g(-1) and A. oryzae 2 × 10(9) CFU g(-1)); and 10 g kg(-1) probiotic mixture (B. subtilis 3.0 × 10(9) CFU g(-1), S. cerevisiae 2.0 × 10(9) CFU g(-1) and A. oryzae 4.0 × 10(9) CFU g(-1)). The respiratory burst activity, white blood cells and hematological parameters were evaluated after four, five and six weeks of feeding. At the end of the growth trial, fish were sampled for intestinal microbiology and challenged by intraperitoneal injection of LD50 concentration of Aeromonas hydrophila and Streptococcus iniae. Mortality was recorded for the following 3 weeks. Results showed that administration of the probiotic had no significant effect on the growth rates of Nile tilapias, although the fish fed probiotics had better feed conversion. Respiratory burst activity, erythrocyte fragility and levels of white blood cells were significantly improved in tilapias fed diet supplemented with probiotic levels (P < 0.05), which may exhibit up-regulating effects on tilapia immune parameters. The cumulative mortality after A. hydrophila and S. iniae challenge decreased in tilapias fed with probiotic (P < 0.05). The present study demonstrated the potential of B. subtilis, S. cerevisiae and A. oryzae combined as beneficial dietary probiotic in juvenile O. niloticus.

  5. A novel seminal plasma glycoprotein of a teleost, the Nile tilapia (Oreochromis niloticus), contains a partial von Willebrand factor type D domain and a zona pellucida-like domain.

    PubMed

    Mochida, Kazuhiko; Matsubara, Takahiro; Andoh, Tadashi; Ura, Kazuhiro; Adachi, Shinji; Yamauchi, Kohei

    2002-05-01

    Our previous study shows that seminal plasma of a teleost, the Nile tilapia, contains a glycoprotein Mr = 120,000 named as SPP (Seminal plasma glycoprotein)120 which forms a homopolymer that has sperm immobilizing activity. In order to elucidate the mechanisms of the formation of the homopolymer and the immobilization of sperm, molecular cloning of SPP120 was conducted. The cDNA for SPP120 contains a complete open reading frame encoding 797 amino acid residues with 14 potential N-glycosylation sites. The predicted amino acid sequence of SPP120 contains a partial von Willebrand factor type D domain and a zona pellucida domain, that are involved in protein-protein adhesion that form filamentous structures in various kinds of cells. This result suggests that SPP120 forms a homopolymer via these domains in seminal plasma and probably interacts with spermatozoa. Northern blotting reveals that the gene is also expressed in ovary, even in ovulated eggs. The results of in situ hybridization indicate that in testis the gene is expressed in Sertoli cells and epithelial cells of sperm ducts, and the localization corresponds to that of the protein analyzed by immunohistochemistry. In the ovary, the gene is expressed at the perinucleolus stage of oocytes; however, the protein is not detected in any cells other than oocytes. PMID:11933161

  6. Optimization of the sublethal dose of silver nanoparticle through evaluating its effect on intestinal physiology of Nile tilapia (Oreochromis niloticus L.).

    PubMed

    Sarkar, Biplab; Jaisai, Mayuree; Mahanty, Arabinda; Panda, Pragnya; Sadique, Mohammad; Nayak, B B; Gallardo, G; Thakur, D; Bhattacharjee, Surajit; Dutta, Joydeep

    2015-01-01

    Silver nanoparticles (SNPs) are widely used in a variety of biomedical and consumer products as an antimicrobial additive. The present study was conducted to evaluate the impacts of low-dose SNPs on intestinal physiology of tilapia (Oreochromis niloticus L.) for assessing its apparent environmental risk due to extensive commercial use. SNPs were synthesized by a chemical reduction method yielding 1-27 nm oval shaped particles. Early fingerlings of tilapia were exposed with two sublethal concentrations (0.8 and 0.4 mg L(-1)) of SNPs for twenty one days period and its impact on the intestinal physiology was evaluated by histochemistry, catalase expression, glutamate dehydrogenase activity, SDS-PAGE and gut micro flora count. Histological analysis showed thinning of intestinal wall, swelling on mucosal layer and immunohistochemical assay exhibited an enhanced catalase expression in SNPs treated fishes. Gut microflora count elicited a dose-dependent depletion and a variable SDS-PAGE profile followed by significant (P < 0.05) elevations in glutamate dehydrogenase activity in SNPs-treated fishes. This study was designed to provide a better understanding of environmentally acceptable, dose-dependent SNPs delivery in fishes and to formulate guidelines in aquatic toxicology. PMID:26030687

  7. SNP marker detection and genotyping in tilapia.

    PubMed

    Van Bers, N E M; Crooijmans, R P M A; Groenen, M A M; Dibbits, B W; Komen, J

    2012-09-01

    We have generated a unique resource consisting of nearly 175 000 short contig sequences and 3569 SNP markers from the widely cultured GIFT (Genetically Improved Farmed Tilapia) strain of Nile tilapia (Oreochromis niloticus). In total, 384 SNPs were selected to monitor the wider applicability of the SNPs by genotyping tilapia individuals from different strains and different geographical locations. In all strains and species tested (O. niloticus, O. aureus and O. mossambicus), the genotyping assay was working for a similar number of SNPs (288-305 SNPs). The actual number of polymorphic SNPs was, as expected, highest for individuals from the GIFT population (255 SNPs). In the individuals from an Egyptian strain and in individuals caught in the wild in the basin of the river Volta, 197 and 163 SNPs were polymorphic, respectively. A pairwise calculation of Nei's genetic distance allowed the discrimination of the individual strains and species based on the genotypes determined with the SNP set. We expect that this set will be widely applicable for use in tilapia aquaculture, e.g. for pedigree reconstruction. In addition, this set is currently used for assaying the genetic diversity of native Nile tilapia in areas where tilapia is, or will be, introduced in aquaculture projects. This allows the tracing of escapees from aquaculture and the monitoring of effects of introgression and hybridization. PMID:22524158

  8. SNP marker detection and genotyping in tilapia.

    PubMed

    Van Bers, N E M; Crooijmans, R P M A; Groenen, M A M; Dibbits, B W; Komen, J

    2012-09-01

    We have generated a unique resource consisting of nearly 175 000 short contig sequences and 3569 SNP markers from the widely cultured GIFT (Genetically Improved Farmed Tilapia) strain of Nile tilapia (Oreochromis niloticus). In total, 384 SNPs were selected to monitor the wider applicability of the SNPs by genotyping tilapia individuals from different strains and different geographical locations. In all strains and species tested (O. niloticus, O. aureus and O. mossambicus), the genotyping assay was working for a similar number of SNPs (288-305 SNPs). The actual number of polymorphic SNPs was, as expected, highest for individuals from the GIFT population (255 SNPs). In the individuals from an Egyptian strain and in individuals caught in the wild in the basin of the river Volta, 197 and 163 SNPs were polymorphic, respectively. A pairwise calculation of Nei's genetic distance allowed the discrimination of the individual strains and species based on the genotypes determined with the SNP set. We expect that this set will be widely applicable for use in tilapia aquaculture, e.g. for pedigree reconstruction. In addition, this set is currently used for assaying the genetic diversity of native Nile tilapia in areas where tilapia is, or will be, introduced in aquaculture projects. This allows the tracing of escapees from aquaculture and the monitoring of effects of introgression and hybridization.

  9. Diplostomiasis in cultured and wild tilapia Oreochromis niloticus in Guerrero State, Mexico.

    PubMed

    Violante-González, Juan; García-Varela, Martín; Rojas-Herrera, Agustín; Guerrero, Salvador Gil

    2009-09-01

    This paper is a comparative study of Diplostomum (Austrodiplostomum) compactum (Lutz, 1928) in Nile tilapia Oreochromis niloticus (Linneo) from two fish farms and two nearby coastal lagoons in Guerrero state, Mexico. The higher infections levels in cultured tilapia than wild tilapia is attributed to higher fish densities in the culture systems and higher abundance of the snail Biomphalaria cf. havanensis (Pteiffer), first intermediate host of this parasite in freshwater and brackish water systems. PMID:19452167

  10. Evaluation of the impact of dietary petroselinic acid on the growth performance, fatty acid composition, and efficacy of long chain-polyunsaturated fatty acid biosynthesis of farmed Nile tilapia.

    PubMed

    Teoh, Chaiw-Yee; Ng, Wing-Keong

    2013-06-26

    The present study aimed to investigate the potential role of dietary petroselinic acid (PSA) in enhancing the n-3 long-chain polyunsaturated fatty acid (LC-PUFA) content in fish tissues. Three isolipidic casein-based diets were formulated to comprise graded levels of PSA (0, 10, or 20% of total fatty acid) with the incremented inclusion of coriander seed oil. Fish growth and nutrient digestibility were not significantly (P > 0.05) influenced by dietary PSA level. In general, dietary PSA affected the fatty acid composition of tilapia tissues and whole-body, which reflected dietary fatty acid ratios. Dietary PSA significantly (P < 0.05) increased β-oxidation, particularly on α-linolenic acid (18:3n-3) and linoleic acid (18:2n-6). This study provided evidence that PSA, a pseudoproduct mimicking the structure of 18:3n-6, did reduce Δ-6 desaturation on 18:2n-6 but, contrary to popular speculation, did not stimulate more Δ-6 desaturase activity on 18:3n-3. The overall Δ-6 desaturase enzyme activity may be suppressed at high dietary levels of PSA. Nevertheless, the n-3 and n-6 LC-PUFA biosynthesis was not significantly inhibited by dietary PSA, indicating that the bioconversion efficiency is not modulated only by Δ-6 desaturase. The deposition of n-3 LC-PUFA in liver and fillet lipids was higher in fish fed PSA-supplemented diets.

  11. Pubertal effects of 17α-methyltestosterone on GH-IGF-related genes of the hypothalamic-pituitary-liver-gonadal axis and other biological parameters in male, female and sex-reversed Nile tilapia.

    PubMed

    Phumyu, Nonglak; Boonanuntanasarn, Surintorn; Jangprai, Araya; Yoshizaki, Goro; Na-Nakorn, Uthairat

    2012-06-01

    The influence of 17α-methyltestosterone (MT) on growth responses, biological parameters and the expression of genes involved in the GH-IGF pathway of the hypothalamic-pituitary-liver-gonadal axis were investigated in female, male, and sex-reversed Nile tilapia to evaluate the relationship between sex and MT-induced changes in these parameters. Female fish had a lower growth rate than male and sex-reversed fish, and MT increased growth performance and duodenal villi in females. Most but not all biological parameters of sex-reversed fish were similar to those of male fish. Male fish had higher red blood cell counts and hemoglobin levels than female and sex-reversed fish, suggesting that these hematological indices reflect a higher metabolic rate in male fish. Greater blood triglyceride levels indicated the vitellogenin process in female fish. MT increased the alternative complement activity in female fish (P<0.05). Sex and MT had no significant effects on the hypothalamic mRNAs of GHRH and PACAP. Although not statistically significant, females tended to have higher GH mRNA levels than male and sex-reversed fish. Additionally, MT tended to decrease and increase GH mRNA levels in female and male fish, respectively. There were significant differences among sexes in the expression of GHR, and IGF mRNAs at the peripheral level in the liver and gonads. Females had lower hepatic GHRs and higher ovarian GHRs than male and sex-reversed fish. While the mRNA levels of IGF-1 were lower in the ovary, the levels of IGF-2 were higher compared with those in testes. A significant correlation between GHRs and IGFs was demonstrated in the liver and gonad (except for IGF-1). Multiple regression analysis showed a significant relationship between GH mRNA and both GHRs and IGFs in the liver and gonad. MT exerted androgenic and, to some extent, estrogenic effects on several physiological parameters and GH-IGF action.

  12. Molecular characterization and expression analyses of cDNAs encoding the thioredoxin-interacting protein and selenoprotein P genes and histological changes in Nile tilapia (Oreochromis niloticus) in response to silver nanoparticle exposure.

    PubMed

    Thummabancha, Kubpaphas; Onparn, Nuttaphon; Srisapoome, Prapansak

    2016-02-15

    Herein, Nile tilapia thioredoxin-interacting protein (On-TXNIP) and selenoprotein P (On-SEPP) cDNAs were cloned and characterized. The full-length On-TXNIP cDNA contained 2 arrestin domains, 2 conserved cysteine residues that bind to thioredoxin to inhibit thioredoxin function, and 2 PPXY motifs, which negatively regulate the protein by stimulating binding to E3 ubiquitin ligase. The On-SEPP cDNA contained 17 selenocysteines (Sec) encoded by the TGA codon, which can be recognized as either a stop codon or a Sec codon. The On-SEPP cDNA also carried 2 typical SECIS elements located in the 3'UTR that are important for selenocysteine translation. Evolutionary analyses of both the On-TXNIP and On-SEPP genes revealed that these genes are closely related to the TXNIP and SEPP genes in zebrafish (Danio rerio), with amino acid similarities of 91.8% and 61.9%, respectively. A normal tissue distribution analysis indicated that the On-TXNIP and On-SEPP genes were ubiquitously expressed in all tissues examined, and the highest expression levels of these genes were observed in peripheral blood leukocytes (PBLs) and the trunk kidney, respectively. The expression levels of On-TXNIP and On-SEPP transcripts were acutely and chronically analyzed following the injection of fish with 1, 10 or 100mg/kg silver nanoparticles (Ag NPs). Significant up-regulation of On-TXNIP and On-SEPP transcripts was observed in the liver, spleen, and head kidney at the early phase of Ag NP exposure (hours 6 through 48). Down-regulation of On-SEPP transcripts was clearly observed in the liver at weeks 1 to 4. Histopathology analysis demonstrated that the fish livers exhibited a dramatic infiltration of Kupffer cells, elevated bi-nucleated cells, expanded sinusoidal blood congestion and severe necrosis in a dose-dependent manner. Based on these findings, coupling of the expression analysis of these two cellular stress response genes and histopathological observation of fish exposed to Ag NPs should be

  13. Molecular characterization and expression analyses of cDNAs encoding the thioredoxin-interacting protein and selenoprotein P genes and histological changes in Nile tilapia (Oreochromis niloticus) in response to silver nanoparticle exposure.

    PubMed

    Thummabancha, Kubpaphas; Onparn, Nuttaphon; Srisapoome, Prapansak

    2016-02-15

    Herein, Nile tilapia thioredoxin-interacting protein (On-TXNIP) and selenoprotein P (On-SEPP) cDNAs were cloned and characterized. The full-length On-TXNIP cDNA contained 2 arrestin domains, 2 conserved cysteine residues that bind to thioredoxin to inhibit thioredoxin function, and 2 PPXY motifs, which negatively regulate the protein by stimulating binding to E3 ubiquitin ligase. The On-SEPP cDNA contained 17 selenocysteines (Sec) encoded by the TGA codon, which can be recognized as either a stop codon or a Sec codon. The On-SEPP cDNA also carried 2 typical SECIS elements located in the 3'UTR that are important for selenocysteine translation. Evolutionary analyses of both the On-TXNIP and On-SEPP genes revealed that these genes are closely related to the TXNIP and SEPP genes in zebrafish (Danio rerio), with amino acid similarities of 91.8% and 61.9%, respectively. A normal tissue distribution analysis indicated that the On-TXNIP and On-SEPP genes were ubiquitously expressed in all tissues examined, and the highest expression levels of these genes were observed in peripheral blood leukocytes (PBLs) and the trunk kidney, respectively. The expression levels of On-TXNIP and On-SEPP transcripts were acutely and chronically analyzed following the injection of fish with 1, 10 or 100mg/kg silver nanoparticles (Ag NPs). Significant up-regulation of On-TXNIP and On-SEPP transcripts was observed in the liver, spleen, and head kidney at the early phase of Ag NP exposure (hours 6 through 48). Down-regulation of On-SEPP transcripts was clearly observed in the liver at weeks 1 to 4. Histopathology analysis demonstrated that the fish livers exhibited a dramatic infiltration of Kupffer cells, elevated bi-nucleated cells, expanded sinusoidal blood congestion and severe necrosis in a dose-dependent manner. Based on these findings, coupling of the expression analysis of these two cellular stress response genes and histopathological observation of fish exposed to Ag NPs should be

  14. Replacement of dietary fish oils by alpha-linolenic acid-rich oils lowers omega 3 content in tilapia flesh.

    PubMed

    Karapanagiotidis, Ioannis T; Bell, Michael V; Little, David C; Yakupitiyage, Amararatne

    2007-06-01

    A 20-week feeding trial was conducted to determine whether increasing linolenic acid (18:3n-3) in vegetable oil (VO) based diets would lead to increased tissue deposition of 22:6n-3 in Nile tilapia (Oreochromis niloticus). Five isonitrogenous and isoenergetic diets were supplemented with 3% of either linseed oil (LO), a mixture of linseed oil with refined palm olein oil (PO) (LO-PO 2:1) and a mixture of refined palm olein oil with linseed oil (PO-LO 3:2) or with fish oil (FO) or corn oil (CO) as controls. The PO-LO, LO-PO and LO diets supplied a similar amount of 18:2n-6 (0.5% of diet by dry weight) and 0.5, 0.7 and 1.1% of 18:3n-3, respectively. Increased dietary 18:3n-3 caused commensurate increases in longer-chain n-3 PUFA and decreases in longer-chain n-6 PUFA in the muscle lipids of tilapia. However, the biosynthetic activities of fish fed the LO-based diets were not sufficient to raise the tissue concentrations of 20:5n-3, 22:5n-3 and 22:6n-3 to those of fish fed FO. The study suggests that tilapia (O. niloticus) has a limited capacity to synthesise 20:5n-3 and 22:6n-3 from dietary 18:3n-3. The replacement of FO in the diet of farmed tilapia with vegetable oils could therefore lower tissue concentrations of 20:5n-3 and 22:6n-3, and consequently produce an aquaculture product of lower lipid nutritional value for the consumer.

  15. Nile Delta

    Atmospheric Science Data Center

    2013-04-15

    article title:  The Nile River Delta     View Larger Image ... of eastern Africa. At the apex of the fertile Nile River Delta is the Egyptian capital city of Cairo. To the west are the Great Pyramids ...

  16. Effectiveness of Aquaflor (50% florfenicol) administered in feed to control mortality associated with Streptococcus iniae in tilapia at a commercial tilapia production facility

    USGS Publications Warehouse

    Gaikowski, Mark P.; Schleis, Susan M.; Leis, Eric; Lasee, Becky A.; Endris, Richard G.

    2014-01-01

    The efficacy of Aquaflor (florfenicol; FFC) to control mortality caused by Streptococcus iniae in tilapia was evaluated under field conditions. The trial was initiated following presumptive diagnosis of S. iniae infection in a mixed group of fingerling (mean, 4.5 g) Nile Tilapia Oreochromis niloticus and a hybrid of Nile Tilapia×Blue Tilapia O. aureus. Diagnoses included mortality in source tank; examination of clinical signs and presence or absence of gram-positive cocci in brain, and collection of samples for microbiological review and disease confirmation of 60 moribund fish. Following presumptive diagnosis, tilapia (83/tank) were randomly transferred to each of 20 test tanks receiving the same water as the source tank (test tank water was not reused). Tilapia were offered either nonmedicated control feed or FFC-medicated feed (FFC at 15 mg/kg body weight/d; 10 tanks per regimen) for 10 consecutive days followed by a 14-d observation period during which only the nonmedicated control feed was offered. Streptococcus iniae was presumptively identified during pretreatment necropsy and confirmed by polymerase chain reaction assay; S. iniae was confirmed in samples taken during the dosing period but was not detected during the postdosing period. The FFC disk diffusion zone of inhibition ranged from 29 to 32 mm, while the minimum inhibitory concentration of FFC ranged from 2 to 4 μg/mL for the S. iniae isolates collected. Survival of tilapia assigned to the FFC-dose group was significantly greater at 14 d posttreatment than that of the nonmedicated controls. The odds of tilapia assigned to the FFC-dose group surviving to the end of the postdosing period were 1.34 times the odds of survival of tilapia assigned to the nonmedicated control group. There were no clinically apparent adverse effects associated with the administration of FFC-medicated feed in this study.

  17. Nile Delta

    Atmospheric Science Data Center

    2013-04-16

    ... Mediterranean Sea. The Nile provides a year-round source of water as well as fertile silt deposits that have supported agricultural ... waterway, although in the twentieth century that role became less important. The false color image uses the infrared, red, ...

  18. Probiotic Pediococcus acidilactici modulates both localised intestinal- and peripheral-immunity in tilapia (Oreochromis niloticus).

    PubMed

    Standen, B T; Rawling, M D; Davies, S J; Castex, M; Foey, A; Gioacchini, G; Carnevali, O; Merrifield, D L

    2013-10-01

    The application of probiotics in aquaculture has received concerted research efforts but the localised intestinal immunological response of fish to probiotic bacteria is poorly understood. Therefore, a study was conducted to evaluate the probiotic effect of Pediococcus acidilactici on Nile tilapia (Oreochromis niloticus) with specific emphasis on intestinal health and probiotic levels as well as system level responses such as growth performance, feed utilization and haemato-immunological parameters under non-challenged conditions. Fish (9.19 ± 0.04 g) were fed either a control diet or a P. acidilactici supplemented diet (at 2.81 × 10(6) CFU g(-)(1)) for six weeks. At the end of the study the probiotic was observed to populate the intestine, accounting for ca. 3% (1.59 × 10(5) CFU g(-)(1)) of the cultivable intestinal bacterial load. Real-time PCR indicated that the probiotic treatment may potentiate the immune-responsiveness of the intestine as up-regulation of the gene expression of the pro-inflammatory cytokine TNFα was observed in the probiotic fed fish (P < 0.05). Light microscopy observations revealed elevated intraepithelial leucocyte (IEL) levels in the intestine of P. acidilactici fed tilapia after six weeks (P < 0.05) of feeding and a trend towards elevated goblet cells was also observed after six weeks feeding (P = 0.08). Concomitantly at week six, along with elevated IELs and elevated TNFα mRNA levels in the intestine, an increased abundance of circulating neutrophils and monocytes were observed in fish fed the probiotic supplemented diet (P < 0.05). This haemopoietic expansion of innate immune cells could be reflective of an elevated state of immuno-readiness. Together these results suggest that the probiotic has a protective action on the intestinal mucosal cells, stimulating the innate immune response after feeding for a period of six weeks. These immunological modulations did not impair growth performance or the remaining haematological and

  19. Quaternary history of the White Nile

    NASA Astrophysics Data System (ADS)

    williams, martin

    2014-05-01

    The White Nile only joined the Blue Nile ~0.3 Ma ago. It provides much of the low water discharge to the Nile. Without this contribution, in very dry years the Nile would dry up during the winter months. Owing to its very gentle flood gradient of 1: 100,000, the White Nile has an unusually complete alluvial record. High White Nile flood levels dated by OSL are synchronous with sapropel units S8, S7, S6, S5 and S1 in the East Mediterranean, which have astronomical ages of 217, 195, 172, 124 and 8 ka, respectively. Blue Nile palaeochannels that flow into the former White Nile complete the flood record, and coincide with sapropel units S4, S3 and S2, with respective ages of 102, 81 and 55 ka. The two most recent phases of very high White Nile flow were marked by widespread flooding across the lower White Nile valley during the last interglacial and the terminal Pleistocene - the latter coinciding with the abrupt return of the summer monsoon at 14.5 ka and the synchronous onset of humid conditions across the Sahara and East Africa, which ended suddenly at 5 ka, when desiccation set in. This humid phase was not uniformly wet; nor was the late Holocene uniformly dry. High White Nile flood levels have calibrated radiocarbon ages of 14.7-13.1, 9.7-9.0, 7.9-7.6, 6.3 and 3.2-2.8 ka obtained on freshwater gastropod shells. It was during these times that the White Nile valley was occupied successively by Mesolithic, Neolithic and Meroitic societies. West of the lower White Nile shallow ponds fed by local runoff supported an abundant gastropod fauna between 9.9 and 7.6 ka, with peak wetness at 9.0-8.4 ka, coeval with Mesolithic barbed bone harpoon sites east of the lower White Nile. The drier intervals recorded in the White Nile valley appear to coincide with times of polar cooling and more widespread tropical aridity.

  20. Tilapia sex determination: Where temperature and genetics meet.

    PubMed

    Baroiller, J F; D'Cotta, H; Bezault, E; Wessels, S; Hoerstgen-Schwark, G

    2009-05-01

    This review deals with the complex sex determining system of Nile tilapia, Oreochromis niloticus, governed by the interactions between a genetic determination and the influence of temperature, shown in both domestic and wild populations. Naturally sex reversed individuals are strongly suggested in two wild populations. This can be due to the masculinising temperatures which some fry encounter during their sex differentiation period when they colonise shallow waters, and/or to the influence of minor genetic factors. Differences regarding a) thermal responsiveness of sex ratios between and within Nile tilapia populations, b) maternal and paternal effects on temperature dependent sex ratios and c) nearly identical results in offspring of repeated matings, demonstrate that thermosensitivity is under genetic control. Selection experiments to increase the thermosensitivity revealed high responses in the high and low sensitive lines. The high-line showed approximately 90% males after 2 generations of selection whereas the weakly sensitive line had 54% males. This is the first evidence that a surplus of males in temperature treated groups can be selected as a quantitative trait. Expression profiles of several genes (Cyp19a, Foxl2, Amh, Sox9a,b) from the gonad and brain were analysed to define temperature action on the sex determining/differentiating cascade in tilapia. The coexistence of GSD and TSD is discussed. PMID:19101647

  1. Resource recovery from septic tank effluent using duckweed-based tilapia aquaculture.

    PubMed

    El-Shafai, Saber A; Abdel-Gawad, Fagr Kh; Samhan, Farag; Nasr, Fayza A

    2013-01-01

    Two parallel duckweed ponds were deployed to utilize nutrients from the effluent of a septic tank treating domestic wastewater. The effluent and fresh biomass of duckweed pond were fed to two subsequent fish ponds stocked with Nile tilapia (Oreochromis niloticus). Fish ponds receiving freshwater and commercial feed were used as control. The results of specific growth rate and feed conversion ratio showed no significant difference between the control ponds and treatment ponds. On the other hand, the total and net fish yields were significantly higher in the control. Microbial analysis revealed contamination of gills, intestine and liver of fish in the treatment ponds. The activity of the immune response genes was up-regulated in the brain and liver of the treatment samples. A micronucleus assay revealed a similar percentage of micronuclei in the polychromatic erythrocytes of blood in the control and treatment samples, while the treatment samples a had higher incidence of micronuclei in the polychromatic erythrocytes of gills, compared with the control.

  2. West Nile virus

    MedlinePlus

    ... believe West Nile virus is spread when a mosquito bites an infected bird and then bites a person. ... avoid getting West Nile virus infection after a mosquito bite. People in good health generally do not develop ...

  3. Evaluation of distiller’s dried grains with solubles (DDGS) from different grain sources as dietary protein for hybrid tilapia, Oreochromis niloticus x O. Aureus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of distiller’s dried grains with solubles (DDGS) from different sources on growth performance, hematology, and immunity of hybrid tilapia, Oreochromis niloticus x O. aureus, were evaluated. Sex-reversed, all-male hybrid tilapia (3.72 ± 0.08 g initial weight) were fed diets in which 30% o...

  4. Growth and body composition of nile tilapia, Oreochromis niloticus, fry fed organic diets containing yeast extract and soybean meal as replacements for fish meal, with and without supplemental lysine and methionine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantities of fishmeal (FM) have remained level for the past several decades; however, demand has dramatically increased due to its inclusion in all animal production as a high quality protein source. Soybean meal (SBM) is the most widely-used plant-protein ingredient for replacing various proportio...

  5. Effects on growth and body composition in Nile tilapia, Oreochromis niloticus, fry fed organic diets containing yeast extract and soybean meal as total replacement of fish meal without amino acid supplementation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fish meal (FM) is the main protein source in numerous aquaculture diets due to its palatability and quality. Quantities of FM have remained constant for the past several decades; however, demand has dramatically increased due to its inclusion in diets used for the global aquaculture industry. Ther...

  6. The effects of five different glycans on innate immune responses by phagocytes of hybrid tilapia and Japanese eels Anguilla japonica.

    PubMed

    Wang, Way-Shyan; Hung, Shao-Wen; Lin, Yu-Hsing; Tu, Ching-Yu; Wong, Min-Liang; Chiou, Shiow-Her; Shieh, Meng-Tong

    2007-03-01

    The aim of this study was to evaluate the immune responses in hybrid tilapia (Nile tilapia Oreochromis niloticus x Mozambique tilapia O. mossambicus) and Japanese eels Anguilla japonica after treatment with five glycans: barley, krestin, MacroGard, scleroglucan, and zymosan. The effects of the glycans on the innate immune responses of the fish were investigated using the phagocytic index (PI), lysozyme activity, complement opsonization, and activation assay. The results of the lysozyme assay demonstrated that the lysozyme activities increased after treatment with glycans. Moreover, based on the PI, treatment with each of the five glycans resulted in increased phagocytic activities in anterior kidney and peripheral blood phagocytes in both tilapia and Japanese eels. The opsonic effect of complement on phagocytosis in tilapia and Japanese eels were investigated using baker's yeast, which served as the activator in the classical complement pathway (CCP) and in the alternative complement pathway (ACP). Tilapia and Japanese eel sera that were treated with glycans greatly enhanced phagocytosis. The classical pathway--hemolytic complement titer (CH50) of Japanese eels treated with glycans was slightly increased in vitro and in vivo. While glycan treatment enhanced the CCP of both species in vitro and in vivo, the alternative pathway-hemolytic complement titer (ACH50) was only increased in vitro and in vivo in glycan-treated tilapia. Thus, it follows that the ACP must have been activated in tilapia treated with glycans. However, in Japanese eels, the ACH50 of the ACP activation assay was undetected in vitro or in vivo due to possible unknown factors in the Japanese eel serum that caused lysis of the rabbit red blood cells. Our study investigated the effects of glycans used to enhance phagocytosis and activate both of the complement pathways involved in stimulating the innate immune responses of Japanese eels and tilapia. PMID:18236632

  7. Behaviours Associated with Acoustic Communication in Nile Tilapia (Oreochromis niloticus)

    PubMed Central

    Longrie, Nicolas; Poncin, Pascal; Denoël, Mathieu; Gennotte, Vincent; Delcourt, Johann; Parmentier, Eric

    2013-01-01

    Background Sound production is widespread among fishes and accompanies many social interactions. The literature reports twenty-nine cichlid species known to produce sounds during aggressive and courtship displays, but the precise range in behavioural contexts is unclear. This study aims to describe the various Oreochromis niloticus behaviours that are associated with sound production in order to delimit the role of sound during different activities, including agonistic behaviours, pit activities, and reproduction and parental care by males and females of the species. Methodology/Principal Findings Sounds mostly occur during the day. The sounds recorded during this study accompany previously known behaviours, and no particular behaviour is systematically associated with sound production. Males and females make sounds during territorial defence but not during courtship and mating. Sounds support visual behaviours but are not used alone. During agonistic interactions, a calling Oreochromis niloticus does not bite after producing sounds, and more sounds are produced in defence of territory than for dominating individuals. Females produce sounds to defend eggs but not larvae. Conclusion/Significance Sounds are produced to reinforce visual behaviours. Moreover, comparisons with O. mossambicus indicate two sister species can differ in their use of sound, their acoustic characteristics, and the function of sound production. These findings support the role of sounds in differentiating species and promoting speciation. They also make clear that the association of sounds with specific life-cycle roles cannot be generalized to the entire taxa. PMID:23620756

  8. Human Streptococcus agalactiae isolate in Nile tilapia (Oreochromis niloticus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae, the Lancefield group B Streptococcus (GBS), long recognized as a mammalian pathogen, is an emerging pathogen to fish. We show that a GBS serotype Ia, multilocus sequence type ST-7 isolate from a human neonatal meningitis clinical case causes disease signs and mortality in N...

  9. Microbiological quality of fish grown in wastewater-fed and non-wastewater-fed fishponds in Hanoi, Vietnam: influence of hygiene practices in local retail markets.

    PubMed

    Lan, Nguyen Thi Phong; Dalsgaard, Anders; Cam, Phung Dac; Mara, Duncan

    2007-06-01

    Mean water quality in two wastewater-fed ponds and one non-wastewater-fed pond in Hanoi, Vietnam was approximately 10(6) and approximately 10(4) presumptive thermotolerant coliforms (pThC) per 100 ml, respectively. Fish (common carp, silver carp and Nile tilapia) grown in these ponds were sampled at harvest and in local retail markets. Bacteriological examination of the fish sampled at harvest from both types of pond showed that they were of very good quality (2 - 3 pThC g(-1) fresh muscle weight), despite the skin and gut contents being very contaminated (10(2) - 10(3) pThC g(-1) fresh weight and 10(4) - 10(6) pThC g(-1) fresh weight, respectively). These results indicate that the WHO guideline quality of < or = 1000 faecal coliforms per 100 ml of pond water in wastewater-fed aquaculture is quite restrictive and represents a safety factor of approximately 3 orders of magnitude. However, when the fish from both types of pond were sampled at the point of retail sale, quality deteriorated to 10(2) - 10(5) pThC g(-1) of chopped fresh fish (mainly flesh and skin contaminated with gut contents); this was due to the practice of the local fishmongers in descaling and chopping up the fish from both types of pond with the same knife and on the same chopping block. Fishmonger education is required to improve their hygienic practices; this should be followed by regular hygiene inspections.

  10. Microbiological quality of fish grown in wastewater-fed and non-wastewater-fed fishponds in Hanoi, Vietnam: influence of hygiene practices in local retail markets.

    PubMed

    Lan, Nguyen Thi Phong; Dalsgaard, Anders; Cam, Phung Dac; Mara, Duncan

    2007-06-01

    Mean water quality in two wastewater-fed ponds and one non-wastewater-fed pond in Hanoi, Vietnam was approximately 10(6) and approximately 10(4) presumptive thermotolerant coliforms (pThC) per 100 ml, respectively. Fish (common carp, silver carp and Nile tilapia) grown in these ponds were sampled at harvest and in local retail markets. Bacteriological examination of the fish sampled at harvest from both types of pond showed that they were of very good quality (2 - 3 pThC g(-1) fresh muscle weight), despite the skin and gut contents being very contaminated (10(2) - 10(3) pThC g(-1) fresh weight and 10(4) - 10(6) pThC g(-1) fresh weight, respectively). These results indicate that the WHO guideline quality of < or = 1000 faecal coliforms per 100 ml of pond water in wastewater-fed aquaculture is quite restrictive and represents a safety factor of approximately 3 orders of magnitude. However, when the fish from both types of pond were sampled at the point of retail sale, quality deteriorated to 10(2) - 10(5) pThC g(-1) of chopped fresh fish (mainly flesh and skin contaminated with gut contents); this was due to the practice of the local fishmongers in descaling and chopping up the fish from both types of pond with the same knife and on the same chopping block. Fishmonger education is required to improve their hygienic practices; this should be followed by regular hygiene inspections. PMID:17674570

  11. Quality properties, fatty acids, and biogenic amines profile of fresh tilapia stored in ice.

    PubMed

    Kulawik, Piotr; Özoğul, Fatih; Glew, Robert H

    2013-07-01

    This work determines quality properties and fatty acids content of Nile tilapia (Oreochromis niloticus) stored in ice for 21 d. The quality properties consist of thiobarbituic acid (TBA), total volatile basic nitrogen (TVB-N), trimethylamine (TMA), and microbiological analysis (total viable count (TVC), total coliform, Salmonella and Staphylococcus aureus) and determination of biogenic amines content (histamine, cadaverine, putrescine, spermine, spermidine, 2-phenylethylamine, agmatine, tyramine, and ammonia). Moreover, the fat, moisture, and ash composition as well as fatty acids profile have also been analyzed. The TBA, TVB-N, and biogenic amines analysis showed rather low levels of spoilage even after 21 d of storage. The microbiological analysis, however, showed that tilapia was unsuitable for consumption after just 10 d. The fat, ash, moisture, and fatty acids profile analysis showed that tilapia is not a good source of n-3 fatty acids. The research indicated that the microbiological analysis was the best method to establish spoilage of tilapia stored in ice, of all analytical methods performed in this study.

  12. Shelf life of air and modified atmosphere-packaged fresh tilapia (Oreochromis niloticus) fillets stored under chilled and superchilled conditions.

    PubMed

    Cyprian, Odoli; Lauzon, Hélène L; Jóhannsson, Ragnar; Sveinsdóttir, Kolbrún; Arason, Sigurjón; Martinsdóttir, Emilía

    2013-03-01

    Optimal packaging and storage conditions for fresh tilapia fillets were established by evaluating sensory and microbiological changes, as well as monitoring physicochemical properties. Nile tilapia (Oreochromis niloticus) farmed in recirculation aquaculture system was filleted, deskinned, and packaged in air and 50% CO2/50% N2 prior to chilling and superchilling storage at 1°C and -1°C. Sensory analysis of cooked samples revealed a shelf life of 13-15 days for air-packaged fillets during storage at 1°C and 20 days at -1°C. At the end of shelf life in air-packaged fillets, total viable counts (TVC) and pseudomonads counts reached log 8 colony-forming units (CFU) g(-1). In 50% CO2/50% N2-packaged fillets, the lag phase and generation time of bacteria were extended and recorded counts were below the limit for consumption (tilapia fillets quality and a major factor in influencing retail purchase decisions. In view of that, air packaged at -1°C storage temperature was the optimal condition for fresh tilapia fillets. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) were not good indicators of spoilage of tilapia fillets in this study. PMID:24804022

  13. The Nile River

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of the northern portion of the Nile River was captured by MISR's nadir camera on January 30, 2001 (Terra orbit 5956). The Nile is the longest river in the world, extending for about 6700 kilometers from its headwaters in the highlands of eastern Africa. At the apex of the fertile Nile River Delta is the Egyptian capital city of Cairo. To the west are the Great Pyramids of Giza. North of here the Nile branches into two distributaries, the Rosetta to the west and the Damietta to the east. Also visible in this image is the Suez Canal, a shipping waterway connecting Port Said on the Mediterranean Sea with the Gulf of Suez. The Gulf is an arm of the Red Sea, and is located on the righthand side of the picture. Image credit: NASA/GSFC/LaRC/JPL, MISR Team.

  14. West Nile virus vaccine.

    PubMed

    Monath, T P; Arroyo, J; Miller, C; Guirakhoo, F

    2001-05-01

    Within the past 5 years, West Nile encephalitis has emerged as an important disease of humans and horses in Europe. In 1999, the disease appeared for the first time in the northeastern United States. West Nile virus (a mosquito-borne flavivirus) has flourished in the North American ecosystem and is expected to expand its geographic range. In this review, the rationale for a human and veterinary vaccine is presented and a novel approach for rapid development of a molecularly-defined, live, attenuated vaccine is described. The technology (ChimeriVax) is applicable to the development of vaccines against all flaviviruses, and products against Japanese encephalitis (a close relative of West Nile) and dengue are in or are nearing clinical trials, respectively. ChimeriVax vaccines utilize the safe and effective vaccine against the prototype flavivirus -yellow fever 17D- as a live vector. Infectious clone technology is used to replace the genes encoding the pre-membrane (prM) and envelope (E) protein of yellow fever 17D vaccine with the corresponding genes of the target virus (e.g., West Nile). The resulting chimeric virus contains the antigens responsible for protection against West Nile but retains the replication efficiency of yellow fever 17D. The ChimeriVax technology is well-suited to the rapid development of a West Nile vaccine, and clinical trials could begin as early as mid-2002. Other approaches to vaccine development are briefly reviewed. The aim of this brief review is to describe the features of West Nile encephalitis, a newly introduced infectious disease affecting humans, horses and wildlife in the United States; the rationale for rapid development of vaccines; and approaches to the development of vaccines against the disease.

  15. Nile Delta, Egypt

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The Nile Delta of Egypt (30.0N, 31.0E) irrigated by the Nile River and its many distributaries, is some of the richest farm land in the world and home to some 45 million people, over half of Egypt's population of 57 million. The capital city of Cairo is at the apex of the delta in the middle of the scene. Across the river from Cairo can be seen the three big pyramids and sphinx at Giza and the Suez Canal is just to the right of the delta.

  16. Nile River Delta, Egypt

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The Nile River Delta of Egypt (30.0N, 31.0E) irrigated by the Nile River and its many distributaries, is some of the richest farm land in the world and home to some 45 million people, over half of Egypt's population. The capital city of Cairo is at the apex of the delta. Just across the river from Cairo can be seen the ancient three big pyramids and sphinx at Giza and the Suez Canal is just to the right of the delta.

  17. Discover the Nile River

    ERIC Educational Resources Information Center

    Project WET Foundation, 2009

    2009-01-01

    Bordering on the Fantastic. As the longest river on earth, the Nile passes through 10 countries. Presented through a wide range of activities and a winning array of games, it's also unsurpassed at taking young minds into exploring the world of water, as well as natural and man made wonders.

  18. Genetic Relatedness of Salmonella Serovars Isolated from Catfish (Clarias gariepinus) and Tilapia (Tilapia mossambica) Obtained from Wet Markets and Ponds in Penang, Malaysia.

    PubMed

    Budiati, Titik; Rusul, Gulam; Wan-Abdullah, Wan Nadiah; Chuah, Li-Oon; Ahmad, Rosma; Thong, Kwai Lin

    2016-04-01

    A total of 43 Salmonella enterica isolates belonging to different serovars (Salmonella Albany, Salmonella Agona, Salmonella Corvallis, Salmonella Stanley, Salmonella Typhimurium, Salmonella Mikawasima, and Salmonella Bovismorbificans) were isolated from catfish (Clarias gariepinus) and tilapia (Tilapia mossambica) obtained from nine wet markets and eight ponds in Penang, Malaysia. Thirteen, 19, and 11 isolates were isolated from 9 of 32 catfish, 14 of 32 tilapia, and 11 of 44 water samples, respectively. Fish reared in ponds were fed chicken offal, spoiled eggs, and commercial fish feed. The genetic relatedness of these Salmonella isolates was determined by random amplified polymorphic DNA PCR (RAPD-PCR) using primer OPC2, repetitive extragenic palindromic PCR (REP-PCR), and pulsed-field gel electrophoresis (PFGE). Composite analysis of the RAPD-PCR, REP-PCR, and PFGE results showed that the Salmonella serovars could be differentiated into six clusters and 15 singletons. RAPD-PCR differentiated the Salmonella isolates into 11 clusters and 10 singletons, while REP-PCR differentiated them into 4 clusters and 1 singleton. PFGE differentiated the Salmonella isolates into seven clusters and seven singletons. The close genetic relationship of Salmonella isolates from catfish or tilapia obtained from different ponds, irrespective of the type of feed given, may be caused by several factors, such as the quality of the water, density of fish, and size of ponds. PMID:27052872

  19. Genetic Relatedness of Salmonella Serovars Isolated from Catfish (Clarias gariepinus) and Tilapia (Tilapia mossambica) Obtained from Wet Markets and Ponds in Penang, Malaysia.

    PubMed

    Budiati, Titik; Rusul, Gulam; Wan-Abdullah, Wan Nadiah; Chuah, Li-Oon; Ahmad, Rosma; Thong, Kwai Lin

    2016-04-01

    A total of 43 Salmonella enterica isolates belonging to different serovars (Salmonella Albany, Salmonella Agona, Salmonella Corvallis, Salmonella Stanley, Salmonella Typhimurium, Salmonella Mikawasima, and Salmonella Bovismorbificans) were isolated from catfish (Clarias gariepinus) and tilapia (Tilapia mossambica) obtained from nine wet markets and eight ponds in Penang, Malaysia. Thirteen, 19, and 11 isolates were isolated from 9 of 32 catfish, 14 of 32 tilapia, and 11 of 44 water samples, respectively. Fish reared in ponds were fed chicken offal, spoiled eggs, and commercial fish feed. The genetic relatedness of these Salmonella isolates was determined by random amplified polymorphic DNA PCR (RAPD-PCR) using primer OPC2, repetitive extragenic palindromic PCR (REP-PCR), and pulsed-field gel electrophoresis (PFGE). Composite analysis of the RAPD-PCR, REP-PCR, and PFGE results showed that the Salmonella serovars could be differentiated into six clusters and 15 singletons. RAPD-PCR differentiated the Salmonella isolates into 11 clusters and 10 singletons, while REP-PCR differentiated them into 4 clusters and 1 singleton. PFGE differentiated the Salmonella isolates into seven clusters and seven singletons. The close genetic relationship of Salmonella isolates from catfish or tilapia obtained from different ponds, irrespective of the type of feed given, may be caused by several factors, such as the quality of the water, density of fish, and size of ponds.

  20. FAQ: West Nile Virus and Dead Birds

    MedlinePlus

    ... Education Public Service Videos West Nile Virus & Dead Birds Recommend on Facebook Tweet Share Compartir On this ... dead bird sightings to local authorities. How do birds get infected with West Nile virus? West Nile ...

  1. Francisella Infection in Cultured Tilapia in Thailand and the Inflammatory Cytokine Response.

    PubMed

    Jantrakajorn, Sasibha; Wongtavatchai, Janenuj

    2016-06-01

    Francisella infections developed in freshwater Nile Tilapia Oreochromis niloticus and red tilapia Oreochromis spp. farms in Thailand during 2012-2014. The diseased fish were lethargic and pale in color and showed numerous white nodules in their enlarged spleens. Histopathological examination and electron microscopy suggested that the white nodules were multifocal granulomas consisting of coccobacilli within vacuolated cells. Isolation of Francisella-like bacteria was achieved from 42 of 100 samples, while polymerase chain reaction confirmed Francisella infections in all samples. Analysis of the 16S rRNA gene from samples obtained from three different geographical culture areas revealed more than 99% similarity with F. noatunensis subsp. orientalis. The influence of Francisella infection on inflammatory cytokines was determined on splenic cells of fish intraperitoneally injected with the bacteria (0.8 × 10(5) colony-forming units per fish). Infected tilapia showed significantly greater expression of the pro-inflammatory genes interleukin-1β (IL-1β) and tumor necrotic factor-α (TNF-α) within 24 h postinjection (hpi) and for up to 96 hpi. However, down-regulation of an anti-inflammatory gene, transforming growth factor-β (TGF-β) was observed as early as 24 hpi. This investigation demonstrates that an imbalance between pro- and anti-inflammatory cytokines in response to the infection may account for the substantial number of granulomas in fish hematopoietic tissues that was found in the later stage of the disease. Received September 9, 2015; accepted December 13, 2015. PMID:27196982

  2. Skin and subcutaneous mycoses in tilapia (Oreochromis niloticus) caused by Fusarium oxysporum in coinfection with Aeromonas hydrophila

    PubMed Central

    Cutuli, M. Teresa; Gibello, Alicia; Rodriguez-Bertos, Antonio; Blanco, M. Mar; Villarroel, Morris; Giraldo, Alejandra; Guarro, Josep

    2015-01-01

    Subcutaneous mycoses in freshwater fish are rare infections usually caused by oomycetes of the genus Saprolegnia and some filamentous fungi. To date, Fusarium infections in farmed fish have only been described in marine fish. Here, we report the presence of Fusarium oxysporum in subcutaneous lesions of Nile tilapia (Oreochromis niloticus). Histopathologic evaluation revealed granuloma formation with fungal structures, and the identity of the etiological agent was demonstrated by morphological and molecular analyses. Some of the animals died as a result of systemic coinfection with Aeromonashydrophila PMID:26155462

  3. Dietary sodium requirement determined for juvenile hybrid tilapia (Oreochromis niloticus x O. aureus) reared in fresh water and seawater.

    PubMed

    Shiau, Shi-Yen; Lu, Li-Shan

    2004-04-01

    Two 8-week feeding trials were conducted to determine the dietary Na requirement for juvenile hybrid tilapia (Oreochromis niloticus x O. aureus) reared in fresh water and seawater. In each experiment, NaCl was added to the basal diet at 0, 0.5, 1, 2, 3, 5, or 7 g Na/kg diet (fresh water) and at 0, 0.2, 0.5, 0.8, 1.2, 1.5, 2, or 3 g Na/kg diet (seawater). Each diet was fed to three replicate groups of fish, individual fish initially weighing 0.69 (se 0.01) g, in a closed, recirculating rearing system. In fresh water, the tilapia fed the diet supplemented with 2 g Na/kg diet had significantly (P<0.05) greater weight gain than the fish fed the diets supplemented with >/=3 and fed the diets supplemented with 1-3 g Na/kg diet, followed by the fish fed the diet with 7 g Na/kg diet and lowest in the fish fed the unsupplemented control diet. In seawater, the weight gain, FE and gill Na(+)-K(+) ATPase activity in fish were not affected by the dietary treatment. Analysis by polynomial regression of weight gain, by broken-line regression of gill Na(+)-K(+) ATPase activity and by linear regression of whole-body Na retention of the fish reared in fresh water, indicated that the adequate dietary Na concentration for tilapia is about 1.5 g/kg diet. The present study also suggests that no dietary Na is required for tilapia reared in seawater.

  4. Shelf life of air and modified atmosphere-packaged fresh tilapia (Oreochromis niloticus) fillets stored under chilled and superchilled conditions

    PubMed Central

    Cyprian, Odoli; Lauzon, Hélène L; Jóhannsson, Ragnar; Sveinsdóttir, Kolbrún; Arason, Sigurjón; Martinsdóttir, Emilía

    2013-01-01

    Optimal packaging and storage conditions for fresh tilapia fillets were established by evaluating sensory and microbiological changes, as well as monitoring physicochemical properties. Nile tilapia (Oreochromis niloticus) farmed in recirculation aquaculture system was filleted, deskinned, and packaged in air and 50% CO2/50% N2 prior to chilling and superchilling storage at 1°C and −1°C. Sensory analysis of cooked samples revealed a shelf life of 13–15 days for air-packaged fillets during storage at 1°C and 20 days at −1°C. At the end of shelf life in air-packaged fillets, total viable counts (TVC) and pseudomonads counts reached log 8 colony-forming units (CFU) g−1. In 50% CO2/50% N2-packaged fillets, the lag phase and generation time of bacteria were extended and recorded counts were below the limit for consumption (tilapia fillets quality and a major factor in influencing retail purchase decisions. In view of that, air packaged at −1°C storage temperature was the optimal condition for fresh tilapia fillets. Total volatile basic nitrogen (TVB-N) and trimethylamine (TMA) were not good indicators of spoilage of tilapia fillets in this study. PMID:24804022

  5. Modulation of the intestinal microbiota and morphology of tilapia, Oreochromis niloticus, following the application of a multi-species probiotic.

    PubMed

    Standen, B T; Rodiles, A; Peggs, D L; Davies, S J; Santos, G A; Merrifield, D L

    2015-10-01

    The intestinal microbiota and morphology of tilapia (Oreochromis niloticus) were investigated after the application of a multi-species probiotic containing Lactobacillus reuteri, Bacillus subtilis, Enterococcus faecium and Pediococcus acidilactici (AquaStar(®) Growout). Tilapia (55.03 ± 0.44 g) were fed either a control diet or a probiotic diet (control diet supplemented with AquaStar(®) Growout at 5 g kg(-1)). After four and eight weeks, culture-dependent analysis showed higher levels of lactic acid bacteria (LAB), enterococci and Bacillus spp. in the mucosa and digesta of fish fed AquaStar(®) Growout. At week four, polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) revealed a higher similarity within the probiotic fed replicates than replicates of the control group; after eight weeks, the compositional dissimilarity of the microbiome profiles between the groups was greater than the dissimilarities within each group (P < 0.05). High-throughput sequencing revealed that the probiotic treatment significantly reduced the number of operational taxonomic units and species richness in the digesta. Significantly higher proportions of reads belonging to Proteobacteria and Cyanobacteria were detected in the control group whereas the probiotic-fed fish displayed a significantly higher abundance of reads assigned to the Firmicutes (which accounted for >99 % of reads). Bacillus, Cetobacterium and Mycobacterium were the dominant genera in the digesta of control fish whereas Bacillus, Enterococcus and Pediococcus were the largest constituents in probiotic-fed fish. The addition of AquaStar(®) Growout to tilapia diets led to increased populations of intraepithelial leucocytes, a higher absorptive surface area index and higher microvilli density in the intestine. These data suggest that AquaStar(®) Growout can modulate both the intestinal microbiota and morphology of tilapia.

  6. Modulation of the intestinal microbiota and morphology of tilapia, Oreochromis niloticus, following the application of a multi-species probiotic.

    PubMed

    Standen, B T; Rodiles, A; Peggs, D L; Davies, S J; Santos, G A; Merrifield, D L

    2015-10-01

    The intestinal microbiota and morphology of tilapia (Oreochromis niloticus) were investigated after the application of a multi-species probiotic containing Lactobacillus reuteri, Bacillus subtilis, Enterococcus faecium and Pediococcus acidilactici (AquaStar(®) Growout). Tilapia (55.03 ± 0.44 g) were fed either a control diet or a probiotic diet (control diet supplemented with AquaStar(®) Growout at 5 g kg(-1)). After four and eight weeks, culture-dependent analysis showed higher levels of lactic acid bacteria (LAB), enterococci and Bacillus spp. in the mucosa and digesta of fish fed AquaStar(®) Growout. At week four, polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) revealed a higher similarity within the probiotic fed replicates than replicates of the control group; after eight weeks, the compositional dissimilarity of the microbiome profiles between the groups was greater than the dissimilarities within each group (P < 0.05). High-throughput sequencing revealed that the probiotic treatment significantly reduced the number of operational taxonomic units and species richness in the digesta. Significantly higher proportions of reads belonging to Proteobacteria and Cyanobacteria were detected in the control group whereas the probiotic-fed fish displayed a significantly higher abundance of reads assigned to the Firmicutes (which accounted for >99 % of reads). Bacillus, Cetobacterium and Mycobacterium were the dominant genera in the digesta of control fish whereas Bacillus, Enterococcus and Pediococcus were the largest constituents in probiotic-fed fish. The addition of AquaStar(®) Growout to tilapia diets led to increased populations of intraepithelial leucocytes, a higher absorptive surface area index and higher microvilli density in the intestine. These data suggest that AquaStar(®) Growout can modulate both the intestinal microbiota and morphology of tilapia. PMID:26115752

  7. Depletion of florfenicol amine, marker residue of florfenicol, from the edible fillet of tilapia (Oreochromis niloticus x O. niloticus and O. niloticus x O. aureus) following florfenicol administration in feed

    USGS Publications Warehouse

    Gaikowski, M.P.; Mushtaq, M.; Cassidy, P.; Meinertz, J.R.; Schleis, S.M.; Sweeney, D.; Endris, R.G.

    2010-01-01

    Aquaflor??, a 50% feed premix containing the broad spectrum antibacterial agent florfenicol is available globally to control mortality associated with economically significant systemic bacterial diseases of fish. Florfenicol (FFC) is effective in controlling mortality associated with Streptococcus iniae in tilapia Oreochromis sp. when administered in medicated feed at a dose of 15 mg/kg bodyweight (BW)/d for 10 consecutive days. Our objective was to characterize the depletion of the FFC marker residue, florfenicol amine (FFA), from the edible tissue of market-weight Nile tilapia O. niloticus x O. niloticus and hybrid tilapia O. niloticus x O. aureus offered feed medicated with FFC at a nominal dose rate of 15 mg/kg BW/d for 12 days. Near market-weight tilapia were obtained from a commercial tilapia farm, distributed to 2 single pass (one for Nile tilapia and one for hybrid tilapia), flow-through systems and maintained at 27 ??C under a 15 h light:9 h dark photoperiod over a 41-d pre-dosing period. During the dosing period, tilapia were offered feed medicated with FFC at a concentration of 1.479 g/kg at 1% BW daily divided in three equal offerings. The initial 10-d dosing period was extended to 12 d because one tank did not consume > 75% of the feed offered during the first two dosing days. The total dose consumed by fish in each of the 2 tanks ranged from 147 to 167 mg/kg. Once during the pre-dose period and on days 1, 2, 4, 7, 14, 21, and 28 of the post-dose period, groups of fish were indiscriminately removed from each tank, measured for weight and length, scaled, filleted, and the skin-on fillets stored at <-70 ??C. Frozen fillets were individually homogenized, extracted, and FFA concentration was determined by high-performance liquid chromatography with UV detection. Florfenicol amine is rapidly eliminated from tilapia fillet after withdrawal from medication and depletion followed first-order kinetics with an estimated half-life of 2.32 d. The FFA tolerance

  8. Shewanella putrefaciens in cultured tilapia detected by a new calcein-loop-mediated isothermal amplification (Ca-LAMP) method.

    PubMed

    Suebsing, Rungkarn; Kampeera, Jantana; Sirithammajak, Sarawut; Pradeep, Padmaja Jayaprasad; Jitrakorn, Sarocha; Arunrut, Narong; Sangsuriya, Pakkakul; Saksmerprome, Vanvimon; Senapin, Saengchan; Withyachumnarnkul, Boonsirm; Kiatpathomchai, Wansika

    2015-12-01

    Shewanella putrefaciens is being increasingly isolated from a wide variety of sources and is pathogenic to many marine and freshwater fish. For better control of this pathogen, there is a need for the development of simple and inexpensive but highly specific, sensitive, and rapid detection methods suitable for application in field laboratories. Our colorogenic loop-mediated isothermal amplification (LAMP) assay combined with calcein (Ca-LAMP) for unaided visual confirmation of LAMP amplicons is a simple method for fish pathogen detection in cultured tilapia. Here, we describe the detection of S. putrefaciens using the same platform. As before, the method gave positive results (orange to green color change) in 45 min at 63°C with sensitivity 100 times higher than that of a conventional PCR assay, with no cross-amplification of other known fish bacterial pathogens tested. Using the assay with 389 samples of gonads, fertilized eggs, and fry of farmed Nile and red tilapia Oreochromis spp., 35% of samples were positive for S. putrefaciens. The highest prevalence was found in samples of gonads (55%) and fertilized eggs (55%) from adult breeding stocks, indicating that S. putrefaciens could be passed on easily to fry used for stocking production ponds. Tissue tropism assays revealed that the spleen showed the highest colonization by S. putrefaciens in naturally infected tilapia and that it would be the most suitable organ for screening and monitoring fish stocks for presence of the bacteria. PMID:26648105

  9. Depletion of florfenicol amine in tilapia (Oreochromis sp.) maintained in a recirculating aquaculture system following Aquaflor®-medicated feed therapy

    USGS Publications Warehouse

    Gaikowski, Mark P.; Whitsel, Melissa K.; Charles, Shawn; Schleis, Susan M.; Crouch, Louis S.; Endris, Richard G.

    2015-01-01

    Aquaflor® [50% w w−1 florfenicol (FFC)], is approved for use in freshwater-reared warmwater finfish which include tilapia Oreochromis spp. in the United States to control mortality from Streptococcus iniae. The depletion of florfenicol amine (FFA), the marker residue of FFC, was evaluated after feeding FFC-medicated feed to deliver a nominal 20 mg FFC kg−1 BW d−1 dose (1.33× the label use of 15 mg FFC kg−1 BW d−1) to Nile tilapia O. niloticus and hybrid tilapia O. niloticus × O. aureus held in a recirculating aquaculture system (RAS) at production-scale holding densities. Florfenicol amine concentrations were determined in fillets taken from 10 fish before dosing and from 20 fish at nine time points after dosing (from 1 to 240 h post-dosing). Water samples were assayed for FFC before, during and after the dosing period. Parameters monitored included daily feed consumption and biofilter function (levels of ammonia, nitrite and nitrate). Mean fillet FFA concentration decreased from 13.77 μg g−1 at 1-h post dosing to 0.39 μg g−1 at 240-h post dosing. Water FFC concentration decreased from a maximum of 1400 ng mL−1 at 1 day post-dosing to 847 ng mL−1 at 240 h post-dosing. There were no adverse effects noted on fish, feed consumption or biofilter function associated with FFC-medicated feed administration to tilapia.

  10. Mechanical and thermal properties of irradiated films based on Tilapia ( Oreochromis niloticus) proteins

    NASA Astrophysics Data System (ADS)

    Sabato, S. F.; Nakamurakare, N.; Sobral, P. J. A.

    2007-11-01

    Proteins are considered potential material in natural films as alternative to traditional packaging. When gamma radiation is applied to protein film forming solution it resulted in an improvement in mechanical properties of whey protein films. The objective of this work was the characterization of mechanical and thermal properties of irradiated films based on muscle proteins from Nile Tilapia ( Oreochromis niloticus). The films were prepared according to a casting technique with two levels of plasticizer: 25% and 45% glycerol and irradiated in electron accelerator type Radiation Dynamics, 0.550 MeV at dose range from 0 to 200 kGy. Thermal properties and mechanical properties were determined using a differential scanning calorimeter and a texture analyzer, respectively. Radiation from electron beam caused a slightly increase on its tensile strength characteristic at 100 kGy, while elongation value at this dose had no reduction.

  11. West Nile virus meningoencephalitis

    PubMed Central

    DeBiasi, Roberta L.; Tyler, Kenneth L.

    2013-01-01

    SUMMARY Since its first appearance in the US in 1999, West Nile virus (WNV) has emerged as the most common cause of epidemic meningoencephalitis in North America. In the 6 years following the 1999 outbreak, the geographic range and burden of the disease in birds, mosquitoes and humans has greatly expanded to include the 48 contiguous US and 7 Canadian provinces, as well as Mexico, the Caribbean islands and Colombia. WNV has shown an increasing propensity for neuroinvasive disease over the past decade, with varied presentations including meningitis, encephalitis and acute flaccid paralysis. Although neuroinvasive disease occurs in less than 1% of infected individuals, it is associated with high mortality. From 1999–2005, more than 8,000 cases of neuroinvasive WNV disease were reported in the US, resulting in over 780 deaths. In this review, we discuss epidemiology, risk factors, clinical features, diagnosis and prognosis of WNV meningoencephalitis, along with potential treatments. PMID:16932563

  12. Global study of microbial communites in tilipia gut fed sludge-infused diets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The goal of this project was to examine the impact of microbial diversity in feed on gut communities of fish. To do so, tilapia larvae were fed three experimental diets incorporated with sludge produced under either aerobic, methanogenic or denitrifying conditions. Microbial diversity between differ...

  13. Effects of dietary Lactobacillus plantarum and AHL lactonase on the control of Aeromonas hydrophila infection in tilapia.

    PubMed

    Liu, Wenshu; Ran, Chao; Liu, Zhi; Gao, Qian; Xu, Shude; Ringø, Einar; Myklebust, Reidar; Gu, Zemao; Zhou, Zhigang

    2016-08-01

    This study addressed the effects of dietary Lactobacillus plantarum or/and N-acylated homoserine lactonase (AHL lactonase) on controlling Aeromonas  hydrophila infection in juvenile hybrid tilapia (Oreochromis niloticus♀ × O. aureus ♂). Fish were fed Lb. plantarum subsp. plantarum strain JCM1149 (10(8)  CFU/g feed) or/and AHL lactonase AIO6 (4 U/g) and were exposed to a chronic challenge of A. hydrophila NJ-1 (10(5)  cells/mL) for 14 days. Intestinal (foregut) alkaline phosphatase (IAP) activities were evaluated 1 day post challenge to reflect the resistance of fish against A. hydrophila infection. Parallel groups of fish with the same dietary assignments while unchallenged were also included to investigate the effect of dietary Lb. plantarum or/and AIO6 supplementation on gut health of tilapia. The results showed that IAP activity was significantly lower in fish fed with diets supplemented with Lb. plantarum JCM1149 or the combination of Lb. plantarum JCM1149 and AIO6, indicating enhanced resistance against A. hydrophila. Light microscopy and transmission electron microscopy images of foregut revealed damage caused by A. hydrophila NJ-1, but dietary Lb. plantarumJCM1149 or/and AIO6 significantly alleviated the damages. Compared to the fish immersed in A. hydrophila NJ-1, dietary Lb. plantarum JCM1149 or AIO6 could maintain the microvilli length in the foregut of tilapia. However, among the unchallenged groups of fish, the microvilli length in the foregut of tilapia fed AIO6 (singly or combination) and the microvilli density of tilapia fed AIO6 (singly) were significantly lower than those of the control, though the microvilli density in the combination treatment was significantly improved. Additionally, the dietary Lb. plantarum JCM1149 could down-regulate the expression of stress-related gene in the gut after the acute phase. In conclusion, the dietary Lb. plantarum JCM1149 is recommended to control the A. hydrophila infection in

  14. Nile River, Lake Nasser, Aswan Dam, Egypt

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Egypt's High Aswan Dam on the Nile River at the first cataracts, Nile River, (24.0N, 33.0E) was completed in 1971 to provide cheap hydroelectric power and to regulate the historically uneven flow of the Nile River. The contrast between the largely base rock desert east of the Nile versus the sand covered desert west of the river and the ancient irrigated floodplain downstream from the damsite is clearly shown.

  15. Molecular characterization and virulence gene profiling of pathogenic Streptococcus agalactiae populations from tilapia (Oreochromis sp.) farms in Thailand.

    PubMed

    Kayansamruaj, Pattanapon; Pirarat, Nopadon; Katagiri, Takayuki; Hirono, Ikuo; Rodkhum, Channarong

    2014-05-19

    Streptococcus spp. were recovered from diseased tilapia in Thailand during 2009-2010 (n = 33), and were also continually collected from environmental samples (sediment and water) from tilapia farms for 9 months in 2011 (n = 25). The relative percent recovery of streptococci from environmental samples was 13-67%. All streptococcal isolates were identified as S. agalactiae (group B streptococci [GBS]) by a species-specific polymerase chain reaction. In molecular characterization assays, 4 genotypic categories comprised of 1) molecular serotypes, 2) the infB allele, 3) virulence gene profiling patterns (cylE, hylB, scpB, lmb, cspA, dltA, fbsA, fbsB, bibA, gap, and pili backbone-encoded genes), and 4) randomly amplified polymorphic DNA (RAPD) fingerprinting patterns, were used to describe the genotypic diversity of the GBS isolates. There was only 1 isolate identified as molecular serotype III, while the others were serotype Ia. Most GBS serotype Ia isolates had an identical infB allele and virulence gene profiling patterns, but a large diversity was established by RAPD analysis with diversity tending to be geographically dependent. Experimental infection of Nile tilapia (Oreochromis niloticus) revealed that the GBS serotype III isolate was nonpathogenic in the fish, while all 5 serotype Ia isolates (3 fish and 2 environmental isolates) were pathogenic, with a median lethal dose of 6.25-7.56 log10 colony-forming units. In conclusion, GBS isolates from tilapia farms in Thailand showed a large genetic diversity, which was associated with the geographical origins of the bacteria. PMID:24842288

  16. The White Nile sedimentary system

    NASA Astrophysics Data System (ADS)

    Garzanti, Eduardo; Andò, Sergio; Padoan, Marta; Resentini, Alberto; Vezzoli, Giovanni; Villa, Igor

    2014-05-01

    The Nile River flows for ~6700 km from south of the Equator to finally reach the Mediterranean Sea at northern subtropical latitudes (Woodward et al. 2007). This is the longest sedimentological laboratory on Earth, a unique setting in which we are investigating changes in sediment composition associated with diverse chemical and physical processes, including weathering and hydraulic sorting. The present study focuses on the southern branch of the Nile across 20° of latitude, from hyperhumid Burundi and Rwanda highlands in central Africa to Khartoum, the capital city of Sudan at the southern edge of the Sahara. Our study of the Kagera basin emphasizes the importance of weathering in soils at the source rather than during stepwise transport, and shows that the transformation of parent rocks into quartzose sand may be completed in one sedimentary cycle (Garzanti et al. 2013a). Micas and heavy minerals, less effectively diluted by recycling than main framework components, offer the best key to identify the original source-rock imprint. The different behaviour of chemical indices such as the CIA (a truer indicator of weathering) and the WIP (markedly affected by quartz dilution) helps us to distinguish strongly weathered first-cycle versus polycyclic quartz sands (Garzanti et al. 2013b). Because sediment is efficiently trapped in East African Rift lakes, the composition of Nile sediments changes repeatedly northwards across Uganda. Downstream of both Lake Kyoga and Lake Albert, quartzose sands are progressively enriched in metamorphiclastic detritus supplied from tributaries draining amphibolite-facies basements. The evolution of White Nile sediments across South Sudan, a scarcely accessible region that suffered decades of civil war, was inferred from the available information (Shukri 1950), integrated by original petrographic, heavy-mineral and geochemical data (Padoan et al. 2011). Mineralogical and isotopic signatures of Bahr-el-Jebel and Sobat sediments, derived

  17. Dietary microbial phytase exerts mixed effects on the gut health of tilapia: a possible reason for the null effect on growth promotion.

    PubMed

    Hu, Jun; Ran, Chao; He, Suxu; Cao, Yanan; Yao, Bin; Ye, Yuantu; Zhang, Xuezhen; Zhou, Zhigang

    2016-06-01

    The present study evaluated the effects of dietary microbial phytase on the growth and gut health of hybrid tilapia (Oreochromis niloticus ♀×Oreochromis aureus ♂), focusing on the effect on intestinal histology, adhesive microbiota and expression of immune-related cytokine genes. Tilapia were fed either control diet or diet supplemented with microbial phytase (1000 U/kg). Each diet was randomly assigned to four groups of fish reared in cages (3×3×2 m). After 12 weeks of feeding, weight gain and feed conversion ratio of tilapia were not significantly improved by dietary microbial phytase supplementation. However, significantly higher level of P content in the scales, tighter and more regular intestinal mucosa folds were observed in the microbial phytase group and the microvilli density was significantly increased. The adhesive gut bacterial communities were strikingly altered by microbial phytase supplementation (0·41fed diet supplemented with microbial phytase, as indicated by the up-regulated intestinal expressions of the cytokine genes (tnf-α and tgf-β) and hsp70. In addition, the gut microvilli height was significantly decreased in the phytase group. These results indicate that dietary microbial phytase may exert mixed effects on hybrid tilapia, and can guide our future selection of phytases as aquafeed additives - that is, eliminating those that can stimulate intestinal inflammation. PMID:27080419

  18. Use of probiotics in diets of Tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    AAquaculture is one of the fastest growing sectors of agriculture globally. Production in freshwater and marine fisheries has plateaued, and the continued demand for seafood and need for affordable protein sources in third world countries will ensure growth of aquaculture in the future. Tilapia are ...

  19. A review of piscine islet xenotransplantation using wild-type tilapia donors and the production of transgenic tilapia expressing a "humanized" tilapia insulin.

    PubMed

    Wright, James R; Yang, Hua; Hyrtsenko, Olga; Xu, Bao-You; Yu, Weiming; Pohajdak, Bill

    2014-01-01

    Most islet xenotransplantation laboratories have focused on porcine islets, which are both costly and difficult to isolate. Teleost (bony) fish, such as tilapia, possess macroscopically visible distinct islet organs called Brockmann bodies which can be inexpensively harvested. When transplanted into diabetic nude mice, tilapia islets maintain long-term normoglycemia and provide human-like glucose tolerance profiles. Like porcine islets, when transplanted into euthymic mice, they are rejected in a CD4 T-cell-dependent manner. However, unlike pigs, tilapia are so phylogenetically primitive that their cells do not express α(1,3)Gal and, because tilapia are highly evolved to live in warm stagnant waters nearly devoid of dissolved oxygen, their islet cells are exceedingly resistant to hypoxia, making them ideal for transplantation within encapsulation devices. Encapsulation, especially when combined with co-stimulatory blockade, markedly prolongs tilapia islet xenograft survival in small animal recipients, and a collaborator has shown function in diabetic cynomolgus monkeys. In anticipation of preclinical xenotransplantation studies, we have extensively characterized tilapia islets (morphology, embryologic development, cell biology, peptides, etc.) and their regulation of glucose homeostasis. Because tilapia insulin differs structurally from human insulin by 17 amino acids, we have produced transgenic tilapia whose islets stably express physiological levels of humanized insulin and have now bred these to homozygosity. These transgenic fish can serve as a platform for further development into a cell therapy product for diabetes.

  20. Dietary medicinal plant extracts improve growth, immune activity and survival of tilapia Oreochromis mossambicus.

    PubMed

    Immanuel, G; Uma, R P; Iyapparaj, P; Citarasu, T; Peter, S M Punitha; Babu, M Michael; Palavesam, A

    2009-05-01

    The effects of supplementing diets with acetone extract (1% w/w) from four medicinal plants (Bermuda grass Cynodon dactylon, H(1), beal Aegle marmelos, H(2), winter cherry Withania somnifera, H(3) and ginger Zingiber officinale, H(4)) on growth, the non-specific immune response and ability to resist pathogen infection in tilapia Oreochromis mossambicus were assessed. In addition, the antimicrobial properties of the extract were assessed against Vibrio alginolyticus, Vibrioparahaemolyticus, Vibrio mimicus, Vibrio campbelli, Vibrio vulnificus, Vibrio harveyi and Photobacterium damselae. Oreochromis mossambicus were fed 5% of their body mass per day for 45 days, and those fed the experimental diets showed a greater increase in mass (111-139%) over the 45 days compared to those that received the control diet (98%). The specific growth rate of O. mossambicus fed the four diets was also significantly greater (1.66-1.93%) than control (1.52%) diet-fed fish. The blood plasma chemistry analysis revealed that protein, albumin, globulin, cholesterol, glucose and triglyceride levels of experimental fish were significantly higher than that of control fish. Packed cell volume of the blood samples of experimental diet-fed fish was also significantly higher (34.16-37.95%) than control fish (33.0%). Leucocrit value, phagocytic index and lysozyme activity were enhanced in fish fed the plant extract-supplemented diets. The acetone extract of the plants inhibited growth of Vibrio spp. and P. damselae with extracts from W. somnifera showing maximum growth inhibition. A challenge test with V. vulnificus showed 100% mortality in O. mossambicus fed the control diet by day 15, whereas the fish fed the experimental diets registered only 63-80% mortality at the end of challenge experiment (30 days). The cumulative mortality index for the control group was 12,000, which was equated to 1.0% mortality, and accordingly, the lowest mortality of 0.35% was registered in H(4)-diet-fed group. PMID

  1. The utilization of Vallisneria aethiopica, Brassica oleracea and Pennisetum clandestinum by Tilapia rendalli

    NASA Astrophysics Data System (ADS)

    Hlophe, S. N.; Moyo, N. A. G.

    A common lawn grass; kikuyu grass, an abundant vegetable; cabbage and vallisneria a common macrophyte were tested for utilisation by two size classes of a herbivorous fish, Tilapia rendalli held in glass aquarium tanks. The test feeds were given to sub-adult T. rendalli for 133 days at 8% body weight and juvenile fish for 84 days at 15% body weight. Sub-adult and juvenile fish fed kikuyu grass attained a higher specific growth rate, higher protein efficiency ratio and better food conversion ratio than those fed cabbage and vallisneria. This is explained by the differences in the protein content, higher levels of lysine and the sulphur-containing amino acid, methionine in kikuyu grass. Palatability studies of the juveniles also showed that kikuyu was most preferred. However, sub-adults preferred vallisneria, kikuyu and cabbage respectively. The possible reasons for the selection are discussed.

  2. Human food safety and environmental hazards associated with the use of methyltestosterone and other steroids in production of all-male tilapia.

    PubMed

    Mlalila, Nichrous; Mahika, Charles; Kalombo, Lonji; Swai, Hulda; Hilonga, Askwar

    2015-04-01

    In recent years, all-male cultures of Nile tilapia (Oreochromis niloticus) have been the most preferred mode of production in aquaculture industry. All-male individuals achieve higher somatic growth rate and shut high energy losses associated with gonadal development and reproduction. The economic advantages of culturing all-male tilapia have led to the development of procedures for producing unisex cultures, using 17α-methyltestosterone (MT). Despite widespread use of the MT in tilapia farming, the implications of hormone treatment in relation to human health and the environment have raised a number of concerns in the scientific community. In this review, the hormonal application processes, economic and ecological significance of MT, food safety and residual MT, comparative uses of steroids in aquaculture, animal husbandry, and medicine have been briefly reviewed for regulatory guidelines, and finally, future research perspectives have been addressed. The review can be used as policy-making guidelines in aquaculture framework development as can be emphasized in African continent, among others. The most important conclusion to draw is that the quantity of MT used in conventional practice is large compared to the actual dose required for sex reversal, fish produced are safe for human consumptions, and the environmental hazards should be further emphasized.

  3. Influence of good manufacturing practices on the shelf life of refrigerated fillets of tilapia (Oreochromis niloticus) packed in modified atmosphere and gamma-irradiated.

    PubMed

    Monteiro, Maria Lúcia Guerra; Mársico, Eliane Teixeira; Mano, Sérgio Borges; Teixeira, Claudia Emília; da Cruz Silva Canto, Anna Carolina Vilhena; de Carvalho Vital, Helio; Conte-Júnior, Carlos Adam

    2013-07-01

    This study evaluated the influence of good manufacturing practices (GMP) on the shelf life of refrigerated fillets of Nile tilapia (Oreochromis niloticus) packed in modified atmosphere packaging (MAP) and irradiated. In a first series of experiments, 120 tilapia fillets kept under controlled sanitary conditions were purchased from a fish market managed by a cooperative. A second lot totaling 200 tilapia fillets was obtained under controlled storage conditions from a pilot plant. The combined effects of MAP (40% CO2 and 60% N2) and irradiation (1.5 kGy) were investigated by monitoring physical and chemical (total volatile bases and pH), bacteriological (aerobic heterotrophic mesophilic and psychrophilic bacteria) and sensory (acceptance test) changes in the samples. The quality of samples decreased with storage time regardless of the treatment, remaining higher in fillets produced in the pilot plant in comparison with the commercially produced fillets. The observed shelf life of nonirradiated commercially produced fillets was only 3 days, compared to 8 days for those produced in the pilot plant, probably due to GMP in the latter. It was concluded that, even with a combination of proven conservation methods for meats, the adoption of good manufacturing practices still remains essential before, during, and after the filleting process in order to ensure the effectiveness of the entire treatment. PMID:24804034

  4. Influence of good manufacturing practices on the shelf life of refrigerated fillets of tilapia (Oreochromis niloticus) packed in modified atmosphere and gamma-irradiated

    PubMed Central

    Monteiro, Maria Lúcia Guerra; Mársico, Eliane Teixeira; Mano, Sérgio Borges; Teixeira, Claudia Emília; da Cruz Silva Canto, Anna Carolina Vilhena; de Carvalho Vital, Helio; Conte-Júnior, Carlos Adam

    2013-01-01

    This study evaluated the influence of good manufacturing practices (GMP) on the shelf life of refrigerated fillets of Nile tilapia (Oreochromis niloticus) packed in modified atmosphere packaging (MAP) and irradiated. In a first series of experiments, 120 tilapia fillets kept under controlled sanitary conditions were purchased from a fish market managed by a cooperative. A second lot totaling 200 tilapia fillets was obtained under controlled storage conditions from a pilot plant. The combined effects of MAP (40% CO2 and 60% N2) and irradiation (1.5 kGy) were investigated by monitoring physical and chemical (total volatile bases and pH), bacteriological (aerobic heterotrophic mesophilic and psychrophilic bacteria) and sensory (acceptance test) changes in the samples. The quality of samples decreased with storage time regardless of the treatment, remaining higher in fillets produced in the pilot plant in comparison with the commercially produced fillets. The observed shelf life of nonirradiated commercially produced fillets was only 3 days, compared to 8 days for those produced in the pilot plant, probably due to GMP in the latter. It was concluded that, even with a combination of proven conservation methods for meats, the adoption of good manufacturing practices still remains essential before, during, and after the filleting process in order to ensure the effectiveness of the entire treatment. PMID:24804034

  5. Influence of good manufacturing practices on the shelf life of refrigerated fillets of tilapia (Oreochromis niloticus) packed in modified atmosphere and gamma-irradiated.

    PubMed

    Monteiro, Maria Lúcia Guerra; Mársico, Eliane Teixeira; Mano, Sérgio Borges; Teixeira, Claudia Emília; da Cruz Silva Canto, Anna Carolina Vilhena; de Carvalho Vital, Helio; Conte-Júnior, Carlos Adam

    2013-07-01

    This study evaluated the influence of good manufacturing practices (GMP) on the shelf life of refrigerated fillets of Nile tilapia (Oreochromis niloticus) packed in modified atmosphere packaging (MAP) and irradiated. In a first series of experiments, 120 tilapia fillets kept under controlled sanitary conditions were purchased from a fish market managed by a cooperative. A second lot totaling 200 tilapia fillets was obtained under controlled storage conditions from a pilot plant. The combined effects of MAP (40% CO2 and 60% N2) and irradiation (1.5 kGy) were investigated by monitoring physical and chemical (total volatile bases and pH), bacteriological (aerobic heterotrophic mesophilic and psychrophilic bacteria) and sensory (acceptance test) changes in the samples. The quality of samples decreased with storage time regardless of the treatment, remaining higher in fillets produced in the pilot plant in comparison with the commercially produced fillets. The observed shelf life of nonirradiated commercially produced fillets was only 3 days, compared to 8 days for those produced in the pilot plant, probably due to GMP in the latter. It was concluded that, even with a combination of proven conservation methods for meats, the adoption of good manufacturing practices still remains essential before, during, and after the filleting process in order to ensure the effectiveness of the entire treatment.

  6. Effects of low molecular weight sodium alginate on growth performance, immunity, and disease resistance of tilapia, Oreochromis niloticus.

    PubMed

    Van Doan, Hien; Tapingkae, Wanaporn; Moonmanee, Tossapol; Seepai, Apichart

    2016-08-01

    Present study was carried out to evaluate the effects of low molecular weight sodium alginate (LMWSA) as potential prebiotic source on growth performance, innate immunity and disease resistance of tilapia, Oreochromis niloticus. Three hundred twenty fish were divided into four treatments and fed following diets 0 (T1- Control), 10 (T2), 20 (T3) and 30 (T4) g kg(-1) LMWSA for period of 60 days. A Completely Randomized Design with four replications was applied. At the end of experiment, fish in each replication were weighed and specific growth rate (SGR) and feed conversion ratio (FCR) were calculated. Five randomly selected fish were used for innate immune response measurement. Another ten fish were randomly selected for challenge test against Streptococcus agalactiae for a period of 18 days. The lysozyme, complement, phagocytosis, and respiratory burst activities were detected after 60 days of feeding trial and after challenge test. The results indicated that fish fed diet 10 g kg(-1) LMWSA significantly improved SGR and FCR after 60 days of feeding trial. The lysozyme, phagocytosis, respiratory burst, and complement activities were significantly higher in fish fed LMWSA diets compared to control. Fish fed 10 g kg(-1) LMWSA had greatest values compared to fish fed 20 and 30 g kg(-1) LMWSA. The survival rate of O. niloticus was significantly improved in fish fed LMWSA diets after challenge with S. agalactiae for 18 days. However, no significant difference in survival rate was observed among LMWSA supplemented diets. It is indicated that fish fed 10, 20 and 30 g kg(-1) LMWSA diets can stimulate growth performance, innate immunity and disease resistance in tilapia against S. agalactiae.

  7. Effects of low molecular weight sodium alginate on growth performance, immunity, and disease resistance of tilapia, Oreochromis niloticus.

    PubMed

    Van Doan, Hien; Tapingkae, Wanaporn; Moonmanee, Tossapol; Seepai, Apichart

    2016-08-01

    Present study was carried out to evaluate the effects of low molecular weight sodium alginate (LMWSA) as potential prebiotic source on growth performance, innate immunity and disease resistance of tilapia, Oreochromis niloticus. Three hundred twenty fish were divided into four treatments and fed following diets 0 (T1- Control), 10 (T2), 20 (T3) and 30 (T4) g kg(-1) LMWSA for period of 60 days. A Completely Randomized Design with four replications was applied. At the end of experiment, fish in each replication were weighed and specific growth rate (SGR) and feed conversion ratio (FCR) were calculated. Five randomly selected fish were used for innate immune response measurement. Another ten fish were randomly selected for challenge test against Streptococcus agalactiae for a period of 18 days. The lysozyme, complement, phagocytosis, and respiratory burst activities were detected after 60 days of feeding trial and after challenge test. The results indicated that fish fed diet 10 g kg(-1) LMWSA significantly improved SGR and FCR after 60 days of feeding trial. The lysozyme, phagocytosis, respiratory burst, and complement activities were significantly higher in fish fed LMWSA diets compared to control. Fish fed 10 g kg(-1) LMWSA had greatest values compared to fish fed 20 and 30 g kg(-1) LMWSA. The survival rate of O. niloticus was significantly improved in fish fed LMWSA diets after challenge with S. agalactiae for 18 days. However, no significant difference in survival rate was observed among LMWSA supplemented diets. It is indicated that fish fed 10, 20 and 30 g kg(-1) LMWSA diets can stimulate growth performance, innate immunity and disease resistance in tilapia against S. agalactiae. PMID:27238426

  8. [West Nile fever/encephalitis].

    PubMed

    Takasaki, Tomohiko

    2007-12-01

    West Nile virus (WNV), a member of the family Flaviviridae (genus Flavivirus), is a mosquito-borne virus first isolated in 1937 in the West Nile district of Uganda. The disease in humans is characterized by a dengue-like illness with fever, and a more severe form is characterized by central nervous system involvement, including encephalitis, meningitis, and myelitis. WN encephalitis was first reported in the Western Hemisphere in the summer of 1999, there was an outbreak in New York City. Epidemic WNV strains in North America are severely pathogenic, however, attenuated WNV strains were found in Texas and Mexico in 2003. The principal vectors of WNV transmission in North America are Culex. pipiens, Cx. Quinquefasciatus, Cx. restuans, Cx salinarius and Cx talsalis. The number of WN fever case has exceeded 27,000 since 1999 in the United States and 4,600 since 2002 in Canada. The first imported case of West Nile fever in Japan was confirmed in September, 2005. The patient had returned to Japan from the United States and developed symptoms the next day. There is currently no WN vaccine for use in humans. An inactivated WNV vaccine for use in horses has been available since 2001. A DNA vaccine, a chimeric live attenuated vaccine, and a recombinant vaccine have also been licensed for use in horses.

  9. Molecular cloning of vasa gene and the effects of LHRH-A on its expression in blue tilapia Oreochromis aureus.

    PubMed

    Xiao, Jun; Luo, Yongju; Chen, Libing; Yang, Li; Huang, Yulin; Guo, Zhongbao; Guo, Enyan; Tang, Zhanyang; Zhang, Ming; Gan, Xi

    2013-08-01

    The full length of vasa cDNA in blue tilapia Oreochromis aureus was cloned and sequenced using reverse transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). Nucleotide sequence analysis revealed that the cDNA contained 2,143 bp and was consisted of a 48-bp 5' untranslated terminal region (5'-UTR), a 157-bp 3' untranslated terminal region (3'-UTR) and a 1,938-bp open reading frame (ORF) which encoded 645 amino acids. Homological protein analysis showed that vasa in O. aureus was highly conserved with Nile tilapia Oreochromis niloticus. Tissue distribution expression analysis indicated that vasa was specifically expressed in the gonads. Using in situ hybridization, we found that vasa was expressed in spermatogonia and spermatocytes rather than spermatids and sperm. In order to examine the influence of luteinizing hormone releasing hormone analog (LHRH-A) on vasa, the in vivo injections were performed different concentrations of LHRH-A. Our results showed that LHRH-A induced meiosis and down-regulated vasa mRNA expression. In summary, our results showed that vasa was specifically expressed in gonads and LHRH-A inhibited vasa expression in the testis. Our results also suggested that LHRH-A could regulate vasa gene expression in O. aureus testis. PMID:23224831

  10. Tilapia Piscidin 4 (TP4) Stimulates Cell Proliferation and Wound Closure in MRSA-Infected Wounds in Mice

    PubMed Central

    Huang, Hang-Ning; Chan, Yi-Lin; Wu, Chang-Jer; Chen, Jyh-Yih

    2015-01-01

    Antimicrobial peptides (AMPs) are endogenous antibiotics that directly affect microorganisms, and also have a variety of receptor-mediated functions. One such AMP, Tilapia piscidin 4 (TP4), was isolated from Nile tilapia (Oreochromis niloticus); TP4 has antibacterial effects and regulates the innate immune system. The aim of the present study was to characterize the role of TP4 in the regulation of wound closure in mice and proliferation of a keratinocyte cell line (HaCaT) and fibroblast cell line (Hs-68). In vitro, TP4 stimulated cell proliferation and activated collagen I, collagen III, and keratinocyte growth factor (KGF) gene expression in Hs-68 cells, which induces keratin production by HaCaT cells. This effect was detectable at TP4 concentrations of 6.25 µg/mL in both cell lines. In vivo, TP4 was found to be highly effective at combating peritonitis and wound infection caused by MRSA in mouse models, without inducing adverse behavioral effects or liver or kidney toxicity. Taken together, our results indicate that TP4 enhances the survival rate of mice infected with the bacterial pathogen MRSA through both antimicrobial and wound closure activities mediated by epidermal growth factor (EGF), transforming growth factor (TGF), and vascular endothelial growth factor (VEGF). The peptide is likely involved in antibacterial processes and regulation of tissue homeostasis in infected wounds in mice. Overall, these results suggest that TP4 may be suitable for development as a novel topical agent for wound dressing. PMID:25955756

  11. Assessment of Heavy-Metal Pollution in Sediments and Tilapia Fish Species in Kafue River of Zambia.

    PubMed

    Mbewe, Gezile; Mutondo, Moola; Maseka, Kenneth; Sichilongo, Kwenga

    2016-10-01

    We report results from an evaluation of the levels of heavy metals, i.e., copper (Cu), cadmium (Cd), lead (Pb), nickel (Ni), manganese (Mn), chromium (Cr), and iron (Fe) in sediment and tilapia fish samples from a wide stretch of the Kafue river of Zambia. In sediment samples, the highest Pb and Fe concentrations were recorded at Hippo Dam, i.e., 36.2 ± 0.1 mg/kg dw and 733 ± 37 mg/kg dw at Kafue Town, respectively. Other notably high metal concentrations in sediment were Cr at Kafue Bridge (42.5 ± 0.1 mg/kg dw [dw]), Cu at Mpongwe (233 ± 5 mg/kg dw), and Mn at Kafue Town (133 ± 1 mg/kg dw); it was highest at Ithezi Tezhi Dam at 166 ± 1 mg/kg d. Three fish species, i.e., three-spot bream Tilapia andersonii, red-breasted bream T. rendalli, and nile tilapia Oreochromis niloticus were evaluated for levels of the seven metals. The concentrations of the metals in these fish species afforded estimation of the biota sediment-accumulation factor, which is the ratio of the concentration of the metal in liver to that in the sediment. The coefficients of condition (K) values, which give an indication of the health of the fish, were also estimated. The K values ranged from 2.5 ± 0.5 to 5.1 ± 0.6 in all of the three fish species. Partial least squares analysis showed that heavy metals are generally sequestered evenly in all of the parts of all of the three fish species except for elevated levels of Mn, Cd, and Pb in the liver samples. PMID:27401599

  12. Signatures of selection in tilapia revealed by whole genome resequencing.

    PubMed

    Xia, Jun Hong; Bai, Zhiyi; Meng, Zining; Zhang, Yong; Wang, Le; Liu, Feng; Jing, Wu; Wan, Zi Yi; Li, Jiale; Lin, Haoran; Yue, Gen Hua

    2015-09-16

    Natural selection and selective breeding for genetic improvement have left detectable signatures within the genome of a species. Identification of selection signatures is important in evolutionary biology and for detecting genes that facilitate to accelerate genetic improvement. However, selection signatures, including artificial selection and natural selection, have only been identified at the whole genome level in several genetically improved fish species. Tilapia is one of the most important genetically improved fish species in the world. Using next-generation sequencing, we sequenced the genomes of 47 tilapia individuals. We identified a total of 1.43 million high-quality SNPs and found that the LD block sizes ranged from 10-100 kb in tilapia. We detected over a hundred putative selective sweep regions in each line of tilapia. Most selection signatures were located in non-coding regions of the tilapia genome. The Wnt signaling, gonadotropin-releasing hormone receptor and integrin signaling pathways were under positive selection in all improved tilapia lines. Our study provides a genome-wide map of genetic variation and selection footprints in tilapia, which could be important for genetic studies and accelerating genetic improvement of tilapia.

  13. CONCURRENT INFECTIONS (PARASITISM AND BACTERIAL DIESEASE) in TILAPIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most laboratory studies to date with respect to disease in tilapia have focused on a single parasite or a single bacterial pathogen. In intensive tilapia aquaculture, the reality of a single disease agent resulting in death loss is probably small. More likely, multiple disease agents are present (...

  14. Concurrent Infections (Parasitism and Bacterial Disease) in Tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most laboratory disease studies in tilapia to date have focused on a single parasite or a single bacterial pathogen. In intensive tilapia aquaculture, the reality of a single disease agent resulting in death-loss may be small. More likely, multiple disease agents are present (i.e., parasites, bacter...

  15. Signatures of selection in tilapia revealed by whole genome resequencing

    PubMed Central

    Hong Xia, Jun; Bai, Zhiyi; Meng, Zining; Zhang, Yong; Wang, Le; Liu, Feng; Jing, Wu; Yi Wan, Zi; Li, Jiale; Lin, Haoran; Hua Yue, Gen

    2015-01-01

    Natural selection and selective breeding for genetic improvement have left detectable signatures within the genome of a species. Identification of selection signatures is important in evolutionary biology and for detecting genes that facilitate to accelerate genetic improvement. However, selection signatures, including artificial selection and natural selection, have only been identified at the whole genome level in several genetically improved fish species. Tilapia is one of the most important genetically improved fish species in the world. Using next-generation sequencing, we sequenced the genomes of 47 tilapia individuals. We identified a total of 1.43 million high-quality SNPs and found that the LD block sizes ranged from 10–100 kb in tilapia. We detected over a hundred putative selective sweep regions in each line of tilapia. Most selection signatures were located in non-coding regions of the tilapia genome. The Wnt signaling, gonadotropin-releasing hormone receptor and integrin signaling pathways were under positive selection in all improved tilapia lines. Our study provides a genome-wide map of genetic variation and selection footprints in tilapia, which could be important for genetic studies and accelerating genetic improvement of tilapia. PMID:26373374

  16. Parasite treatment reduced Flavobacterium columnare infection in tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterium Flavobacterium columnare and parasite Trichodina are common pathogens of cultured fish. The authors conducted a study to evaluate whether treatment of Trichodina parasitized tilapia with formalin would improve fish survival and reduce F. columnare infection in fish. Tilapia parasitized by...

  17. Feeding motivation as a personality trait in Nile tilapia (Oreochromis niloticus): role of serotonergic neurotransmission.

    PubMed

    Silva, Patricia I M; Martins, Catarina I M; Höglund, Erik; Gjøen, Hans Magnus; Øverli, Øyvind

    2014-10-01

    Consistent individual variation in behaviour and physiology (i.e. animal personality or coping style) has emerged as a central topic in many biological disciplines. Yet, underlying mechanisms of crucial personality traits like feeding behaviour in novel environments remain unclear. Comparative studies, however, reveal a strong degree of evolutionary conservation of neural mechanisms controlling such behaviours throughout the vertebrate lineage. Previous studies have indicated duration of stress-induced anorexia as a consistent individual characteristic in teleost fishes. This study aims to determine to what degree brain 5-hydroxytryptamine (5-HT, serotonin) activity pertains to this aspect of animal personality, as a correlate to feed anticipatory behaviour and recovery of feed intake after transfer to a novel environment. Crucial to the definition of animal personality, a strong degree of individual consistency in different measures of feeding behaviour (feeding latency and feeding score), was demonstrated. Furthermore, low serotonergic activity in the hypothalamus was highly correlated with a personality characterized by high feeding motivation, with feeding motivation represented as an overall measure incorporating several behavioural parameters in a Principle Component Analyses (PCA). This study thus confirms individual variation in brain 5-HT neurotransmission as a correlate to complex behavioural syndromes related to feeding motivation. PMID:24858238

  18. Parasite fauna of farmed Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) in Uganda.

    PubMed

    Akoll, Peter; Konecny, Robert; Mwanja, Wilson W; Nattabi, Juliet K; Agoe, Catherine; Schiemer, Fritz

    2012-01-01

    An intensive parasite survey was conducted in 2008 to better understand the parasite fauna occurrence, distribution and diversity in the commercial aquaculture fish species in Uganda. A total of 265 fish collected from hatcheries and grow-out systems were examined for parasites using routine parasitological techniques. The survey yielded 17 parasite species: 11 from Oreochromis niloticus and ten from Clarias gariepinus. Four parasites-Amirthalingamia macracantha, Monobothrioides sp., Zoogonoides sp. and a member of the family Amphilinidae-were recorded for the first time in the country. The parasite diversity was similar between hosts; however, O. niloticus was dominated by free-living stage-transmitted parasites in lower numbers, whereas both trophically and free-living stage-transmitted parasites were equally represented in C. gariepinus in relatively high intensities. The patterns in parasite numbers and composition in the two hosts reflect differences in fish habitat use and diet. A shift in parasite composition from monoxenous species-dominated communities in small-sized fish to heteroxenous in large fishes was recorded in both hosts. This was linked to ontogenetic feeding changes and prolonged exposure to parasites. Polyculture systems showed no effect on parasite intensity and composition. The gills were highly parasitized, mainly by protozoans and monogeneans. Generally, the occurrence and diversity of parasites in these fish species highlight the likelihood of disease outbreak in the proposed intensive aquaculture systems. This calls for raising awareness in fish health management among potential farmers, service providers and researchers.

  19. Glutathione and its related enzymes in the gonad of Nile Tilapia (Oreochromis niloticus).

    PubMed

    Hamed, R R; Saleh, N S M; Shokeer, A; Guneidy, R A; Abdel-Ghany, S S

    2016-02-01

    Glutathione (GSH) concentration, the activity of its metabolizing enzymes, glutathione transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), and the antioxidant enzyme catalase (CAT) in O. niloticus ovary and testis were examined. GSH concentration of O. niloticus testis exhibited high concentration (129 ± 21 nmol/g tissue) compared with GSH concentration (49.2 ± 8.3 nmol/g tissue) in the ovary. GST, GPx, GR, and CAT activities of O. niloticus testis exhibited high values compared with their corresponding values in ovary homogenates. However, protein concentration in ovary homogenates exhibited higher values (175 ± 40.6 mg) compared with testis homogenates (27.1 ± 3.7 mg). O. niloticus ovary was less effective in excretion of xenobiotices compared with the testis, where its function is mainly in increasing the protein content of the eggs; however, in O. niloticus testis, the glutathione cycle operated in accelerated way in the direction of reduced GSH production in order to protect the maturation stages in a save way. A simple reproducible procedure for the purification of GST from O. niloticus ovary was established. The enzymes proved to be homogenous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and its molecular weight was calculated to be 25.1 kDa. GST of O. niloticus ovary exhibited maximum activity at pH 7.5. The Michaelis-Menten constant (K(m)) of the purified ovary GST for GSH and CDNB was 0.076 mM and 1.0 mM, respectively. Cibacron blue was the most potent inhibitor of ovary GST activity (IC50 value, concentration of inhibitor that will give 50% inhibition, equal 0.002 μM). The specific activity of GST toward different electrophilic substrates was determined. GST activity toward benzyl isothiocyanate was the highest compared with phenethyl isothiocyanate and allyl isothiocyanate.

  20. Influence of moderate hypoxia on vaccine efficacy against Vibrio anguillarum in Oreochromis niloticus (Nile tilapia).

    PubMed

    Gallage, Sanchala; Katagiri, Takayuki; Endo, Makoto; Futami, Kunihiko; Endo, Masato; Maita, Masashi

    2016-04-01

    Hypoxia is known as a potential immunomodulator in fish. This study therefore assesses the impact of chronic, moderate hypoxia on vaccine efficacy in Oreochromis niloticus. Serum antibody titer was used as a surrogate marker to detect vaccine efficacy. The fish were acclimatized to either moderate hypoxia (55 ± 5% DO) or normoxia (85 ± 5%DO) and immunized with formalin inactivated Vibrio anguillarum. Significantly, a higher antibody titer was found in normoxic fish than in moderate hypoxia. The normoxic group titer peaked at 14th dpv (days post vaccination) while the moderate hypoxic group peaked at 21st or 28th dpv. The absolute blood lymphocyte counts and serum bactericidal activities against V. anguillarum were significantly higher in normoxic fish. Serum killing of V. anguillarum appeared to be mainly via antibody-dependent classical complement pathway. Furthermore, the first week following vaccination appears critical for antibody production. This view was further supported by results obtained from gene expression assay, where the transcription level of all the detected immune related genes (IgM, IL-1 β, TCR-β, MHC-II β), except B cell activating factor, were significantly suppressed following exposure to moderate hypoxia. The overall results highlight that even though moderate hypoxia is not easily detectable in Oreochromis niloticus, it negatively affects antibody production by suppressing and delaying antibody response, ultimately affecting vaccine efficacy.

  1. The safety of 17a-methyltestosterone administered in feed to larval Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Techniques developed to control sexual differentiation in fishes have typically involved androgen or estrogen (i.e., steroid) treatment, which directs sexual differentiation toward males or females. Treatment regimens have included immersion of larval fish in water containing a steroid, incorporati...

  2. Environmental cadium exposure and metabolic responses of the Nile tilapia, Oreochromis niloticus.

    PubMed

    Almeida, J A; Novelli, E L; Dal Pai Silva, M; Júnior, R A

    2001-01-01

    The contamination of water by metal compounds is a worldwide environmental problem. This study was undertaken to evaluate the impact of short-term cadmium exposure on metabolic patterns of the freshwater fish Oreochromis niloticus. The fish were exposed to 320, 640, 1,280 and 2,560 microg/l sublethal concentrations of Cd++ (CdCl2) in water for 7 days. The specific activities of the enzymes phosphofructo kinase (PFK-E.C.2.7.1.11.), lactate dehydrogenase (LDH-E.C.1.1.1.27.) and creatine kinase (CKE.C.2.7.3.2.) were decreased in white muscle after cadmium treatments, indicating decreases in the capacity of glycolysis in this tissue. Cadmium exposure induced increased glucose concentration in white muscle of fish. On the other hand, cadmium exposure at sublethal concentrations increased phosphofructo kinase and LDH in red muscle of fish. Cadmium significantly decreased total protein concentrations in liver and white muscle regardless of tissue glycogen levels. The data suggest that cadmium acts as a stressor, leading to metabolic alterations similar to those observed in starvation.

  3. GENOMIC DIVERSITY OF STREPTOCCOCUS AGALACTIAE ISOLATES FROM MULTIPLE HOSTS AND THEIR INFECTIVITY IN NILE TILAPIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our laboratory has conducted multiple studies to investigate the genomic diversity of GBS isolates from different phylogenetic hosts and geographical regions. We have examined fish and dolphin GBS strains using phenotypic, serological typing and multilocus sequence typing (MLST) techniques and comp...

  4. Feeding motivation as a personality trait in Nile tilapia (Oreochromis niloticus): role of serotonergic neurotransmission.

    PubMed

    Silva, Patricia I M; Martins, Catarina I M; Höglund, Erik; Gjøen, Hans Magnus; Øverli, Øyvind

    2014-10-01

    Consistent individual variation in behaviour and physiology (i.e. animal personality or coping style) has emerged as a central topic in many biological disciplines. Yet, underlying mechanisms of crucial personality traits like feeding behaviour in novel environments remain unclear. Comparative studies, however, reveal a strong degree of evolutionary conservation of neural mechanisms controlling such behaviours throughout the vertebrate lineage. Previous studies have indicated duration of stress-induced anorexia as a consistent individual characteristic in teleost fishes. This study aims to determine to what degree brain 5-hydroxytryptamine (5-HT, serotonin) activity pertains to this aspect of animal personality, as a correlate to feed anticipatory behaviour and recovery of feed intake after transfer to a novel environment. Crucial to the definition of animal personality, a strong degree of individual consistency in different measures of feeding behaviour (feeding latency and feeding score), was demonstrated. Furthermore, low serotonergic activity in the hypothalamus was highly correlated with a personality characterized by high feeding motivation, with feeding motivation represented as an overall measure incorporating several behavioural parameters in a Principle Component Analyses (PCA). This study thus confirms individual variation in brain 5-HT neurotransmission as a correlate to complex behavioural syndromes related to feeding motivation.

  5. Influence of moderate hypoxia on vaccine efficacy against Vibrio anguillarum in Oreochromis niloticus (Nile tilapia).

    PubMed

    Gallage, Sanchala; Katagiri, Takayuki; Endo, Makoto; Futami, Kunihiko; Endo, Masato; Maita, Masashi

    2016-04-01

    Hypoxia is known as a potential immunomodulator in fish. This study therefore assesses the impact of chronic, moderate hypoxia on vaccine efficacy in Oreochromis niloticus. Serum antibody titer was used as a surrogate marker to detect vaccine efficacy. The fish were acclimatized to either moderate hypoxia (55 ± 5% DO) or normoxia (85 ± 5%DO) and immunized with formalin inactivated Vibrio anguillarum. Significantly, a higher antibody titer was found in normoxic fish than in moderate hypoxia. The normoxic group titer peaked at 14th dpv (days post vaccination) while the moderate hypoxic group peaked at 21st or 28th dpv. The absolute blood lymphocyte counts and serum bactericidal activities against V. anguillarum were significantly higher in normoxic fish. Serum killing of V. anguillarum appeared to be mainly via antibody-dependent classical complement pathway. Furthermore, the first week following vaccination appears critical for antibody production. This view was further supported by results obtained from gene expression assay, where the transcription level of all the detected immune related genes (IgM, IL-1 β, TCR-β, MHC-II β), except B cell activating factor, were significantly suppressed following exposure to moderate hypoxia. The overall results highlight that even though moderate hypoxia is not easily detectable in Oreochromis niloticus, it negatively affects antibody production by suppressing and delaying antibody response, ultimately affecting vaccine efficacy. PMID:26915308

  6. Oxidative stress response in Nile tilapia (Oreochromis niloticus) exposed to textile mill effluent.

    PubMed

    Zagal, Abuzer; Mazmanci, Birgül

    2011-02-01

    Textile mill effluent is an important pollution factor because of its organic and inorganic substances content. In this study, toxic effects of textile mill effluent on fish Oreochromis niloticus were investigated by using antioxidant enzymes and lipid peroxidation (LPO) responses. Superoxide dismutase (SOD), catalase (CAT) enzyme activities and lipid peroxidation by means of thiobarbituric reactive substances (TBARS) level were measured in liver and gill tissues of fish. The fish were exposed to non-lethal concentrations (0.1%, 1% and 10%) of textile mill effluent for 15, 30 and 45 days. In control group, fish were left in aquariums containing tap water without chlorine. As a result, the activities of SOD, CAT enzymes and level of TBARS in the liver and gill increased in 15, 30 and 45 days after 1% and 10% doses application. PMID:20858649

  7. Nile Tilapia Infectivity by Genomically Diverse Streptoccocus agalactiae Isolates from Multiple Hosts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae, Lancefield group B Streptococcus (GBS), is recognized for causing cattle mastitis, human neonatal meningitis, and fish meningo-encephalitis. We investigated the genomic diversity of GBS isolates from different phylogenetic hosts and geographical regions using serological t...

  8. Genomic Diversity of Streptoccocus agalactiae Isolates from Multiple Hosts and Their Infectivity in Nile Tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae, the Lancefield group B Streptococcus (GBS), has a broad host range and can be pathogenic to numerous animals, including fish. GBS is most recognized for causing cattle mastitis and human neonatal meningitis, it also causes fatal meningo-encephalitis in fish. We investigat...

  9. Alteration in gene expression in Nile tilapia (Oreochromis niloticus) juveniles submitted to fasting and refeeding.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the most important biological processes in living organisms that are affected by environmental fluctuations is growth, and the skeletal muscle growth in fish is dependent on proliferation and differentiation of myogenic precursor cells that are activated by Myogenic Regulatory Factors or inhi...

  10. Late Pleistocene and Holocene environments in the Nile basin

    NASA Astrophysics Data System (ADS)

    Williams, Martin A. J.

    2009-10-01

    Owing to the very gently sloping nature of the flood plain in the lower White Nile valley, which is underlain by a former lake-bed, the depositional record in that area is unusually well preserved. In Egypt and along the Blue Nile phases of erosion have destroyed segments of the sedimentary record, but the White Nile sequence is a good proxy for both the main Nile and the Blue Nile. During the last 15 ka, at least, times of high flow in the Blue Nile and main Nile were synchronous with those in the White Nile. Not all the White Nile flood deposits have been preserved but calibrated radiocarbon dates obtained on fossil freshwater and amphibious Pila shells and fish bones indicate that White Nile levels were high around 14.7-13.1 ka, 9.7-9.0 ka, 7.9-7.6 ka, 6.3 ka and 3.2-2.8 ka. The Blue Nile record is more fragmentary and that of the main Nile even more so except for the Holocene Nile delta. Calibrated radiocarbon ages for high Blue Nile flows indicate very high flood levels towards 13.9-13.2 ka, 8.6 ka, 7.7 ka and 6.3 ka. Incision by the Blue Nile and main Nile has caused progressive incision in the White Nile amounting to at least 4 m since the terminal Pleistocene ˜ 15 ka ago and at least 2 m over the past 9 ka. The Blue Nile seems to have cut down at least 10 m since ˜ 15 ka and at least 4 m since 9 ka. The time-transgressive and relatively late inception of plant domestication in the Nile valley may partly reflect this history of incision. Nile incision would propagate upstream into the White Nile valley, draining previously swampy areas along the valley floor, which would then become accessible to cultivation.

  11. Depletion of florfenicol amine in tilapia (Oreochromis sp.) maintained in a recirculating aquaculture system following Aquaflor®-medicated feed therapy

    USGS Publications Warehouse

    Gaikowski, Mark P.; Whitsel, Melissa K.; Charles, Shawn; Schleis, Susan M.; Crouch, Louis S.; Endris, Richard G.

    2013-01-01

    Aquaflor® [50% w w−1 florfenicol (FFC)], is approved for use in freshwater-reared warmwater finfish which include tilapia Oreochromis spp. in the United States to control mortality from Streptococcus iniae. The depletion of florfenicol amine (FFA), the marker residue of FFC, was evaluated after feeding FFC-medicated feed to deliver a nominal 20 mg FFC kg−1 BW d−1 dose (1.33× the label use of 15 mg FFC kg−1 BW d−1) to Nile tilapia O. niloticus and hybrid tilapia O. niloticus × O. aureus held in a recirculating aquaculture system (RAS) at production-scale holding densities. Florfenicol amine concentrations were determined in fillets taken from 10 fish before dosing and from 20 fish at nine time points after dosing (from 1 to 240 h post-dosing). Water samples were assayed for FFC before, during and after the dosing period. Parameters monitored included daily feed consumption and biofilter function (levels of ammonia, nitrite and nitrate). Mean fillet FFA concentration decreased from 13.77 μg g−1 at 1-h post dosing to 0.39 μg g−1 at 240-h post dosing. Water FFC concentration decreased from a maximum of 1400 ng mL−1 at 1 day post-dosing to 847 ng mL−1 at 240 h post-dosing. There were no adverse effects noted on fish, feed consumption or biofilter function associated with FFC-medicated feed administration to tilapia.

  12. The goitrogen 6-n-propyl-2-thiouracil (PTU) given during testis development increases Sertoli and germ cell numbers per cyst in fish: the tilapia (Oreochromis niloticus) model.

    PubMed

    Matta, Sérgio L P; Vilela, Daniel A R; Godinho, Hugo P; França, Luiz R

    2002-03-01

    The main objectives of the present study were to investigate the effects of 6-n-propyl-2-thiouracil (PTU) on Sertoli cell proliferation, germ cell number, and testis size in Nile tilapias (Oreochromis niloticus). In this regard, young fish (approximately 1 g BW and approximately 3.5 cm total in length) were treated for a period of 40 d with different concentrations (100 and 150 ppm) of PTU. The animals were killed and analyzed on d 1, 30, 40, 98, and 208 after the beginning of the treatment. On d 30 and 40 the spermatogenic process was delayed in fish treated with PTU compared with the control group. Also at these periods, treated tilapia had decreased (P < 0.05) body weight and total length. On d 98 body weight and total length had recovered in PTU-treated fish and were similar (P > 0.05) to those of the controls. However, testis weight and gonadosomatic index (testis mass/body weight) were approximately 100% higher (P < 0.05) in treated tilapia. Similarly, the area occupied by seminiferous tubules, the number of Sertoli cells and germ cells per cyst, and the number of Leydig cells per testis were significantly (P < 0.05) greater in treated fish. Nevertheless, nuclear volume and individual Leydig cell volume were significantly lower (P < 0.05) in tilapia receiving PTU treatment. Compared with controls, at 208 d all parameters analyzed presented the same trend as that observed at 98 d. In general, at 98 d the different PTU concentrations used during the treatment period induced similar effects. However, at 208 d the mean values observed for several parameters were significantly higher (P < 0.05) in fish exposed to 150 ppm. Probably due to the higher density of Sertoli cells per cyst in treated tilapia, these cells presented a smaller (P < 0.05) nucleolus and a trend to decrease its support capacity (efficiency). However, the meiotic index (germ cell loss during the two meiotic divisions) was similar (P > 0.05) in the three groups of fish investigated. Remarkably

  13. Persistence of West Nile virus.

    PubMed

    Garcia, Melissa N; Hasbun, Rodrigo; Murray, Kristy O

    2015-02-01

    West Nile virus (WNV) is a widespread global pathogen that results in significant morbidity and mortality. Data from animal models provide evidence of persistent renal and neurological infection from WNV; however, the possibility of persistent infection in humans and long-term neurological and renal outcomes related to viral persistence remain largely unknown. In this paper, we provide a review of the literature related to persistent infection in parallel with the findings from cohorts of patients with a history of WNV infection. The next steps for enhancing our understanding of WNV as a persistent pathogen are discussed.

  14. Dietary Aloe vera improves plasma lipid profile, antioxidant, and hepatoprotective enzyme activities in GIFT-tilapia (Oreochromis niloticus) after Streptococcus iniae challenge.

    PubMed

    Gabriel, Ndakalimwe Naftal; Qiang, Jun; Ma, Xin Yu; He, Jie; Xu, Pao; Liu, Kai

    2015-10-01

    The current study investigated the effects of dietary Aloe vera on plasma lipid profile status, antioxidant, and hepatoprotective enzyme activities of GIFT-tilapia juveniles under Streptococcus iniae challenge. Five dietary groups were designed including a control and 100 % Aloe powder incorporated into a tilapia feed at 0.5, 1, 2, and 4 %/kg feed, which were administered for 8 weeks. Fish fed dietary Aloe at 4 %/kg feed significantly reduced in total cholesterol, while triacylglycerol reduced (P < 0.05) in those fed 0.5, 2, and 4 % Aloe/kg feed compared to unsupplemented ones. High-density lipoprotein was significantly elevated in fish fed 0.5 and 1 % Aloe/kg feed compared to unsupplemented ones, and no significant changes (P > 0.05) were noted in low-density lipoprotein among test groups. Furthermore, high activities of superoxide dismutase, catalase, and glutathione peroxide in liver tissues were observed in Aloe-supplemented fish compared to unsupplemented ones, before and after S. iniae challenge (7.7 × 10(6) CFU cells/mL). Variations were also noted in malondialdehyde activity throughout the trial, but no significant difference (P > 0.05) was observed between groups. Meanwhile, Aloe-supplemented fish reduced serum aspartate and alanine aminotransferase (AST and ALT) activities before and after challenge. Based on the second-order polynomial regression analysis, dietary Aloe inclusion levels less than or equal to 1.88, 1.86, and 2.79 %/kg feed were determined to be suitable in improving plasma lipid profile status, antioxidant, and hepatoprotective enzyme activities in GIFT-tilapia in this study, respectively. Thus, A. vera extracts may be recommended as a tilapia feed supplement to enhance fish antioxidant and hepatoprotective capacities, especially during disease outbreaks.

  15. Dietary Aloe vera improves plasma lipid profile, antioxidant, and hepatoprotective enzyme activities in GIFT-tilapia (Oreochromis niloticus) after Streptococcus iniae challenge.

    PubMed

    Gabriel, Ndakalimwe Naftal; Qiang, Jun; Ma, Xin Yu; He, Jie; Xu, Pao; Liu, Kai

    2015-10-01

    The current study investigated the effects of dietary Aloe vera on plasma lipid profile status, antioxidant, and hepatoprotective enzyme activities of GIFT-tilapia juveniles under Streptococcus iniae challenge. Five dietary groups were designed including a control and 100 % Aloe powder incorporated into a tilapia feed at 0.5, 1, 2, and 4 %/kg feed, which were administered for 8 weeks. Fish fed dietary Aloe at 4 %/kg feed significantly reduced in total cholesterol, while triacylglycerol reduced (P < 0.05) in those fed 0.5, 2, and 4 % Aloe/kg feed compared to unsupplemented ones. High-density lipoprotein was significantly elevated in fish fed 0.5 and 1 % Aloe/kg feed compared to unsupplemented ones, and no significant changes (P > 0.05) were noted in low-density lipoprotein among test groups. Furthermore, high activities of superoxide dismutase, catalase, and glutathione peroxide in liver tissues were observed in Aloe-supplemented fish compared to unsupplemented ones, before and after S. iniae challenge (7.7 × 10(6) CFU cells/mL). Variations were also noted in malondialdehyde activity throughout the trial, but no significant difference (P > 0.05) was observed between groups. Meanwhile, Aloe-supplemented fish reduced serum aspartate and alanine aminotransferase (AST and ALT) activities before and after challenge. Based on the second-order polynomial regression analysis, dietary Aloe inclusion levels less than or equal to 1.88, 1.86, and 2.79 %/kg feed were determined to be suitable in improving plasma lipid profile status, antioxidant, and hepatoprotective enzyme activities in GIFT-tilapia in this study, respectively. Thus, A. vera extracts may be recommended as a tilapia feed supplement to enhance fish antioxidant and hepatoprotective capacities, especially during disease outbreaks. PMID:26109009

  16. Ixodid and Argasid Tick Species and West Nile Virus

    PubMed Central

    Uzcátegui, Nathalie Yumari; Gould, Ernest Andrew; Nuttall, Patricia Anne

    2004-01-01

    Control of West Nile virus (WNV) can only be effective if the vectors and reservoirs of the virus are identified and controlled. Although mosquitoes are the primary vectors, WNV has repeatedly been isolated from ticks. Therefore tick-borne transmission studies were performed with an ixodid (Ixodes ricinus) and an argasid tick species (Ornithodoros moubata). Both species became infected after feeding upon viremic hosts, but I. ricinus ticks were unable to maintain the virus. In contrast, O. moubata ticks were infected for at least 132 days, and the infection was maintained through molting and a second bloodmeal. Infected O. moubata ticks transmitted the virus to rodent hosts, albeit at a low level. Moreover, the virus was nonsystemically transmitted between infected and uninfected O. moubata ticks co-fed upon uninfected hosts. Although ticks are unlikely to play a major role in WNV transmission, our findings suggest that some species have the potential to act as reservoirs for the virus. PMID:15200855

  17. Shifting Sediment Sources in the Quaternary Nile

    NASA Astrophysics Data System (ADS)

    Woodward, Jamie; Macklin, Mark; Fielding, Laura; Millar, Ian; Williams, Martin

    2016-04-01

    Invited Paper The Nile basin contains the longest river channel system in the world and drains about one tenth of the African continent. A dominant characteristic of the modern Nile is the marked spatial and temporal variability in the flux of water and sediment. Because the major headwater basins of the Nile are linked to key elements of the global climate system, the sedimentary records in the basin have attracted good deal of attention from the Quaternary palaeoclimate and palaeohydrology communities. Various approaches (from heavy minerals to strontium isotopes) have been employed to examine present and past patterns of sediment yield in the basin. A good deal of work has been carried out on the long sediment records in the delta and offshore which provide high resolution archives of hydrological changes in the upstream basin as well fluctuations in the input of dust from the desert. The sediment load of the modern desert Nile (downstream of Khartoum) is dominated by sediment inputs from the Blue Nile (61 +/- 5%) and Atbara (35 +/- 4%), whilst the White Nile contribution is meagre (3 +/- 2%) (Padoan et al. 2011). Recent work has shown that these values were very different during humid phases of the Quaternary when stronger Northern Hemisphere summer insolation produced wetter conditions across North Africa. In the early Holocene, for example, the Nile floodplain in Northern Sudan shows a tributary wadi input of 40-50%. This paper will review three decades of work on the sediment delivery dynamics of the Quaternary Nile and explore their palaeoclimatic implications. Padoan, M., Garzanti, E., Harlavan, Y., Villa, I.M. (2011) Tracing Nile sediment sources by Sr and Nd isotope signatures (Uganda, Ethiopia, Sudan). Geochim. Cosmochim. Acta 75 (12), 3627-3644.

  18. West Nile Virus and wildlife

    USGS Publications Warehouse

    Marra, P.P.; Griffing, S.; Caffrey, C.; Kilpatrick, A.M.; McLean, R.; Brand, C.; Saito, E.; Dupuis, A.P.; Kramer, L.; Novak, R.

    2004-01-01

    West Nile virus (WNV) has spread rapidly across North America, resulting in human deaths and in the deaths of untold numbers of birds, mammals, and reptiles. The virus has reached Central America and the Caribbean and may spread to Hawaii and South America. Although tens of thousands of birds have died, and studies of some bird species show local declines, few regionwide declines can be attributed to WNV. Predicting future impacts of WNV on wildlife, and pinpointing what drives epidemics, will require substantial additional research into host susceptibility, reservoir competency, and linkages between climate, mosquitoes, and disease. Such work will entail a collaborative effort between scientists in governmental research groups, in surveillance and control programs, and in nongovernmental organizations. West Nile virus was not the first, and it will not be the last, exotic disease to be introduced to the New World. Its spread in North America highlights the need to strengthen animal monitoring programs and to integrate them with research on disease ecology.

  19. Sublethal toxicity and accumulation of cadmium in Tilapia aurea

    SciTech Connect

    Papoutsoglou, S.E.; Abel, P.D.

    1988-09-01

    Study of the sublethal toxicity of pollutants to fish has mainly been confined to North American and North European species, many of them of little direct commercial importance. Tilapia spp. are important food fishes in many countries and are increasingly important in aquaculture. Relatively little information exists on their susceptibility to many pollutants. A recent study indicated that Tilapia aurea was among the more resistant species to cadmium, in terms of lethal toxicity of the metal. The present papers reports an investigation into the sublethal toxicity of cadmium in Tilapia aurea.

  20. Coupling of methylmercury uptake with respiration and water pumping in freshwater tilapia Oreochromis niloticus.

    PubMed

    Wang, Rui; Wong, Ming-Hung; Wang, Wen-Xiong

    2011-09-01

    The relationships among the uptake of toxic methylmercury (MeHg) and two important fish physiological processes-respiration and water pumping--in the Nile tilapia (Oreochromis niloticus) were explored in the present study. Coupled radiotracer and respirometric techniques were applied to measure simultaneously the uptake rates of MeHg, water, and oxygen under various environmental conditions (temperature, dissolved oxygen level, and water flow). A higher temperature enhanced MeHg influx and the oxygen consumption rate but had no effect on the water uptake, indicating the influence of metabolism on MeHg uptake. The fish showed a high tolerance to hypoxia, and the oxygen consumption rate was not affected until the dissolved oxygen concentration decreased to extremely low levels (below 1 mg/L). The MeHg and water uptake rates increased simultaneously as the dissolved oxygen level decreased, suggesting the coupling of water flux and MeHg uptake. The influence of fish swimming performance on MeHg uptake was also investigated for the first time. Rapidly swimming fish showed significantly higher uptake rates of MeHg, water, and oxygen, confirming the coupling relationships among respiration, water pumping, and metal uptake. Moreover, these results support that MeHg uptake is a rate-limiting process involving energy. Our study demonstrates the importance of physiological processes in understanding mercury bioaccumulation in fluctuating aquatic environments.

  1. The impact of rearing environment on the development of gut microbiota in tilapia larvae

    PubMed Central

    Giatsis, Christos; Sipkema, Detmer; Smidt, Hauke; Heilig, Hans; Benvenuti, Giulia; Verreth, Johan; Verdegem, Marc

    2015-01-01

    This study explores the effect of rearing environment on water bacterial communities (BC) and the association with those present in the gut of Nile tilapia larvae (Oreochromis niloticus, Linnaeus) grown in either recirculating or active suspension systems. 454 pyrosequencing of PCR-amplified 16S rRNA gene fragments was applied to characterize the composition of water, feed and gut bacteria communities. Observed changes in water BC over time and differences in water BCs between systems were highly correlated with corresponding water physico-chemical properties. Differences in gut bacterial communities during larval development were correlated with differences in water communities between systems. The correlation of feed BC with those in the gut was minor compared to that between gut and water, reflected by the fact that 4 to 43 times more OTUs were shared between water and gut than between gut and feed BC. Shared OTUs between water and gut suggest a successful transfer of microorganisms from water into the gut, and give insight about the niche and ecological adaptability of water microorganisms inside the gut. These findings suggest that steering of gut microbial communities could be possible through water microbial management derived by the design and functionality of the rearing system. PMID:26658351

  2. Effects of partially replacing dietary soybean meal or cottonseed meal with completely hydrolyzed feather meal (defatted rice bran as the carrier) on production, cytokines, adhesive gut bacteria, and disease resistance in hybrid tilapia (Oreochromis niloticus ♀ × Oreochromis aureus ♂).

    PubMed

    Zhang, Zhen; Xu, Li; Liu, Wenshu; Yang, Yalin; Du, Zhenyu; Zhou, Zhigang

    2014-12-01

    We formulated experimental diets for hybrid tilapia to investigate the effects of replacing dietary soybean meal (SBM) or cottonseed meal (CSM) by completely hydrolyzed feather meal (defatted rice bran as the carrier; abbreviated as CHFM), with emphasis on fish growth, the composition of adhesive gut bacteria, intestinal and hepatic immune responses, and disease resistance. A series of four isonitrogenous (33% crude protein) and isolipidic (6% crude lipid) diets were formulated to replace the isonitrogenous percentages of CSM or SBM by 6% or 12% CHFM. Quadruplicate groups of healthy and uniformly sized hybrid tilapia were assigned to each experimental diet. Fish were hand fed three times a day for 8 weeks at a rearing temperature of 25-28 °C. The growth performance of hybrid tilapia fed diets with partial replacement of dietary SBM or CSM with CHFM was comparable to the group of fish fed the control diet. The CHFM-containing diets affected the intestinal autochthonous bacterial community in similar ways. All CHFM-containing diets stimulated the expression of heat shock protein 70 in the intestine but suppressed its expression in the liver. Only the CHFM6/SBM diet stimulated the expression of interleukin-1β in intestine, and no effects were observed in all diets to the expression of interleukin-1β in liver. Thus, regarding the immune response in the intestine and liver, CHFM is a good alternative protein source that induces less stress in the host. CHFM did not affect disease resistance to Aeromonas hydrophila infection in hybrid tilapia. These data suggest that CHFM is a good alternative to partially replace SBM and CSM in tilapia feed. PMID:25304546

  3. Effects of partially replacing dietary soybean meal or cottonseed meal with completely hydrolyzed feather meal (defatted rice bran as the carrier) on production, cytokines, adhesive gut bacteria, and disease resistance in hybrid tilapia (Oreochromis niloticus ♀ × Oreochromis aureus ♂).

    PubMed

    Zhang, Zhen; Xu, Li; Liu, Wenshu; Yang, Yalin; Du, Zhenyu; Zhou, Zhigang

    2014-12-01

    We formulated experimental diets for hybrid tilapia to investigate the effects of replacing dietary soybean meal (SBM) or cottonseed meal (CSM) by completely hydrolyzed feather meal (defatted rice bran as the carrier; abbreviated as CHFM), with emphasis on fish growth, the composition of adhesive gut bacteria, intestinal and hepatic immune responses, and disease resistance. A series of four isonitrogenous (33% crude protein) and isolipidic (6% crude lipid) diets were formulated to replace the isonitrogenous percentages of CSM or SBM by 6% or 12% CHFM. Quadruplicate groups of healthy and uniformly sized hybrid tilapia were assigned to each experimental diet. Fish were hand fed three times a day for 8 weeks at a rearing temperature of 25-28 °C. The growth performance of hybrid tilapia fed diets with partial replacement of dietary SBM or CSM with CHFM was comparable to the group of fish fed the control diet. The CHFM-containing diets affected the intestinal autochthonous bacterial community in similar ways. All CHFM-containing diets stimulated the expression of heat shock protein 70 in the intestine but suppressed its expression in the liver. Only the CHFM6/SBM diet stimulated the expression of interleukin-1β in intestine, and no effects were observed in all diets to the expression of interleukin-1β in liver. Thus, regarding the immune response in the intestine and liver, CHFM is a good alternative protein source that induces less stress in the host. CHFM did not affect disease resistance to Aeromonas hydrophila infection in hybrid tilapia. These data suggest that CHFM is a good alternative to partially replace SBM and CSM in tilapia feed.

  4. FAQ: General Questions about West Nile Virus

    MedlinePlus

    ... or meningitis (inflammation of the lining of the brain and spinal cord). West Nile virus transmission has been documented in Europe and the Middle East, Africa, India, parts of Asia, and Australia. It was first detected ...

  5. Compensatory growth in hybrid tilapia ( Oreochromis mossambicus ×O. niloticus) reared in seawater, following restricted feeding

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Cui, Yibo; Yang, Yunxia; Cai, Fasheng

    2004-12-01

    Hybrid tilapia weighing 7.71 g were reared in seawater at 24.0 29.0°C for 8 weeks. The controls were fed to satiation twice a day throughout the experiment, whereas treatment groups were fed at 0.5%, 1.5% or 3.0% body weight per day for 4 weeks, and then to satiation for the remainder of the experiment. During the first 4-week period, there was a curvilinear relationship between growth rate and ration size. Fish fed 0.5% and 1.5% rations displayed compensatory growth response of 2 weeks duration during realimentation. The weight-adjusted growth rate of fish fed at 3% ration was not significantly different from that of the controls by the end of the experiment, when none of the treatment groups had caught up in body weight with the controls. Hyperphagia was observed for the first 2 weeks of realimenatation in fish previously fed at 3% ration, but persisted for the whole realimentation period in groups previously fed at 0.5% and 1.5% rations. None of the feed restricted groups showed improved digestibility, feed efficiency, or protein and energy retention efficiency.

  6. West Nile virus: North American experience

    USGS Publications Warehouse

    Hofmeister, Erik K.

    2011-01-01

    West Nile virus, a mosquito-vectored flavivirus of the Japanese encephalitis serogroup, was first detected in North America following an epizootic in the New York City area in 1999. In the intervening 11 years since the arrival of the virus in North America, it has crossed the contiguous USA, entered the Canadian provinces bordering the USA, and has been reported in the Caribbean islands, Mexico, Central America and, more recently, South America. West Nile virus has been reported in over 300 species of birds in the USA and has caused the deaths of thousands of birds, local population declines of some avian species, the clinical illness and deaths of thousands of domestic horses, and the clinical disease in over 30 000 Americans and the deaths of over 1000. Prior to the emergence of West Nile virus in North America, St. Louis encephalitis virus and Dengue virus were the only other known mosquito-transmitted flaviviruses in North America capable of causing human disease. This review will discuss the North American experience with mosquito-borne flavivirus prior to the arrival of West Nile virus, the entry and spread of West Nile virus in North America, effects on wild bird populations, genetic changes in the virus, and the current state of West Nile virus transmission.

  7. West Nile virus: North American experience.

    PubMed

    Hofmeister, Erik K

    2011-09-01

    West Nile virus, a mosquito-vectored flavivirus of the Japanese encephalitis serogroup, was first detected in North America following an epizootic in the New York City area in 1999. In the intervening 11 years since the arrival of the virus in North America, it has crossed the contiguous USA, entered the Canadian provinces bordering the USA, and has been reported in the Caribbean islands, Mexico, Central America and, more recently, South America. West Nile virus has been reported in over 300 species of birds in the USA and has caused the deaths of thousands of birds, local population declines of some avian species, the clinical illness and deaths of thousands of domestic horses, and the clinical disease in over 30 000 Americans and the deaths of over 1000. Prior to the emergence of West Nile virus in North America, St. Louis encephalitis virus and Dengue virus were the only other known mosquito-transmitted flaviviruses in North America capable of causing human disease. This review will discuss the North American experience with mosquito-borne flavivirus prior to the arrival of West Nile virus, the entry and spread of West Nile virus in North America, effects on wild bird populations, genetic changes in the virus, and the current state of West Nile virus transmission.

  8. The aquaculture potential of Tilapia rendalli in relation to its feeding habits and digestive capabilities

    NASA Astrophysics Data System (ADS)

    Hlophe, S. N.; Moyo, N. A. G.

    Tilapia rendalli is a predominately macrophagous fish. However, it was able to colonise an oligotrophic dam (Flag Boshielo) with limited macrophytes. Therefore, the diet of T. rendalli in this dam was investigated; its stomach contents were examined over 12 months. A size related dietary shift was evident. Juveniles fed mainly on zooplankton while sub-adult and adult fish grazed on both macrophytes and marginal vegetation. T. rendalli’s ability to strive in an environment with limited food resources led to a subsequent study to determine its aquaculture potential. Its growth performance was compared to that of the commonly cultured Oreochromis mossambicus. Juveniles of both species were fed a commercial tilapia diet for 60 days. Specific growth rate and protein efficiency ratio was comparable to that of O. mossambicus (P > 0.05, ANOVA). Feed conversion ratio was significantly higher (P < 0.05) in T. rendalli (1.43) than in O. mossambicus (1.25) indicating a better efficiency in feed utilisation by O. mossambicus. At a physiological level, protease, lipase and cellulase activities did not differ significantly between the two fish species (P > 0.05). Amylase activities were significantly higher (P < 0.05) in T. rendalli than in O. mossambicus. The highest amylase activities were recorded in the proximal intestines as 26.34 and 22.00 μmol/min/mg protein in T. rendalli and O. mossambicus respectively. This may be an indicator that T. rendalli is better equipped to digest plant diets. T. rendalli may be the aquaculture species of choice for emerging fish farmers who cannot afford the highly priced fishmeal as a protein source in fish diets.

  9. West Nile Virus in California

    PubMed Central

    Lothrop, Hugh; Chiles, Robert; Madon, Minoo; Cossen, Cynthia; Woods, Leslie; Husted, Stan; Kramer, Vicki; Edman, John

    2004-01-01

    West Nile virus (WNV) was first isolated in California during July 2003 from a pool of Culex tarsalis collected near El Centro, Imperial County. WNV transmission then increased and spread in Imperial and Coachella Valleys, where it was tracked by isolation from pools of Cx. tarsalis, seroconversions in sentinel chickens, and seroprevalence in free-ranging birds. WNV then dispersed to the city of Riverside, Riverside County, and to the Whittier Dam area of Los Angeles County, where it was detected in dead birds and pools of Cx. pipiens quinquefasciatus. By October, WNV was detected in dead birds collected from riparian corridors in Los Angeles, west to Long Beach, and through inland valleys south from Riverside to San Diego County. WNV was reported concurrently from Arizona in mid-August and from Baja, Mexico, in mid-November. Possible mechanisms for virus introduction, amplification, and dispersal are discussed. PMID:15496236

  10. N Isotopes in Nile Sediments (ethiopia, Sudan)

    NASA Astrophysics Data System (ADS)

    Padoan, M.; Villa, I. M.; Garzanti, E.; Galbusera, M.; Quistini, S.; Peruta, L.; El Kammar, A.

    2009-04-01

    The Nile is the most important river of the Eastern Mediterranean. Its water and sediment fluxes have greatly influenced marine circulation throughout the Quaternary, and are widely considered as possible causes for stagnation and formation of sapropel (Krom et al., 1999a; 2002; Talbot et al., 2000; Freydier et al., 2001; Weldeab et al., 2002; Scrivner et al., 2004). Variations in annual flooding and baseflow of the river Nile, controlled by climate changes, had major impact on the rise and demise of Egyptian dynasties (Stanley et al., 2003). In order to better define sedimentary sources of the Nile system and to obtain more robust results, we have analyzed Nd isotopes in sediments of all its major Sudanese and Ethiopian tributaries (Atbara, Gash, Abay, Didesa, Dabus, White Nile, Bahr Ez Zeraf) in several replicate samples. Analyses were carried out on distinct mud and sand fractions (<40 microns and 125-180 microns) of 30 samples, and systematic changes related to grain size and hydraulic-sorting processes could thus be investigated. On the same samples, companion studies are being carried out on Sr isotopes (Padoan et al., 2007) and on Pb isotopes at the Geological Survey of Israel (Harlavan et al., in preparation). Overall, isotopic signals are markedly different between the White Nile system, derived from largely Archean to Paleoproterozoic basement rocks, and Ethiopian tributaries, derived in diverse proportions from largely Neoproterozoic rift-shoulder basements and overlying Oligocene flood basalts. Isotopic signals of Main Nile sediments downstream of the Atbara confluence are close to those of Blue Nile sediments, indicating that detritus is mainly provided by the latter (Garzanti et al., 2006). In the White Nile branch, the 143Nd/144Nd ratio of the mud fraction is lower in the Bahr Ez Zeraf (0.51167) than in the White Nile downstrean of the Sobat confluence (0.51219), revealing significant sediment influx from the latter. In Blue Nile and Atbara branches

  11. West Nile Virus Encephalitis and Myocarditis in Wolf and Dog

    PubMed Central

    Heinz-Taheny, Kathleen; Osborne, Tanasa S.; Novak, Robert J.; Lewis, Beth A.; Firth, Margaret L.

    2003-01-01

    In the third season (2002) of the West Nile virus epidemic in the United States, two canids (wolf and dog) were diagnosed with West Nile virus encephalitis and myocarditis with similarities to known affected species (humans, horses, and birds). The West Nile virus infections were confirmed by immunohistochemistry and polymerase chain reaction. PMID:14609468

  12. Effects of replacing soybean meal with rubber seed meal on growth, antioxidant capacity, non-specific immune response, and resistance to Aeromonas hydrophila in tilapia (Oreochromis niloticus × O. aureus).

    PubMed

    Deng, Junming; Mai, Kangsen; Chen, Liqiao; Mi, Haifeng; Zhang, Lu

    2015-06-01

    This study evaluated the effects of replacing soybean meal (SBM) with rubber seed meal (RSM) on growth, antioxidant capacity, non-specific immune response and resistance to Aeromonas hydrophila in tilapia (Oreochromis niloticus × Oreochromis aureus). Five experimental diets were formulated with 0 (control), 10, 20, 30, and 40% RSM replacing graded levels of SBM, respectively. Fish were fed one of the five experimental diets for eight weeks, and then challenged by A. hydrophila via intraperitoneal injection and kept for seven days. Dietary RSM inclusion level up to 30% did not affect the weight gain and daily growth coefficient, whereas these were depressed by a further inclusion. Fish fed diet with 40% RSM showed the lowest serum total antioxidant capacity, lysozyme, alternative complement pathway, respiratory burst and phagocytic activities. Dietary RSM inclusion gradually depressed the post-challenge survival rate, and that was significantly lower in fish fed diet with 40% RSM compared to fish fed the control diet. Conversely, the inclusion of RSM generally increased the serum total cholesterol level, the plasma alanine aminotransferase and aspartate aminotransferase activities, and these were significantly higher in fish fed diet with 40% RSM compared to fish fed the control diet. The results indicated that RSM can be included at level up to 30% in diet for tilapia without obvious adverse effects on the growth, antioxidant capacity, non-specific immune response and resistance to A. hydrophila infection, whereas these were depressed by a further inclusion.

  13. West Nile Virus Drug Discovery

    PubMed Central

    Lim, Siew Pheng; Shi, Pei-Yong

    2013-01-01

    The outbreak of West Nile virus (WNV) in 1999 in the USA, and its continued spread throughout the Americas, parts of Europe, the Middle East and Africa, underscored the need for WNV antiviral development. Here, we review the current status of WNV drug discovery. A number of approaches have been used to search for inhibitors of WNV, including viral infection-based screening, enzyme-based screening, structure-based virtual screening, structure-based rationale design, and antibody-based therapy. These efforts have yielded inhibitors of viral or cellular factors that are critical for viral replication. For small molecule inhibitors, no promising preclinical candidate has been developed; most of the inhibitors could not even be advanced to the stage of hit-to-lead optimization due to their poor drug-like properties. However, several inhibitors developed for related members of the family Flaviviridae, such as dengue virus and hepatitis C virus, exhibited cross-inhibition of WNV, suggesting the possibility to re-purpose these antivirals for WNV treatment. Most promisingly, therapeutic antibodies have shown excellent efficacy in mouse model; one of such antibodies has been advanced into clinical trial. The knowledge accumulated during the past fifteen years has provided better rationale for the ongoing WNV and other flavivirus antiviral development. PMID:24300672

  14. Depletion of florfenicol amine in tilapia (Oreochromis sp.) maintained in a recirculating aquaculture system following Aquaflor(R)-medicated feed therapy (20 mg/kg BW/d for 10 days)

    USGS Publications Warehouse

    Gaikowski, Mark P.; Whitsel, Melissa K.; Charles, Shawn; Schleis, Susan M.; Crouch, Louis S.; Endris, Richard G.

    2013-01-01

    Aquaflor® [50% w w−1 florfenicol (FFC)], is approved for use in freshwater-reared warmwater finfish which include tilapia Oreochromis spp. in the United States to control mortality from Streptococcus iniae. The depletion of florfenicol amine (FFA), the marker residue of FFC, was evaluated after feeding FFC-medicated feed to deliver a nominal 20 mg FFC kg−1 BW d−1 dose (1.33× the label use of 15 mg FFC kg−1 BW d−1) to Nile tilapia O. niloticus and hybrid tilapia O. niloticus × O. aureus held in a recirculating aquaculture system (RAS) at production-scale holding densities. Florfenicol amine concentrations were determined in fillets taken from 10 fish before dosing and from 20 fish at nine time points after dosing (from 1 to 240 h post-dosing). Water samples were assayed for FFC before, during and after the dosing period. Parameters monitored included daily feed consumption and biofilter function (levels of ammonia, nitrite and nitrate). Mean fillet FFA concentration decreased from 13.77 μg g−1 at 1-h post dosing to 0.39 μg g−1 at 240-h post dosing. Water FFC concentration decreased from a maximum of 1400 ng mL−1 at 1 day post-dosing to 847 ng mL−1 at 240 h post-dosing. There were no adverse effects noted on fish, feed consumption or biofilter function associated with FFC-medicated feed administration to tilapia.

  15. Impacts of West Nile Virus on wildlife

    USGS Publications Warehouse

    Saito, E.K.; Wild, M.A.

    2004-01-01

    The recent epidemic of West Nile virus in the United States proved to be unexpectedly active and was the largest epidemic of the virus ever recorded. Much remains to be discovered about the ecology and epidemiology of West Nile virus in the United States, including which species are important in maintaining the virus in nature, why some species are more susceptible to lethal infection, and what environmental factors are important in predicting future epidemics. These factors will likely vary regionally, depending on local ecological characteristics. Until scientists better understand the virus and factors influencing its activity, predicting its effects for future seasons is impossible. However, experts are certain about one thing: West Nile virus is here to stay.

  16. Inapparent Streptococcus agalactiae infection in adult/commercial tilapia.

    PubMed

    Sun, Jiufeng; Fang, Wei; Ke, Bixia; He, Dongmei; Liang, Yuheng; Ning, Dan; Tan, Hailing; Peng, Hualin; Wang, Yunxin; Ma, Yazhou; Ke, Changwen; Deng, Xiaoling

    2016-01-01

    We report on inapparent infections in adult/commercial tilapia in major tilapia fish farms in Guangdong. A total of 146 suspected isolates were confirmed to be S. agalactiae using an API 20 Strep system and specific PCR amplification. All isolates were identified as serotype Ia using multiplex serotyping PCR. An MLST assay showed single alleles of adhP (10), atr (2), glcK (2), glnA (1), pheS (1), sdhA (3) and tkt (2), and this profile was designated 'unique ST 7'. The analysis of virulence genes resulted in 10 clusters, of which dltr-bca-sodA-spb1-cfb-bac (62, 42.47%) was the predominant virulence gene profile. The PFGE analysis of S. agalactiae yielded 6 distinct PFGE types (A, B, C, D, F and G), of which Pattern C (103) was the predominant type, accounting for approximately 70.55% (103/146) of the total S. agalactiae strains. Therefore, unlike what has been found in juvenile tilapia, in which PFGE pattern D/F is the major prevalent pattern, we found that pattern C was the major prevalent pattern in inapparent infected adult/commercial tilapia in Guangdong, China. In conclusion, we close a gap in the current understanding of S. agalactiae epidemiology and propose that researchers should be alert for inapparent S. agalactiae infections in adult/commercial tilapia to prevent a potential threat to food safety. PMID:27215811

  17. Inapparent Streptococcus agalactiae infection in adult/commercial tilapia

    PubMed Central

    Sun, Jiufeng; Fang, Wei; Ke, Bixia; He, Dongmei; Liang, Yuheng; Ning, Dan; Tan, Hailing; Peng, Hualin; Wang, Yunxin; Ma, Yazhou; Ke, Changwen; Deng, Xiaoling

    2016-01-01

    We report on inapparent infections in adult/commercial tilapia in major tilapia fish farms in Guangdong. A total of 146 suspected isolates were confirmed to be S. agalactiae using an API 20 Strep system and specific PCR amplification. All isolates were identified as serotype Ia using multiplex serotyping PCR. An MLST assay showed single alleles of adhP (10), atr (2), glcK (2), glnA (1), pheS (1), sdhA (3) and tkt (2), and this profile was designated ‘unique ST 7’. The analysis of virulence genes resulted in 10 clusters, of which dltr-bca-sodA-spb1-cfb-bac (62, 42.47%) was the predominant virulence gene profile. The PFGE analysis of S. agalactiae yielded 6 distinct PFGE types (A, B, C, D, F and G), of which Pattern C (103) was the predominant type, accounting for approximately 70.55% (103/146) of the total S. agalactiae strains. Therefore, unlike what has been found in juvenile tilapia, in which PFGE pattern D/F is the major prevalent pattern, we found that pattern C was the major prevalent pattern in inapparent infected adult/commercial tilapia in Guangdong, China. In conclusion, we close a gap in the current understanding of S. agalactiae epidemiology and propose that researchers should be alert for inapparent S. agalactiae infections in adult/commercial tilapia to prevent a potential threat to food safety. PMID:27215811

  18. West Nile Virus: Review of the Literature

    PubMed Central

    Petersen, Lyle R.; Brault, Aaron C.; Nasci, Roger S.

    2015-01-01

    IMPORTANCE Since its introduction in North America in 1999,West Nile virus has produced the 3 largest arboviral neuroinvasive disease outbreaks ever recorded in the United States. OBJECTIVE To review the ecology, virology, epidemiology, clinical characteristics, diagnosis, prevention, and control of West Nile virus, with an emphasis on North America. EVIDENCE REVIEW PubMed electronic database was searched through February 5, 2013. United States national surveillance data were gathered from the Centers for Disease Control and Prevention. FINDINGS West Nile virus is now endemic throughout the contiguous United States, with 16 196 human neuroinvasive disease cases and 1549 deaths reported since 1999. More than 780 000 illnesses have likely occurred. To date, incidence is highest in the Midwest from mid-July to early September. West Nile fever develops in approximately 25% of those infected, varies greatly in clinical severity, and symptoms may be prolonged. Neuroinvasive disease (meningitis, encephalitis, acute flaccid paralysis) develops in less than 1% but carries a fatality rate of approximately 10%. Encephalitis has a highly variable clinical course but often is associated with considerable long-term morbidity. Approximately two-thirds of those with paralysis remain with significant weakness in affected limbs. Diagnosis usually rests on detection of IgM antibody in serum or cerebrospinal fluid. Treatment is supportive; no licensed human vaccine exists. Prevention uses an integrated pest management approach, which focuses on surveillance, elimination of mosquito breeding sites, and larval and adult mosquito management using pesticides to keep mosquito populations low. During outbreaks or impending outbreaks, emphasis shifts to aggressive adult mosquito control to reduce the abundance of infected, biting mosquitoes. Pesticide exposure and adverse human health events following adult mosquito control operations for West Nile virus appear negligible. CONCLUSIONS AND

  19. N Isotopes in Nile Sediments (ethiopia, Sudan)

    NASA Astrophysics Data System (ADS)

    Padoan, M.; Villa, I. M.; Garzanti, E.; Galbusera, M.; Quistini, S.; Peruta, L.; El Kammar, A.

    2009-04-01

    The Nile is the most important river of the Eastern Mediterranean. Its water and sediment fluxes have greatly influenced marine circulation throughout the Quaternary, and are widely considered as possible causes for stagnation and formation of sapropel (Krom et al., 1999a; 2002; Talbot et al., 2000; Freydier et al., 2001; Weldeab et al., 2002; Scrivner et al., 2004). Variations in annual flooding and baseflow of the river Nile, controlled by climate changes, had major impact on the rise and demise of Egyptian dynasties (Stanley et al., 2003). In order to better define sedimentary sources of the Nile system and to obtain more robust results, we have analyzed Nd isotopes in sediments of all its major Sudanese and Ethiopian tributaries (Atbara, Gash, Abay, Didesa, Dabus, White Nile, Bahr Ez Zeraf) in several replicate samples. Analyses were carried out on distinct mud and sand fractions (<40 microns and 125-180 microns) of 30 samples, and systematic changes related to grain size and hydraulic-sorting processes could thus be investigated. On the same samples, companion studies are being carried out on Sr isotopes (Padoan et al., 2007) and on Pb isotopes at the Geological Survey of Israel (Harlavan et al., in preparation). Overall, isotopic signals are markedly different between the White Nile system, derived from largely Archean to Paleoproterozoic basement rocks, and Ethiopian tributaries, derived in diverse proportions from largely Neoproterozoic rift-shoulder basements and overlying Oligocene flood basalts. Isotopic signals of Main Nile sediments downstream of the Atbara confluence are close to those of Blue Nile sediments, indicating that detritus is mainly provided by the latter (Garzanti et al., 2006). In the White Nile branch, the 143Nd/144Nd ratio of the mud fraction is lower in the Bahr Ez Zeraf (0.51167) than in the White Nile downstrean of the Sobat confluence (0.51219), revealing significant sediment influx from the latter. In Blue Nile and Atbara branches

  20. Quality of Dried Bacillus NP5 and its Effect on Growth Performance of Tilapia (Oreochromis niloticus).

    PubMed

    Utami, Diah Ayu Satyari; Widanarni; Suprayudi, M Agus

    2015-02-01

    The main things that need to be considered in the preparation of probiotics are viability during preparation and storage which are the disadvantages of the use of fresh culture probiotics. Dried probiotic can be applied through the feed, easy to be applied and has a long shelf life but application of dried probiotic in aquaculture is still not widely studied. This study aimed to evaluate the quality of dried Bacillus NP5 as the probiotic through in vitro assays and determine the best dose for the growth performance of tilapia. The treatment of in vitro assays including the production of dried probiotic without using of the coating material and dried by spray drying method (NS); freeze drying method (NF); with using of the coating material and dried by spray drying method (WS); freeze drying method (WF). The treatment which showed the best result at in vitro assays was applied for in vivo assays. The in vivo assays containing 4 treatments and 5 replicates which were control (K) and the administration of dried Bacillus NP5 Rf(R) (10(10) CFU g(-1)) in feed with dose of 0.5% (A), 1% (B) and 2% (C). The fish fed 3 times a day by at satiation for 28 days. Probiotic that encapsulated by maltodextrin and dried by spray drying method that stored in room temperature had the higher percentage product, viability after drying process and storage. The administration of 0.5% dried Bacillus NP5 showed the best growth performance in tilapia. PMID:26364359

  1. Complete mitochondrial DNA sequences of the Victoria tilapia (Oreochromis variabilis) and Redbelly Tilapia (Tilapia zilli): genome characterization and phylogeny analysis.

    PubMed

    Kinaro, Zachary Omambia; Xue, Liangyi; Volatiana, Josies Ancella

    2016-07-01

    The Cichlid fishes have played an important role in evolutionary biology, population studies and aquaculture industry with East African species representing a model suited for studying adaptive radiation and speciation for cichlid genome projects in which closely related genomes are fast emerging presenting questions on phenotype-genotype relations. The complete mitochondrial genomes presented here are for two closely related but eco-morphologically distinct Lake Victoria basin cichlids, Oreochromis variabilis, an endangered native species and Tilapia zilli, an invasive species, both of which are important economic fishes in local areas. The complete mitochondrial genomes determined for O. variabilis and T. zilli are 16 626 and 16,619 bp, respectively. Both the mitogenomes contain 13 protein-coding genes, 22 tRNAs, 2 rRNAs and a non-coding control region, which are typical of vertebrate mitogenomes. Phylogenetic analyses of the two species revealed that though both lie within family Cichlidae, they are remotely related. PMID:27158785

  2. Determining the Palaeodrainage of the Nile River from a Provenance Study of the Nile Delta Cone Sediments

    NASA Astrophysics Data System (ADS)

    Fielding, L.; Najman, Y.; Millar, I.; Butterworth, P.; Garzanti, E.; Kneller, B. C.

    2014-12-01

    This study documents the palaeodrainage history of the Nile River, in particular the time of its transition from a small locally sourced drainage network to the initiation of an extensive catchment. Today, the Nile drains as far south as Lake Victoria, with the White Nile draining largely cratonic rocks of Archean to Proterozoic age and the Blue Nile draining Cenozoic Ethiopian Continental Flood Basalts and Neoproterozoic basement. However, the timing of catchment expansion to the river's current extent is highly debated. Two end member models are: A) The Blue Nile did not connect with the lower Nile until the Late Messinian, and the White Nile not until 0.5 Ma. In this model, the pre-Messinian Nile delta sediments are locally derived from the Red Sea Hills (RSH) (Issawi and McCauley 1992). B) The Blue Nile has been connected to the lower Nile since the Oligocene (Burke and Wells 1989). Onshore fieldwork characterised each possible source area (Ethiopian flood basalts, Archean craton, and Neoproterozoic basement and Phanerozoic cover sequences of the RSH) using petrography, geochemistry and isotope studies. Tertiary-aged Nile delta sediments provide a unique archive of the river's palaeodrainage history, which were analysed from conventional core from exploration and appraisal wells in order to identify the occurrence (if any) of these sources in the delta geological record. Heavy mineral, petrographic, U/Pb rutile and Lu/Hf zircon analyses indicate Blue Nile and/or RSH input to the Nile delta since at least the Oligocene with very little input from the White Nile. Sr and Nd whole-rock analyses of mud samples allow discrimination between the Blue Nile and RSH sources and may, subject to further analyses, confirm Blue Nile input to the delta since the Oligocene. U-Pb zircon analyses reveal the presence of 20-30 Ma zircons in both the modern river sediments from the Ethiopian Highlands and the Nile Delta core from the early Miocene to present day indicating a

  3. Determining the palaeodrainage of the Nile river from a provenance study of the Nile delta cone sediments

    NASA Astrophysics Data System (ADS)

    Fielding, Laura; Najman, Yani; Millar, Ian; Butterworth, Peter; Garzanti, Eduardo; Kneller, Ben

    2014-05-01

    This study documents the palaeodrainage history of the Nile River, in particular the time of its transition from a small locally sourced drainage network to the initiation of an extensive catchment. Today, the Nile drains as far south as Lake Victoria, with the White Nile draining largely cratonic rocks of Archean to Proterozoic age and the Blue Nile draining Cenozoic Ethiopian Continental Flood Basalts and Neoproterozoic basement. However, the timing of catchment expansion to the river's current extent is highly debated. Two end member models are: A) The Blue Nile did not connect with the lower Nile until the Late Messinian, and the White Nile not until 0.5 Ma. In this model, the pre-Messinian Nile delta sediments are locally derived from the Red Sea Hills (RSH) (Issawi and McCauley 1992). B) The Blue Nile has been connected to the lower Nile since the Oligocene (Burke and Wells 1989). Onshore fieldwork characterised each possible source area (Ethiopian flood basalts, Archean craton, and Neoproterozoic basement and Phanerozoic cover sequences of the RSH) using petrography, geochemistry and isotope studies. Tertiary-aged Nile delta sediments provide a unique archive of the river's palaeodrainage history, which were analysed from conventional core from exploration and appraisal wells in order to identify the occurrence (if any) of these sources in the delta geological record. Heavy mineral, petrographic, U/Pb rutile and Lu/Hf zircon analyses indicate Blue Nile and/or RSH input to the Nile delta since at least the Oligocene with very little input from the White Nile. Sr and Nd whole-rock analyses of mud samples allow discrimination between the Blue Nile and RSH sources and may, subject to further analyses, confirm Blue Nile input to the delta since the Oligocene. U-Pb zircon analyses reveal the presence of 20-30 Ma zircons in both the modern river sediments from the Ethiopian Highlands and the Nile Delta core from the early Miocene to present day indicating a

  4. Habitat associations, reproduction and diet of the Guinean tilapia Tilapia guineensis of the Gambia River floodplains.

    PubMed

    Louca, V; Lindsay, S W; Piyapong, C; Lucas, M C

    2010-06-01

    The ecology of the Guinean tilapia Tilapia guineensis a dominant species of the lower Gambia River floodplains and an important food source in parts of West Africa was studied to better understand the threat posed from construction of a barrage across the river. The catch per unit effort (CPUE) of T. guineensis was positively associated with conductivity and dissolved oxygen and negatively associated with water depth and the % vegetation cover. Diet studies indicated that the T. guineensis is primarily an iliophage. The peak of reproduction was at the beginning of the rainy season. CPUE peaked in May, just before the first rains, and subsequently declined, probably reflecting movement into newly flooded habitat. Median size at maturity was 11.6 cm total length, L(T), for females and 12.5 cm L(T) for males. L(T)-frequency analysis indicated several juvenile cohorts as well as very young fish on the floodplains each month, suggesting continuation of reproduction throughout the rainy season. The impending construction of a hydroelectric dam on the Gambia River is likely to affect T. guineensis negatively through anticipated changes in the hydrology of the river.

  5. Habitat associations, reproduction and diet of the Guinean tilapia Tilapia guineensis of the Gambia River floodplains.

    PubMed

    Louca, V; Lindsay, S W; Piyapong, C; Lucas, M C

    2010-06-01

    The ecology of the Guinean tilapia Tilapia guineensis a dominant species of the lower Gambia River floodplains and an important food source in parts of West Africa was studied to better understand the threat posed from construction of a barrage across the river. The catch per unit effort (CPUE) of T. guineensis was positively associated with conductivity and dissolved oxygen and negatively associated with water depth and the % vegetation cover. Diet studies indicated that the T. guineensis is primarily an iliophage. The peak of reproduction was at the beginning of the rainy season. CPUE peaked in May, just before the first rains, and subsequently declined, probably reflecting movement into newly flooded habitat. Median size at maturity was 11.6 cm total length, L(T), for females and 12.5 cm L(T) for males. L(T)-frequency analysis indicated several juvenile cohorts as well as very young fish on the floodplains each month, suggesting continuation of reproduction throughout the rainy season. The impending construction of a hydroelectric dam on the Gambia River is likely to affect T. guineensis negatively through anticipated changes in the hydrology of the river. PMID:20557603

  6. Low-fat frankfurters from protein concentrates of tilapia viscera and mechanically separated tilapia meat.

    PubMed

    Cavenaghi-Altemio, Angela D; Alcade, Lígia B; Fonseca, Gustavo G

    2013-11-01

    In order to develop a healthy low-fat frankfurter-type sausage, different formulations were developed with tilapia viscera surimi (T1) and two with mechanically separated tilapia meat (MSTM) surimi (T2 and T3), all without pig lard addition. Due to technological problems observed for T1 sausage during cooking, it was not further investigated. The functionality of the other two formulations was evaluated based on proximate composition, pH, water activity, and texture. Finally, microbiological and sensory analyses based on acceptance tests were performed. Listeria monocytogenes and Salmonella spp. were found to be absent. T2 showed higher frequencies for the attributes color (90.0%) and overall acceptability (86.7%), while T3 showed higher frequencies for taste (86.7%) and texture (96.7%). The surimi concentration was reflected in the physical properties of the sausages. It was found that the addition of MSTM surimi to sausage favored greater cutting strength (3.9 N for T2 and 4.9 N for T3). Beyond the surimi utilization, the total replacement of pig lard by cassava starch and soybean protein had also contributed with the texture properties. PMID:24804055

  7. Low-fat frankfurters from protein concentrates of tilapia viscera and mechanically separated tilapia meat

    PubMed Central

    Cavenaghi-Altemio, Angela D; Alcade, Lígia B; Fonseca, Gustavo G

    2013-01-01

    In order to develop a healthy low-fat frankfurter-type sausage, different formulations were developed with tilapia viscera surimi (T1) and two with mechanically separated tilapia meat (MSTM) surimi (T2 and T3), all without pig lard addition. Due to technological problems observed for T1 sausage during cooking, it was not further investigated. The functionality of the other two formulations was evaluated based on proximate composition, pH, water activity, and texture. Finally, microbiological and sensory analyses based on acceptance tests were performed. Listeria monocytogenes and Salmonella spp. were found to be absent. T2 showed higher frequencies for the attributes color (90.0%) and overall acceptability (86.7%), while T3 showed higher frequencies for taste (86.7%) and texture (96.7%). The surimi concentration was reflected in the physical properties of the sausages. It was found that the addition of MSTM surimi to sausage favored greater cutting strength (3.9 N for T2 and 4.9 N for T3). Beyond the surimi utilization, the total replacement of pig lard by cassava starch and soybean protein had also contributed with the texture properties. PMID:24804055

  8. Maine-Niles Association of Special Recreation.

    ERIC Educational Resources Information Center

    Iowa Univ., Iowa City. Recreation Education Program.

    Presented are duplications of the responses given by Maine-Niles Association of Special Recreation (Skokie, Illinois) as part of a project to collect, share, and compile information about, and techniques in the operation of 18 community action models for recreation services to the disabled. Model programs are categorized as consumer, client…

  9. Protective Behavior and West Nile Virus Risk

    PubMed Central

    Elliott, Susan J.; Gibson, Brian; Fearon, Margaret; Nosal, Robert; Drebot, Michael; D'Cuhna, Colin; Harrington, Daniel; Smith, Stephanie; George, Pauline; Eyles, John

    2005-01-01

    We conducted a cross-sectional, household survey in Oakville, Ontario, where an outbreak of West Nile virus (WNV) in 2002 led to an unprecedented number of cases of meningitis and encephalitis. Practicing >2 personal protective behavior traits reduced the risk for WNV infection by half. PMID:16229774

  10. Tracking Nile Delta vulnerability to Holocene change.

    PubMed

    Marriner, Nick; Flaux, Clément; Morhange, Christophe; Stanley, Jean-Daniel

    2013-01-01

    Understanding deltaic resilience in the face of Holocene climate change and human impacts is an important challenge for the earth sciences in characterizing the full range of present and future wetland responses to global warming. Here, we report an 8000-year mass balance record from the Nile Delta to reconstruct when and how this sedimentary basin has responded to past hydrological shifts. In a global Holocene context, the long-term decrease in Nile Delta accretion rates is consistent with insolation-driven changes in the 'monsoon pacemaker', attested throughout the mid-latitude tropics. Following the early to mid-Holocene growth of the Nile's deltaic plain, sediment losses and pronounced erosion are first recorded after ~4000 years ago, the corollaries of falling sediment supply and an intensification of anthropogenic impacts from the Pharaonic period onwards. Against the backcloth of the Saharan 'depeopling', reduced river flow underpinned by a weakening of monsoonal precipitation appears to have been particularly conducive to the expansion of human activities on the delta by exposing productive floodplain lands for occupation and irrigation agriculture. The reconstruction suggests that the Nile Delta has a particularly long history of vulnerability to extreme events (e.g. floods and storms) and sea-level rise, although the present sediment-starved system does not have a direct Holocene analogue. This study highlights the importance of the world's deltas as sensitive archives to investigate Holocene geosystem responses to climate change, risks and hazards, and societal interaction.

  11. Visualising DNA in Classrooms Using Nile Blue

    ERIC Educational Resources Information Center

    Milne, Christine; Roche, Scott; McKay, David

    2008-01-01

    Giving students the opportunity to extract, manipulate and visualise DNA molecules enhances a constructivist approach to learning about modern techniques in biology and biotechnology Visualisation usually requires agarose gel electrophoresis and staining. In this article, we report on an alternative DNA stain, Nile Blue A, that may be used in the…

  12. Does The Nile Reflect Solar Variability?

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, Alexander; Feynman, Joan; Yung, Yuk

    2006-01-01

    Historical records of the Nile water level provide a unique opportunity to investigate the possibility that solar variability influences the Earth's climate. Particularly important are the annual records of the water level, which are uninterrupted for the years 622-1470 A.D. These records are non-stationary, so that standard spectral analyses cannot adequately characterize them. Here the Empirical Mode Decomposition technique, which is designed to deal with nonstationary, nonlinear time series, becomes useful. It allows the identification of two characteristic time scales in the water level data that can be linked to solar variability: the 88 year period and a time scale of about 200 years. These time scales are also present in the concurrent aurora data. Auroras are driven by coronal mass ejections and the rate of auroras is an excellent proxy for solar variability. Analysis of auroral data contemporaneous with the Nile data shows peaks at 88 years and about 200 years. This suggests a physical link between solar variability and the low frequency variations of the Nile water level. The link involves the influence of solar variability on the North Annual Mode of atmospheric variability and its North Atlantic and Indian Oceans patterns that affect rainfall over Eastern Equatorial Africa where the Nile originates.

  13. Water balance dynamics in the Nile Basin

    USGS Publications Warehouse

    Senay, G.B.; Asante, Kwasi; Artan, G.

    2009-01-01

    Understanding the temporal and spatial dynamics of key water balance components of the Nile River will provide important information for the management of its water resources. This study used satellite-derived rainfall and other key weather variables derived from the Global Data Assimilation System to estimate and map the distribution of rainfall, actual evapotranspiration (ETa), and runoff. Daily water balance components were modelled in a grid-cell environment at 0.1 degree (~10 km) spatial resolution for 7 years from 2001 through 2007. Annual maps of the key water balance components and derived variables such as runoff and ETa as a percent of rainfall were produced. Generally, the spatial patterns of rainfall and ETa indicate high values in the upstream watersheds (Uganda, southern Sudan, and southwestern Ethiopia) and low values in the downstream watersheds. However, runoff as a percent of rainfall is much higher in the Ethiopian highlands around the Blue Nile subwatershed. The analysis also showed the possible impact of land degradation in the Ethiopian highlands in reducing ETa magnitudes despite the availability of sufficient rainfall. Although the model estimates require field validation for the different subwatersheds, the runoff volume estimate for the Blue Nile subwatershed is within 7.0% of a figure reported from an earlier study. Further research is required for a thorough validation of the results and their integration with ecohydrologic models for better management of water and land resources in the various Nile Basin ecosystems. Published in 2009 by John Wiley & Sons, Ltd.

  14. Vaccines in development against West Nile virus.

    PubMed

    Brandler, Samantha; Tangy, Frederic

    2013-10-01

    West Nile encephalitis emerged in 1999 in the United States, then rapidly spread through the North American continent causing severe disease in human and horses. Since then, outbreaks appeared in Europe, and in 2012, the United States experienced a new severe outbreak reporting a total of 5,387 cases of West Nile virus (WNV) disease in humans, including 243 deaths. So far, no human vaccine is available to control new WNV outbreaks and to avoid worldwide spreading. In this review, we discuss the state-of-the-art of West Nile vaccine development and the potential of a novel safe and effective approach based on recombinant live attenuated measles virus (MV) vaccine. MV vaccine is a live attenuated negative-stranded RNA virus proven as one of the safest, most stable and effective human vaccines. We previously described a vector derived from the Schwarz MV vaccine strain that stably expresses antigens from emerging arboviruses, such as dengue, West Nile or chikungunya viruses, and is strongly immunogenic in animal models, even in the presence of MV pre-existing immunity. A single administration of a recombinant MV vaccine expressing the secreted form of WNV envelope glycoprotein elicited protective immunity in mice and non-human primates as early as two weeks after immunization, indicating its potential as a human vaccine.

  15. West Nile Virus: Symptoms and Treatment

    MedlinePlus

    ... Nile virus infection are available. Over-the-counter pain relievers can be used to reduce fever and relieve some symptoms In severe cases, patients often need to be hospitalized to receive supportive treatment, such as intravenous fluids, pain medication, and nursing ...

  16. 20,000 years of Nile River dynamics and environmental changes in the Nile catchment area as inferred from Nile upper continental slope sediments

    NASA Astrophysics Data System (ADS)

    Revel, Marie; Ducassou, E.; Skonieczny, C.; Colin, C.; Bastian, L.; Bosch, D.; Migeon, S.; Mascle, J.

    2015-12-01

    Multi-proxy analysis of two marine sediment cores (MS27PT and MD04-2726) from the Nile continental slope provides evidence of changes in Nile sediment discharge related to changes in Ethiopian African Monsoon (EAM) precipitation, and allows us to reconstruct changes in Nile River runoff, vegetation and erosion in the Nile headwaters. Sediment element composition and neodymium isotopic composition reveal significant changes in clastic sediment provenance, with sources oscillating between a Saharan aeolian contribution during the Last Glacial Maximum/deglacial transition and during the Late Holocene, and a Blue/Atbara Nile fluvial contribution during the African Humid Period (AHP). This study provides a new understanding of past environmental changes. Between 14.6 and 14.13 ka there was a major input of sediments from the Ethiopian Highlands, consistent with a stronger EAM at that time. Climate in the Nile basin was wetter between 14.8 and 8.4 ka, with a corresponding increase in Blue Nile water and sediment discharge via the main Nile into the Eastern Mediterranean. The gradual climatic transition from the AHP to the present-day dry climate was reflected in a decrease in Blue Nile sediment deposition and flood discharge between 8.4 and 3.7 ka, with aridity at a maximum between 3.7 and 2.6 ka. The onset of drier conditions in the Blue Nile basin seems to have begun before the 8.2 ka cooling event in the North Atlantic. We speculate that the climatic change from the wet AHP to the dry late Holocene may have been a result of a break in the low latitude dynamic equilibrium between climate, vegetation and erosion, which may in turn have affected the climate in higher latitudes. Reduced Nile flow may also have had an impact on Levantine Intermediate Water originating in the Eastern Mediterranean through an increase in intermediate water formation.

  17. Drought in the Nile Basin: characterizing variability, quantifying uncertainty, and studying processes with the Nile Land Data Assimilation System

    NASA Astrophysics Data System (ADS)

    Alo, C. A.; Zaitchik, B. F.; Habib, S.; Anderson, M. C.; Ozdogan, M.

    2010-12-01

    The Nile Land Data Assimilation System (Nile LDAS) has been developed to support studies of hydrologic variability, land cover patterns, and climate change impacts in the countries that share the Nile basin. Here we present results of retrospective Nile LDAS simulations that examine climatic and hydrologic variability across the basin in recent decades. Use of Nile LDAS in this study allows us to compare patterns of drought as captured by different precipitation datasets—including Tropical Rainfall Measurement Mission (TRMM) precipitation products, the CPC Merged Analysis of Precipitation (CMAP), and multiple meteorological reanalyses—different land surface models—including Noah Land Surface Model, the Common Land Model, and Catchment LSM—and independent satellite observations—including the Gravity Recovery and Climate Experiment (GRACE). Results of Nile LDAS simulations show distinct temporal and spatial patterns of drought across the climatic gradients of the Nile basin. These results also demonstrate that diagnosis of drought patterns is sensitive to choice of meteorological dataset and land surface model. We present an objective classification of drought susceptibility zones based on the results of these Nile LDAS simulations, including assessment of confidence and uncertainty. Lastly, we discuss the possible drivers of hydrological variability at the local to the basin scale. Follow-on studies are in progress to merge, compare, and improve Nile LDAS datasets in order to provide optimal estimates of hydrological states and fluxes in the Nile basin, with the ultimate objective of improving drought analysis and response in an evolving climate.

  18. Susceptibility, metacercarial burden, and mortality of juvenile silver barb, common carp, mrigal, and tilapia following exposure to Haplorchis taichui.

    PubMed

    Kopolrat, Kulthida; Sithithaworn, Paiboon; Tesana, Smarn; Andrews, Ross H; Petney, Trevor N

    2015-04-01

    Fish-borne zoonotic trematodes (FZT) including heterophyids and opisthorchiids are prevalent in native and aquaculture fish in Southeast Asia. FZT are reported highly prevalent in juvenile aquaculture fish that belonged to the family Heterophyidae, particularly Haplorchis taichui. Aquaculture fish are reported to have varying levels of natural infection with H. taichui, but data for their susceptibility as well as resistance to infection are not available. The aim of this study was to determine the susceptibility of five aquaculture fish to H. taichui. Experimental infections were performed by exposing fish individually to 0 (control), 50, 100, or 200 H. taichui cercariae for 12 h. Metacercarial burden was measured at 45 days postinfection. Three out of five fish species, silver barb (Barbonymus gonionotus), common carp (Cyprinus carpio), and mrigal (Cirrhinus mrigala), were highly susceptible to H. taichui infection with percentage ranging from 93.33 to 100%. The Nile and red tilapia were not susceptible to infection. Among the susceptible fish species, silver barb had higher intensity of H. taichui metacercariae than common carp and mrigal (P < 0.001). Metacercarial burden significantly correlated with the dose of cercarial infection (P < 0.001). Our findings that common aquaculture fish species have varying degrees of susceptibility to H. taichui infection provide important information to reduce parasite transmission in aquaculture fish.

  19. Molecular evolution of the Slc15 family and its response to waterborne copper and mercury exposure in tilapia.

    PubMed

    Huang, Qiansheng; Vera Delgado, Juan Manuel; Seni Pinoargote, Oscar David; Llaguno, Ricardo Avellán

    2015-06-01

    The solute carrier 15 family (Slc15), also called oligopeptide transporter family (Pept), was well-known for its role in the cellular uptake of di/tripeptides and peptide-like molecules. Our understanding of Slc15 family has already been enlarged since the rapid increasing of genome information; however, efforts are still expected to reveal the diversification of the family in an evolutionary manner. In the study, the sequence information were collected and analyzed through eleven eukaryotic organism representatives, especially in fish species. Gene expansion was observed through the evolution of the family. Further study was carried out with the representative species-Nile tilapia (Oreochromis niloticus). Tissue expression profiles were compared among members of the Slc15 family. Generally, they were all highly expressed both in the intestine and stomach, however, different members possessed its special tissue expression pattern. The mRNA levels of all the members (except Slc15a4) decreased after fasting while refeeding could restore the expression level. The recovery ability was impaired after exposure to environmental relevant concentration of copper (Cu(2+), 160 nmol/L). By contrast, mercury (Hg(2+), 25 nmol/L) did not exert significant impact on the recovery ability.

  20. Purification and characterization of a mannose recognition lectin from Oreochromis niloticus (tilapia fish): cytokine production in mice splenocytes.

    PubMed

    da Silva, Cynarha Daysy Cardoso; Coriolano, Marília Cavalcanti; da Silva Lino, Mércia Andréa; de Melo, Cristiane Moutinho Lagos; de Souza Bezerra, Ranilson; de Carvalho, Elba Verônica Matoso Maciel; Dos Santos, Athiê Jorge Guerra; Pereira, Valéria Rêgo Alves; Coelho, Luana Cassandra Breitenbach Barroso

    2012-01-01

    The aim of this work was to purify and partially characterize a mannose recognition lectin from Nile tilapia (Oreochromis niloticus) serum, named OniL. OniL was isolated through precipitation with ammonium sulfate and affinity chromatography (Concanavalin A-Sepharose 4B). In addition, we evaluated carbohydrate specificity, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) profiles, and in vitro immunomodulatory activity on mice splenocyte experimental cultures through cytotoxic assays and cytokine production. The ammonium sulfate fraction F2 showed the highest specific hemagglutinating activity (331) and was applied to affinity matrix. Adsorbed proteins (OniL) were eluted with methyl-α-D: -mannopyranoside. OniL, a 17-kDa protein by SDS-PAGE constituted by subunits of 11 and 6.6 kDa, showed highest affinity for methyl-α-D: -mannopyranoside and D: -mannose. Immunological assays, in vitro, showed that OniL did not show cytotoxicity against splenocytes, induced higher IFN-γ production and lower IL-10 as well as nitrite release. In conclusion, OniL lectin was successfully purified and showed a preferential Th1 response in mice splenocytes. PMID:22081327

  1. Molecular evolution of the Slc15 family and its response to waterborne copper and mercury exposure in tilapia.

    PubMed

    Huang, Qiansheng; Vera Delgado, Juan Manuel; Seni Pinoargote, Oscar David; Llaguno, Ricardo Avellán

    2015-06-01

    The solute carrier 15 family (Slc15), also called oligopeptide transporter family (Pept), was well-known for its role in the cellular uptake of di/tripeptides and peptide-like molecules. Our understanding of Slc15 family has already been enlarged since the rapid increasing of genome information; however, efforts are still expected to reveal the diversification of the family in an evolutionary manner. In the study, the sequence information were collected and analyzed through eleven eukaryotic organism representatives, especially in fish species. Gene expansion was observed through the evolution of the family. Further study was carried out with the representative species-Nile tilapia (Oreochromis niloticus). Tissue expression profiles were compared among members of the Slc15 family. Generally, they were all highly expressed both in the intestine and stomach, however, different members possessed its special tissue expression pattern. The mRNA levels of all the members (except Slc15a4) decreased after fasting while refeeding could restore the expression level. The recovery ability was impaired after exposure to environmental relevant concentration of copper (Cu(2+), 160 nmol/L). By contrast, mercury (Hg(2+), 25 nmol/L) did not exert significant impact on the recovery ability. PMID:25897688

  2. Phenotypic Variation among Culex pipiens Complex (Diptera: Culicidae) Populations from the Sacramento Valley, California: Horizontal and Vertical Transmission of West Nile Virus, Diapause Potential, Autogeny, and Host Selection

    PubMed Central

    Nelms, Brittany M.; Kothera, Linda; Thiemann, Tara; Macedo, Paula A.; Savage, Harry M.; Reisen, William K.

    2013-01-01

    The vector competence and bionomics of Culex pipiens form pipiens L. and Cx. pipiens f. molestus Forskäl were evaluated for populations from the Sacramento Valley. Both f. pipiens and f. molestus females became infected, produced disseminated infections, and were able to transmit West Nile virus. Form molestus females also transmitted West Nile virus vertically to egg rafts and F1 progeny, whereas f. pipiens females only transmitted to egg rafts. Culex pipiens complex from urban Sacramento blood-fed on seven different avian species and two mammalian species. Structure analysis of blood-fed mosquitoes identified K = 4 genetic clusters: f. molestus, f. pipiens, a group of genetically similar hybrids (Cluster X), and admixed individuals. When females were exposed as larvae to midwinter conditions in bioenvironmental chambers, 85% (N = 79) of aboveground Cx. pipiens complex females and 100% (N = 34) of underground f. molestus females did not enter reproductive diapause. PMID:24043690

  3. Phenotypic variation among Culex pipiens complex (Diptera: Culicidae) populations from the Sacramento Valley, California: horizontal and vertical transmission of West Nile virus, diapause potential, autogeny, and host selection.

    PubMed

    Nelms, Brittany M; Kothera, Linda; Thiemann, Tara; Macedo, Paula A; Savage, Harry M; Reisen, William K

    2013-12-01

    The vector competence and bionomics of Culex pipiens form pipiens L. and Cx. pipiens f. molestus Forskäl were evaluated for populations from the Sacramento Valley. Both f. pipiens and f. molestus females became infected, produced disseminated infections, and were able to transmit West Nile virus. Form molestus females also transmitted West Nile virus vertically to egg rafts and F1 progeny, whereas f. pipiens females only transmitted to egg rafts. Culex pipiens complex from urban Sacramento blood-fed on seven different avian species and two mammalian species. Structure analysis of blood-fed mosquitoes identified K = 4 genetic clusters: f. molestus, f. pipiens, a group of genetically similar hybrids (Cluster X), and admixed individuals. When females were exposed as larvae to midwinter conditions in bioenvironmental chambers, 85% (N = 79) of aboveground Cx. pipiens complex females and 100% (N = 34) of underground f. molestus females did not enter reproductive diapause. PMID:24043690

  4. Cl- uptake mechanism in freshwater-adapted tilapia (Oreochromis mossambicus).

    PubMed

    Chang, I-Chi; Hwang, Pung-Pung

    2004-01-01

    In this study, the correlation between Cl(-) influx in freshwater tilapia and various transporters or enzymes, the Cl(-)/HCO(3)(-) exchanger, Na(+),K(+)-ATPase, V-type H(+)-ATPase, and carbonic anhydrase were examined. The inhibitors 2x10(-4) M ouabain (a Na(+),K(+)-ATPase inhibitor), 10(-5) M NEM (a V-type H(+)-ATPase inhibitor), 10(-2) M ACTZ (acetazolamide, a carbonic anhydrase inhibitor), and 6x10(-4) M DIDS (a Cl(-)/HCO(3)(-) exchanger inhibitor) caused 40%, 60%-80%, 40%-60%, and 40%-60% reduction in Cl(-) influx of freshwater tilapia, respectively. The inhibitor 2x10(-4) M ouabain also caused 50%-65% inhibition in gill Na(+),K(+)-ATPase activity. Western blot results showed that protein levels of gill Na(+),K(+)-ATPase, V-type H(+)-ATPase, and carbonic anhydrase in tilapia acclimated in low-Cl(-) freshwater were significantly higher than those acclimated to high-Cl(-) freshwater. Based on these data, we conclude that Na(+),K(+)-ATPase, V-H(+)-ATPase, the Cl(-)/HCO(3)(-) exchanger, and carbonic anhydrase may be involved in the active Cl(-) uptake mechanism in gills of freshwater-adapted tilapia. PMID:15286914

  5. Geochemistry of sediments and surface soils from the Nile Delta and lower Nile valley studied by epithermal neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Arafa, Wafaa M.; Badawy, Wael M.; Fahmi, Naglaa M.; Ali, Khaled; Gad, Mohamed S.; Duliu, Octavian G.; Frontasyeva, Marina V.; Steinnes, Eiliv

    2015-07-01

    The distributions of 36 major and trace elements in 40 surface soil and sediment samples collected from the Egyptian section of the river Nile were determined by epithermal neutron activation analysis and compared with corresponding data for the Upper Continental Crust and North American Shale Composite. Their relative distributions indicate the presence of detrital material of igneous origin, most probably resulting from weathering on Ethiopian highlands and transported by the Blue Nile, the Nile main tributary. The distributions of the nickel, zinc, and arsenic contents suggest that the lower part of the Nile and its surroundings including the Nile Delta is not seriously polluted with metals from local human activity. The geographical distributions of Na, Cl, and I as well as results of principal component analysis suggest atmospheric supply of these elements from the ocean. In general the present data may contribute to a better understanding of the geochemistry of the Nile sediments.

  6. Tilapia culture in conjunction with irrigation and urban farming. Final report

    SciTech Connect

    Bondari, K.; Threadgill, E.D.; Bender, J.A.

    1983-05-01

    This study involved 2 experiments. Exp. I was designed to determine the potential use of tilapia culture (Tilapia aurea) incorporated into an integrated irrigation system capable of (1) removing algae and other aquatic plants from the pond water by feeding, and (2) providing some resource recovery through growth and reproduction. Exp. II was conducted to determine the potential use of blue tilapia in urban farming. Facilities included a passive solar greenhouse attached to a renovated residential house, an indoor pond located in the greenhouse for overwintering tilapia, and an outdoor pond for the summer growth.

  7. West Nile virus infection in children.

    PubMed

    Barzon, Luisa; Pacenti, Monia; Sinigaglia, Alessandro; Berto, Alessandro; Trevisan, Marta; Palù, Giorgio

    2015-01-01

    West Nile virus (WNV) is an emerging flavivirus responsible for an increasing number of outbreaks of neuroinvasive disease in North America, Europe, and neighboring countries. Almost all WNV infections in humans are transmitted through the bite of infected mosquitoes. Transmission during pregnancy and through breastfeeding has been reported, but the risk seems to be very low. West Nile disease in children is less common (1-5% of all WNV cases) and associated with milder symptoms and better outcome than in elderly individuals, even though severe neuroinvasive disease and death have been reported also among children. However, the incidence of WNV infection and disease in children is probably underestimated and the disease spectrum is not fully understood because of lack of reporting and underdiagnosis in children. Infection is diagnosed by detection of WNV-specific antibodies in serum and WNV RNA in plasma and urine. Since no effective WNV-specific drugs are available, therapy is mainly supportive.

  8. Did Nile flooding sink two ancient cities?

    PubMed

    Said, Rushdi

    2002-01-01

    The discovery of the two cities of Herakleion and East Canopus under the waters of the Bay of Abu Qir (east of Alexandria, Egypt) stirred worldwide attention when it was first announced in the summer of 2000. Their disappearance some 1,250 years ago has been ascribed by Stanley, Goddio and Schnepp to a strong Nile flood that caused riverbank failure and the destruction of the two cities, rather than to the action of earthquakes, as was first proposed when the ruins were discovered. But I believe that this interpretation is flawed, because no flood could have reached the Abu Qir Bay at the time of the disappearance of the two cities, as the Canopic branch of the Nile, along whose banks they were situated, had dried to a trickle more than 200 years earlier. PMID:11780107

  9. Effects of Wheat Naturally Contaminated with Fusarium Mycotoxins on Growth Performance and Selected Health Indices of Red Tilapia (Oreochromis niloticus × O. mossambicus).

    PubMed

    Tola, Siriporn; Bureau, Dominique P; Hooft, Jamie M; Beamish, Frederick W H; Sulyok, Michael; Krska, Rudolf; Encarnação, Pedro; Petkam, Rakpong

    2015-06-01

    An 8-week feeding trial was conducted to examine effects of wheat naturally contaminated with Fusarium mycotoxins (deoxynivalenol, DON 41 mg·kg(-1)) on growth performance and selected health indices of red tilapia (Oreochromis niloticus × O. mossambicus; initial weight = 4.3 g/fish). Five experimental diets were formulated by replacement of clean wheat with naturally contaminated wheat resulting in graded levels of DON and zearalenone (ZEN) (Diet 1 0.07/0.01, Diet 2 0.31/0.09, Diet 3 0.50/0.21, Diet 4 0.92/0.37 and Diet 5 1.15/0.98 mg·kg(-1)). Groups of 50 fish were randomly allocated into each of 20 aquaria and fed to near-satiety for eight weeks. Growth rate, feed intake and feed efficiency of fish fed the experimental diets decreased linearly with increasing levels of Fusarium mycotoxins (p < 0.05). Although growth depression was associated with feeding diets naturally contaminated with Fusarium mycotoxins, especially DON, no biochemical and histopathological parameters measured in blood and liver appeared affected by Fusarium mycotoxin concentrations of diets (p > 0.05). Though there was no clear evidence of overt DON toxicity to red tilapia, it is recommended that feed ingredients should be screened for Fusarium mycotoxin contamination to ensure optimal growth performance. PMID:26035489

  10. Effects of Wheat Naturally Contaminated with Fusarium Mycotoxins on Growth Performance and Selected Health Indices of Red Tilapia (Oreochromis niloticus × O. mossambicus)

    PubMed Central

    Tola, Siriporn; Bureau, Dominique P.; Hooft, Jamie M.; Beamish, Frederick W. H.; Sulyok, Michael; Krska, Rudolf; Encarnação, Pedro; Petkam, Rakpong

    2015-01-01

    An 8-week feeding trial was conducted to examine effects of wheat naturally contaminated with Fusarium mycotoxins (deoxynivalenol, DON 41 mg·kg−1) on growth performance and selected health indices of red tilapia (Oreochromis niloticus × O. mossambicus; initial weight = 4.3 g/fish). Five experimental diets were formulated by replacement of clean wheat with naturally contaminated wheat resulting in graded levels of DON and zearalenone (ZEN) (Diet 1 0.07/0.01, Diet 2 0.31/0.09, Diet 3 0.50/0.21, Diet 4 0.92/0.37 and Diet 5 1.15/0.98 mg·kg−1). Groups of 50 fish were randomly allocated into each of 20 aquaria and fed to near-satiety for eight weeks. Growth rate, feed intake and feed efficiency of fish fed the experimental diets decreased linearly with increasing levels of Fusarium mycotoxins (p < 0.05). Although growth depression was associated with feeding diets naturally contaminated with Fusarium mycotoxins, especially DON, no biochemical and histopathological parameters measured in blood and liver appeared affected by Fusarium mycotoxin concentrations of diets (p > 0.05). Though there was no clear evidence of overt DON toxicity to red tilapia, it is recommended that feed ingredients should be screened for Fusarium mycotoxin contamination to ensure optimal growth performance. PMID:26035489

  11. [West Nile virus and its vectors].

    PubMed

    Ozer, Nurdan

    2006-01-01

    There are more than five hundred known arthropod-borne viruses (arboviruses) all around the world and approximately hundred of them may cause disease in humans. During the past 20 years there has been a dramatic resurgence or emergence of epidemic arboviral diseases affecting both humans and domestic animals. Many factors play important roles in the emergence of arboviral diseases like Yellow Fever, Dengue, West Nile encephalitis, and of other diseases such as malaria and leishmaniasis in countries where they have not been previously encountered and in the increase in incidences where they have been under control. Some of these are demographic factors such as global population increase and uncontrolled urbanization; social changes such as modern transportation, human encroachment on natural disease hotspots; changes in agricultural activities such as the use of new irrigation techniques; deforestation; genetic changes in the pathogens; preventive measures and probably global climate changes. Mosquitoes are among the most important vectors carrying viruses belonging to Alphavirus, Flavivirus, Bunyavirus and Phlebovirus genera. All of the above factors have contributed to the increase in mosquito populations and closer contact between humans and mosquito vectors. West Nile virus notable after the epidemic of 1996 in Romania in Europe is one of the latest examples indicating that viruses can jump continents and produce epidemics. In this review article, the distribution of West Nile virus and its principal vectors and also its importance by means of public health, have been discussed.

  12. Host feeding patterns of established and potential mosquito vectors of West Nile virus in the eastern United States.

    PubMed

    Apperson, Charles S; Hassan, Hassan K; Harrison, Bruce A; Savage, Harry M; Aspen, Stephen E; Farajollahi, Ary; Crans, Wayne; Daniels, Thomas J; Falco, Richard C; Benedict, Mark; Anderson, Michael; McMillen, Larry; Unnasch, Thomas R

    2004-01-01

    An important variable in determining the vectorial capacity of mosquito species for arthropod-borne infections is the degree of contact of the vector and the vertebrate reservoir. This parameter can be estimated by examining the host-feeding habits of vectors. Serological and polymerase chain reaction based methods have been used to study the host-feedings patterns of 21 mosquito species from New York, New Jersey, and Tennessee, 19 of which previously have been found infected with West Nile virus. Mammalophilic mosquito species in New Jersey and New York fed primarily upon white-tailed deer, while those from Memphis, Tennessee, fed mainly upon domestic dogs. A total of 24 different avian host species were detected among the avian-derived blood meals. American Robin, Northern Cardinal, Northern Mockingbird, Tufted Titmouse, and Brown-headed Cowbird were common avian hosts, while blood meals derived from the American Crow were relatively rare. Although the majority of common host species were potentially among the most abundant birds at each location, the proportion of blood meals from the most commonly fed upon avian species was greater than was predicted based upon the likely abundance of these species alone. These findings suggest that vector species for West Nile virus may preferentially feed upon certain avian hosts.

  13. Doubly fed induction machine

    DOEpatents

    Skeist, S. Merrill; Baker, Richard H.

    2005-10-11

    An electro-mechanical energy conversion system coupled between an energy source and an energy load including an energy converter device having a doubly fed induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer coupled to the energy converter device to control the flow of power or energy through the doubly fed induction machine.

  14. The Carbon Cycle at the Nile Headwaters

    NASA Astrophysics Data System (ADS)

    Jones, Michael; Saunders, Matthew

    2014-05-01

    The carbon cycle at the Nile headwaters M B Jones, School of Natural Sciences, Trinity College, University of Dublin, Dublin 2, Ireland M Saunders, Environmental and Biochemical Sciences Group, The James Hutton Institute, Aberdeen, Scotland River systems play an integral role in the global carbon cycle by connecting the terrestrial biosphere, the atmosphere and the oceans. Extensive wetland systems, such as those found in the Amazon region, have been shown to export significant amounts of carbon to river waters as dissolved carbon dioxide (CO2) that can be transported and emitted hundreds of km downstream. The assessment of both regional and global carbon budgets could therefore be improved by quantifying these lateral carbon fluxes, especially from highly productive temporarily or permanently flooded areas where substantial CO2 evasion from inland waters can occur. The Nile is the longest river in the world and the headwaters are located in the extensive Papyrus dominated wetlands in central Africa that are associated with Lake Victoria. From its source the White Nile flows northwards through wetlands in Uganda and Sudan before it joins the Blue Nile. Papyrus wetlands have been shown to be some of the most productive global ecosystems, with recorded rates of aerial net primary productivity of up to 3.09 kg C m-2 yr-1. In addition, where anaerobic conditions occur they also accumulate large amounts of carbon in the form of peat, and under these circumstances they represent a significant carbon sink. However, as water moves through these wetlands and is exchanged with surrounding rivers and lakes significant quantities of dissolved organic and inorganic carbon as well as suspended particulate organic matter are exported, which are either released further downstream by degassing, decomposition or deposition. Information on such losses from these wetland ecosystems is extremely sparse but in order to better constrain ecosystem scale carbon dynamics more accurate

  15. Nile behaviour and Upper Palaeolithic humans in Upper Egypt

    NASA Astrophysics Data System (ADS)

    Vermeersch, Pierre M.

    2014-05-01

    There is evidence of a decreasing human occupation of the Upper Egyptian Nile valley during the MIS 5 to MIS 3 period. Whereas very large extraction sites of the Middle Stone Age have been recorded, only very few sites of the Upper Palaeolithic have been found. The best explanation of this fact is that during the Late Middle Stone Age and the Upper Palaeolithc there was nearly no need for raw materials because there was only a very restricted population present in Upper Egypt. From about 22 ka BP an important population increase is registered by the presence of numerous Late Palaeolithic sites. During the whole LGM there is abundant presence of humans along the Nile Valley in Upper Egypt. This population was mainly living from fishing. There seems to be an abrupt end of the Palaeolithic occupation after 12.8 ka BP. Until now, no sites were found in the Valley until some rare Epipaleolithic sites occur about 8.0 ka BP. It will be suggested that these population changes are influenced by the river Nile behaviour. The best interpretation of the observations in the Upper Egyptian Nile Valley is the hypothesis that at the same time that Nile flow was reduced because of the dryness in its source area, the impact of aeolian activity was increased over Northeast Africa. The increased aeolian activity by northern winds in the Fayum and Wadi Ryan during the LGM resulted in the accumulation of aeolian sand in the valley. That aeolian sand was transported along the western Nile valley cliffs until it was accumulated when the Nile Valley change it S-N direction, such as at Nag'Hammadi. At other places sand was invading the Nile valley, directly from the Western Desert, creating a damming of the Nile at several places such as Armant and Aswan. As Nile flow was quite reduced, the Nile was unable to erode all the incoming sand and the Nile water with its important clay content was dammed. At several places large lakes were created in the Nile Valley. Those lakes were an ideal

  16. A microwave-irradiated Streptococcus agalactiae vaccine provides partial protection against experimental challenge in Nile tilapia, Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microwave irradiation, as opposed to formalin exposure, has not routinely been used in the preparation of killed vaccines despite the advantages of decreased chemical toxicity, ability to kill cells quickly, ease of completion requiring only a standard microwave, and potential increased protein cons...

  17. Non-infectivity of Cattle Streptococcus agalactiae in Nile Tilapia, Oreochromis niloticus and Channel Catfish, Ictalurus punctatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Streptococcus agalactiae is classified as a Lancefield’s group B Streptococcus (GBS). It is the causative bacterium of streptococcosis that is responsible for severe economic losses in wild and cultured fish, worldwide. Streptococcus agalactiae also causes bovine mastitis. Only limited comparativ...

  18. FISH in micronucleus test demonstrates aneugenic action of rotenone in a common freshwater fish species, Nile tilapia (Oreochromis niloticus).

    PubMed

    Melo, Karina M; Grisolia, Cesar K; Pieczarka, Julio C; de Souza, Ludmilla R; Filho, José de Souza; Nagamachi, Cleusa Y

    2014-05-01

    Aneuploidies are numerical genetic alterations that lead to changes in the normal number of chromosomes due to abnormal segregation during cell division. This type of alteration can occur spontaneously or as a result of exposure to mutagenic agents. The presence of these agents in the environment has increased concern about potential damage to human health. Rotenone, derived from plants of the genera Derris and Lonchocarpus, is a product that is used all over the world as a pesticide and piscicide. Before establishing its potential and efficiency for these purposes, it is essential to know more about the possible adverse effects that it may cause. The current work aimed to evaluate the mutagenic potential of rotenone using fish from the species Oreochromis niloticus, as well as to help in understanding its action mechanism. Our results showed the mutagenic potential of rotenone evidenced by increased formation of micronuclei and nuclear buds at low doses of exposure. The use of fluorescence in situ hybridisation technique made it possible to measure the aneugenic potential of the substance, probably due to its impairment of mitotic spindle formation.

  19. Effects feeding zilpaterol hydrochloride on growth performance, fillet yeild, and body composition of rainbow trout, nile, tilapia, and channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zilpaterol hydrochloride (ZH) is a potent ß-adrenergic agonist (BAA) that has been used in feedlot cattle to increase average daily gain, feed efficiency, yield of trimmed cuts, and dress out percent. While positive effects of ZH have been observed in cattle, there have been no reports of this prod...

  20. Efficacy of florfenicol for control of mortality with Francisella noatunensis subsp. orientalis in Nile tilapia, oreochromis niloticus (L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Francisella noatunensis subsp. orientalis (Fno) (syn. F. asiatica) is an emergent Gram-negative facultative intracellular bacterium. Although it is considered one of the most pathogenic bacteria in fish, there are no commercially available treatments of vaccines. The objective of this project was ...

  1. Toxicity evaluation of copper oxide bulk and nanoparticles in Nile tilapia, Oreochromis niloticus, using hematological, bioaccumulation and histological biomarkers.

    PubMed

    Abdel-Khalek, Amr A; Badran, Shereen R; Marie, Mohamed-Assem S

    2016-08-01

    The increased industrial applications of nanoparticles (NPs) augment the possibility of their deposition into aquatic ecosystems and threatening the aquatic life. So, this study aimed to provide a comparable toxicological effects of nano-CuO and bulk CuO on a common freshwater fish, Oreochromis niloticus. Fish were exposed to two selected doses (1/10 and 1/20 of the LC50/96 h) of both nano-/bulk CuO for 30 days. Based on the studied hematological parameters (RBCs count, hemoglobin content and hematocrit%), the two selected concentrations of CuO in their nano- and bulk sizes were found to induce significant decrease in all studied parameters. But, nano-CuO-treated fish showed the maximum decrease in all recorded parameters among the all studied groups especially at the low concentration of 1/20 LC50/96 h. Hematological status was also confirmed using the calculated blood indices (MCV, MHC and MCHC). In case of bulk CuO-treated groups, the significant decrease in the studied hematological parameters was not followed by any change in MCV and MCH (normocytic anemia), while fish that exposed to NPs showed a significant increase in all calculated blood parameters reflecting erythrocytes swelling which is related to the intracellular osmotic disorders (macrocytic anemia). Regarding metal bioaccumulation factor, the results showed that CuO NPs had more efficiency to internalize fish tissues (liver, kidneys, gills, skin and muscle). The accumulation pattern of Cu metal was ensured by histopathological investigation of liver, kidneys and gills. The histopathological analysis revealed various alterations that varied between adaptation responses and permanent tissue damage.

  2. Response of AMP-activated protein kinase and energy metabolism to acute nitrite exposure in the Nile tilapia Oreochromis niloticus.

    PubMed

    Xu, Zhixin; Li, Erchao; Xu, Chang; Gan, Lei; Qin, Jian G; Chen, Liqiao

    2016-08-01

    Adenosine monophosphate-activated protein kinase (AMPK) is a prevalent mammalian energy metabolism sensor, but little is known about its role as an energy sensor in fish experiencing stress. We aimed to study AMPK in Oreochromis niloticus on both the molecular and the physical level. We found that the cDNAs encoding the AMPKα1 and AMPKα2 variants of the O. niloticus catalytic α subunit were 1753bp and 2563 bp long and encoded 571 and 557 amino acids, respectively. Both the AMPKα1 and the AMPKα2 isoform possess structural features similar to mammalian AMPKα, including a phosphorylation site at Thr172 in the N-terminus, and exhibit high homology with other fish and vertebrate AMPKα sequences (81.3%-98.1%). mRNA encoding the AMPKα isoforms was widely expressed in various tissues with distinctive patterns. AMPKα1 and AMPKα2 were primarily expressed in the intestines and brain, respectively. Under acute nitrite challenge, the mRNA encoding the AMPKα isoforms, as well as AMPK activity, changed over time. Its recovery period in freshwater, combined with the fact that it is highly conserved, suggests that fish AMPK, like its mammalian orthologues, acts as an energy metabolism sensor. Furthermore, subsequent decreases in AMPK mRNA levels and activity suggested that its action was transient but efficient. Physically, glucose, lactic acid and TGs in plasma, as well as energy materials in the hepatopancreas and muscle, were significantly altered over time, indicating changes in energy metabolism during the experimental period. These data have enabled us to characterize energy utilization in O. niloticus and further illustrate the role of fish AMPK as an energy sensor. This study provides new insight into energy metabolism and sensing by AMPK in teleost and necessitates further study of the multiple physiologic roles of AMPK in fish.

  3. Branchial O(2) chemoreceptors in Nile tilapia Oreochromis niloticus: Control of cardiorespiratory function in response to hypoxia.

    PubMed

    Zeraik, Vivian M; Belão, Thiago C; Florindo, Luiz Henrique; Kalinin, Ana L; Rantin, F Tadeu

    2013-09-01

    This study examined the distribution and orientation of gill O(2) chemoreceptors in Oreochromis niloticus and their role in cardiorespiratory responses to graded hypoxia. Intact fish, and a group with the first gill arch excised (operated), were submitted to graded hypoxia and their cardiorespiratory responses (oxygen uptake - V˙O(2) , breathing frequency - fR, ventilatory stroke volume - VT, gill ventilation - V˙G, O(2) extraction from the ventilatory current - EO(2) , and heart rate - fH) were compared. Their responses to bolus injections of NaCN into the bloodstream (internal) or ventilatory water stream (external) were also determined. The V˙O(2) of operated fish was significantly lower at the deepest levels of hypoxia. Neither reflex bradycardia nor ventilatory responses were completely abolished by bilateral excision of the first gill arch. EO(2) of the operated group was consistently lower than the intact group. The responses to internal and external NaCN included transient decreases in fH and increases in fR and Vamp (ventilation amplitude). These cardiorespiratory responses were attenuated but not abolished in the operated group, indicating that chemoreceptors are not restricted to the first gill arch, and are sensitive to oxygen levels in both blood and water.

  4. Response of AMP-activated protein kinase and energy metabolism to acute nitrite exposure in the Nile tilapia Oreochromis niloticus.

    PubMed

    Xu, Zhixin; Li, Erchao; Xu, Chang; Gan, Lei; Qin, Jian G; Chen, Liqiao

    2016-08-01

    Adenosine monophosphate-activated protein kinase (AMPK) is a prevalent mammalian energy metabolism sensor, but little is known about its role as an energy sensor in fish experiencing stress. We aimed to study AMPK in Oreochromis niloticus on both the molecular and the physical level. We found that the cDNAs encoding the AMPKα1 and AMPKα2 variants of the O. niloticus catalytic α subunit were 1753bp and 2563 bp long and encoded 571 and 557 amino acids, respectively. Both the AMPKα1 and the AMPKα2 isoform possess structural features similar to mammalian AMPKα, including a phosphorylation site at Thr172 in the N-terminus, and exhibit high homology with other fish and vertebrate AMPKα sequences (81.3%-98.1%). mRNA encoding the AMPKα isoforms was widely expressed in various tissues with distinctive patterns. AMPKα1 and AMPKα2 were primarily expressed in the intestines and brain, respectively. Under acute nitrite challenge, the mRNA encoding the AMPKα isoforms, as well as AMPK activity, changed over time. Its recovery period in freshwater, combined with the fact that it is highly conserved, suggests that fish AMPK, like its mammalian orthologues, acts as an energy metabolism sensor. Furthermore, subsequent decreases in AMPK mRNA levels and activity suggested that its action was transient but efficient. Physically, glucose, lactic acid and TGs in plasma, as well as energy materials in the hepatopancreas and muscle, were significantly altered over time, indicating changes in energy metabolism during the experimental period. These data have enabled us to characterize energy utilization in O. niloticus and further illustrate the role of fish AMPK as an energy sensor. This study provides new insight into energy metabolism and sensing by AMPK in teleost and necessitates further study of the multiple physiologic roles of AMPK in fish. PMID:27262938

  5. Toxicity evaluation of copper oxide bulk and nanoparticles in Nile tilapia, Oreochromis niloticus, using hematological, bioaccumulation and histological biomarkers.

    PubMed

    Abdel-Khalek, Amr A; Badran, Shereen R; Marie, Mohamed-Assem S

    2016-08-01

    The increased industrial applications of nanoparticles (NPs) augment the possibility of their deposition into aquatic ecosystems and threatening the aquatic life. So, this study aimed to provide a comparable toxicological effects of nano-CuO and bulk CuO on a common freshwater fish, Oreochromis niloticus. Fish were exposed to two selected doses (1/10 and 1/20 of the LC50/96 h) of both nano-/bulk CuO for 30 days. Based on the studied hematological parameters (RBCs count, hemoglobin content and hematocrit%), the two selected concentrations of CuO in their nano- and bulk sizes were found to induce significant decrease in all studied parameters. But, nano-CuO-treated fish showed the maximum decrease in all recorded parameters among the all studied groups especially at the low concentration of 1/20 LC50/96 h. Hematological status was also confirmed using the calculated blood indices (MCV, MHC and MCHC). In case of bulk CuO-treated groups, the significant decrease in the studied hematological parameters was not followed by any change in MCV and MCH (normocytic anemia), while fish that exposed to NPs showed a significant increase in all calculated blood parameters reflecting erythrocytes swelling which is related to the intracellular osmotic disorders (macrocytic anemia). Regarding metal bioaccumulation factor, the results showed that CuO NPs had more efficiency to internalize fish tissues (liver, kidneys, gills, skin and muscle). The accumulation pattern of Cu metal was ensured by histopathological investigation of liver, kidneys and gills. The histopathological analysis revealed various alterations that varied between adaptation responses and permanent tissue damage. PMID:26947705

  6. Modulation of genotoxicity and endocrine disruptive effects of malathion by dietary honeybee pollen and propolis in Nile tilapia (Oreochromis niloticus)

    PubMed Central

    Kandiel, Mohamed M.M.; El-Asely, Amel M.; Radwan, Hasnaa A.; Abbass, Amany A.

    2013-01-01

    The present study aimed at verifying the usefulness of dietary 2.5% bee-pollen (BP) or propolis (PROP) to overcome the genotoxic and endocrine disruptive effects of malathion polluted water in Oreochromis niloticus (O. niloticus). The acute toxicity test was conducted in O. niloticus in various concentrations (0–8 ppm); mortality rate was assessed daily for 96 h. The 96 h-LC50 was 5 ppm and therefore 1/5 of the median lethal concentration (1 ppm) was used for chronic toxicity assessment. In experiment (1), fish (n = 8/group) were kept on a diet (BP/PROP or without additive (control)) and exposed daily to malathion in water at concentration of 5 ppm for 96 h “acute toxicity experiment”. Protective efficiency against the malathion was verified through chromosomal aberrations (CA), micronucleus (MN) and DNA-fragmentation assessment. Survival rate in control, BP and PROP groups was 37.5%, 50.0% and 100.0%, respectively. Fish in BP and PROP groups showed a significant (P < 0.05) reduction in the frequency of CA (57.14% and 40.66%), MN (53.13% and 40.63%) and DNA-fragmentation (53.08% and 30.00%). In experiment (2), fish (10 males and 5 females/group) were kept on a diet with/without BP for 21 days before malathion-exposure in water at concentration of 0 ppm (control) or 1 ppm (Exposed) for further 10 days “chronic toxicity experiment”. BP significantly (P < 0.05) reduced CA (86.33%), MN (82.22%) and DNA-fragmentation (93.11%), prolonged the sperm motility when exposed to 0.01 ppm of pollutant in vitro and increased the estradiol level in females comparing to control. In conclusion, BP can be used as a feed additive for fish prone to be raised in integrated fish farms or cage culture due to its potency to chemo-protect against genotoxicity and sperm-teratogenicity persuaded by malathion-exposure. PMID:25685536

  7. West Nile virus ecology in a tropical ecosystem in Guatemala.

    PubMed

    Morales-Betoulle, Maria E; Komar, Nicholas; Panella, Nicholas A; Alvarez, Danilo; López, María R; Betoulle, Jean-Luc; Sosa, Silvia M; Müller, María L; Kilpatrick, A Marm; Lanciotti, Robert S; Johnson, Barbara W; Powers, Ann M; Cordón-Rosales, Celia

    2013-01-01

    West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States.

  8. Partial sodium replacement in tilapia steak without loss of acceptability.

    PubMed

    Monteiro, Maria Lúcia G; Mársico, Eliane T; Canto, Anna Carolina V C S; Costa-Lima, Bruno R C; Lázaro, César A; Cruz, Adriano G; Conte-Júnior, Carlos A

    2015-06-01

    The aim of this study was to evaluate physical and sensory characteristics of low-sodium tilapia steaks restructured with microbial transglutaminase. Polyphosphate (0.4%), condiment mixes-onion powder and garlic powder (2.5%), water (10.0%), transglutaminase (1.0%), and different types of salts (1.5%) were mixed with non-commercial sized fillets. Substitution of NaCl by KCl or MgCl2 (at 50% each) affected quality attributes and decreased (P < 0.05) consumer acceptability. The tri-salt steaks (KCl, MgCl2, and NaCl at 1:1:2 ratio) improved some attributes and increased (P < 0.05) acceptability and purchase intention. We conclude that potassium and magnesium chlorides are possible replacers of salt (NaCl) in restructured tilapia steaks and potentially decrease the risk factor for heart failure associated with high sodium consumption. PMID:24831644

  9. Partial sodium replacement in tilapia steak without loss of acceptability.

    PubMed

    Monteiro, Maria Lúcia G; Mársico, Eliane T; Canto, Anna Carolina V C S; Costa-Lima, Bruno R C; Lázaro, César A; Cruz, Adriano G; Conte-Júnior, Carlos A

    2015-06-01

    The aim of this study was to evaluate physical and sensory characteristics of low-sodium tilapia steaks restructured with microbial transglutaminase. Polyphosphate (0.4%), condiment mixes-onion powder and garlic powder (2.5%), water (10.0%), transglutaminase (1.0%), and different types of salts (1.5%) were mixed with non-commercial sized fillets. Substitution of NaCl by KCl or MgCl2 (at 50% each) affected quality attributes and decreased (P < 0.05) consumer acceptability. The tri-salt steaks (KCl, MgCl2, and NaCl at 1:1:2 ratio) improved some attributes and increased (P < 0.05) acceptability and purchase intention. We conclude that potassium and magnesium chlorides are possible replacers of salt (NaCl) in restructured tilapia steaks and potentially decrease the risk factor for heart failure associated with high sodium consumption.

  10. Distribution of LPXRFa, a gonadotropin-inhibitory hormone ortholog peptide, and LPXRFa receptor in the brain and pituitary of the tilapia.

    PubMed

    Ogawa, Satoshi; Sivalingam, Mageswary; Biran, Jakob; Golan, Matan; Anthonysamy, Rachel Shalini; Levavi-Sivan, Berta; Parhar, Ishwar S

    2016-10-01

    In vertebrates, gonadotropin-releasing hormone (GnRH) and gonadotropin-inhibitory hormone (GnIH), respectively, regulate reproduction in positive and negative manners. GnIH belongs to the LPXRFa family of peptides previously identified in mammalian and nonmammalian vertebrates. Studying the detailed distribution of LPXRFa as well as its receptor (LPXRFa-R) in the brain and pituitary is important for understanding their multiple action sites and potential functions. However, the distribution of LPXRFa and LPXRFa-R has not been studied in teleost species, partially because of the lack of fish-specific antibodies. Therefore, in the present study, we generated specific antibodies against LPXRFa and its receptor from Nile tilapia (Oreochromis niloticus), and examined their distributions in the brain and pituitary by immunohistochemistry. Tilapia LPXRFa-immunoreactive neurons lie in the posterior ventricular nucleus of the caudal preoptic area, whereas LPXRFa-R-immunoreactive cells are distributed widely. Double immunofluorescence showed that neither LPXRFa-immunoreactive fibers nor LPXRFa-R is closely associated or coexpressed with GnRH1, GnRH3, or kisspeptin (Kiss2) neurons. In the pituitary, LPXRFa fibers are closely associated with gonadotropic endocrine cells [expressing luteinizing hormone (LH) and follicle-stimulating hormone (FSH)], with adrenocorticomelanotropic cells [corticotropin (ACTH) and α-melanotropin (α-MSH)], and with somatolactin endocrine cells. In contrast, LPXRFa-R are expressed only in LH, ACTH, and α-MSH cells. These results suggest that LPXRFa and LPXRFa-R signaling acts directly on the pituitary cells independent from GnRH or kisspeptin and could play multiple roles in reproductive and nonreproductive functions in teleosts. J. Comp. Neurol. 524:2753-2775, 2016. © 2016 Wiley Periodicals, Inc. PMID:26917324

  11. Utilization of shrimp industry waste in the formulation of tilapia (Oreochromis niloticus Linnaeus) feed.

    PubMed

    Oliveira Cavalheiro, José Marcelino; Oliveira de Souza, Erivelto; Bora, Pushkar Singh

    2007-02-01

    A rapid expansion of fisheries is demanding an adequate supply of efficient, nutritious and inexpensive fish feed, because feed contributes highly to the cost of fish production. Shrimp head, a waste product from the shrimp export industry qualifies as an economical, abundant and good quality protein source for fish feeds. In the present work, shrimp head silage powder, which contained approximately 40% protein, was used as a substitute for fish flour. Four feeds, in the form of pellets, were prepared by substituting shrimp head silage for fish flour at 0%, 33.3%, 66.6% and 100% dietary levels. Other ingredients such as corn, soy, bovine blood, cassava and corn cob flours, soy oil, vitamin premix, salt, and other components also were used in the formulation. A commercial fish feed was used as the control. The proximate composition of these feeds did not differ significantly at p>0.05, except for the protein content of the control feed, which was about 30.6% versus 35.4-36.9% protein in the other diets. No significant differences (p>0.05 level) in weight and length of juveniles fed with the different feeds during a period of 60 days were observed. In all cases, an excellent correlation (0.9950-0.9996) between weight and length of juveniles was observed. No significant difference in growth of juveniles fed on R1, R2, R3, or R4, or the control feed, was observed. Similarly, the proximate analyses of the flesh of juveniles did not present significant differences (p>0.05). The result of the study indicates that the shrimp head silage could replace fish flour as an ingredient in tilapia feed with economic advantages and without sacrificing the quality of the feed.

  12. Utilization of shrimp industry waste in the formulation of tilapia (Oreochromis niloticus Linnaeus) feed.

    PubMed

    Oliveira Cavalheiro, José Marcelino; Oliveira de Souza, Erivelto; Bora, Pushkar Singh

    2007-02-01

    A rapid expansion of fisheries is demanding an adequate supply of efficient, nutritious and inexpensive fish feed, because feed contributes highly to the cost of fish production. Shrimp head, a waste product from the shrimp export industry qualifies as an economical, abundant and good quality protein source for fish feeds. In the present work, shrimp head silage powder, which contained approximately 40% protein, was used as a substitute for fish flour. Four feeds, in the form of pellets, were prepared by substituting shrimp head silage for fish flour at 0%, 33.3%, 66.6% and 100% dietary levels. Other ingredients such as corn, soy, bovine blood, cassava and corn cob flours, soy oil, vitamin premix, salt, and other components also were used in the formulation. A commercial fish feed was used as the control. The proximate composition of these feeds did not differ significantly at p>0.05, except for the protein content of the control feed, which was about 30.6% versus 35.4-36.9% protein in the other diets. No significant differences (p>0.05 level) in weight and length of juveniles fed with the different feeds during a period of 60 days were observed. In all cases, an excellent correlation (0.9950-0.9996) between weight and length of juveniles was observed. No significant difference in growth of juveniles fed on R1, R2, R3, or R4, or the control feed, was observed. Similarly, the proximate analyses of the flesh of juveniles did not present significant differences (p>0.05). The result of the study indicates that the shrimp head silage could replace fish flour as an ingredient in tilapia feed with economic advantages and without sacrificing the quality of the feed. PMID:16624557

  13. Identification of a Novel RNA Virus Lethal to Tilapia

    PubMed Central

    Eyngor, Marina; Zamostiano, Rachel; Kembou Tsofack, Japhette Esther; Berkowitz, Asaf; Bercovier, Hillel; Tinman, Simon; Lev, Menachem; Hurvitz, Avshalom; Galeotti, Marco; Eldar, Avi

    2014-01-01

    Tilapines are important for the sustainability of ecological systems and serve as the second most important group of farmed fish worldwide. Significant mortality of wild and cultured tilapia has been observed recently in Israel. The etiological agent of this disease, a novel RNA virus, is described here, and procedures allowing its isolation and detection are revealed. The virus, denominated tilapia lake virus (TiLV), was propagated in primary tilapia brain cells or in an E-11 cell line, and it induced a cytopathic effect at 5 to 10 days postinfection. Electron microscopy revealed enveloped icosahedral particles of 55 to 75 nm. Low-passage TiLV, injected intraperitoneally in tilapia, induced a disease resembling the natural disease, which typically presents with lethargy, ocular alterations, and skin erosions, with >80% mortality. Histological changes included congestion of the internal organs (kidneys and brain) with foci of gliosis and perivascular cuffing of lymphocytes in the brain cortex; ocular inflammation included endophthalmitis and cataractous changes of the lens. The cohabitation of healthy and diseased fish demonstrated that the disease is contagious and that mortalities (80 to 100%) occur within a few days. Fish surviving the initial mortality were immune to further TiLV infections, suggesting the mounting of a protective immune response. Screening cDNA libraries identified a TiLV-specific sequence, allowing the design of a PCR-based diagnostic test. This test enables the specific identification of TiLV in tilapines and should help control the spread of this virus worldwide. PMID:25232154

  14. Treatment of Trichodina sp. reduced load of Flavobacterium colummnare and improved survival of hybrid tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parasites and bacteria are common inhabitants in water of fish farms. The effect of parasite treatment on Flavobacterium columnare infection in tilapia is currently unknown. This study evaluated whether treatment of Trichodina sp. parasitized hybrid tilapia (Oreochromis niloticus × O. aureus) would...

  15. From non-covalent binding to irreversible DNA lesions: nile blue and nile red as photosensitizing agents

    NASA Astrophysics Data System (ADS)

    Gattuso, Hugo; Besancenot, Vanessa; Grandemange, Stéphanie; Marazzi, Marco; Monari, Antonio

    2016-06-01

    We report a molecular modeling study, coupled with spectroscopy experiments, on the behavior of two well known organic dyes, nile blue and nile red, when interacting with B-DNA. In particular, we evidence the presence of two competitive binding modes, for both drugs. However their subsequent photophysical behavior is different and only nile blue is able to induce DNA photosensitization via an electron transfer mechanism. Most notably, even in the case of nile blue, its sensitization capabilities strongly depend on the environment resulting in a single active binding mode: the minor groove. Fluorescence spectroscopy confirms the presence of competitive interaction modes for both sensitizers, while the sensitization via electron transfer, is possible only in the case of nile blue.

  16. From non-covalent binding to irreversible DNA lesions: nile blue and nile red as photosensitizing agents

    PubMed Central

    Gattuso, Hugo; Besancenot, Vanessa; Grandemange, Stéphanie; Marazzi, Marco; Monari, Antonio

    2016-01-01

    We report a molecular modeling study, coupled with spectroscopy experiments, on the behavior of two well known organic dyes, nile blue and nile red, when interacting with B-DNA. In particular, we evidence the presence of two competitive binding modes, for both drugs. However their subsequent photophysical behavior is different and only nile blue is able to induce DNA photosensitization via an electron transfer mechanism. Most notably, even in the case of nile blue, its sensitization capabilities strongly depend on the environment resulting in a single active binding mode: the minor groove. Fluorescence spectroscopy confirms the presence of competitive interaction modes for both sensitizers, while the sensitization via electron transfer, is possible only in the case of nile blue. PMID:27329409

  17. Probiotic legacy effects on gut microbial assembly in tilapia larvae

    PubMed Central

    Giatsis, Christos; Sipkema, Detmer; Ramiro-Garcia, Javier; Bacanu, Gianina M.; Abernathy, Jason; Verreth, Johan; Smidt, Hauke; Verdegem, Marc

    2016-01-01

    The exposure of fish to environmental free-living microbes and its effect on early colonization in the gut have been studied in recent years. However, little is known regarding how the host and environment interact to shape gut communities during early life. Here, we tested whether the early microbial exposure of tilapia larvae affects the gut microbiota at later life stages. The experimental period was divided into three stages: axenic, probiotic and active suspension. Axenic tilapia larvae were reared either under conventional conditions (active suspension systems) or exposed to a single strain probiotic (Bacillus subtilis) added to the water. Microbial characterization by Illumina HiSeq sequencing of 16S rRNA gene amplicons showed the presence of B. subtilis in the gut during the seven days of probiotic application. Although B. subtilis was no longer detected in the guts of fish exposed to the probiotic after day 7, gut microbiota of the exposed tilapia larvae remained significantly different from that of the control treatment. Compared with the control, fish gut microbiota under probiotic treatment was less affected by spatial differences resulting from tank replication, suggesting that the early probiotic contact contributed to the subsequent observation of low inter-individual variation. PMID:27670882

  18. Screening and identification of a microsatellite marker associated with sex in Wami tilapia, Oreochromis urolepis hornorum.

    PubMed

    Zhu, Huaping; Liu, Zhigang; Lu, Maixin; Gao, Fengying; Ke, Xiaoli; Ma, Dongmei; Huang, Zhanghan; Cao, Jianmeng; Wang, Miao

    2016-06-01

    In this study, primer pairs of 15 microsatellite markers associated with sex determination of tilapia were selected and amplified in Wami tilapia, Oreochromis urolepis hornorum. While one marker, UNH168, on linkage group 3 (LG3) was associated (P <0.001) with the phenotypic sex in the experimental population, nine genotypes were detected in both sexes. Only 99-bp allele was detected in the female samples, while 141, 149 and 157-bp alleles were present in both male and female samples. UNH168 was localized by fluorescence in situ hybridization (FISH) on the long arm of the largest tilapia chromosome pair (chromosome 1, equivalent to LG3). This sex-linked microsatellite marker could potentially be used for marker-assisted selection in tilapia breeding programmes to produce monosex male tilapia. PMID:27350670

  19. Nile Blue derivatives as lysosomotropic photosensitizers

    NASA Astrophysics Data System (ADS)

    Lin, Chi-Wei; Shulok, Janine R.; Kirley, S. D.; Cincotta, Louis; Foley, James W.

    1991-06-01

    The benzophenoxazines, including several Nile blue analogues, are a unique group of dyes that localize selectively in animal tumors. Chemical modifications of Nile blue A can yield derivatives with high 1O2 quantum yields. These derivatives represent a group of potentially effective photosensitizers for selective phototherapy of malignant tumors. In vitro evaluation of these derivatives has indicated that those with high 1O2 yields are very effective in mediating the photocytotoxicity of tumor cells. This photodynamic effect is most likely mediated through the action of 1O2, since photoirradiation under D2O enhanced and under hypoxic conditions diminished the photocytotoxic action. The subcellular localization of these photosensitizers in bladder tumor cells in culture was examined by light and fluorescence microscopies as well as by histochemical and biochemical studies. The results indicate that these dyes are localized primarily in the lysosome. The cellular uptake and retention of these dyes is energy- and pH-dependent. Agents such as nigericin, which alter the transmembrane pH gradient, reduced uptake and enhanced efflux of the dyes, while agents such as valinomycin, which reduce cellular membrane potential, had no effect on the uptake. These findings are consistent with having ion-trapping as the mechanism for the uptake of these dyes. Photoirradiation of sensitizer-treated cells obliterated lysosomes in a light-dose and drug-dose dependent fashion. Release of the hydrolytic enzymes may be the main cause for subsequent cell death since the cytolytic effect was reduced by a specific inhibitor of lysosomal proteolytic enzyme. A lysosomotropic photosensitization mechanism is therefore proposed for the photocytotoxic action of the Nile blue derivatives. This mechanism may provide an approach to the development of new photosensitizers for the effective and selective destruction of malignant tumors.

  20. Tracking Nile Delta Vulnerability to Holocene Change

    PubMed Central

    Marriner, Nick; Flaux, Clément; Morhange, Christophe; Stanley, Jean-Daniel

    2013-01-01

    Understanding deltaic resilience in the face of Holocene climate change and human impacts is an important challenge for the earth sciences in characterizing the full range of present and future wetland responses to global warming. Here, we report an 8000-year mass balance record from the Nile Delta to reconstruct when and how this sedimentary basin has responded to past hydrological shifts. In a global Holocene context, the long-term decrease in Nile Delta accretion rates is consistent with insolation-driven changes in the ‘monsoon pacemaker’, attested throughout the mid-latitude tropics. Following the early to mid-Holocene growth of the Nile’s deltaic plain, sediment losses and pronounced erosion are first recorded after ~4000 years ago, the corollaries of falling sediment supply and an intensification of anthropogenic impacts from the Pharaonic period onwards. Against the backcloth of the Saharan ‘depeopling’, reduced river flow underpinned by a weakening of monsoonal precipitation appears to have been particularly conducive to the expansion of human activities on the delta by exposing productive floodplain lands for occupation and irrigation agriculture. The reconstruction suggests that the Nile Delta has a particularly long history of vulnerability to extreme events (e.g. floods and storms) and sea-level rise, although the present sediment-starved system does not have a direct Holocene analogue. This study highlights the importance of the world’s deltas as sensitive archives to investigate Holocene geosystem responses to climate change, risks and hazards, and societal interaction. PMID:23922692

  1. Separation and characterization of alpha-chain subunits from tilapia (Tilapia zillii) skin gelatin using ultrafiltration.

    PubMed

    Chen, Shulin; Tang, Lanlan; Su, Wenjin; Weng, Wuyin; Osako, Kazufumi; Tanaka, Munehiko

    2015-12-01

    Alpha-chain subunits were separated from tilapia skin gelatin using ultrafiltration, and the physicochemical properties of obtained subunits were investigated. As a result, α1-subunit and α2-subunit could be successfully separated by 100 kDa MWCO regenerated cellulose membranes and 150 kDa MWCO polyethersulfone membranes, respectively. Glycine was the most dominant amino acid in both α1-subunit and α2-subunit. However, the tyrosine content was higher in α2-subunit than in α1-subunit, resulting in strong absorption near 280 nm observed in the UV absorption spectrum. Based on the DSC analysis, it was found that the glass transition temperatures of gelatin, α1-subunit and α2-subunit were 136.48 °C, 126.77 °C and 119.43 °C, respectively. Moreover, the reduced viscosity and denaturation temperature of α1-subunit were higher than those of α2-subunit, and the reduced viscosity reached the highest when α-subunits were mixed with α1/α2 ratio of approximately 2, suggesting that α1-subunit plays a more important role in the thermostability of gelatin than α2-subunit.

  2. Dietary Aloe vera supplementation on growth performance, some haemato-biochemical parameters and disease resistance against Streptococcus iniae in tilapia (GIFT).

    PubMed

    Gabriel, Ndakalimwe Naftal; Qiang, Jun; He, Jie; Ma, Xin Yu; Kpundeh, Mathew D; Xu, Pao

    2015-06-01

    This study investigated effects of dietary Aloe vera on growth performance, some haemato-biochemical parameters and disease resistance against Streptococcus iniae in tilapia (GIFT). Five groups were designed including a basal diet (control) and 100% A. vera powder incorporated in fish feed at 0.5% 1%, 2%, and 4%/kg feed, which were administered for 8 weeks. Fish fed 0.5%, 1%, and 2% A. vera supplemented diet significantly improved (p < 0.05) weight gain, absolute growth rate and specific growth rate. Feed intake significantly increased in fish fed with A. vera diet at 1% and 2%/kg feed. Feed efficiency ratio, feed conversion ratio, and hepatosomatic index were significantly enhanced in 4% A. vera supplemented fish over unsupplemented ones (p < 0.05). Several haemato-biochemical indices were examined before and after fish were challenged with S. iniae pathogen containing 7.7 × 10(6) CFU cells mL(-1). A. vera supplemented fish showed a significant increase (p < 0.05) in red blood cells, hematocrits (Hb), hemoglobin (Hb), white blood cells (WBC), neutrophils, monocytes, eosinophils, serum total protein, glucose and cortisol after challenge when compared to unsupplemented ones. Meanwhile, 4% A. vera supplemented fish showed a decrease (p < 0.05) in RBC, Hb, Ht, WBC, and mean corpuscular hemoglobin (MCH) after challenge compared to unsupplemented ones and other supplemented ones. In addition, lower mean corpuscular volume values (MCV) (p < 0.05) were observed in fish fed with A. vera diet at 2% and 4% A. vera/kg feed than those fed unsupplemented diet. Unchallenged fish fed 0.5%, 1%, and 2% A. vera showed significantly higher values (p < 0.05) of mean corpuscular hemoglobin concentration (MCHC) than those fed unsupplemented diet and 4% A. vera supplemented diet. There was a significant increase (p < 0.05) in the neutrophil to lymphocyte ratio (N/L) within experimental groups after challenge; N/L ratio in A. vera unsupplemented fish and those supplemented with A. vera

  3. Skin manifestations of West Nile virus infection.

    PubMed

    Del Giudice, P; Schuffenecker, I; Zeller, H; Grelier, M; Vandenbos, F; Dellamonica, P; Counillon, E

    2005-01-01

    West Nile virus (WNV) infection is a potentially lethal arbovirus infection. Many notable outbreaks have occurred during the last few years throughout the world, including Europe and the USA. The severity of the disease is mainly related to the neurological complications. A maculopapular exanthema is reported as a clinical sign of the disease. Recently an outbreak of WNV infection occurred in southern France. Three patients out of 6 had a similar skin roseola-like eruption. The cluster of 3 cases of similar febrile roseola of unexplained cause during the same week led to the diagnosis of the first WNV human outbreak in France for 40 years. PMID:16286745

  4. Polychlorinated Biphenyls Water Pollution along the River Nile, Egypt.

    PubMed

    Megahed, Ayman Mohamed; Dahshan, Hesham; Abd-El-Kader, Mahdy A; Abd-Elall, Amr Mohamed Mohamed; Elbana, Mariam Hassan; Nabawy, Ehab; Mahmoud, Hend A

    2015-01-01

    Ten polychlorinated biphenyl (PCB) congeners were determined in water samples collected along the River Nile using gas chromatography-electron capture detector (GC-ECD). PCB concentrations ranged from 14 to 20 μg/L, which were higher than those reported in previous studies, indicating serious PCB pollution in the River Nile. PCB congener profiles varied depending on the sampling sties. PCB-138 was the predominant congener accounting for more than 18% of total PCBs. The composition of PCB congeners in the water revealed that highly chlorinated PCB technical mixtures such as Aroclor 1254 was the main PCB production historically used in Egypt. An increasing trend in PCB levels from the upper stream to the Nile estuaries was observed. The calculated flux of PCBs indicated that 6.8 tons of PCBs is dumped into the Mediterranean Sea each year from the River Nile. The hazard quotients and carcinogenic risk caused by PCB pollution in the River Nile were above the acceptable level indicating that PCBs in the River Nile water pose adverse health effects for all age groups. Our findings revealed that PCBs possess a serious risk to the Egyptian population that depends mainly on the River Nile as a source of water. Thus, stricter legislation and regulatory controls should be applied to reduce the risk of PCBs in Egypt. PMID:26798844

  5. Nile Delta vegetation response to Holocene climate variability

    USGS Publications Warehouse

    Bernhardt, Christopher E.; Horton, Benjamin P.; Stanley, Jean-Daniel

    2012-01-01

    A 7000 yr palynologic record from Burullus Lagoon, Nile Delta, Egypt, is assessed to investigate changes in terrestrial vegetation in response to Nile flow. Previous studies in this region have shown that sea-level rise in the early to mid-Holocene, and markedly increased human land use during the past several centuries, altered vegetation in and around the lagoon. The pollen record from this study documents changes in delta vegetation that likely reflect variations in Nile flow. We suggest that Cyperaceae pollen is a sensitive marker of precipitation over the Nile headwaters and the resultant Nile flow. Decreases in Cyperaceae pollen, interpreted as a marker for diminished Nile flow, as well as the increase in relative abundance of microscopic charcoal, occurred at ca. 6000–5500, ca. 5000, ca. 4200, and ca. 3000 cal. yr B.P. (calibrated years before present). These correspond to extreme regional and global aridity events associated with a more southerly mean position of the Intertropical Convergence Zone. These changes, also recorded by other proxy studies, indicate that several marked regional drought events affected the Nile Delta region and impacted ancient Egyptian and Middle Eastern civilizations.

  6. Polychlorinated Biphenyls Water Pollution along the River Nile, Egypt

    PubMed Central

    Megahed, Ayman Mohamed; Dahshan, Hesham; Abd-El-Kader, Mahdy A.; Abd-Elall, Amr Mohamed Mohamed; Elbana, Mariam Hassan; Nabawy, Ehab; Mahmoud, Hend A.

    2015-01-01

    Ten polychlorinated biphenyl (PCB) congeners were determined in water samples collected along the River Nile using gas chromatography-electron capture detector (GC-ECD). PCB concentrations ranged from 14 to 20 μg/L, which were higher than those reported in previous studies, indicating serious PCB pollution in the River Nile. PCB congener profiles varied depending on the sampling sties. PCB-138 was the predominant congener accounting for more than 18% of total PCBs. The composition of PCB congeners in the water revealed that highly chlorinated PCB technical mixtures such as Aroclor 1254 was the main PCB production historically used in Egypt. An increasing trend in PCB levels from the upper stream to the Nile estuaries was observed. The calculated flux of PCBs indicated that 6.8 tons of PCBs is dumped into the Mediterranean Sea each year from the River Nile. The hazard quotients and carcinogenic risk caused by PCB pollution in the River Nile were above the acceptable level indicating that PCBs in the River Nile water pose adverse health effects for all age groups. Our findings revealed that PCBs possess a serious risk to the Egyptian population that depends mainly on the River Nile as a source of water. Thus, stricter legislation and regulatory controls should be applied to reduce the risk of PCBs in Egypt. PMID:26798844

  7. Vector competence of three North American strains of Aedes albopictus for West Nile virus.

    PubMed

    Sardelis, Michael R; Turell, Michael J; O'Guinn, Monica L; Andre, Richard G; Roberts, Donald R

    2002-12-01

    To evaluate the potential for North American (NA) Aedes albopictus to transmit West Nile virus (WN), mosquito strains derived from 3 NA sources (Frederick County, Maryland, FRED strain; Cheverly, MD, CHEV strain; Chambers and Liberty counties, Texas, TAMU strain) were tested. These strains were tested along with a previously tested strain from a Hawaiian source (OAHU strain). Mosquitoes were fed on 2- to 3-day-old chickens previously inoculated with a New York strain (Crow 397-99) of WN. All of the NA strains were competent laboratory vectors of WN, with transmission rates of 36, 50, 83, and 92% for the FRED, CHEV, OAHU, and TAMU strains, respectively. The extrinsic incubation period for WN in Ae. albopictus held at 26 degrees C was estimated to be 10 days. Based on efficiency of viral transmission, evidence of natural infection, bionomics, and distribution, Ae. albopictus could be an important bridge vector of WN in the southeastern USA.

  8. Vector competence of Culex tarsalis from Orange County, California, for West Nile virus.

    PubMed

    Turell, Michael J; O'Guinn, Monica L; Dohm, David J; Webb, James P; Sardelis, Michael R

    2002-01-01

    To evaluate the vector competence of Culex tarsalis Coquillett for West Nile virus (WN), females reared from larvae collected in Huntington Beach, Orange County, CA, were fed on 2-3-day-old chickens previously inoculated with a New York strain (Crow 397-99) of WN. The Cx. tarsalis mosquitoes were efficient laboratory vectors of WN, with estimated transmission rates of 81% and 91% for mosquitoes that ingested 10(6.5) or 10(7.3) plaque-forming units of WN/mL of blood, respectively. Based on efficiency of viral transmission and the role of this species in the transmission of the closely related St. Louis encephalitis virus, Cx. tarsalis should be considered a potentially important vector of WN in the western United States.

  9. Bioavailability of heavy metals in fresh water Tilapia nilotica (Oreachromis niloticus Linnaeus, 1758): potential risk to fishermen and consumers.

    PubMed

    El-Sadaawy, Manal M; El-Said, Ghada F; Sallam, Neama A

    2013-01-01

    The study was undertaken to assess the accumulation of some heavy metals (Cr, Co, Cu, Ni, Zn, Pb and Cd) in different tissues (muscle, gills, heart, liver, brain, bone and skin) of Tilapia nilotica. It is one of the most edible fish species in Egypt and was collected from a commercial fish farm in order to evaluate their potential risk to fishermen and consumers. This fish farm is fed with discharged water containing agricultural, industrial, sewage and domestic wastes. The length-weight relation and condition factor calculation of Tilapia nilotica samples showed a significant linear regression (r(2) = 0.920) and an average condition factor of 4.1 g/cm(3). This indicated that the health status for the studied fish samples was good. Metal pollution index (MPI) values for the determined heavy metals in the different tissues reflected that the muscle was the only tissue that had the lowest content. Provisional Tolerable Weekly Intake (PTWI) values for the investigated heavy metals were lower than those reported for the permissible limits. The data were evaluated by using ANOVA statistical analysis. For appraising the human health risk effects of heavy metals in fish muscle, estimated dietary intake (EDI) and hazard quotient (HQ) were determined. HQ levels indicated that Cr and Co were the only heavy metals among the determined ones that had values more than unity. Also, their relative contributions in fish consumptions were Cr> Co> Pb> Ni> Cu> Cd> Zn. The highest average HQ value of chromium determined in this study referred to the possible adverse effects of Cr on human health. Accordingly, the potential public health risks from dietary exposure to hazardous contaminants in fish species from fish farms must be continually subjected to research, regulation and debate.

  10. Chitosan extends the shelf-life of filleted tilapia ( Oreochromis niloticus) during refrigerated storage

    NASA Astrophysics Data System (ADS)

    Cao, Rong; Liu, Qi; Yin, Bangzhong; Wu, Biao

    2012-09-01

    Shelf-life extension of aquatic products is of significant economical importance. To determine the potential effect of chitosan on the shelf-life of filleted tilapia, this study analyzed the bacterial community diversity in fresh and spoiled tilapia fillets stored at (4 ± 1)°C and examined the antimicrobial activity of chitosan against relevant bacteria isolates. Results showed that Pseudomonas (20%) and Aeromonas (16%) were abundant in fresh tilapia fillets, whereas Pseudomonas (52%), Aeromonas (32%) and Staphylococcus (12%) were dominant in the spoiled samples. Chitosan showed wide-spectrum antibacterial activity against bacteria isolated from tilapia and 5.0 g L-1 chitosan was selected for application in preservation. We further determined the shelf-life of chitosan-treated, filleted tilapia stored at (4 ± 1)°C based on microbiological, biochemical and sensory analyses. Results showed that the shelf-life of chitosan-treated, filleted tilapia was extended to 12 d, whereas that of untreated, control samples was 6 d. These indicate that chitosan, as a natural preservative, has great application potential in the shelf-life extension of tilapia fillets.

  11. Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil.

    PubMed

    Favaro, E G P; Sipaúba-Tavares, L H; Milstein, A

    2015-11-01

    In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study. PMID:26602348

  12. Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil.

    PubMed

    Favaro, E G P; Sipaúba-Tavares, L H; Milstein, A

    2015-11-01

    In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study.

  13. West Nile virus infection in Ogbomoso: serological evidence.

    PubMed

    Kolawole, Oladipo Elijah; Kola, Oloke Julius

    2015-01-01

    A seroepidemiological study for West Nile virus was carried out in an urban and rural settlements in Ogbomoso for its IgM and IgG. Human sera was obtained and West Nile virus IgM and IgG was determined using Enzyme Linked Immunosorbent Assay technique. Out of 93 subjects tested, 19.4% and 12.9% were positive for IgG and IgM, respectively. Among the urban dwellers, 23.40% were positive for both IgG and IgM, while the rural dwellers had 15.22% for IgG and 2.17% for IgM. Test for pure antibody to West Nile virus revealed that 23.7% had the virus while 8.6% had antibodies that cross reacted for other flaviviruses. Results show that West Nile virus is circulating in Ogbomoso and its environ which might have accounted for malaria like infection in the region.

  14. 21 CFR 866.3940 - West Nile virus serological reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3940 West Nile... detection aids in the clinical laboratory diagnosis of viral meningitis/encephalitis caused by West...

  15. 21 CFR 866.3940 - West Nile virus serological reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3940 West Nile... detection aids in the clinical laboratory diagnosis of viral meningitis/encephalitis caused by West...

  16. 21 CFR 866.3940 - West Nile virus serological reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3940 West Nile... detection aids in the clinical laboratory diagnosis of viral meningitis/encephalitis caused by West...

  17. 21 CFR 866.3940 - West Nile virus serological reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3940 West Nile... detection aids in the clinical laboratory diagnosis of viral meningitis/encephalitis caused by West...

  18. 21 CFR 866.3940 - West Nile virus serological reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3940 West Nile... detection aids in the clinical laboratory diagnosis of viral meningitis/encephalitis caused by West...

  19. Comparative severity of experimentally induced mycobacteriosis in striped bass Morone saxatilis and hybrid tilapia Oreochromis spp.

    PubMed

    Wolf, J C; Smith, S A

    1999-11-30

    Twenty striped bass Morone saxatilis and 20 hybrid tilapia Oreochromis niloticus x O. mossambicus x O. aureus each received a single intramuscular injection of 1.6 x 10(6) colony forming units per gram body weight of Mycobacterium marinum. Striped bass manifested significantly greater clinical and microscopic disease compared to tilapia. Whereas all the striped bass had died or were clinically ill by Day 8 post-infection, there was no apparent disruption of normal behaviour, physical appearance, or growth in any of the sacrificed or surviving tilapia. Histologically, granulomas in striped bass were generally larger and less discrete, with a higher proportion of heavily vacuolated macrophages, and large cores of necrotic cells. Visceral granulomas in tilapia were smaller, with a higher proportion of epithelioid macrophages, more pigment-containing cells, more peripheral lymphocytes, and virtually no central necrosis. Visceral granulomas were 18-fold more numerous in striped bass than in tilapia. Based upon histomorphometric data, mean proportions of acid-fast bacteria within pronephros granulomas were 4-fold greater in striped bass than tilapia, and striped bass granulomas averaged more than twice as large as tilapia granulomas. In the anterior kidney of striped bass, a positive correlation existed between mean mycobacterial proportions and mean necrosis scores. In tilapia, mean mycobacterial proportions correlated negatively with mean granuloma numbers, whereas there was no correlation between these parameters in striped bass. Results suggest that intrinsic functional differences in the immunologic systems of striped bass and hybrid tilapia may contribute to inter-species variation in mycobacteriosis susceptibility.

  20. Comparative severity of experimentally induced mycobacteriosis in striped bass Morone saxatilis and hybrid tilapia Oreochromis spp.

    PubMed

    Wolf, J C; Smith, S A

    1999-11-30

    Twenty striped bass Morone saxatilis and 20 hybrid tilapia Oreochromis niloticus x O. mossambicus x O. aureus each received a single intramuscular injection of 1.6 x 10(6) colony forming units per gram body weight of Mycobacterium marinum. Striped bass manifested significantly greater clinical and microscopic disease compared to tilapia. Whereas all the striped bass had died or were clinically ill by Day 8 post-infection, there was no apparent disruption of normal behaviour, physical appearance, or growth in any of the sacrificed or surviving tilapia. Histologically, granulomas in striped bass were generally larger and less discrete, with a higher proportion of heavily vacuolated macrophages, and large cores of necrotic cells. Visceral granulomas in tilapia were smaller, with a higher proportion of epithelioid macrophages, more pigment-containing cells, more peripheral lymphocytes, and virtually no central necrosis. Visceral granulomas were 18-fold more numerous in striped bass than in tilapia. Based upon histomorphometric data, mean proportions of acid-fast bacteria within pronephros granulomas were 4-fold greater in striped bass than tilapia, and striped bass granulomas averaged more than twice as large as tilapia granulomas. In the anterior kidney of striped bass, a positive correlation existed between mean mycobacterial proportions and mean necrosis scores. In tilapia, mean mycobacterial proportions correlated negatively with mean granuloma numbers, whereas there was no correlation between these parameters in striped bass. Results suggest that intrinsic functional differences in the immunologic systems of striped bass and hybrid tilapia may contribute to inter-species variation in mycobacteriosis susceptibility. PMID:10686670

  1. Effects of cadmium and environmental pollution on metallothionein and cytochrome P450 in Tilapia

    SciTech Connect

    Ueng, Y.F.; Meng, L.M.; Hung, Y.Y.; Ueng, T.H.; Liu, C.; Lai, C.F.

    1996-07-01

    Tilapia are widely distributed freshwater fish frequently used for environmental toxicology, comparative biochemistry and physiology studies. Tilapia can persist in a highly polluted habitat and have the potential for the development as a biological monitor of environmental pollution. Metallothioneins (MTs) are a group of small-molecular-weight cytoplasmic proteins induced in many animals including fish, following exposure to metals such as cadmium, copper, zinc, and mercury. An increasing number of reports have indicated that fish MT induction is a sensitive measure of metal contamination in the environment. Fish cytochrome (P450)-dependent monooxygenases are inducible by many environmental pollutants including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Extensive studies have suggested that fish monooxygenase can serve as a biochemical marker for exposure to PAH- and PCB-types of pollutants. Tilapia P450 is highly responsive to the inductive effects of PAH and PCBs. Tilapia collected from a polluted section of a river showed higher levels of P450 and dependent monooxygenase activities than tilapia collected from an unpolluted section. Previous studies showed that pretreatment with Cd decreased microsomal monooxygenase activities in fish such as plaice, bass, and trout. However, direct information regarding the effects of heavy metals on tilapia P450 are not available. Reports concerning the effect of heavy metal on tilapia MT are scarce. The purpose of the present study was to determine the ability of cadmium to modulate P450 and MT in tilapia liver and gill. In addition, we have extended our study to feral tilapia collected from Er-Jen Stream, a polluted river in Taiwan. 16 refs., 1 fig., 2 tabs.

  2. Plasma diagnostics for FED

    SciTech Connect

    Nelson, W.D.

    1981-01-01

    An overview of the plasma diagnostic instruments recommended for the Fusion Engineering Device (FED) is described. First the role and need for plasma diagnostics is discussed. This is followed by an identification of particles and radiation eminating from the plasma. Next some design considerations are presented for the overall set of diagnostic instruments. Finally, instruments used for control and for plasma performance measurements are included in separate lists.

  3. Lethal toxicity of cadmium to Cyprinus carpio and Tilapia aurea

    SciTech Connect

    Not Available

    1986-09-01

    There have been several studies of the lethal toxicity of cadmium to freshwater fishes, but further information is required on a number of points. For example, the shallow slope which is characteristic of the cadmium toxicity curve makes interspecific comparisons difficult. There also is a paucity of information on cadmium toxicity to non-Salmonid European species. As part of a study of the water quality requirements of cultured fish species in the Mediterranean, the authors report on the lethal toxicity of cadmium to two such species, the common carp Cyprinus carpio, and Tilapia aurea, for which little information has previously been reported.

  4. West Nile Virus Infection of Birds, Mexico

    PubMed Central

    Guerrero-Sánchez, Sergio; Cuevas-Romero, Sandra; Nemeth, Nicole M.; Trujillo-Olivera, María Teresa Jesús; Worwa, Gabriella; Dupuis, Alan; Brault, Aaron C.; Kramer, Laura D.; Komar, Nicholas

    2011-01-01

    West Nile virus (WNV) has caused disease in humans, equids, and birds at lower frequency in Mexico than in the United States. We hypothesized that the seemingly reduced virulence in Mexico was caused by attenuation of the Tabasco strain from southeastern Mexico, resulting in lower viremia than that caused by the Tecate strain from the more northern location of Baja California. During 2006–2008, we tested this hypothesis in candidate avian amplifying hosts: domestic chickens, rock pigeons, house sparrows, great-tailed grackles, and clay-colored thrushes. Only great-tailed grackles and house sparrows were competent amplifying hosts for both strains, and deaths occurred in each species. Tecate strain viremia levels were higher for thrushes. Both strains produced low-level viremia in pigeons and chickens. Our results suggest that certain avian hosts within Mexico are competent for efficient amplification of both northern and southern WNV strains and that both strains likely contribute to bird deaths. PMID:22172633

  5. Systems analysis of West Nile virus infection.

    PubMed

    Suthar, Mehul S; Pulendran, Bali

    2014-06-01

    Emerging and re-emerging mosquito-borne viruses continue to pose a significant threat to human health throughout the world. Over the past decade, West Nile virus (WNV), Dengue virus (DENV), and Chikungunya virus (CHIKV), have caused annual epidemics of virus-induced encephalitis, hemorrhagic fever\\shock syndromes, and arthritis, respectively. Currently, no specific antiviral therapies or vaccines exist for use in humans to combat or prevent these viral infections. Thus, there is a pressing need to define the virus-host interactions that govern immunity and infection outcome. Recent technological breakthroughs in 'omics' resources and high-throughput based assays are beginning to accelerate antiviral drug discovery and improve on current strategies for vaccine design. In this review, we highlight studies with WNV and discuss how traditional and systems biological approaches are being used to rapidly identify novel host targets for therapeutic intervention and develop a deeper conceptual understanding of the host response to virus infection.

  6. Vector-Host Interactions Governing Epidemiology of West Nile Virus in Southern California

    PubMed Central

    Molaei, Goudarz; Cummings, Robert F.; Su, Tianyun; Armstrong, Philip M.; Williams, Greg A.; Cheng, Min-Lee; Webb, James P.; Andreadis, Theodore G.

    2010-01-01

    Southern California remains an important focus of West Nile virus (WNV) activity, with persistently elevated incidence after invasion by the virus in 2003 and subsequent amplification to epidemic levels in 2004. Eco-epidemiological studies of vectors-hosts-pathogen interactions are of paramount importance for better understanding of the transmission dynamics of WNV and other emerging mosquito-borne arboviruses. We investigated vector-host interactions and host-feeding patterns of 531 blood-engorged mosquitoes in four competent mosquito vectors by using a polymerase chain reaction (PCR) method targeting mitochondrial DNA to identify vertebrate hosts of blood-fed mosquitoes. Diagnostic testing by cell culture, real-time reverse transcriptase-PCR, and immunoassays were used to examine WNV infection in blood-fed mosquitoes, mosquito pools, dead birds, and mammals. Prevalence of WNV antibodies among wild birds was estimated by using a blocking enzyme-linked immunosorbent assay. Analyses of engorged Culex quinquefasciatus revealed that this mosquito species acquired 88.4% of the blood meals from avian and 11.6% from mammalian hosts, including humans. Similarly, Culex tarsalis fed 82% on birds and 18% on mammals. Culex erythrothorax fed on both birds (59%) and mammals (41%). In contrast, Culex stigmatosoma acquired all blood meals from avian hosts. House finches and a few other mostly passeriform birds served as the main hosts for the blood-seeking mosquitoes. Evidence of WNV infection was detected in mosquito pools, wild birds, dead birds, and mammals, including human fatalities during the study period. Our results emphasize the important role of house finches and several other passeriform birds in the maintenance and amplification of WNV in southern California, with Cx. quinquefasciatus acting as both the principal enzootic and “bridge vector” responsible for the spillover of WNV to humans. Other mosquito species, such as Cx. tarsalis and Cx. stigmatosoma, are

  7. Omega-6 (n-6) and omega-3 (n-3) fatty acids in tilapia and human health: a review.

    PubMed

    Young, Kaolin

    2009-01-01

    A recent publication questions the nutritional value of tilapia in the human diet following the movement to eat fish for their omega fatty acid (FA) content. It suggests that tilapia have an elevated amount of omega-6 FAs (n-6) and a deficient amount of omega-3 FAs (n-3), a possibly unhealthy proportion for humans. A high n-6:n-3 ratio is problematic because too much arachidonic acid, an n-6 FA, promotes inflammation, which aggravates heart disease and other illnesses. This paper analyzes the numbers from different tilapia composition studies in an effort to understand the range of n-6 and n-3 totals and ratios present in both farmed and wild tilapia. Generally, wild tilapia have more n-3 FAs than farmed tilapia, but diet adjustments can alter the body composition of the domesticated variety. Consumers should consider fish as part of a balanced diet and evaluate their FA needs on an individual basis.

  8. Shelf Life and Quality Study of Minced Tilapia with Nori and Hijiki Seaweeds as Natural Additives

    PubMed Central

    Ribeiro, Ingridy Simone; Shirahigue, Ligianne Din; Ferraz de Arruda Sucasas, Lia; Anbe, Lika; da Cruz, Pedro Gomes; Gallo, Cláudio Rosa; Carpes, Solange Teresinha; Marques, Marcos José; Oetterer, Marília

    2014-01-01

    The extraction of mechanically separated meat has emerged as an attractive process. However, it increases the incorporation of oxygen and, consequently, of flavors due to rancidity. Thus, preservatives must be added. The objective of this study was to evaluate the shelf life of minced tilapia to replace synthetic preservatives with Hijiki and Nori seaweeds extracts. The application of the extracts had no effect on the chemical composition of the minced tilapia. The seaweed extracts had inhibitory effect on total volatile base nitrogen. The minced tilapia complied with the microbiological standard set by Brazilin law. The panelists detected no differences in the rancid aroma and only minor differences were detected in the color of the products. It can be concluded that the minced tilapia with added seaweed extracts were within quality standards during frozen storage. PMID:25478593

  9. Characterization of a Novel Orthomyxo-like Virus Causing Mass Die-Offs of Tilapia

    PubMed Central

    Bacharach, Eran; Mishra, Nischay; Briese, Thomas; Zody, Michael C.; Kembou Tsofack, Japhette Esther; Zamostiano, Rachel; Berkowitz, Asaf; Ng, James; Nitido, Adam; Corvelo, André; Toussaint, Nora C.; Abel Nielsen, Sandra Cathrine; Hornig, Mady; Del Pozo, Jorge; Bloom, Toby; Ferguson, Hugh

    2016-01-01

    ABSTRACT Tilapia are an important global food source due to their omnivorous diet, tolerance for high-density aquaculture, and relative disease resistance. Since 2009, tilapia aquaculture has been threatened by mass die-offs in farmed fish in Israel and Ecuador. Here we report evidence implicating a novel orthomyxo-like virus in these outbreaks. The tilapia lake virus (TiLV) has a 10-segment, negative-sense RNA genome. The largest segment, segment 1, contains an open reading frame with weak sequence homology to the influenza C virus PB1 subunit. The other nine segments showed no homology to other viruses but have conserved, complementary sequences at their 5′ and 3′ termini, consistent with the genome organization found in other orthomyxoviruses. In situ hybridization indicates TiLV replication and transcription at sites of pathology in the liver and central nervous system of tilapia with disease. PMID:27048802

  10. Phosphorous digestibility and activity of intestinal phytase in hybrid tilapia, Oreochromis niloticus X O. aureus

    USGS Publications Warehouse

    La Vorgna, M.W.; Hafez, Y.; Hughes, S.G.; Handwerker, T.

    2003-01-01

    Experiments were conducted to determine the degree to which phytate-bound phosphorus from plant protein sources could be used by hybrid tilapia (Oreochromis niloticus X O. aureus). Utilizing an inert marker technique with chromic oxide, hybrid tilapia in our study were effective at utilizing both inorganic and phytate phosphorus as evidenced by average apparent digestibility values of 93.2% and 90.0% for total and phytate phosphorus, respectively. Analysis of the intestinal brush border membrane of the tilapia revealed enzyme activity that was capable of hydrolyzing phytic acid. The presence of phytic acid hydrolyzing enzyme activity in the intestinal brush border provides a probable mechanism by which these hybrid tilapia are able to utilize phytate phosphorus effectively. ?? 2003 by The Haworth Press, Inc. All rights reserved.

  11. X-ray-induced changes in growth of Mozambique tilapia

    SciTech Connect

    Jana, B.B.; Basu, M.

    1995-01-01

    Early fry (30 d postfertilization) and 7-8-week-old Mozambique tilapias (Tilapia mossambica) were exposed to X rays in dosages of 50, 100, 200, 300, 400 or 500 roentgens and reared in outdoor culture tanks between May 1981 and October 1988. Fish of either sex that were irradiated as fry grew faster than controls at all test X-ray doses. Among fish irradiated at 7-8 weeks, males grew significantly faster, but females grew significantly slower, than controls at all test doses. X-ray-induced changes in growth were dose-dependent: growth rates of fry (both sexes) and of juvenile males rose relative to those of controls with increased radiation dose. The growth increase per unit of radiation dose was higher for fry than for older juveniles. The length-weight regression was steeper for irradiated males than for controls. The average weights of F{sub 1} offspring of irradiated fish were greatly reduced as compared with controls, which suggests the transfer of the detrimental effects of X rays from irradiated parents to their offspring. 39 refs., 3 figs., 3 tabs.

  12. Tilapia male urinary pheromone stimulates female reproductive axis.

    PubMed

    Huertas, Mar; Almeida, Olinda G; Canário, Adelino V M; Hubbard, Peter C

    2014-01-15

    Mozambique tilapia males congregate in leks where they establish dominance hierarchies and attract females to spawn in sandy pits. Dominant males store more urine than subordinates and the pattern of urination and the high sensitivity of females to male urine suggest chemical signalling via the urine. Here we show that pre-ovulated and post-spawn females when exposed to dominant male urine increased significantly, in less than 1h, the release rate of the maturation-inducing steroid 17,20β-dihydroxypregn-4-en-3-one which is maintained elevated for at least 6h. This indicates a pheromonal role for male urine in the synchronisation of spawning. Furthermore, we show that the lack of affinity of 17,20βP to sex steroid binding globulin explains, at least partly, its rapid release and lack of detection in the blood. Thus tilapia urine involvement in several communication processes confirms that cichlids have evolved a sophisticated chemical signalling system together with their complex visual, acoustic and behavioural displays.

  13. Molecular cloning, functional identification and expressional analyses of FasL in Tilapia, Oreochromis niloticus.

    PubMed

    Ma, Tai-yang; Wu, Jin-ying; Gao, Xiao-ke; Wang, Jing-yuan; Zhan, Xu-liang; Li, Wen-sheng

    2014-10-01

    FasL is the most extensively studied apoptosis ligand. In 2000, tilapia FasL was identified using anti-human FasL monoclonal antibody by Evans's research group. Recently, a tilapia FasL-like protein of smaller molecule weight was predicted in Genbank (XM_003445156.2). Based on several clues drawn from previous studies, we cast doubt on the authenticity of the formerly identified tilapia FasL. Conversely, using reverse transcription polymerase chain reaction (RT-PCR), the existence of the predicted FasL-like was verified at the mRNA level (The Genbank accession number of the FasL mRNA sequence we cloned is KM008610). Through multiple alignments, this FasL-like protein was found to be highly similar to the FasL of the Japanese flounder. Moreover, we artificially expressed the functional region of the predicted protein and later confirmed its apoptosis-inducing activity using a methyl thiazolyl tetrazolium (MTT) assay, Annexin-V/Propidium iodide (PI) double staining, and DNA fragment detection. Supported by these evidences, we suggest that the predicted protein is the authentic tilapia FasL. To advance this research further, tilapia FasL mRNA and its protein across different tissues were quantified. High expression levels were identified in the tilapia immune system and sites where active cell turnover conservatively occurs. In this regard, FasL may assume an active role in the immune system and cell homeostasis maintenance in tilapia, similar to that shown in other species. In addition, because the distribution pattern of FasL mRNA did not synchronize with that of the protein, post-transcriptional expression regulation is suggested. Such regulation may be dominated by potential adenylate- and uridylate-rich elements (AREs) featuring AUUUA repeats found in the 3' untranslated region (UTR) of tilapia FasL mRNA. PMID:24950416

  14. Parameters of Mosquito-Enhanced West Nile Virus Infection

    PubMed Central

    Moser, Lindsey A.; Lim, Pei-Yin; Styer, Linda M.; Kramer, Laura D.

    2015-01-01

    ABSTRACT The arthropod-borne West Nile virus (WNV) emerged in New York State in 1999 and quickly spread throughout the United States. Transmission is maintained in an enzootic cycle in which infected mosquitoes transmit the virus to susceptible hosts during probing and feeding. Arthropod-derived components within the viral inoculum are increasingly acknowledged to play a role in infection of vertebrate hosts. We previously showed that Culex tarsalis mosquito saliva and salivary gland extract (SGE) enhance the in vivo replication of WNV. Here, we characterized the effective dose, timing, and proximity of saliva and SGE administration necessary for enhancement of WNV viremia using a mouse model. Mosquito saliva and SGE enhanced viremia in a dose-dependent manner, and a single mosquito bite or as little as 0.01 μg of SGE was effective at enhancing viremia, suggesting a potent active salivary factor. Viremia was enhanced when SGE was injected in the same location as virus inoculation from 24 h before virus inoculation through 12 h after virus inoculation. These results were confirmed with mosquito saliva deposited by uninfected mosquitoes. When salivary treatment and virus inoculation were spatially separated, viremia was not enhanced. In summary, the effects of mosquito saliva and SGE were potent, long lasting, and localized, and these studies have implications for virus transmission in nature, where vertebrate hosts are fed upon by both infected and uninfected mosquitoes over time. Furthermore, our model provides a robust system to identify the salivary factor(s) responsible for enhancement of WNV replication. IMPORTANCE Mosquito-borne viruses are a significant class of agents causing emerging infectious diseases. WNV has caused over 18,000 cases of neuroinvasive disease in the United States since its emergence. We have shown that Culex tarsalis mosquito saliva and SGE enhance the replication of WNV. We now demonstrate that saliva and SGE have potent, long

  15. Comparative Transcriptome Analysis Identifies Candidate Genes Related to Skin Color Differentiation in Red Tilapia

    PubMed Central

    Zhu, Wenbin; Wang, Lanmei; Dong, Zaijie; Chen, Xingting; Song, Feibiao; Liu, Nian; Yang, Hui; Fu, Jianjun

    2016-01-01

    Red tilapia is becoming more popular for aquaculture production in China in recent years. However, the pigmentation differentiation in genetic breeding is the main problem limiting its development of commercial red tilapia culture and the genetic basis of skin color variation is still unknown. In this study, we conducted Illumina sequencing of transcriptome on three color variety red tilapia. A total of 224,895,758 reads were generated, resulting in 160,762 assembled contigs that were used as reference contigs. The contigs of red tilapia transcriptome had hits in the range of 53.4% to 86.7% of the unique proteins of zebrafish, fugu, medaka, three-spined stickleback and tilapia. And 44,723 contigs containing 77,423 simple sequence repeats (SSRs) were identified, with 16,646 contigs containing more than one SSR. Three skin transcriptomes were compared pairwise and the results revealed that there were 148 common significantly differentially expressed unigenes and several key genes related to pigment synthesis, i.e. tyr, tyrp1, silv, sox10, slc24a5, cbs and slc7a11, were included. The results will facilitate understanding the molecular mechanisms of skin pigmentation differentiation in red tilapia and accelerate the molecular selection of the specific strain with consistent skin colors. PMID:27511178

  16. Comparative Transcriptome Analysis Identifies Candidate Genes Related to Skin Color Differentiation in Red Tilapia.

    PubMed

    Zhu, Wenbin; Wang, Lanmei; Dong, Zaijie; Chen, Xingting; Song, Feibiao; Liu, Nian; Yang, Hui; Fu, Jianjun

    2016-01-01

    Red tilapia is becoming more popular for aquaculture production in China in recent years. However, the pigmentation differentiation in genetic breeding is the main problem limiting its development of commercial red tilapia culture and the genetic basis of skin color variation is still unknown. In this study, we conducted Illumina sequencing of transcriptome on three color variety red tilapia. A total of 224,895,758 reads were generated, resulting in 160,762 assembled contigs that were used as reference contigs. The contigs of red tilapia transcriptome had hits in the range of 53.4% to 86.7% of the unique proteins of zebrafish, fugu, medaka, three-spined stickleback and tilapia. And 44,723 contigs containing 77,423 simple sequence repeats (SSRs) were identified, with 16,646 contigs containing more than one SSR. Three skin transcriptomes were compared pairwise and the results revealed that there were 148 common significantly differentially expressed unigenes and several key genes related to pigment synthesis, i.e. tyr, tyrp1, silv, sox10, slc24a5, cbs and slc7a11, were included. The results will facilitate understanding the molecular mechanisms of skin pigmentation differentiation in red tilapia and accelerate the molecular selection of the specific strain with consistent skin colors. PMID:27511178

  17. A White Nile megalake during the last interglacial period

    NASA Astrophysics Data System (ADS)

    Barrows, Timothy T.; Williams, Martin A. J.; Mills, Stephanie C.; Duller, Geoff A. T.; Fifield, L. Keith; Haberlah, David; Tims, Stephen G.; Williams, Frances M.

    2014-05-01

    The eastern Sahara Desert of Africa is one of the most climatically sensitive areas on Earth, varying from lake-studded savannah woodland to hyperarid desert over the course of a glacial-interglacial cycle. In currently semiarid Sudan there is widespread evidence that a very large freshwater lake once filled the White Nile River valley (Barrows et al., 2014). Here we present the first quantitative estimate for the dimensions of the lake and a direct age for the emplacement of its shoreline. Using a profile dating approach with the cosmogenic nuclide 10Be, we estimate an exposure age of 109 ± 8 ka for this megalake, indicating that it probably formed during the last interglacial period. This age is supported by optically stimulated luminescence dating of Blue Nile paleochannels associated with the lake. Using a high-resolution digital elevation model, we estimate that the lake was more than 45,000 km2 in area, making it comparable to the largest freshwater lakes on Earth today. We attribute the lake's existence to seasonal flood pulses as a result of local damming of the White Nile by a more southern position of the Blue Nile and greatly increased precipitation associated with an enhanced monsoon. References Barrows, T.T., Williams, M.A.J., Mills, S.C., Duller, G.A.T., Fifield, L.K., Haberlah, D., Tims, S.G., Williams, F.M., 2014. A White Nile megalake during the last interglacial period. Geology. 10.1130/g35238.1

  18. Effect of Kima drain wastewaters on Nile river waters

    SciTech Connect

    Soltan, M.E.

    1995-09-01

    The influence of industrial and domestic wastewaters discharged from the Kima drain (Aswan, Egypt) on the quality of the Nile River waters is described by measuring the concentrations of inorganic nonmetals (free CO{sub 2}, CO{sub 3}{sup 2-}, HCO{sub 3}{sup {minus}}, OH{sup -}, Cl{sup -}, SO{sub 4}{sup 2-}, PO{sub 4}{sup 3-}, NO{sub 2}{sup -}, NO{sub 2}{sup -}, NO{sub 3}{sup -}, SiO{sub 2}, COD, DO and pH value), metals (Al, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Pb, and Zn), and the physical parameters (cond., T{degrees}C, SS, and DS). Kima drain wastewaters exhibit high concentrations of dissolved salts, particularly close to where the waste of the Kima factory enters, but decrease substantially near the end of the Kima drain. The reason is the dilution factor, aeration, sedimentation, oxidation reductions, and the biochemical effects. A slight increase of the dissolved solids (DS) in the Nile river water at the Kima drain does not effect the Nile river water quality, as the regeneration of the Nile water continuously (the Nile River receives 200 Mm{sup 3}/d of fresh water from the High Dam Lake) prevents the accretion of the concentrations of metals and anions. Statistical analysis of the database exhibits positive, good, and interesting correlation coefficient values. 28 refs., 2 figs.

  19. [West Nile virus transmission risk in the Czech Republic].

    PubMed

    Vlčková, J; Rupeš, V; Horáková, D; Kollárová, H; Holý, O

    2015-06-01

    West Nile Virus (WNV) belongs to the family Flaviviridae. It is transmitted to humans by mosquitoes, capable of sucking blood on birds and mammals, most often by mosquitoes of the genus Culex. In humans, the virus was first identified in 1937 in the West Nile region, Uganda, Africa. Later, the virus spread and caused more or less severe epidemics of West Nile fever in North Africa, Europe, Asia, and North and South America. During the last two decades, WNV has been on the rise and is currently ranked as one of the most prevalent arboviruses in the world. In humans, WNV infection mostly occurs as asymptomatic, but may have a more severe or even fatal course in older and weakened patients. Humans may become infected not only by mosquitoes that acquire the virus from infected birds, but also through a blood transfusion, organ transplant, breast milk and transplacental transmission, or contact with infected animals, their blood, and tissues. The first autochthonous human case of West Nile fever in the Czech Republic was reported from South Moravia in 1997. In 2013, another case of West Nile fever emerged in this country, in the Ostrava area. The issue of WNV has recently been studied from many different perspectives, as evidenced by many original and review papers. This article briefly reviews the essential knowledge about this virus and its spread.

  20. Safety of West Nile Virus vaccines in sandhill crane chicks

    USGS Publications Warehouse

    Olsen, G.H.; Miller, K.J.; Docherty, D.E.; Bochsler, V.S.; Folk, Martin J.; Nesbitt, Stephen A.

    2008-01-01

    West Nile virus arrived in North America in 1999 and has spread across the continent in the ensuing years. The virus has proven deadly to a variety of native avian species including sandhill cranes (Grus canadensis). In order to provide safe and efficacious protection for captive and released populations of whooping cranes (G. americana), we have conducted a series of four research projects. The last of these was a study of the effects of two different West Nile virus vaccines on young Florida sandhill crane (G. c. pratensis) chicks and subsequent challenge with the virus. We found that vaccinating crane chicks as early as day 7 post-hatch caused no adverse reactions or noticeable morbidity. We tested both a commercial equine vaccine West Nile - Innovator (Fort Dodge Laboratories, Fort Dodge, Iowa) and a new recombinant DNA vaccine (Centers for Disease Control). We had a 33% mortality in control chicks (n =6) from West Nile virus infection, versus 0% mortality in two groups of vaccinated chicks (n = 12), indicating the two vaccines tested were not only safe but effective in preventing West Nile virus.

  1. West Nile Virus Ecology in a Tropical Ecosystem in Guatemala

    PubMed Central

    Morales-Betoulle, Maria E.; Komar, Nicholas; Panella, Nicholas A.; Alvarez, Danilo; López, María R.; Betoulle, Jean-Luc; Sosa, Silvia M.; Müller, María L.; Kilpatrick, A. Marm; Lanciotti, Robert S.; Johnson, Barbara W.; Powers, Ann M.; Cordón-Rosales, Celia

    2013-01-01

    West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States. PMID:23149586

  2. Growth of breast-fed and formula-fed infants.

    PubMed

    Ziegler, Ekhard E

    2006-01-01

    Growth and nutrition during infancy are being viewed with renewed interest because of the possibility that they may be linked to cardiovascular and metabolic health in later life. Of particular interest are differences between breast- and formula-fed infants with regard to nutrient intake and growth because breastfeeding has been shown to be associated with a reduced risk of obesity in later life. During the first 6-8 weeks of life there is little difference in growth (gain in weight and length) between breast- and formula-fed infants. However, from about 2 months of age to the end of the first year of life formula-fed infants gain weight and length more rapidly than breast-fed infants. There are no consistent differences in adiposity during the first 4-5 months of life, but during the later part of the first year of life the preponderance of the evidence suggests that breast-fed infants are leaner than formula-fed infants. Formula-fed infants at 4-5 months of age show higher plasma levels of insulin-like growth factor-1 (IGF-1), insulin and certain amino acids than breast-fed infants. Whereas the protein intake of breast-fed infants decreases with age and closely matches the requirements for protein during the early months of life, the protein intake of formula-fed infants exceeds requirements after the first 1-2 months of life. The data are consistent with the hypothesis that differences in protein intake are mainly responsible for differences in growth between breast- and formula-fed infants. Differences in energy intake probably are responsible for differences in adiposity observed in older infants.

  3. [West Nile virus: a reality in Mexico].

    PubMed

    Téllez, Ildefonso; Calderón, Oscar; Franco-Paredes, Carlos; del Río, Carlos

    2006-01-01

    West Nile virus (WNV) is a RNA virus of the Flaviridae, genus flavivirus family. It is a neuropathogenic virus causing disease in birds, horses and humans. WNVis transmitted by the vector mosquito Culex sp. The virus life 's cycle includes mosquitoes as vectors and birds as natural hosts. Humans are accidental hosts. Since the introduction of the Epidemiological Surveillance Program at the Ministry ofHealth. we have documented 90 positive test results among birds out of 1,223 cases studied in Mexico as of September IS. 2005. The incubation period in humans after a mosquito bite ranges from 3 to 14 days. Disease is characterized by early onset fever, general malaise, decreased appetite, nausea, vomiting, headaches, myalgias, enlarged lymph nodes andrash. Neurological manifestations include encephalitis andflaccid paralysis, which are present in less than 1% of subjects infected with WNV. Older patients display more adverse outcomes including death. The diagnosis is made by the determination of specific IgM and JgG antibodies in serum and/or cerebrospinal fluid. There is no antiviral treatment to date against WNV but interferon ?2b, and WNVspec4ic-immunoglobulin have been used Prevention is therefore the key to control the infection.

  4. Equine vaccine for West Nile virus.

    PubMed

    Ng, T; Hathaway, D; Jennings, N; Champ, D; Chiang, Y W; Chu, H J

    2003-01-01

    To meet the urgent need of controlling West Nile virus (WNV) infection in the equine population, we have developed a killed WNV vaccine. A dose titration study in horses was first conducted to evaluate serum neutralization antibody responses against WNV in these animals. Horses were vaccinated intramuscularly twice with the test vaccine at low, medium and high dose, three weeks apart. Serum samples were collected periodically and were measured for serum neutralizing antibody using a plaque reduction neutralization test. Significant increases in serum neutralizing antibody were detected in all three dosage groups 14 days post the second vaccination. Twelve months after the second vaccination, horses vaccinated with the medium dose of WNV vaccine and non-vaccinated control horses were experimentally challenged with WNV. Nine out of 11 (81.8%) controls developed viraemia after challenge while only one out of 19 (5.3%) vaccinates had transient viraemia, representing a 94% preventable fraction. In a separate study, the safety of the killed WNV vaccine was demonstrated under field conditions. A total of 648 horses, including 32 pregnant mares, were enrolled in the study. During the two weeks post vaccination period, no local or systemic adverse reactions were observed following 96% of the vaccinations administered while mild, transient injection site reactions were noted in a small number of horses. These results indicate that the killed WNV vaccine developed by Fort Dodge Animal Health is safe and efficacious.

  5. West Nile virus: should pediatricians care?

    PubMed

    Smith, Jennifer C; Mailman, Tim; MacDonald, Noni E

    2014-11-01

    Given the recurrent serious outbreaks of West Nile Virus (WNV) in the United States over the past decade, the spread to Canada and South America, the recurrent outbreaks in Europe, and the potential for serious neurological disease even in children under 18 years, paediatricians in affected areas must consider WNV in the differential diagnosis of all children presenting with aseptic meningitis, encephalitis and acute flaccid paralysis. Additionally, given that WNV encephalitis can occur after WNV infection, suspicion for neurological WNV disease must remain high even after otherwise benign febrile illnesses if the child lives in or has traveled to an affected region. Under-diagnosis in the pediatric population is likely a serious problem, necessitating further educational efforts. More follow-up studies of WNV neurological disease in children and youth are needed to better understand the potential long-term sequelae during vulnerable times of neurodevelopment and neural remodeling. Similarly, more research is need on short and long-term fetal outcomes of maternal WNV infection.

  6. Host heterogeneity dominates West Nile virus transmission

    PubMed Central

    Marm Kilpatrick, A; Daszak, Peter; Jones, Matthew J; Marra, Peter P; Kramer, Laura D

    2006-01-01

    Heterogeneity in host populations and communities can have large effects on the transmission and control of a pathogen. In extreme cases, a few individuals give rise to the majority of secondary infections, which have been termed super spreading events. Here, we show that transmission of West Nile virus (WNV) is dominated by extreme heterogeneity in the host community, resulting in highly inflated reproductive ratios. A single relatively uncommon avian species, American robin (Turdus migratorius), appeared to be responsible for the majority of WNV-infectious mosquitoes and acted as the species equivalent of a super spreader for this multi-host pathogen. Crows were also highly preferred by mosquitoes at some sites, while house sparrows were significantly avoided. Nonetheless, due to their relative rarity, corvids (crows and jays) were relatively unimportant in WNV amplification. These results challenge current beliefs about the role of certain avian species in WNV amplification and demonstrate the importance of determining contact rates between vectors and host species to understand pathogen transmission dynamics. PMID:16928635

  7. West Nile Virus: is a vaccine needed?

    PubMed

    Martina, Byron E E; Koraka, Penelope; Osterhaus, Albert D M E

    2010-02-01

    West Nile virus (WNV) is a neurotropic Flavivirus that was associated with sporadic outbreaks of meningoencephalitis in Africa and the Middle East until 1999, when a more virulent strain emerged in the US that caused thousands of infections among humans and horses, with reported fatality rates between 10 and 50%. Although the epidemiology of WNV is changing into a more endemic pattern in the US, and the incidence of neuroinvasive disease is decreasing, the long-term effects of resolved WNV infections in humans, characterized as persistent movement disorders and various functional disabilities, are a significant cause of morbidity. In addition, the horse industry is also negatively impacted by WNV infections, resulting in significant economic losses. Together with the fact that WNV is a potential bioterrorism agent, these factors suggest that there is a need for the development of a safe and effective vaccine against WNV. The increased understanding of WNV pathogenesis and correlates of protection enables the rational design of such a vaccine. Several experimental vaccines have been tested in preclinical models and some have undergone clinical trials. The challenges related to the development of cheaper, safer and more effective vaccines for use in both humans and horses are likely to be overcome by new technological developments in the field of vaccinology.

  8. A Review of Vaccine Approaches for West Nile Virus

    PubMed Central

    Iyer, Arun V.; Kousoulas, Konstantin G.

    2013-01-01

    The West Nile virus (WNC) first appeared in North America in 1999. The North American lineages of WNV were characterized by the presence of neuroinvasive and neurovirulent strains causing disease and death in humans, birds and horses. The 2012 WNV season in the United States saw a massive spike in the number of neuroinvasive cases and deaths similar to what was seen in the 2002–2003 season, according to the West Nile virus disease cases and deaths reported to the CDC by year and clinical presentation, 1999–2012, by ArboNET (Arboviral Diseases Branch, Centers for Disease Control and Prevention). In addition, the establishment and recent spread of lineage II WNV virus strains into Western Europe and the presence of neurovirulent and neuroinvasive strains among them is a cause of major concern. This review discusses the advances in the development of vaccines and biologicals to combat human and veterinary West Nile disease. PMID:24025396

  9. Nile delta: Recent geological evolution and human impact

    SciTech Connect

    Stanley, D.J.; Warne, A.G. )

    1993-04-30

    Few countries in the world are as dependent on water from a single source as Egypt. The natural Nile cycle of flow and sediment discharge has been disrupted by human intervention, including closure of the High Aswan Dam; this intervention has resulted in a series of responses that now threaten the northern Nile delta. Erosion, salinization, and pollution are inducing a marked decline in agricultural productivity and loss of land and coastal lagoons at a time when the population is expanding exponentially. Geological analyses of radiocarbon-dated cores across the northern delta are used to interpret the interaction of sea-level changes, climatic oscillations, subsidence, and transport processes during the past 35,000 years. Recognition of long-term trends of these natural factors provides a basis to evaluate the profound impact of human activity and to assess future changes in the Nile delta ecosystem.

  10. The first reported case of West Nile encephalitis in Korea.

    PubMed

    Hwang, Jihye; Ryu, Ho-Sung; Kim, Hyunjin; Lee, Sang-Ahm

    2015-03-01

    West Nile encephalitis was first identified in 1937, but until now, it was never diagnosed in Korea. A 58-yr-old Korean man was admitted with headache and cognitive dysfunction. The patient had been on a business trip in Guinea. Cerebrospinal fluid (CSF) showed pleocytosis. The patient complained of both leg weakness,and arachnoiditis and myelitis were observed on lumbar magnetic resonance imaging (MRI). A specific neutralizing antibody for West Nile virus was positive in serum. After a treatment with interferon-α 3mu, follow up CSF findings recovered completely after 3 months later. The first case of West Nile encephalitis in Korea was imported from Guinea, and was cured successfully.

  11. The Fed's Year of Transition

    ERIC Educational Resources Information Center

    Schug, Mark C.; Niederjohn, Scott

    2006-01-01

    The purpose of this article is to: (1) Examine the historical development of the Federal Reserve System; (2) Provide background on Ben Bernanke, the new Fed chairman; (3) Explain the basic tools of monetary policy used by the Fed; (4) Examine the causes of the Great Depression, a topic of special interest to Bernanke; and (5) Provide some key…

  12. Development of effective therapies against West Nile virus infection.

    PubMed

    Diamond, Michael S

    2005-12-01

    Since its entry into North America in 1999, West Nile virus has spread throughout the USA and Canada, and now annually causes a clinical spectrum of human disease ranging from a self-limiting acute febrile illness to potentially lethal encephalitis. Although no therapy is currently approved for use in humans, several strateg