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Sample records for culuwiya tilapiae nasir

  1. The Comparative Study of Morals and Democracy and Their Effect on the Behavioral Reflections of Khawaja Nasir Al-Din Tusi and John Dewey

    Science.gov (United States)

    Mirzaei, Khalil; Golestani, Sayyed Hashem; Vaezi, Sayyed Hossain

    2016-01-01

    This study was aimed at comparatively analyzing morals and democracy from John Dewey and Khawaja Nasir al-Din Tusi's viewpoint. It also sought the effect of the two philosophers' viewpoint about morals and democracy and behavioral reflections. The purpose of this study was also to become familiar with the effect of morals and democracy on…

  2. La imagen del Miramamolín al Nasir (1199-1213 en las fuentes cristianas del siglo XIII

    Directory of Open Access Journals (Sweden)

    Alvira Cabrer, Martín

    1996-12-01

    Full Text Available In contemporary Christian sources, the images of the Almohade calif Muhammad al-Nasir, the defeated Miramamolin in great battle of Las Navas de Tolosa (1212, make possible to notice mental and ideological notions shared by the Medieval West of Xlllth Century. For the Europeans, the fear to the powerful Almohade Empire reflected by sources was employed by some chroniclers, with a propagandistic intention, to improve Spanish Crusade or disparage the political and religious enemies of Papacy. For the Spaniards, the al-Nasir's image refered to his role in the campaign of 1212. About the Miramamolin, the chroniclers projected the image of "the other one" supported by the ideology of war in Christian West. Thus, the victorious king's virtues, Alphonse VIII of Castille —faith, humility, courage, loyalty and generosity— opposed to the defeated calif's vices —unbelief, pride, cowardice, disloyalty and covetousness—, generating two opposite models wich purpose was, on the one hand, to exalte the victorious Christians and, on the other hand, to create an explicative recourse of religious and providencial character for, in the chroniclers's mentality, to make sense out of the cause of Muslim desaster in the battle of 1212.[fr] Dans les sources chrétiennes contemporaines, les images du caliphe almohade Muhammad al-Nasir, le Miramamolin vaincu dans la grinde bataille de Las Navas de Tolosa (1212, permettent d'observer des notions mentales et idéologiques partagées par l'Occident médiéval du XIIIe siècle. Pour l'Europe en général, la crainte au puissant Empire Almohade que reflètent les sources, servit à certains chroniqueurs, avec un esprit propagandiste, à favoriser la Croisade d'Espagne ou à enlever le prestige aux ennemis religieuse et politiques de la Papauté. Pour les espagnols, l'image de al-Nasir se centra en son rôle pendant la campagne de 1212. Sur le Miramamolin, les chroniqueurs projetèrent l'image de "l'autre" qui soutenait

  3. Tilapia: environmental and nutritional requirements

    Science.gov (United States)

    Tilapia are an important species to global aquaculture production. Their adaptability to a wide range of environmental and nutritional conditions and their ability to grow and reproduce make them a prime species for aquaculture. Nonetheless, to achieve maximum performance in culture, tilapia requir...

  4. Tilapia culture in Kuwait: constraints and solutions

    OpenAIRE

    Ridha, M.T.

    2006-01-01

    Tilapia farming in Kuwait is in its early stages. Slow growth, high production cost and poor demand are the major constraints to the expansion of tilapia culture in Kuwait. This article presents some suggestions for overcoming these problems to improve the economic feasibility of tilapia culture in Kuwait.

  5. pyrene on its expression in Nile tilapia

    African Journals Online (AJOL)

    FMV

    2013-11-27

    Nov 27, 2013 ... Full Length Research Paper ... The full-length cDNA was 2107 base pair ... amino acid sequence of Nile tilapia CYP1B1 shows similarities of 79.7, 70.3, 65.7, 65.4, 65.0 ... was determined in liver, intestine and muscle of tilapia.

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

    Science.gov (United States)

    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...

  7. Complete mitochondrial genome of Zebra tilapia, Tilapia buttikoferi.

    Science.gov (United States)

    Mu, Xi-Dong; Liu, Chao; Wang, Xue-Jie; Liu, Yi; Hu, Yin-Chang; Luo, Jian-Ren

    2016-01-01

    We determined the complete mitochondrial genome of Tilapia buttikoferi, which was 16,577 bp in length with an A + T content of 53.0%, containing 13 protein-coding genes, 2 rRNAs, 22 tRNAs and a complete control region. The gene arrangement was similar to that of typical fishes. The total base composition of the mitogenome was 25.6% T, 30.8% C, 27.4% A and 16.2% G. Of the 13 protein-coding genes, 12 genes start with an ATG codon, except for COX1 with GTG. Seven (ND1, ND2, COX1, ATPase8, ATPase6, ND4L and ND6) used TAA or AGA as the termination codon, whereas six (COX2, COX3, ND3, ND4, ND5 and cyt b) had incomplete stop codon T. Its control region was atypical in being short at 861 bp, and contained TACAT motif and one microsatellite-like region (TA)7. This mitogenome sequence data may be useful for phylogenetic and systematic analyses within the family Cichlaidae.

  8. Low-fat frankfurters from protein concentrates of tilapia viscera and mechanically separated tilapia meat

    OpenAIRE

    Cavenaghi-Altemio, Angela D; Alcade, Lígia B; Gustavo G. Fonseca

    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 ...

  9. Production of Genetically Improved Organic Nile Tilapia

    NARCIS (Netherlands)

    Charo, H.; Komen, J.; Bovenhuis, H.; Rezk, M.A.; Ponzoni, R.W.

    2008-01-01

    Demand for organic products for human consumption has been on the increase due to the belief that organic products are safer and healthier to the consumer and the environment. In developing countries, Nile tilapia (Oreochromis niloticus) is usually grown in low-input organically fed ponds with littl

  10. Use of probiotics in diets of Tilapia

    Science.gov (United States)

    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 ...

  11. A review of piscine islet xenotransplantation using wild-type tilapia donors and the production of transgenic tilapia expressing a "humanized" tilapia insulin.

    Science.gov (United States)

    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.

  12. Heritability of cold tolerance in Nile tilapia, Oreochromis niloticus, juveniles

    NARCIS (Netherlands)

    Charo-Karisa, H.; Rezk, M.A.; Bovenhuis, H.; Komen, J.

    2005-01-01

    The inability of tilapia to tolerate low temperatures is of major economic concern as it reduces their growing season and leads to over winter mortality. In this study, cold tolerance of juvenile Nile tilapia, Oreochromis niloticus, was investigated and heritability estimates obtained. A total of 80

  13. Parasite treatment reduced Flavobacterium columnare infection in tilapia

    Science.gov (United States)

    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...

  14. Business plan Tilapia cage farming in Tete Zambezi Valley, Mozambique

    NARCIS (Netherlands)

    Meer, van der Magnus; Brouwer, Herman

    2015-01-01

    Tete province offers great opportunities for cage farming of tilapia in Lake Cahora Bassa. The climate and water quality are favourable for fish production, and the fast economic developments in the region will facilitate fish sales. In Tete tilapia (pende) is highly valued food. Major markets for t

  15. Signatures of selection in tilapia revealed by whole genome resequencing.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 ...

  17. Technical evaluation of tilapia (Oreochromis niloticus) monoculture and tilapia-prawn (Macrobrachium rosenbergii) polyculture in earthen ponds with or without substrates for periphyton development

    NARCIS (Netherlands)

    Uddin, S.; Farzana, A.; Fatema, M.K.; Azim, M.E.; Wahab, M.A.; Verdegem, M.C.J.

    2007-01-01

    The effects of periphyton grown on bamboo substrate, on growth and production of Nile tilapia, Oreochromis niloticus (Genetically Improved Farmed Tilapia strain) in monoculture and polyculture with the freshwater prawn (Macrobrachium rosenbergii) were studied and economically evaluated. The experime

  18. Sublethal effects of industrial chemicals on fish fingerlings ( Tilapia ...

    African Journals Online (AJOL)

    Sublethal effects of industrial chemicals on fish fingerlings ( Tilapia guineensis ) ... African Journal of Biotechnology ... sublethal concentrations (1.56, 3.13 mg/l) of neatex (industrial detergent) and norust CR 486 (corrosion inhibitor) using the ...

  19. Estimation of water pollution by genetic biomarkers in tilapia and ...

    African Journals Online (AJOL)

    GREGO

    2007-04-02

    Apr 2, 2007 ... Key words: Water pollution, heavy metals, metalothionein, catfish, tilapia, real time, PCR, GOT, GPT, acid phosphatase. ... estimate the effect of heavy metals pollutants as indica- ..... Sublethal effects of toxic chemicals on.

  20. Shelflife of whole fresh Lake Malawi tilapia ( Oreochromis species ...

    African Journals Online (AJOL)

    Shelflife of whole fresh Lake Malawi tilapia ( Oreochromis species – Chambo ) stored ... African Journal of Food, Agriculture, Nutrition and Development ... However, as a highly perishable commodity, knowledge regarding how long fresh fish ...

  1. PCR-cloning of tilapia ATP7A cDNA and its mRNA levels in tissues of tilapia following copper administrations.

    Science.gov (United States)

    Chen, Dong Shi; Chan, King Ming

    2011-10-01

    We are studying the toxicity of copper to tilapia and zebrafish and have found that the copper tolerance of tilapia and the sensitivity of zebrafish were due to several proteins' regulation mechanisms that were related to the effects of reactive oxygen species, mitochondrion copper transport, and stress response. To further reveal the mechanism of copper tolerance and sensitivity in tilapia and zebrafish, a full length cDNA of ATP7A was obtained in tilapia. Using real time quantitative PCR, the differential regulations of ATP7A in tilapia and zebrafish were studied. It was found that Cu(2+) gave a higher induction of ATP7A in tilapia than zebrafish, both in vivo and in vitro. These results suggest that the copper tolerance of tilapia may be due to higher expression level of ATP7A.

  2. NUTRITIVE COMPOSITION OF RED TILAPIA REARED IN FRESHWATER AND BRACKISHWATER

    Directory of Open Access Journals (Sweden)

    Raden Roro Sri Pudji Sinarni Dewi

    2012-06-01

    Full Text Available The aim of this research was to investigate the nutritive composition (especially fatty acids in red tilapia that was reared in freshwater and brackishwater. The fatty acid contents were determined by gas chromatography. The fatty acids profile were -3 (linolenic acid, eicosapentaenoic acid/EPA, docosahexaenoic acid/DHA, -6 (linoleic acid, arachidonic acid/AA, and -9 (oleic acid. Red tilapia samples were obtained from Research Institute for Fish Breeding, Sukamandi, West Java (freshwater ponds and Congot, Yogyakarta (brackishwater ponds; salinity 20 ppt. In this research, red tilapia reared in different ecosystems showed different fatty acid profiles. Red tilapia inhabiting brackishwater ecosystem has EPA (0.26±0.05%, DHA (3.42±0.26%, and linoleic acid (17.20±0.56% content higher than freshwater ecosystem (EPA = 0%; DHA = 0.67±0.44%; linoleic acid = 9.08±4.76%, except for linolenic acid (0.30±0.15% vs 0.25±0.10%, arachidonic acid (0.77±0.39% vs 0.93±0.13% and oleic acid (38.67±2.58% vs 37.44±0.74%. The ratio of -6/-3 in red tilapia inhabiting freshwater ecosystem was about 11/1. The culture tilapia in brackishwater ecosystem decrease -6/-3 ratio (4.5:1. So that for human health, it will be better to consume brackishwater red tilapia than freshwater red tilapia.

  3. DNA fingerprinting of salinity resistance of full-sib Nile tilapia, Blue ...

    African Journals Online (AJOL)

    ******

    2012-05-01

    May 1, 2012 ... marine and brackish environments for aquaculture become a vital alternative ... Egypt. Fry production. Purebred of each Nile tilapia, O. niloticus and Blue tilapia, O. ..... considers a great potential for the development and.

  4. Adropin induction of lipoprotein lipase expression in tilapia hepatocytes.

    Science.gov (United States)

    Lian, Anji; Wu, Keqiang; Liu, Tianqiang; Jiang, Nan; Jiang, Quan

    2016-01-01

    The peptide hormone adropin plays a role in energy homeostasis. However, biological actions of adropin in non-mammalian species are still lacking. Using tilapia as a model, we examined the role of adropin in lipoprotein lipase (LPL) regulation in hepatocytes. To this end, the structural identity of tilapia adropin was established by 5'/3'-rapid amplification of cDNA ends (RACE). The transcripts of tilapia adropin were ubiquitously expressed in various tissues with the highest levels in the liver and hypothalamus. The prolonged fasting could elevate tilapia hepatic adropin gene expression, whereas no effect of fasting was observed on hypothalamic adropin gene levels. In primary cultures of tilapia hepatocytes, synthetic adropin was effective in stimulating LPL release, cellular LPL content, and total LPL production. The increase in LPL production also occurred with parallel rises in LPL gene levels. In parallel experiments, adropin could elevate cAMP production and up-regulate protein kinase A (PKA) and PKC activities. Using a pharmacological approach, cAMP/PKA and PLC/inositol trisphosphate (IP3)/PKC cascades were shown to be involved in adropin-stimulated LPL gene expression. Parallel inhibition of p38MAPK and Erk1/2, however, were not effective in these regards. Our findings provide, for the first time, evidence that adropin could stimulate LPL gene expression via direct actions in tilapia hepatocytes through the activation of multiple signaling mechanisms.

  5. Fecal strings Associated with Streptococcus agalactiae Infection in Nile Tilapia, Oreochromis niloticus

    Science.gov (United States)

    Nile tilapia (Oreochromis niloticus) were experimentally-infected with Streptococcus agalactiae for several infectivity and vaccine studies. Some of the S. agalactiae-infected tilapia produced considerably longer (up to 20 cm in length) fecal waste strings than historically observed from tilapia at...

  6. Natural mating in Nile tilapia (Oreochromis niloticus L.) : implications for reproductive success, inbreeding and cannibalism

    NARCIS (Netherlands)

    Fessehaye, Y.

    2006-01-01

    Niletilapia ( Oreochromis niloticus L.) is one of the most important species among the commercially farmed tilapias. Both small-scale and commercial production of tilapia is rapidly expanding in many countries of the world because t

  7. Natural mating in Nile tilapia (Oreochromis niloticus L.) : implications for reproductive success, inbreeding and cannibalism

    NARCIS (Netherlands)

    Fessehaye, Y.

    2006-01-01

    Niletilapia ( Oreochromis niloticus L.) is one of the most important species among the commercially farmed tilapias. Both small-scale and commercial production of tilapia is rapidly expanding in many countries of the world because t

  8. Streptococcus agalactiae infection in tilapia (Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Suanyuk, N.

    2005-02-01

    Full Text Available Streptococcus agalactiae was isolated from cultured tilapia in Surat Thani province. Isolates were Gram-positive cocci, catalase negative, alpha-haemolytic and serogroup B. Streptococcal-infected fish showed various swimming abnormalities such as swimming on their side, erratic surface or bottom swimming including serpentine movement, exophthalmia and opacity. Internally, splenomegaly, ascites as well as pale liver discoloration were observed. Fish experimentally infected by peritoneal injection using 101 -108 CFU/ fish showed 20-90% mortality within 10 days and the LD50 was 3.60x101 - 1.72x107 CFU. Haematocrit, haemoglobin, plasma protein and blood cell values of infected and moribund fish were significantly decreased. Histopathological findings included the occurrence of inflammation, cells necrosis, infiltration of lymphocytes and the formation of granulomas in the infected organs.

  9. 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.

    Science.gov (United States)

    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.

  10. Identification of SNARE proteins in fish-Tilapia Oreochromis niloticus

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiaohang; LAM Patrick P L; LIN Xuezheng; LIU Chenlin; BIAN Ji; GAISANO Herbert

    2007-01-01

    SNARE proteins are a group of membrane-associated proteins involved in exocytosis, secretion and membrane trafficking events in eukaryotic cells. Research on SNARE protein biology has become a more attractive field in recent years, which is applied to marine biology specifically to the fish Tilapia (Oreochromis niloticus). Plasma membrane fractions of different tissues of Tilapia, including brain, liver-pancreas, intestine, skin and muscle, were extracted, and immuno-decorated with isoform-specific antibodies to the SNARE families and associated proteins. The presence of Syntaxins -1A, 2 and 3, SNAP-23 and SNAP-25, VAMP-2, Munc-18-1 and Munc-13 in the brain was identified, which were differentially distributed in the other organ tissues of the fish Tilapia. The distinct distribution of SNARE and associated proteins will serve as the basis for further investigation into their special secretory function in these tissues of the fish.

  11. Habitat associations, reproduction and diet of the Guinean tilapia Tilapia guineensis of the Gambia River floodplains.

    Science.gov (United States)

    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.

  12. Low-fat frankfurters from protein concentrates of tilapia viscera and mechanically separated tilapia meat.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  14. Use of coffee pulp as feed ingredient for tilapia culture

    NARCIS (Netherlands)

    Ulloa Rojas, J.B.

    2002-01-01

    This research focused on the feasibility of using coffee pulp (CoP) in diets for tilapia ( Oreochromis aureus ). First, a literature survey analyzed the limitations of CoP as an animal foodstuff (several antinutritional factors: ANF's, and high fibre contents),

  15. Use of coffee pulp as feed ingredient for tilapia culture

    NARCIS (Netherlands)

    Ulloa Rojas, J.B.

    2002-01-01

    This research focused on the feasibility of using coffee pulp (CoP) in diets for tilapia ( Oreochromis aureus ). First, a literature survey analyzed the limitations of CoP as an animal foodstuff (several antinutritional factors: ANF's, and high fibre contents), different ways to upgrade the CoP nutr

  16. Histological Changes of Liver in Overfed Young Nile Tilapia

    NARCIS (Netherlands)

    Taddesse, F.; Huh, M.D.; Bai, S.C.; Vijverberg, J.

    2014-01-01

    We investigated histopathologically liver structural responses of Nile Tilapia Oreochromis niloticus towards overfeeding. Mixed population of O. niloticus with mean weight of 55±3.83 g was acclimated for one week. Then, the fish were separated into control and treatment groups. Glass aquariums with

  17. Morphological variation of Nile tilapia populations from major water ...

    African Journals Online (AJOL)

    ACSS

    1Aquaculture Research and Development Center, Kajjansi, Box 530, ... important to establish the existing strains in a manner that is phenotypically discernible where ... morphological variation among the different populations of Nile tilapia and the fish could be grouped ..... Evolutionary history of Nile perch Lates sp. inferred.

  18. Growth performance and feed utilization of Tilapia zillii (Gervais ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-06

    Jul 6, 2009 ... of Tilapia zillii fed diets where poultry by-product meal replaced fish meal protein at 0, 50 and 100% levels in high ... product meal and meat and bone meal have high protein contents .... A similar trend was observed in diet.

  19. Bacteria Associated with Fresh Tilapia Fish (Oreochromis niloticus ...

    African Journals Online (AJOL)

    acer

    Available online at http://ajol.info/index.php/njbas/index. Nigerian ... Central Market in Sokoto, Nigeria. S.A. Shinkafi and V.C. ... The isolates were found to be of medical importance. Keywords: Bacteria, Tilapia fish and Sokoto central market.

  20. Identification of a novel RNA virus lethal to tilapia.

    Science.gov (United States)

    Eyngor, Marina; Zamostiano, Rachel; Kembou Tsofack, Japhette Esther; Berkowitz, Asaf; Bercovier, Hillel; Tinman, Simon; Lev, Menachem; Hurvitz, Avshalom; Galeotti, Marco; Bacharach, Eran; Eldar, Avi

    2014-12-01

    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.

  1. Stocking rate effects in a tilapia biofloc production system

    Science.gov (United States)

    Production efficiency is improved when the culture organism can grow rapidly to the desired target weight. Stocking rate is known to affect fish growth, but little information is available for tilapia grown in a biofloc technology (BFT) production system. The objective of this study was to quantify ...

  2. Impacts of parasite infection on columnaris disease of tilapia

    Science.gov (United States)

    There is no information available on whether parasite infection will increase the susceptibility of tilapia to Flavobacterium columnare and whether parasite treatment could improve fish survival after F. columnare exposure. Two trials were conducted to evaluate 1) the susceptibility of hybrid tilapi...

  3. Social dominance in tilapia is associated with gonadotroph hyperplasia.

    Science.gov (United States)

    Golan, Matan; Levavi-Sivan, Berta

    2013-10-01

    Tilapias are emerging as one of the most important fish in worldwide aquaculture and are also widely used as model fish in the study of reproduction and behavior. During the reproductive season, male tilapia are highly territorial and form spawning pits in which the dominant males court and spawn with available females. Non-territorial males stand a much lower chance of reproducing. Using transgenic tilapia in which follicle stimulating hormone (FSH) gonadotrophs were fluorescently labeled with enhanced green fluorescent protein (EGFP), we studied the effect of social dominance on the hormonal profile and pituitary cell populations in dominant and non-dominant males. Immunofluorescence studies showed that FSH-EGFP-transgenic fish reliably express EGFP in FSH-secreting cells. EGFP expression pattern differed from that of luteinizing hormone. Dominant males had larger gonads as well as higher levels of androgens and gonadotropins in the plasma. Pituitaries of dominant males exhibited higher gonadotropin content and gene expression. Flow cytometry revealed pituitary hyperplasia as well as FSH cell hyperplasia and increased granulation. Taken together, these findings suggest that gonadotroph hyperplasia as well as increased production by individual cells underlie the increased reproductive activity of dominant tilapia males.

  4. Optimisation of selective breeding program for Nile tilapia (Oreochromis niloticus)

    NARCIS (Netherlands)

    Trong, T.Q.

    2013-01-01

      The aim of this thesis was to optimise the selective breeding program for Nile tilapia in the Mekong Delta region of Vietnam. Two breeding schemes, the “classic” BLUP scheme following the GIFT method (with pair mating) and a rotational mating scheme with own performance selection

  5. Breeding for improved production of Nile tilapia (Oreochromis niloticus L.)

    NARCIS (Netherlands)

    Rutten, M.J.M.

    2005-01-01

    The aim of this thesis was to generate knowledge that supports the design of breeding programs for Nile tilapia targeting genetic improvement of body weight and fillet yield to serve the European market. To this end, both the genetic variation and the performance levels of different strains of tilap

  6. Human Streptococcus agalactiae Isolate in Nile Tilapia (Oreochromis niloticus)

    OpenAIRE

    Evans, Joyce J.; Phillip H. Klesius; Pasnik, David J.; Bohnsack, John F.

    2009-01-01

    Streptococcus agalactiae, the Lancefield group B streptococcus (GBS) long recognized as a mammalian pathogen, is an emerging concern with regard to fish. We show that a GBS serotype Ia multilocus sequence type ST-7 isolate from a clinical case of human neonatal meningitis caused disease and death in Nile tilapia (Oreochromis niloticus).

  7. Business plan Tilapia Pond Farming in the Zambezi Valley, Mozambique

    NARCIS (Netherlands)

    Brouwer, Herman; Meer, van der Magnus

    2015-01-01

    This business plan has been prepared for local entrepreneurs who would like to expand their business portfolio or to start a value chain business in the aquaculture sector in the Zambezi Valley, Mozambique.

    Freshwater aquaculture in Mozambique consists mainly of small-scale tilapia producti

  8. Exceptional cardiac anoxia tolerance in tilapia (Oreochromis hybrid).

    Science.gov (United States)

    Lague, Sabine L; Speers-Roesch, Ben; Richards, Jeffrey G; Farrell, Anthony P

    2012-04-15

    Anoxic survival requires the matching of cardiac ATP supply (i.e. maximum glycolytic potential, MGP) and demand (i.e. cardiac power output, PO). We examined the idea that the previously observed in vivo downregulation of cardiac function during exposure to severe hypoxia in tilapia (Oreochromis hybrid) represents a physiological strategy to reduce routine PO to within the heart's MGP. The MGP of the ectothermic vertebrate heart has previously been suggested to be ∼70 nmol ATP s(-1) g(-1), sustaining a PO of ∼0.7 mW g(-1) at 15°C. We developed an in situ perfused heart preparation for tilapia (Oreochromis hybrid) and characterized the routine and maximum cardiac performance under both normoxic (>20 kPa O(2)) and severely hypoxic perfusion conditions (tilapia heart maintained a routine normoxic cardiac output (Q) and PO under all hypoxic conditions, a result that contrasts with the hypoxic cardiac downregulation previously observed in vivo under less severe conditions. Thus, we conclude that the in vivo downregulation of routine cardiac performance in hypoxia is not needed in tilapia to balance cardiac energy supply and demand. Indeed, the MGP of the tilapia heart proved to be quite exceptional. Measurements of myocardial lactate efflux during severe hypoxia were used to calculate the MGP of the tilapia heart. The MGP was estimated to be 172 nmol ATP s(-1) g(-1) at 22°C, and allowed the heart to generate a PO(max) of at least ∼3.1 mW g(-1), which is only 30% lower than the PO(max) observed with normoxia. Even with this MGP, the additional challenge of acidosis during severe hypoxia decreased maximum ATP turnover rate and PO(max) by 30% compared with severe hypoxia alone, suggesting that there are probably direct effects of acidosis on cardiac contractility. We conclude that the high maximum glycolytic ATP turnover rate and levels of PO, which exceed those measured in other ectothermic vertebrate hearts, probably convey a previously unreported anoxia tolerance

  9. PROPOLIS, THE ALTERNATIVE NATURAL MATERIAL FOR SEX REVERSAL IN TILAPIA

    Directory of Open Access Journals (Sweden)

    Didik Ariyanto

    2012-12-01

    Full Text Available Growth of tilapia male is better than female. Practically, cultured of all male population are more efficient than that of mixed sex population. Sex reversal with 17-methyltestosterone hormone is the most popular technique to make all or nearly all male tilapia. But, alternative substitution materials for sex reversal must be found due to limited application of this synthetic hormone that caused of its carcinogenic potential on human body. Besides that, 17-methyltestosterones are also suspected as the unfriendly material for environment. Several early studies were conducted to find the alternative materials for sex reversal in tilapia. One of the highly potential material found is aromatase inhibitors, the materials which are function to inhibit the secretion of aromatase, the catalyst enzyme in the bio-synthetic of estrogen from androgen. Due to the chemical characteristic materials and relatively high price of aromatase inhibitor, we tried to find the natural material which has similar composition or function to that compound. One of the natural suspected materials which has similar function with aromatase inhibitors is propolis. Chrysin as apart of flavonoid compound found in the propolis shows the most potent inhibitors of aromatase. Early study showed that application of propolis up to 3 mL.kg-1 of feed resulted the highest percentage of male in tilapia. Based on that study, the optimum dosage of propolis for sex reverse of the tilapia has not been known. This study was conducted to know the optimum dosage of a commercial propolis for sex reversal in tilapia, especially in NIFI red tilapia. The dosages proposed in this study were 3, 4, 5 and 6 mL propolis.kg-1 of feed. Sex reversal was carried out in aquarium for 35 days. Rearing of fingerling fish for 2 months was conducted in hapas suspended in earthen pond. The result showed that application of 5 mL propolis.kg-1 of feed resulted the highest proportion of male

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

    Science.gov (United States)

    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.

  11. Does feeding frequency affect utilization of added amino acids in Nile tilapia?

    OpenAIRE

    Hoque, Rezaul; Bajgai, Biswas

    2014-01-01

    Nile tilapia (Oreochromis niloticus) is one of the major farmed fish species, with main production in Asia, South and Central America that can tolerate a wide range of environmental stress and easily adapt with low quality of feed ingredients. The aims of the experiments were to determine effects of feeding frequency on utilization of protein and energy in Nile tilapia, to quantify differences in excretion of ammonia and ammonium in Nile tilapia fed the same daily ration, distributed over 2 a...

  12. Environmental color affects Nile tilapia reproduction

    Directory of Open Access Journals (Sweden)

    Volpato G.L.

    2004-01-01

    Full Text Available We investigated the effects of environmental color on the reproductive behavior of Nile tilapia, Oreochromis niloticus. Two environmental colors were tested by covering the aquarium (60 x 60 x 40 cm with white (12 groups or blue (13 groups cellophane and observing reproductive behavior in groups of 2 males (10.27 ± 0.45 cm and 3 females (10.78 ± 0.45 cm each. After assignment to the respective environmental color (similar luminosity = 100 to 120 Lux, the animals were observed until reproduction (identified by eggs in the female's mouth or up to 10 days after the first nest building. Photoperiod was from 6:00 h to 18:00 h every day. Food was offered in excess once a day and water quality was similar among aquaria. Daily observations were made at 8:00, 11:00, 14:00 and 17:00 h regarding: a latency to the first nest, b number of nests, c gravel weight removed (the male excavates the nest in the bottom of the aquarium, d nest area, and e mouthbrooding incubation (indication of reproduction. The proportion of reproducing fish was significantly higher (6 of 13 in the group exposed to the blue color compared the group exposed to the white color (1 of 12; Goodman's test of proportions. Moreover, males under blue light removed significantly larger masses of gravel (blue = 310.70 ± 343.50 g > white = 130.38 ± 102.70 g; P = 0.01 and constructed wider nests (blue = 207.93 ± 207.80 cm² > white = 97.68 ± 70.64 cm²; P = 0.03 than the control (white. The other parameters did not differ significantly between light conditions. We concluded that reproduction in the presence of blue light was more frequent and intense than in the presence of white light.

  13. Current Situation and Problems of Export-oriented Tilapia Processing in Guangxi and Countermeasures

    Institute of Scientific and Technical Information of China (English)

    Ying; ZHANG; Gaozhong; JIANG; Qiong; ZHANG

    2014-01-01

    Guangxi Zhuang Autonomous Region is an excellent area for tilapia breeding in China,and the development of tilapia industry has received high attention of both the state and Guangxi government. The foreign exchange earning is an essential industrial form of tilapia industry in Guangxi. Thus,enhancing the competitiveness of export-oriented tilapia processing is of great significance to the development of tilapia industry. On the basis of field survey,this paper analyzed current situation of export-oriented tilapia processing in Guangxi. At present,tilapia processing industry in Guangxi has realized preliminary standardization,large-scale and grouping,but it is still faced with some problems and challenges,such as low industrialization level,no balanced marketing,and imperfect product quality safety monitoring measures. Therefore,it is required to create favorable environment for export-oriented tilapia processing industry in Guangxi through enhancing policy support,increasing financial input and supporting tilapia processing leading enterprises.

  14. Molecular characterization and functional analysis of IRF3 in tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Gu, Yi-Feng; Wei, Qun; Tang, Shou-Jie; Chen, Xiao-Wu; Zhao, Jin-Liang

    2016-02-01

    Interferon regulatory factor 3 (IRF3) plays a key role in interferon (IFN) response and binding to the IFN stimulatory response elements (ISREs) within the promoter of IFN and IFN-stimulated genes followed by virus infection. In the current study, we discovered one IRF3 homologue in tilapia genome and analyzed the characterizations and functions of tilapia IRF3. Tilapia IRF3 contains 1368 bp with an ORF of 455 aa. Structurally, tilapia IRF3 protein typically shares the conserved characterizations with other species' IRF3 homologues, displaying conserved DNA-binding domain, IRF association domain, serine-rich C terminal domain, and tryptophan residue cluster. Phylogenetic analysis illustrated that tilapia IRF3 belongs to the IRF3 subfamily. Real-time PCR revealed a broad expression pattern of tilapia IRF3 in various tissues. Subcellular localization analysis showed that tilapia IRF3 mainly resides in the cytoplasm, Western blot demonstrated that IRF3 was distributed in the cytoplasmic fraction. Functionally, IRF3 was found to be transcriptionally up-regulated by the poly I:C stimulation. Moreover, reporter assay elucidated that tilapia IRF3 serves as a regulator in mediating IFN response by increasing the activity of IFN-β and ISRE-containing promoter. These data supported the view that tilapia IRF3 is a potential molecule in IFN immune defense system against viral infection.

  15. Corticotropin-releasing hormone in the teleost stress response: rapid appearance of the peptide in plasma of tilapia (Oreochromis mossambicus).

    NARCIS (Netherlands)

    Pepels, P.P.L.M.; Helvoort, H.A.C. van; Wendelaar Bonga, S.E.; Balm, P.H.

    2004-01-01

    High concentrations (up to 600 pg/ml) of corticotropin-releasing hormone (CRH) were detected in plasma of the teleost fish Oreochromis mossambicus (tilapia) when screening peripheral tissues of tilapia exposed to stress. Notably, the plasma CRH response to stressors in tilapia is much more pronounce

  16. Corticotropin-releasing hormone in the teleost stress response: rapid appearance of the peptide in plasma of tilapia (Oreochromis mossambicus)

    NARCIS (Netherlands)

    Pepels, P.P.L.M.; Helvoort, H.A.C. van; Wendelaar Bonga, S.E.; Balm, P.H.M.

    2004-01-01

    High concentrations (tip to 600 pg/ml) of corticotropin-releasing hormone (CRH) were detected in plasma of the teleost fish Oreochromis mossambicus (tilapia) when screening peripheral tissues of tilapia exposed to stress. Notably, the plasma CRH response to stressors in tilapia is much more pronounc

  17. The culture of Tilapia species in tropical and subtropical conditions

    Directory of Open Access Journals (Sweden)

    De Maeseneer, J.

    1984-01-01

    Full Text Available Although since long known by African fishermen it is only in the last 40 years that Tilapia has been recognized as one of the most promising groups of fish species for culture. The initial successes for culture in Central Africa were followed by several failures mainly because of excessive breeding and early sexual maturity in shallow waterbodies as ponds. From the present knowledge it appears that tilapia has a great future for increasing the productivity in unmanaged environments as man-made lakes and reservoirs primarily destined for the production of hydro-electricity. Careful stocking of paddies and irrigation canals can solve a number of biological problems associated with them and provide an additional though valuable high-protein food source. Great future offers also the culture of tilapia in traditional pond culture especially in polyculture with members of the carp family, mullets and waterfowl in areas of the tropical and subtropical belt. In coastal ponds T, mossambica is a valuable species for sanitary reasons. The culture of tilapia in small farm ponds often meets with failure owing to excessive breeding and stunting unless the all-male technique can be applied through government input and encouragement. As a rule this type of production will be the least attractive. Although Tilapia spp. do not achieve the largest individu al growth their tolerance towards adverse conditions and their acceptance of a wide variety of foodstuffs, primarily waste products from agriculture, their resistance to diseases and (at least in some species their tolerance of crowded environments make them suitable subject for cultures in raceways, circular tanks and cages. Through heavy inputs of water and pelletized feeds nearly incredible annual yields as 2 000 tonnes per ha of water surface (1 and more were realized. This means that this type of production surpasses by far any other known form of animal husbandry but it needs high technological input (thus

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

    Science.gov (United States)

    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.

  19. Some physicochemical properties of two major soluble hepatic glutathione transferases of tilapia (Tilapia zilli).

    Science.gov (United States)

    Bamidele, Olufemi S; Kolawole, Ayodele O; Ajele, Joshua O

    2012-05-15

    Two distinct glutathione transferases from the liver of adult Tilapia zilli were identified and purified to apparent homogeneity by ion-exchange chromatography on DEAE-cellulose and by gel filtration on Sephadex G-150. These major GST forms labeled tzGST1 and tzGST2 accounted for approximately 42% of the activity detectable with 1-chloro-2,4-dinitrobenzene (CDNB) as a typical electrophilic substrate. Apparent subunit and molecular mass values, substrate specificities and sensitivity to inhibitors as well as kinetic studies were used to differentiate the GST forms. SDS/PAGE indicated subunit molecular masses of 22.0 kDa (tzGST1) and 26.1 kDa (tzGST2) while native molecular weight by gel-filtration on sephadex G-100 indicated native molecular masses of 46.8 kDa and 48.0 kDa for tzGST1 and tzGST2 respectively. They appeared to be homodimers. Inhibition studies showed that tzGST1 was more sensitive to ethacrynic acid (EA), hematin, tributyltinacetate (TBTA), triethyltinbromide (TETB), and triphenyltinchloride (TPTC) than tzGST2 with TPTC being the most potent inhibitor. T. zilli GSTs could conjugate CDNB, DCNB, ρ-NBC, and EA with GSH but displayed no observable conjugating activity with NBDCl. The K(m) and V(max) for tzGST1 and tzGST2 with CDNB were 0.56 ± 0.05 mM; 0.24 ± 0.03 μmol/min/ml and 0.91 ± 0.07 mM; 0.14 ± 0.05 μmol/min/ml respectively while K(m) and V(max) with GSH were 0.46 ± 0.02 mM; 0.19 ± 0.20 μmol/min/ml and 1.32 ± 0.15 mM; 0.21 ± 0.07 μmol/min/ml respectively. Denaturation and renaturation studies with guanidine hydrochloride (Gdn-HCl) revealed that concentration of 4.0 M Gdn-HCl completely denatured tzGST1 and the possible isoenzyme was able to renature to 92% of the original activity. The renaturation process was dependent on temperature. The outcome of this study indicated that tzGSTs are possible GST isoenzymes actively present and involve in the detoxification process in the liver of tilapia when the subject is exposed to chemical

  20. Preparation of lasagnas with dried mix of tuna and tilapia

    Directory of Open Access Journals (Sweden)

    Katia Setsuko KIMURA

    Full Text Available Abstract The aim of this study was to develop a lasagna pasta enriched with dried mix of tuna (30% and tilapia (70% and formulate ready lasagna with enriched pasta. Lasagna pasta was elaborated with increasing levels (0, 5, 10 and 15% of dried mix. Moisture, lipids and calories were not different between the inclusion levels; crude protein and ash increased linearly, carbohydrates reduced linearly, according to increasing levels of inclusion. There was an increase in n-3 and n-6 fatty acids with the inclusion of mix in lasagna. Between lasagna prepared with different sauces (tuna, chicken and bolognese, and pasta with 15% mix, it was observed that tuna lasagna had lower moisture content and higher protein, lipids, ash, carbohydrates and calories. All lasagna showed optimal sensory acceptance, indicating that the inclusion of 15% dried mix of tilapia and tuna in the pasta is feasible to improve the nutritional composition of lasagna.

  1. Partial sodium replacement in tilapia steak without loss of acceptability.

    Science.gov (United States)

    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 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.

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

    Science.gov (United States)

    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

  3. Efficacy of an experimentally inactivated Streptococcus agalactiae vaccine in Nile tilapia (Oreochromis niloticus) reared in Brazil

    Science.gov (United States)

    Tilapia aquaculture is one of the fastest growing segments of fish production in Brazil. Nile tilapia (Oreochromis niloticus) is largely cultivated in the state of Parana, where Streptococcus agalactiae is the cause of severe disease outbreaks. The objective of this paper was to evaluate an inactiva...

  4. Quality Index Method developed for gutted and ungutted red tilapia (Oreochromis ssp

    Directory of Open Access Journals (Sweden)

    Nelson Gutiérrez G.

    2015-01-01

    Full Text Available Objective. To develop a Quality Index Method (QIM for gutted and ungutted red tilapia from aquaculture ponds. Materials and methods. 40 specimens of gutted red tilapia and 40 ungutted ones were located in foam polyethylene boxes within layers of ice and storage at 4°C. Three fish were randomly sampled on days 0, 3, 5, 8, 11, 14 and 17 for gutted tilapia, and on days 0, 3, 6, 9, 11, 14 and 16 for ungutted tilapia. A sensorial panel of 8 experts was formed to evaluate the product. With three samples each day with average points of the sensorial attributes proposed in the method, the quality index for gutted and ungutted red tilapia was obtained based on the storage time on ice. Results. The Quality Index Method obtained for gutted and ungutted red tilapia showed maximum values of 21 and 29, respectively. It was adjusted in an increasing lineal model with high correlation between the Quality Index and the storage time on ice. Conclusions. The developed model is useful to determine deterioration levels and to define storage and consumption time. For gutted red tilapia the panel rejected the fish after 8 - 11 days of storage whereas the ungutted red tilapia was rejected after 6 - 9 days.

  5. Bacteriological Quality of Tilapia Fish from Treated Wastewater in Peri-Urban Areas, Morogoro, Tanzania

    DEFF Research Database (Denmark)

    Mhongole, OJ; Mdegela, RH; Kusiluka, LJM

    2016-01-01

    The aim of this study was to assess faecal bacterial contamination in tilapia fish from wastewater treatment ponds at Mzumbe and in pristine water in Mindu dam. Tilapia fish (fish flesh and fish intestines) and water samples were analysed for Escherichia coli and total plate count. The concentrat...

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

    Science.gov (United States)

    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

    2016-08-04

    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.

  7. Primer prueba de desafio controlado en tilapia del Nilo Para Resistencia a Streptococcus iniae

    Science.gov (United States)

    Intensification of tilapia production has resulted in disease outbreaks that negatively affect commercial fish farmers. One bacterial pathogen that commonly causes losses in tilapia production is Streptococcus iniae. Control and prevention of S. iniae can be difficult and requires an integrated fish...

  8. Treatment of Trichodina sp. reduced load of Flavobacterium colummnare and improved survival of hybrid tilapia

    Science.gov (United States)

    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...

  9. Nutritional Profile and Chemical Stability of Pasta Fortified with Tilapia (Oreochromis niloticus) Flour

    Science.gov (United States)

    Monteiro, Maria Lúcia G.; Mársico, Eliane T.; Soares, Manoel S.; Magalhães, Amanda O.; Canto, Anna Carolina V. C. S.; Costa-Lima, Bruno R. C.; Alvares, Thiago S.; Conte, Carlos A.

    2016-01-01

    Physicochemical parameters of pasta enriched with tilapia (Oreochromis niloticus) flour were investigated. Five formulations were prepared with different concentrations of tilapia flour as partial substitute of wheat flour: pasta without tilapia flour (PTF0%), pasta with 6% (PTF6%), 12% (PTF12%), 17% (PTF17%), and 23% (PTF23%) of tilapia flour. The formulations were assessed for proximate composition, fatty acid and amino acid profile on day 1 whereas, instrumental color parameters (L*, a* and b* values), pH, water activity (aw), and lipid and protein oxidation were evaluated on days 1, 7, 14, and 21 of storage at 25°C. Fortification with tilapia flour increased (p tilapia flour decreased (p tilapia flour than their counterparts, and the storage promoted an increase (p tilapia flour has the potential to be a technological alternative to food industry for the nutritional enrichment of traditional pasta with negligible negative effects on the chemical stability of the final product during 21 days at 25°C. PMID:27973565

  10. Dietary supplementation with arachidonic acid in tilapia (Oreochromis mossambicus) reveals physiological effects not mediated by prostaglandins.

    NARCIS (Netherlands)

    Anholt, R.D. van; Spanings, F.A.T.; Koven, W.M.; Wendelaar Bonga, S.E.

    2004-01-01

    This study aims to clarify the role of the polyunsaturated fatty acid arachidonic acid (ArA, 20:4n-6) in the stress response of Mozambique tilapia (Oreochromis mossambicus). ArA is converted into eicosanoids, including prostaglandins, which can influence the response to stressors. Tilapia, a species

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

    Science.gov (United States)

    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 ...

  12. Spring forward with improved Nile tilapia Oreochromis niloticus resistant to Streptococcus iniae and Streptococcus agalactiae IB

    Science.gov (United States)

    Tilapia aquaculture worldwide is valued around US $ 7 billion. Tilapia are an important source of protein for domestic (top 5 most consumed seafoods) and global food security. Two gram postitive bacteria, Streptococcus iniae and S. agalactiae, are responsible for billion dollar losses annually. Gen...

  13. Dietary supplementation with arachidonic acid in tilapia (Oreochromis mossambicus) reveals physiological effects not mediated by prostaglandins.

    NARCIS (Netherlands)

    Anholt, R.D. van; Spanings, F.A.T.; Koven, W.M.; Wendelaar Bonga, S.E.

    2004-01-01

    This study aims to clarify the role of the polyunsaturated fatty acid arachidonic acid (ArA, 20:4n-6) in the stress response of Mozambique tilapia (Oreochromis mossambicus). ArA is converted into eicosanoids, including prostaglandins, which can influence the response to stressors. Tilapia, a species

  14. Polyculture of Nile tilapia and shrimp at different stocking densities

    Directory of Open Access Journals (Sweden)

    Ambrosio Paula Bessa Junior

    2012-07-01

    Full Text Available This study aimed to evaluate the productivity, growth performance and economic feasibility of polyculture of Nile tilapia Oreochromis niloticus and shrimp Litopenaeus vannamei at different stocking densities. Feed was provided based on fish requirements. The experiment was conducted at the Aquaculture facility of the Universidade Federal Rural do Semi-Árido - UFERSA, in a completely randomized design with five treatments and four replicates each. Treatments consisted of a tilapia monoculture with 2 tilapias.m-2; and polyculture with 2 tilapias.m-2 and L. vannamei at four different densities (3, 6, 9 and 12 shrimps.m-2. The initial individual biomass for fish and shrimp were 1.23±0.12 g and 0.133±0.009 g, respectively. Water quality parameters, temperature, dissolved oxygen, pH and transparency were monitored. The experiment lasted 120 days and biomass gain was evaluated every two weeks. Final biomass, survival and feed conversion rates were calculated at the end of the experiment. The economic analysis showed that polyculture systems at stocking densities of nine and twelve shrimps.m-2 resulted in higher gross revenue and operational profits of 120.9% and 97.5% respectively, with mean gross return significantly higher than the monoculture. The O. niloticus and L. vannamei polyculture in oligohaline water was shown to be technically and economically feasible. These two species can be cultured together, without competing for the same resources, because they have different trophic niche, thus increasing productivity and economic returns for the farmers.

  15. Gene expression during oogenesis in the Mozambique tilapia (O. Mossambicus)

    OpenAIRE

    Domingues, Nuno Manuel Cardoso

    2007-01-01

    Dissertação de mest., Biologia Marinha, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2007 Tilapias show a variety of physiological adaptations that allow them to live in different environmental conditions, disturbing local ecosystems where they are introduced by human hand, where they reproduce at faster rates as their cycles are short and constant. They have complex behaviours, with species in the Oreochromis and Sarotherodon genus exhibiting parental c...

  16. Probiotic legacy effects on gut microbial assembly in tilapia larvae

    Science.gov (United States)

    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

  17. Agroindustrial byproducts in diets for Nile tilapia juveniles

    Directory of Open Access Journals (Sweden)

    João Sérgio Oliveira Carvalho

    2012-03-01

    Full Text Available This study was conducted to evaluate performance and body composition of tilapia (Oreochromis niloticus fed diets containing byproducts aerial parts of cassava meal (Manihot esculenta, mesquite pod meal (Prosopis juliflora, cocoa meal (Theobroma cacao and palm kernel cake (Elaeis guineensis and to analyze the economic viability of the feed. A total of 1,350 juvenile males (100 g were distributed in 15 cages (1 m³ in completely randomized design with five treatments (basal diet and four test diets and three replicates. The following aspects were evaluated: final weight, total feed intake, total weight gain, feed conversion, specific growth rate, protein efficiency ratio and survival rate, dry matter, crude protein, fat and ash body, the average cost of feed per kilogram of weight gain and economic efficiency rate. No differences were observed for total consumption of food or survival rate. For other variables, the inclusion of cocoa and cassava meal impaired fish performance. No differences were observed for dry matter, crude protein and body ash. The lower body fat accumulation was recorded for the tilapia fed palm kernel cake. The best economic indicators were found to diets containing palm kernel cake. The byproducts evaluated can be used up to 150 g/kg in feed formulation, providing good performance and economic rate for Nile tilapia.

  18. The Characterization of Fish (Tilapia Collagen Sponge as a Biomaterial

    Directory of Open Access Journals (Sweden)

    Kohei Yamamoto

    2015-01-01

    Full Text Available For scaffold manufacturing, the utility of bioactive natural organic materials derived from marine products is useful and indispensable as an alternative to bovine collagen. The weakest feature of fish collagen for scaffold application is its low degeneration temperature (Td, indicating poor stability of fish collagen in mammals in vivo. We have focused on the tropical fish tilapia as a candidate for generating a clinical scaffold. The aim of this study was to confirm the Td of tilapia type I atelocollagen (TAC for biomedical application. Furthermore, the physical and structural properties were investigated and evaluated as a scaffold on a sponge form. Different concentrations {0.5%, 1.0%, and 2.0% (v/v} of TAC solution were analyzed. Differential scanning calorimetry showed that the Td of TAC was 35-36°C. The scanning electron microscopy results indicated that the pore size (90–160 μm of TAC sponges is acceptable for cell proliferation. The tensile strength of porous sponges was in the range of 0.01–0.07 MPa. These findings indicate that the TAC sponge prepared from tilapia is one of candidates as a scaffold. The 1.0% (v/v concentration of TAC solution is especially recommended to be advantageous for preparing and handling the solution and for sponge formation.

  19. Screening and identification of a microsatellite marker associated with sex in Wami tilapia, Oreochromis urolepis hornorum

    Indian Academy of Sciences (India)

    HUAPING ZHU; ZHIGANG LIU; MAIXIN LU; FENGYING GAO; XIAOLI KE; DONGMEI MA; ZHANGHAN HUANG; IANMENG CAO; MIAO WANG

    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

  20. Current Development Situation,Problem and Countermeasures on Tilapia Seed Industry in Fujian Province

    Institute of Scientific and Technical Information of China (English)

    Gaozhong; JIANG; Fei; SUN; Qun; LI; Quanfu; ZHONG

    2013-01-01

    As one of the four main production areas of China’s tilapia farming,Fujian province plays a critical role in China’s tilapia industry development."Quality seed makes the industry a half success",therefore,the study on seed industry has a very important significance for the development of tilapia industry.Based on the field survey,study and analysis,we found that there is abroad prospect of the seed industry development in Fujian province.However,in recent years,some problems has emerged during the development process,such as the serious germplasm degeneration,frequent disease occurrence,etc.,which to some extent has restricted its further development.Establishment of tilapia seed production base,financial support and quality and security system should be strengthened,so that the tilapia seed industry in Fujian province will get better development.

  1. Experiments to determine the tebuconazole doses (folicur 200 ce on the behaviour of tilapia (tilapia rendalli and pacu (piractus mesopotamicus

    Directory of Open Access Journals (Sweden)

    Mário Rodrigues Peres

    Full Text Available Some of the agricultural practices are given water qualitative risks especially by the use of agrochemicals can cause health and environmental damage. This trial had as an objective to determine the influence of tebuconazole doses on the behaviour of Tilapia rendalli and Piaractus mesopotamicus. The trial was carried out at fish laboratory on march, 2002 at Centro Regional Universitário de Espírito Santo do Pinhal – CREUPI at São Paulo state, Brazil. The treatments tested were different doses of tebuconazole fungicide, that is very used on coffee crop in order to control plant diseases. The results showed difference among tebuconazole doses on the behavior of Tilapia rendalli and Piaractus mesopotamicus, except at 1,94 ppm concentration when both were resistant.

  2. Separation and characterization of alpha-chain subunits from tilapia (Tilapia zillii) skin gelatin using ultrafiltration.

    Science.gov (United States)

    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.

  3. Differential expression analysis in Egyptian redbelly tilapia (Tilapia Zillii exposed to cold stress

    Directory of Open Access Journals (Sweden)

    S. Fawzia

    2016-09-01

    Full Text Available Fish can adapt to a wide range of temperature changes, however, the molecular mechanisms that underlie these adaptations are not fully understood. In this study, fluorescently labeled differential display (FDD technique was used to detect mRNAs that are differentially expressed in hepatic tissues of Tilapia zillii fish subjected to a temperature reduction regime that combined both accelerated and stationary cold stresses. The two arbitrary primers (DD1 and DD2 with the Oligo d(T23-C generated a total of 18 and 37 unknown messenger RNA (UMR bands, respectively. Both DD1 & DD2 arbitrary primers with oligo d(T23-C scored four stress-related unidentified fragments after refining. Using the two arbitrary primers with the Oligo d(T23-G, a total of 371 and 372 UmRs were yielded, respectively. Both arbitrary primers scored nine stress-related unidentified fragments after refining. All UmR were tested for its correlation to time and temperature factors scaled for the current experiment, only four were found to be correlated for both factors. Thus, T. zillii responded to temperature reduction by adjusting the expression of a set number of genes that may be required for their adaptation and tolerance to low environmental temperature.

  4. Identifications of captive and wild tilapia species existing in Hawaii by mitochondrial DNA control region sequence.

    Directory of Open Access Journals (Sweden)

    Liang Wu

    Full Text Available BACKGROUND: The tilapia family of the Cichlidae includes many fish species, which live in freshwater and saltwater environments. Several species, such as O. niloticus, O. aureus, and O. mossambicus, are excellent for aquaculture because these fish are easily reproduced and readily adapt to diverse environments. Historically, tilapia species, including O. mossambicus, S. melanotheron, and O. aureus, were introduced to Hawaii many decades ago, and the state of Hawaii uses the import permit policy to prevent O. niloticus from coming into the islands. However, hybrids produced from O. niloticus may already be present in the freshwater and marine environments of the islands. The purpose of this study was to identify tilapia species that exist in Hawaii using mitochondrial DNA analysis. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we analyzed 382 samples collected from 13 farm (captive and wild tilapia populations in Oahu and the Hawaii Islands. Comparison of intraspecies variation between the mitochondrial DNA control region (mtDNA CR and cytochrome c oxidase I (COI gene from five populations indicated that mtDNA CR had higher nucleotide diversity than COI. A phylogenetic tree of all sampled tilapia was generated using mtDNA CR sequences. The neighbor-joining tree analysis identified seven distinctive tilapia species: O. aureus, O. mossambicus, O. niloticus, S. melanotheron, O. urolepies, T. redalli, and a hybrid of O. massambicus and O. niloticus. Of all the populations examined, 10 populations consisting of O. aureus, O. mossambicus, O. urolepis, and O. niloticus from the farmed sites were relatively pure, whereas three wild populations showed some degree of introgression and hybridization. CONCLUSIONS/SIGNIFICANCE: This DNA-based tilapia species identification is the first report that confirmed tilapia species identities in the wild and captive populations in Hawaii. The DNA sequence comparisons of mtDNA CR appear to be a valid method for

  5. Diet supplemented with probiotic for Nile tilapia in polyculture system with marine shrimp.

    Science.gov (United States)

    Jatobá, Adolfo; Vieira, Felipe do Nascimento; Buglione-Neto, Celso Carlos; Mouriño', José Luiz Pedreira; Silva, Bruno Corrêa; Seiftter, Walter Quadros; Andreatta, Edemar Roberto

    2011-12-01

    The aim of this study was to assess the effect of a probiotic (Lactobacillus plantarum) supplemented diet on Nile tilapia (Oreochromis niloticus) in a polyculture system with marine shrimp (Litopenaeus vannamei) as regards culture performance, hematology, and gut bacterial microbiota. Ten 20-m² pens were arranged in one earthen pond and stocked with 2 fish (41.9 g) m(-2) and 10 shrimp (2.3 g) m(-2), in total of 40 Nile tilapias and 200 shrimp per experimental unit. Tilapia groups in five of the experimental units were fed a commercial diet supplemented with L. plantarum and the other five with an unsupplemented commercial diet (control). After 12 weeks of culture, the tilapia groups fed the probiotic-supplemented diet presented values 13.6, 7.5, and 7.1% higher for feed efficiency, yield, and final weight, respectively. Viable culturable heterotrophic bacteria counts were reduced, and the number of lactic acid bacteria was increased in the gut of fish and shrimp fed the probiotic-supplemented diet. Hematological analyses showed higher number of thrombocytes and leukocytes in tilapia fed the supplemented diet. L. plantarum utilized in this study colonized the gut of tilapia and shrimp and resulted in reduced number of total bacteria and increased tilapia final weight and feed efficiency.

  6. Chitosan extends the shelf-life of filleted tilapia ( Oreochromis niloticus) during refrigerated storage

    Science.gov (United States)

    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.

  7. Effects of season on ecological processes in extensive earthen tilapia ponds in Southeastern Brazil.

    Science.gov (United States)

    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.

  8. Prevalence of Francisella noatunensis subsp. orientalis in cultured tilapia on the island of Oahu, Hawaii.

    Science.gov (United States)

    Soto, Esteban; McGovern-Hopkins, Kathleen; Klinger-Bowen, Ruth; Fox, Bradley K; Brock, James; Antonio, Nathene; Waal, Zelda van der; Rushton, Stephen; Mill, Aileen; Tamaru, Clyde S

    2013-06-01

    Francisellosis is an emergent disease in cultured and wild aquatic animals. The causative agent, Francisella noatunensis subsp. orientalis (Fno), is a gram-negative bacterium recognized as one of the most virulent pathogens of warmwater fish. The main objective of this project was to investigate the prevalence of Fno in cultured tilapia (specifically, Mozambique Tilapia Oreochromis mossambicus, Koilapia [also known as Wami Tilapia] O. hornorum, Blue Tilapia O. aureus, and Nile Tilapia O. niloticus hybrids) on the island of Oahu, Hawaii, using conventional and real-time PCR assays followed by statistical modeling to compare the different diagnostic methods and identify potential risk factors. During 2010 and 2012, 827 fish were collected from different geographical locations throughout the island of Oahu. Upon collection of fish, the water temperature in the rearing system and the length of individual fish were measured. Extraction of DNA from different tissues collected aseptically during necropsy served as a template for molecular diagnosis. High correlation between both molecular methods was observed. Moreover, the bacterium was isolated from infected tilapia on selective media and confirmed to be Fno utilizing a species-specific Taqman-based real-time PCR assay. Although a direct comparison of the prevalence of Fno between the different geographical areas was not possible, the results indicate a high prevalence of Fno DNA in cultured tilapia throughout the farm sites located on Oahu. Of the different tilapia species and hybrids currently cultured in Hawaii, Mozambique Tilapia were more susceptible to infection than Koilapia. Water temperature in the rearing systems and fish size also had a strong effect on the predicted level of infection, with fish held at lower temperatures and smaller fish being more susceptible to piscine francisellosis.

  9. Effects of growth hormone transgenesis on metabolic rate, exercise performance and hypoxia tolerance in tilapia hybrids

    DEFF Research Database (Denmark)

    McKenzie, DJ; Martinez, R; Morales, A

    2003-01-01

    Swimming respirometry was employed to compare inactive metabolic rate (Rr), maximum metabolic rate (Rmax), resultant aerobic scope and maximum sustainable (critical) swimming speed (Ucrit), in growth hormone transgenic (GHT) and wild-type (W) tilapia Oreochromis sp. hybrids. Although the Rr of GHT...... tilapia also exhibited the same capacity to regulate oxygen uptake during progressive hypoxia, despite the fact that the GHT fish were defending a higher demand for O2. The results indicate that ectopic expression of GH raises metabolic rate in tilapia, but the fish compensate for this metabolic load...

  10. Application of highly purified electrolyzed chlorine dioxide for tilapia fillet disinfection.

    Science.gov (United States)

    Yu, Chen-Hsing; Huang, Tzou-Chi; Chung, Chao-Chin; Huang, Hao-Hsun; Chen, Ho-Hsien

    2014-01-01

    This research aimed to develop an electrolysis method to generate high-concentration chlorine dioxide (ClO2) for tilapia fillet disinfection. The designed generator produced up to 3500 ppm of ClO2 at up to 99% purity. Tilapia fillets were soaked in a 400 ppm ClO2 solution for 5, 10, and 25 min. Results show that total plate counts of tilapia, respectively, decreased by 5.72 to 3.23, 2.10, and 1.09 log CFU/g. In addition, a 200 ppm ClO2 solution eliminated coliform bacteria and Escherichia coli in 5 min with shaking treatment. Furthermore, ClO2 and trihalomethanes (THMs) residuals on tilapia fillets were analyzed by GC/MS and were nondetectable (GC-MS detection limit was 0.12 ppb). The results conform to Taiwan's environmental protection regulations and act governing food sanitation.

  11. Shelf Life and Quality Study of Minced Tilapia with Nori and Hijiki Seaweeds as Natural Additives

    Directory of Open Access Journals (Sweden)

    Ingridy Simone Ribeiro

    2014-01-01

    Full Text Available 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.

  12. Increasing salinity tolerance in tilapias: selective breeding using locally available strains

    Directory of Open Access Journals (Sweden)

    Cecilia J. Jaspe

    2011-10-01

    Full Text Available The culture of tilapias is an important industry in most aquaculture producing countries in theworld. Due to the many favorable attributes of this species of fish, including tolerance to wide range ofenvironmental conditions and fast growth rates, interest in its culture is increasing at a rapid pace. Therehave been research initiatives on breeding, genetic improvement and stock manipulation in order toincrease the resistance of this fish to high salinity levels, enabling them to thrive in brackishwater andalmost seawater conditions. Saline-tolerant tilapias have been co-cultured with shrimp in brackishwaterponds as it was believed that tilapias are able to inhibit the occurrence of luminous vibriosis in ponds.This paper describes the selective breeding program that we developed in order to produce high-salinetolerant tilapias by using locally available strains.

  13. A comparative study of the karyotypes of Tilapia rendalli, T. sparrmanii and Oreochromis mossambicus (Cichlidae

    Directory of Open Access Journals (Sweden)

    A. Swanepoel

    1992-07-01

    Full Text Available Optimal chromosome preparations were obtained from stimulated lymphocyte cultures with a new method based on a combination and modification of several techniques. Tilapia rendalli, T. sparrmanii and Oreochromis mossambicus have somatic chromosome numbers of 44, 42 and 44, respectively. Chromosome pairs L1 and L2 are easily identified in all the karyotypes and distinctive of the tilapias. Tilapia sparrmanii has one additional large metacentric chromosome pair(L3, which occurs concurrently with the reduction of two in the total chromosome number. The F chromosomes were divided into two groups, viz a submetacentric (sm and a telocentric (t group. T. rendalli has 8 sm chromosomes, while both T. sparrmanii and O. mossambicus have 6 chromosomes in the sm group. The rest of the F chromosomes were telocentric. The identification of the sex chromosomes in the karyotypes of tilapia has thus far not been possible using standard techniques.

  14. Draft genome sequences of three Aeromonas hybrophila isolates from catfish and tilapia

    Science.gov (United States)

    Aeromonas hydrophila is a Gram-negative bacteria that is particularly adapted to freshwater environments and can cause severe infections in fish and humans. Here we report the draft genomes of three A. hydrophila catfish and tilapia isolates....

  15. Phosphorous digestibility and activity of intestinal phytase in hybrid tilapia, Oreochromis niloticus X O. aureus

    Science.gov (United States)

    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.

  16. Use of fish processing waste as protein source in diet for Nile tilapia (Orechromis niloticus

    Directory of Open Access Journals (Sweden)

    Chotipuntu, P.

    2005-02-01

    Full Text Available Five diets were prepared using fish processing waste meal (FMFP to replace fish meal (FM at inclusion levels of 0, 25, 50, 75 and 100%. Frog diet was used as a control diet. Nile tilapia (Oreochromis niloticus were reared in laboratory conditions for 8 weeks. It was found that substitution levels of protein from FMFP in the tested diets reduced growth and feed efficiency of tilapia (p<0.05. However, the differences looks like significant trend especially that between the 100% substitution level and the frog diet. Substitution of FM by FMFD at 75% reduced cost of feed by 15.35%. It was concluded that up to 75% inclusion of FMFD in the diet of tilapia could support normal growth of Nile tilapia with the potential for substitution of FM.

  17. Male tilapia production techniques: A mini-review | Fuentes-Silva ...

    African Journals Online (AJOL)

    Male tilapia production techniques: A mini-review. ... problems like less dissolved oxygen, greater release of ammonia and feces, heterogeneous sizes and ... technique depending on the market target and the commercial technology available.

  18. Characterization of a Novel Orthomyxo-like Virus Causing Mass Die-Offs of Tilapia

    Directory of Open Access Journals (Sweden)

    Eran Bacharach

    2016-04-01

    Full Text Available 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.

  19. Genetic characterisation of four strains of Nile tilapia (Oreochromie Niloticus L.) using microsatellite markers

    NARCIS (Netherlands)

    Rutten, M.J.M.; Komen, J.; Deerenberg, R.M.; Siwek-Gapinska, M.Z.; Bovenhuis, H.

    2004-01-01

    Four domesticated strains of Nile tilapia (Oreochromis niloticus L.) were genetically characterized using 14 microsatellite markers and 64 animals per strain. Two strains, Chitralada (AIT) and International Development Research Centers (IDRC) were obtained from the AIT institute, Bangkok, Thailand.

  20. Comparative time-course study on pituitary and branchial response to salinity challenge in Mozambique tilapia (Oreochromis mossambicus) and Nile tilapia (O. niloticus).

    Science.gov (United States)

    Velan, Ariel; Hulata, Gideon; Ron, Micha; Cnaani, Avner

    2011-12-01

    The physiological response of Mozambique and Nile tilapia transferred from fresh to brackish (15 ppt) water was compared during a one-week time course. Response in the pituitary was measured by the gene expression pattern of prolactin (PRL I), growth hormone (GH), and calcium-sensing receptor (CaSR), while the response in the gills was measured by the gene expression pattern of the prolactin receptor (PRL-R), Na(+)/K(+)/2Cl(-) cotransporter (NKCC) and Na(+)/Cl(-) cotransporter (NCC), and by activity and expression of Na(+)/K(+)-ATPase (NKA). The time-course curves of plasma osmolality levels indicate a rapid elevation 24 h after transfer, which later decreased and maintained at stable level. PRL I expression decreased in both species, but with stronger response in the Nile tilapia, while no differences were found in the slightly elevated levels of GH mRNA. The branchial response demonstrated a faster up-regulation of NKA and NKCC in the Mozambique tilapia, but similar levels after a week, while Nile tilapia had stronger and constant down-regulation of NCC. The time-course response of the measured osmoregulatory parameters indicate that 24 h after transfer is a critical time point for brackish-water adaptation. The differences in responses to saltwater challenge between Mozambique and Nile tilapia shown in this study may be associated with the differences in saltwater tolerance between these two tilapiine species.

  1. Filter System Performance in a Tilapia Recirculating System

    Directory of Open Access Journals (Sweden)

    Cristian Savin

    2012-10-01

    Full Text Available It is known that recirculating aquaculture systems, although has some advantages, production costs resulting from these production systems are quite high and is mainly due to the filtration system of technological water. Tilapia is one of the most important species in world aquaculture, the second production after carp, because of the advantages it has being reared in any production system: ponds, net-pens, cages, raceways, recirculating systems. Aim of this study was to evaluate the performance of a filter system in a tilapia recirculating system. Experiments were conducted during October – December 2011, during which feeding was done only with feed, Nutra category, ageappropriate granulation. Main physical – chemical parameters of technological water were monitored, pH, dissolved oxygen, nitrite, ammonia and ammonium, both the water entry in the filter and the exit from the filter. Filtration efficiency varied from 2-3% and up to 50-60%, mainly due to rapid loading of the filter and its need for cleaning.

  2. Mercury exposure in the freshwater tilapia Oreochromis niloticus

    Energy Technology Data Exchange (ETDEWEB)

    Wang Rui [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wong Minghung [Croucher Institute for Environmental Sciences, and Department of Biology, Hong Kong Baptist University (Hong Kong); Wang Wenxiong, E-mail: wwang@ust.h [Department of Biology, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2010-08-15

    Mercury (Hg) can be strongly accumulated and biomagnified along aquatic food chain, but the exposure pathway remains little studied. In this study, we quantified the uptake and elimination of both inorganic mercury [as Hg(II)] and methylmercury (as MeHg) in an important farmed freshwater fish, the tilapia Oreochromis niloticus, using {sup 203}Hg radiotracer technique. The dissolved uptake rates of both mercury species increased linearly with Hg concentration (tested at ng/L levels), and the uptake rate constant of MeHg was 4 times higher than that of Hg(II). Dissolved uptake of mercury was highly dependent on the water pH and dissolved organic carbon concentration. The dietborne assimilation efficiency of MeHg was 3.7-7.2 times higher than that of Hg(II), while the efflux rate constant of MeHg was 7.1 times lower. The biokinetic modeling results showed that MeHg was the greater contributor to the overall mercury bioaccumulation and dietary exposure was the predominant pathway. - Trophic transfer was the predominant pathway for mercury accumulation in tilapia, and methylmercury was more important in contributing to Hg accumulation than Hg(II).

  3. Visual communication stimulates reproduction in Nile tilapia, Oreochromis niloticus (L.).

    Science.gov (United States)

    Castro, A L S; Gonçalves-de-Freitas, E; Volpato, G L; Oliveira, C

    2009-04-01

    Reproductive fish behavior is affected by male-female interactions that stimulate physiological responses such as hormonal release and gonad development. During male-female interactions, visual and chemical communication can modulate fish reproduction. The aim of the present study was to test the effect of visual and chemical male-female interaction on the gonad development and reproductive behavior of the cichlid fish Nile tilapia, Oreochromis niloticus (L.). Fifty-six pairs were studied after being maintained for 5 days under one of the four conditions (N = 14 for each condition): 1) visual contact (V); 2) chemical contact (Ch); 3) chemical and visual contact (Ch+V); 4) no sensory contact (Iso) - males and females isolated. We compared the reproductive behavior (nesting, courtship and spawning) and gonadosomatic index (GSI) of pairs of fish under all four conditions. Visual communication enhanced the frequency of courtship in males (mean +/- SEM; V: 24.79 +/- 3.30, Ch+V: 20.74 +/- 3.09, Ch: 0.1 +/- 0.07, Iso: 4.68 +/- 1.26 events/30 min; P communication did not affect the reproductive behavior of pairs nor did it enhance the effects of visual contact. Therefore, male-female visual communication is an effective cue, which stimulates reproduction among pairs of Nile tilapia.

  4. Efficiency of aquatic macrophytes to treat Nile tilapia pond effluents

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    Henry-Silva Gustavo Gonzaga

    2006-01-01

    Full Text Available The effluents from fish farming can increase the quantity of suspended solids and promote the enrichment of nitrogen and phosphorus in aquatic ecosystems. In this context, the aim of this work was to evaluate the efficiency of three species of floating aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Salvinia molesta to treat effluents from Nile tilapia culture ponds. The effluent originated from a 1,000-m² pond stocked with 2,000 male Nile tilapia Oreochromis niloticus. The treatment systems consisted of 12 experimental tanks, three tanks for each macrophyte species, and three control tanks (without plants. Water samples were collected from the: (i fish pond source water, (ii effluent from fish pond and (iii effluents from the treatment tanks. The following water variables were evaluated: turbidity, total and dissolved nitrogen, ammoniacal-N, nitrate-N, nitrite-N, total phosphorus and dissolved phosphorus. E. crassipes and P. stratiotes were more efficient in total phosphorus removal (82.0% and 83.3%, respectively and total nitrogen removal (46.1% and 43.9%, respectively than the S. molesta (72.1% total phosphorus and 42.7% total nitrogen and the control (50.3% total phosphorus and 22.8% total nitrogen, indicating that the treated effluents may be reused in the aquaculture activity.

  5. Proposal of a production and management index (PMI) for tilapia farms.

    Science.gov (United States)

    Muniesa, A; Rey-Castaño, A L; Ruiz-Zarzuela, I; Guarín, M; Iregui, C; de Blas, I

    2016-11-01

    Tilapia is one of the most important species in aquaculture; however, there is no available index to show the performance of a production unit. It is desirable to assess the productivity using indexes, such as the production and management index for shrimps and the European production efficacy factor for broilers. These indexes are based on data production: growth, survival, and feed conversion of a full production cycle. Taking into account these parameters, we propose a production and management index (PMI) for tilapia that is applicable for a specific period of the production cycle. For the construction and validation of the PMI we have used production data from 8,614 monthly records of 2 tilapia farms in Huila Department (Colombia), and because of the complexity of tilapia management, different anomalous situations have been detected and then defined as exceptions. As a result, 419 records were considered extreme values because 1 or more exceptions were met. The value of the PMI varies from 0 (the worst situation) to 3.55, which reflects high variability. We have constructed a PMI for tilapia as the product of 3 elements to obtain a positive value index. Instead of classic parameters, we had to calculate an adapted version of them: the relative average daily growth, the survival (as a complementary value of the estimated monthly mortality), and a feed conversion ratio index. To assess the utility of the PMI, some comparisons were performed using records from black and red tilapia. We observed significant differences depending on tilapia strain (PMI = 1.0248 vs. PMI = 1.1661; PMI = 1.0847 vs. PMI = 1.1011; = 0.026). According to these results, we can conclude that the PMI could be a useful tool for tilapia farmers, despite the complexity of the calculation.

  6. Extraction, characterization and application of gelatina obtained from nile tilapia scale, Oreochromis niloticus (Linnaeus, 1758)

    OpenAIRE

    Maria Emanuella de Oliveira Martins

    2015-01-01

    Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), is one of the most cultivated species in our country. The fish processing industries generate large amounts of waste. In the tilapia processing waste materials represent more than 60%. Collagen is the main protein of connective tissue and is the most abundant protein in mammals, birds and fish. A commercial use of the collagen is gelatin, obtained by partial hydrolysis of collagen. Edible coatings and films are types of protection that can...

  7. Molecular cloning, functional identification and expressional analyses of FasL in Tilapia, Oreochromis niloticus.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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...

  9. Genetically-Improved Tilapia Strains in Africa: Potential Benefits and Negative Impacts

    Directory of Open Access Journals (Sweden)

    Yaw B. Ansah

    2014-06-01

    Full Text Available Two genetically improved tilapia strains (GIFT and Akosombo have been created with Oreochromis niloticus (Nile tilapia, which is native to Africa. In particular, GIFT has been shown to be significantly superior to local African tilapia strains in terms of growth rate. While development economists see the potential for food security and poverty reduction in Africa from culture of these new strains of tilapia, conservationists are wary of potential ecological and genetic impacts on receiving ecosystems and native stocks of tilapia. This study reviews the history of the GIFT technology, and identifies potential environmental and genetic risks of improved and farmed strains and tilapia in general. We also estimate the potential economic gains from the introduction of genetically improved strains in Africa, using Ghana as a case country. Employing a combination of the Economic-Surplus model and Monte Carlo simulation, we found the mean net present value (NPV of the introduction of the GIFT strain in Ghana to be approximately 1% of the country’s gross domestic product. Sensitivity analysis indicated that the difference in growth or yield between the GIFT and locally-available strains has the largest effect on mean NPV. We conclude that improvements in management practices and infrastructure could increase the yield and profitability of the local strains even if genetically-improved strains are not introduced. These improvements also will ensure the realization of the full potential of introduced strains.

  10. Species diversity defends against the invasion of Nile tilapia (Oreochromis niloticus

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    Gu Dang E.

    2014-05-01

    Full Text Available Nile tilapia (Oreochromis niloticus is one of the most widely cultured species globally and has successfully colonized much of the world. Despite numerous studies of this exotic species, how differences in native communities mitigate the consequences of Nile tilapia invasion is unknown. Theory predicts that communities that are more diverse should be more resistant to exotic species, an effect that is referred to as “biotic resistance”, but these effects are spatially dependent and organism-specific. Field surveys and laboratory experiments were conducted to test the theory of “biotic resistance” and ascertain the relationship between native species richness and the invasion of Nile tilapia. In the field, we found that as native species richness increased, the biomass of Nile tilapia was significantly reduced. Consistent with results from the field, our manipulative experiment indicated that the growth of Nile tilapia was negatively related to native species richness. Thus, our study supports the theory of “biotic resistance” and suggests that species biodiversity represents an important defense against the invasion of Nile tilapia.

  11. MicroRNA repertoire for functional genome research in tilapia identified by deep sequencing.

    Science.gov (United States)

    Yan, Biao; Wang, Zhen-Hua; Zhu, Chang-Dong; Guo, Jin-Tao; Zhao, Jin-Liang

    2014-08-01

    The Nile tilapia (Oreochromis niloticus; Cichlidae) is an economically important species in aquaculture and occupies a prominent position in the aquaculture industry. MicroRNAs (miRNAs) are a class of noncoding RNAs that post-transcriptionally regulate gene expression involved in diverse biological and metabolic processes. To increase the repertoire of miRNAs characterized in tilapia, we used the Illumina/Solexa sequencing technology to sequence a small RNA library using pooled RNA sample isolated from the different developmental stages of tilapia. Bioinformatic analyses suggest that 197 conserved and 27 novel miRNAs are expressed in tilapia. Sequence alignments indicate that all tested miRNAs and miRNAs* are highly conserved across many species. In addition, we characterized the tissue expression patterns of five miRNAs using real-time quantitative PCR. We found that miR-1/206, miR-7/9, and miR-122 is abundantly expressed in muscle, brain, and liver, respectively, implying a potential role in the regulation of tissue differentiation or the maintenance of tissue identity. Overall, our results expand the number of tilapia miRNAs, and the discovery of miRNAs in tilapia genome contributes to a better understanding the role of miRNAs in regulating diverse biological processes.

  12. Chitosan Extends the Shelf-life of Filleted Tilapia (Oreochromis niloticus) During Refrigerated Storage

    Institute of Scientific and Technical Information of China (English)

    CAO Rong; LIU Qi; YIN Bangzhong; WU Biao

    2012-01-01

    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)℃ 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)℃ 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 oftilapia fillets.

  13. Ventilation rates indicate stress-coping styles in Nile tilapia

    Indian Academy of Sciences (India)

    Rodrigo E Barreto; Gilson L Volpato

    2011-12-01

    Behavioural responses to stress can form distinct profiles in a wide range of animals: proactive and reactive profiles or coping styles. Stress responsiveness can also differentiate between the behavioural profiles. The tendency to regain feed intake following transfer to a novel social-isolation tank (the speed of acclimation) can discriminate between proactive or reactive profiles. Consequently, differential stress responsiveness can be linked to this feeding behaviour trait. This study shows that ventilation rates of Nile tilapia, Oreochromis niloticus (L.), correlate with the rate of feeding resumption, following transfer to a novel social-isolation aquarium. Therefore, ventilation rate (VR) indicates coping styles; consequently, VR is a proxy for the way fish will deal with environmental challenges.

  14. Blood cues induce antipredator behavior in Nile tilapia conspecifics.

    Directory of Open Access Journals (Sweden)

    Rodrigo Egydio Barreto

    Full Text Available In this study, we show that the fish Nile tilapia displays an antipredator response to chemical cues present in the blood of conspecifics. This is the first report of alarm response induced by blood-borne chemical cues in fish. There is a body of evidence showing that chemical cues from epidermal 'club' cells elicit an alarm reaction in fish. However, the chemical cues of these 'club' cells are restricted to certain species of fish. Thus, as a parsimonious explanation, we assume that an alarm response to blood cues is a generalized response among animals because it occurs in mammals, birds and protostomian animals. Moreover, our results suggest that researchers must use caution when studying chemically induced alarm reactions because it is difficult to separate club cell cues from traces of blood.

  15. Risks for fishborne zoonotic trematodes in tilapia production systems in Guangdong province, China.

    Science.gov (United States)

    Li, Kang; Clausen, Jesper Hedegaard; Murrell, K Darwin; Liu, Liping; Dalsgaard, Anders

    2013-11-15

    Guangdong province is the most important region for tilapia culture in China. However, it is also an endemic region for fishborne zoonotic trematodes (FZT), which pose a risk to human food safety and health. A study was designed to assess the status of trematode parasite infections in tilapia aquaculture systems as an indicator of potential risks from FZT associated with consumption of tilapia. Tilapia from nursery and grow-out ponds were sampled from monoculture, polyculture and integrated aquaculture systems. The results from 388 tilapia examined revealed a very low prevalence (1.5%) of trematode infections (Heterophyidae and Echinostomatidae). Integrated systems using animal manure and latrine wastes as fertilizer did not show a higher prevalence of FZT. Because it was not clear whether the low risk of infection was attributable to existing effective pond management practices or a low risk of spillover of FZT from area sylvatic reservoir hosts, a survey of local wild-caught fish was conducted. Five species of FZT were discovered from a total of 271 wild-caught fish and a mean infection density of 4.0 metacercariae/100g; FZT discovered included intestinal flukes (Haplorchis spp., Procerovum varium, and Metagonimus spp.) and metacercariae tentatively identified as Clonorchis sinenesis. The common occurrence of FZT in wild-caught fish suggests that the presence of FZT in local wild animal reservoirs is substantial, and that although the current aquaculture management systems for tilapia are generally effective in preventing transmission of these parasites into tilapia production systems, the improvement of pond management practices and biosecurity must be maintained at a high level.

  16. Safety of florfenicol administered in feed to tilapia (Oreochromis sp.)

    Science.gov (United States)

    Gaikowski, Mark P.; Wolf, Jeffrey C.; Schleis, Susan M.; Tuomari, Darrell; Endris, Richard G.

    2013-01-01

    The safety of Aquaflor® (50% w/w florfenicol [FFC]) incorporated in feed then administered to tilapia for 20 days (2x the recommended duration) at 0, 15, 45, or 75 mg/kg body weight/day (0, 1, 3, or 5x the recommended dose of 15 mg FFC/kg BW/d) was investigated. Mortality, behavioral change, feed consumption, body size, and gross and microscopic lesions were determined. Estimated delivered doses were >96.9% of target. Three unscheduled mortalities occurred but were considered incidental since FFC-related findings were not identified. Feed consumption was only affected during the last 10 dosing days when the 45 and 75 mg/kg groups consumed only 62.5% and 55.3% of the feed offered, respectively. There were significant, dose-dependent reductions in body size in the FFC-dose groups relative to the controls. Treatment-related histopathological findings included increased severity of lamellar epithelial hyperplasia, increased incidence of lamellar adhesions, decreased incidence of lamellar telangiectasis in the gills, increased glycogen-type and lipid-type hepatocellular vacuolation in the liver, decreased lymphocytes, increased blast cells, and increased individual cell necrosis in the anterior kidney, and tubular epithelial degeneration and mineralization in the posterior kidney. These changes are likely to be of minimal clinical relevance, given the lack of mortality or morbidity observed. This study has shown that FFC, when administered in feed to tilapia at the recommended dose (15 mg FFC/kg BW/day) for 10 days would be well tolerated.

  17. Optimisation of the pond rearing of Nile tilapia (Oreochromis niloticus L.). The impact of stunting processes and recruitment control

    NARCIS (Netherlands)

    Graaf, de G.J.

    2004-01-01

    Stunting is often considered as a major bottleneck for the pond rearing ofNiletilapia ( Oreochromis niloticus niloticus L.) and was a major topic in this study. Neonteny: the earlier breeding of tilapia in ponds takes place, but

  18. Co-induction of hepatic IGF-I and progranulin mRNA by growth hormone in tilapia, Oreochromis mossambiccus

    Science.gov (United States)

    Like IGF-I, progranulin (pgrn) is a growth factor involved in tumorigenesis and wound healing. We report here the identification and characterization of pgrn cDNA in tilapia and the regulation of its expression by growth hormone(GH). The tilapia pgrn cDNA was cloned by RT-PCR ampliWcation, using g...

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

    Science.gov (United States)

    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...

  20. Genetic Relatedness of Salmonella Serovars Isolated from Catfish (Clarias gariepinus) and Tilapia (Tilapia mossambica) Obtained from Wet Markets and Ponds in Penang, Malaysia.

    Science.gov (United States)

    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.

  1. First identification of Francisella noatunensis subsp. orientalis causing mortality in Mexican tilapia Oreochromis spp.

    Science.gov (United States)

    Ortega, Cesar; Mancera, Gerardo; Enríquez, Ricardo; Vargas, Augusto; Martínez, Simón; Fajardo, Raúl; Avendaño-Herrera, Ruben; Navarrete, María José; Romero, Alex

    2016-08-01

    Francisellosis, an emerging disease in tilapia Oreochromis spp., is caused by the facultative, intracellular bacterium Francisella noatunensis subsp. orientalis, which is present in various countries where tilapia farming is commercially important. We confirmed the presence of francisellosis in Mexican tilapia cultures in association with an outbreak during the second semester of 2012. Broodstock fish presented a mortality rate of approximately 40%, and disease was characterized by histologically classified granulomas, or whitish nodules, in different organs, mainly the spleen and kidney. Through DNA obtained from infected tissue and pure cultures in a cysteine heart medium supplemented with hemoglobin, F. noatunensis subsp. orientalis was initially confirmed through the amplification and analysis of the 16S rRNA gene and the internal transcribed spacer region. Phylogenetic analysis of these genes demonstrated close similarity with previously reported F. noatunensis subsp. orientalis sequences obtained from infected tilapia from various countries. The identification of this subspecies as the causative agent of the outbreak was confirmed using the iglC gene as a target sequence, which showed 99.5% identity to 2 F. noatunensis subsp. orientalis strains (Ethime-1 and Toba04). These findings represent the first documented occurrence of francisellosis in Mexican tilapia cultures, which highlights the importance of establishing preventative measures to minimize the spread of this disease within the Mexican aquaculture industry.

  2. Molecular phylogeny and revised classification of the haplotilapiine cichlid fishes formerly referred to as "Tilapia".

    Science.gov (United States)

    Dunz, Andreas R; Schliewen, Ulrich K

    2013-07-01

    African cichlids formerly referred to as "Tilapia" represent a paraphyletic species assemblage belonging to the so called haplotilapiine lineage which gave rise to the spectacular East African cichlid radiations (EARs) as well as to globally important aquaculture species. We present a comprehensive molecular phylogeny of representative haplotilapiine cichlids, combining in one data set four mitochondrial and five nuclear loci for 76 species, and compare it with phylogenetic information of a second data set of 378 mitochondrial ND2 haplotypes representing almost all important "Tilapia" or Tilapia-related lineages as well as most EAR lineages. The monophyly of haplotilapiines is supported, as is the nested sister group relationship of Etia and mouthbrooding tilapiines with the remaining haplotilapiines. The latter are consistently placed in eight monophyletic clades over all datasets and analyses, but several dichotomous phylogenetic relationships appear compromised by cytonuclear discordant phylogenetic signal. Based on these results as well as on extensive morphological evidence we propose a novel generic and suprageneric classification including a (re-)diagnosis of 20 haplotilapiine cichlid genera and nine tribes. New tribes are provided for the former subgenera Coptodon Gervais, 1853, HeterotilapiaRegan, 1920 and PelmatolapiaThys van den Audenaerde, 1969, in addition for "Tilapia" joka, Tilapia sensu stricto and Chilochromis, Etia, Steatocranus sensu stricto, the mouthbrooding tilapiines and for a clade of West African tilapiines.

  3. Cloning and characterization of the gene for L-amino acid oxidase in hybrid tilapia.

    Science.gov (United States)

    Shen, Yubang; Fu, Gui Hong; Liu, Feng; Yue, Gen Hua

    2015-12-01

    Tilapia is the common name for a group of cichlid fishes. Identification of DNA markers significantly associated with important traits in candidate genes may speed up genetic improvement. L-Amino acid oxidase (LAO) plays a crucial role in the innate immune defences of animals. Previously, whether LAO variants were associated with economic traits had not been studied in fish. We characterized the cDNA sequence of the LAO gene of hybrid tilapia (Oreochromis spp.). Its ORF was 1536 bp, encoding a flavoenzyme of 511 amino acids. This gene consisted of seven exons and six introns. Its expression was detected in the intestine, blood, kidney, skin, liver. It was highly expressed in the intestine. After a challenge with a bacterial pathogen, Streptococcus agalactiae, its expression was up-regulated significantly in the liver, intestine and spleen (P tilapia. The investigation of relationship between polymorphism of LAO gene and disease resistance and growth in tilapia showed that one SNP was associated significantly with body length. Further experiments on whether SNPs in the LAO gene are associated with growth in tilapia and other populations could be useful in understanding more functions of the LAO gene.

  4. Protozoan and metazoan parasites of Nile tilapia Oreochromis niloticus cultured in Brazil

    Directory of Open Access Journals (Sweden)

    Wanderson Pantoja MF

    2012-04-01

    Full Text Available Objective. This study describes the parasitic fauna and relative condition factor (Kn in Nile tilapia Oreochromis niloticus L. (Cichlidae from fish farms in the State of Amapá. Material and methods. 123 fish from four fish farms in the state of Amapá, Brazil were necropsied for parasitological and Kn analysis. Results. 64.2% of the examined fish, had the gills infected with Cichlidogyrus tilapiae Paperna, 1960 (Monogenoidea: Dactylogyridae; Ichthyophthirius multifiliis Fouquet, 1876 (Protozoa: Ciliophora, Trichodina Ehrenberg, 1830 and Paratrichodina africana Kazubski & El-Tantawy, 1986 (Protozoa: Trichodinidae. The highest prevalence found corresponded to Monogenoidea C. tilapiae while the lowest corresponded to Trichodinidae. However, I. multifiliis was the parasite that presented the greatest intensity and abundance. The differences found in the infection rates of the different fish farms due to causes further discussed. The parasitism did not influence the relative condition factor (Kn of fish. This was the first record of P. africana in Brazil and occurred in the Eastern Amazon. Conclusions. In Brazil, Lamproglena sp. is an emerging parasite in the Southern and Southeastern regions, but this crustacean was not found in the Nile tilapia in the State of Amapá. The parasitic infections in Nile tilapia farmed in Brazil are caused by protozoan, monogenoidea, crustacea and digenea species, and the regional differences on their prevalence and intensity rates are discussed in this study.

  5. Comparative physical maps derived from BAC end sequences of tilapia (Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Lindblad-Toh Kerstin

    2010-11-01

    Full Text Available Abstract Background The Nile tilapia is the second most important fish in aquaculture. It is an excellent laboratory model, and is closely related to the African lake cichlids famous for their rapid rates of speciation. A suite of genomic resources has been developed for this species, including genetic maps and ESTs. Here we analyze BAC end-sequences to develop comparative physical maps, and estimate the number of genome rearrangements, between tilapia and other model fish species. Results We obtained sequence from one or both ends of 106,259 tilapia BACs. BLAST analysis against the genome assemblies of stickleback, medaka and pufferfish allowed identification of homologies for approximately 25,000 BACs for each species. We calculate that rearrangement breakpoints between tilapia and these species occur about every 3 Mb across the genome. Analysis of 35,000 clones previously assembled into contigs by restriction fingerprints allowed identification of longer-range syntenies. Conclusions Our data suggest that chromosomal evolution in recent teleosts is dominated by alternate loss of gene duplicates, and by intra-chromosomal rearrangements (~one per million years. These physical maps are a useful resource for comparative positional cloning of traits in cichlid fishes. The paired BAC end sequences from these clones will be an important resource for scaffolding forthcoming shotgun sequence assemblies of the tilapia genome.

  6. Tilapia cage culture and the dissolved oxygen trends in Sampaloc Lake, the Philippines.

    Science.gov (United States)

    Santiago, A E; Arcilla, R P

    1993-02-01

    The 28-hectare tilapia cage culture that occupied the 104-hectare Sampaloc Lake, a crater lake, shifted to intensive method in 1986 when tilapia growth slowed done at the beginning of 1982. Thus, commercial feeds became the main source of allochthonous organic matter in the lake. Total feeds given annually for the 28-hectare cage culture at 3 croppings per year amounted to 5250 tons. At feed conversion ratio of 1 : 2 a significant portion of the feeds given ended as organic wastes in the lake. In 1988, tilapia cage operators began experiencing their worst occurrences of fishkill, worth millions of pesos. An assessment of the dissolved oxygen condition of Sampaloc lake in late 1989, 1990 and mid-1991 showed ominous trends which might adversely affect the use of Sampaloc lake for fishery.

  7. APPARENT DIGESTIBILTY EXPERIMENT WITH NILE TILAPIA (OREOCHROMIS NILOTICUS FED DIETS CONTAINING CITRULLUS LANATUS SEEDMEAL

    Directory of Open Access Journals (Sweden)

    Wasiu Adeyemi JIMOH

    2015-12-01

    Full Text Available Apparent digestibility coefficients of nutrients in Citrullus lanatus based diets were determined for Nile tilapia (Oreochromis niloticus using AIA as marker or indicator. 150 tilapia fingerlings of average weight 6.12±0.05g were acclimatized for a week, weighed and allotted into five dietary treatments; CTR, DT2, DT3, DT4 and DT5 containing 0, 15, 30, 45 and 60% Citrullus lanatus respectively. The diets were isonitrogenous, isocaloric and isolipidic. Each treatment was replicated three times with ten fish per replicate. Fish were fed 5% body weight on two equal proportions per day. The results from the study indicated that there was no significant variation (p>0.05 in the apparent organic matter and gross energy digestibility coefficients of the diets; that there was significant (p0.05 in the apparent digestibility coefficients of nutrients (protein, energy, lipid and carbohydrates between the diets up to 30% replacement levels for tilapia.

  8. The MCP-8 gene and its possible association with resistance to Streptococcus agalactiae in tilapia.

    Science.gov (United States)

    Fu, Gui Hong; Wan, Zi Yi; Xia, Jun Hong; Liu, Feng; Liu, Xiao Jun; Yue, Gen Hua

    2014-09-01

    Mast cell proteases play an important role in the regulation of the immune response. We identified the cDNA of the mast cell protease 8 (MCP-8) gene and analyzed its genomic structure in tilapia. The ORF of the MCP-8 was 768 bp, encoding 255 amino acids. Quantitative real-time PCR revealed that the MCP-8 gene was expressed predominantly in spleen, moderately in liver, blood, brain, gill, intestine, skin, and weakly expressed in kidney, muscle and eye. After a challenge with Streptococcus agalactiae, the gene was induced significantly (p 0.05). These results suggest that the MCP-8 gene play an important role in the resistance to S. agalactiae in tilapia. The SNP markers in the MCP-8 gene associated with the resistance to the bacterial pathogen may facilitate selection of tilapia resistant to the bacterial disease.

  9. Experimental early pathogenesis of Streptococcus agalactiae infection in red tilapia Oreochromis spp.

    Science.gov (United States)

    Iregui, C A; Comas, J; Vásquez, G M; Verján, N

    2016-02-01

    Streptococcus agalactiae causes a severe systemic disease in fish, and the routes of entry are still ill-defined. To address this issue, two groups of 33 red tilapia Oreochromis spp. each of 10 g were orally infected with S. agalactiae (n = 30), and by immersion (n = 30), six individuals were control-uninfected fish. Three tilapias were killed at each time point from 30 min to 96 h post-inoculation (pi); controls were killed at 96 h. Samples from most tissues were examined by haematoxylin-eosin (H&E), indirect immunoperoxidase (IPI) and periodic acid-Schiff; only intestine from fish infected by gavage was evaluated by transmission electron microscopy. The results of both experiments suggest that the main entry site of S. agalactiae in tilapia is the gastrointestinal epithelium; mucus seems to play an important defensive role, and environmental conditions may be an important predisposing factor for the infection.

  10. Research findings from the use of probiotics in tilapia aquaculture: A review.

    Science.gov (United States)

    Hai, Ngo Van

    2015-08-01

    This study aims to present research findings from the use of probiotics in tilapia aquaculture. In omnivorous species of tilapia aquaculture, intestines and gonads, rearing water and sediments or even commercial products, can be sources for acquiring appropriate probiotics. Administration of probiotics varies from direct oral/water routine to feed additives, of which the latter is most commonly used. Probiotic applications can be either mono or multiple strains. Dosage and duration of time are significant factors in providing desired results. As probiotics have been proven to be either immune enhancers and/or growth promoters in aquatic animals, several modes of actions of probiotics in enhancement of immune responses, and an improvement of growth and survival rates of tilapia are presented, while the effects of others are not yet understood to the same degree as for other fish species. Some points extracted from the research findings are emphasised for further investigation and development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. UV treatments on the physicochemical properties of tilapia skin and pig skin gelatin.

    Science.gov (United States)

    Wu, C K; Tsai, J S; Chen, Z Y; Sung, W C

    2015-06-01

    Tilapia skin gelatin, pig skin gelatin, and their mousse premixes were exposed to UV irradiation for 103, 206, and 309 kJ/cm(2). All samples after 309 kJ/cm(2) exposure exhibited a significant increase in gel strength, gel forming ability as well as viscosity of solutions. It was shown that UV treatment could also improve the pig skin gelatin foam stability and foam formation ability compared to those of tilapia skin gelatin. Nevertheless, the panelists gave the lowest scores to mousse made with 309 kJ/cm(2) UV-irradiated premix mousse pig skin gelatin. Tilapia skin gelatin could be used as a substitute ingredient for premix mousse made from pig skin gelatin.

  12. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    Science.gov (United States)

    Sockalingam, K.; Abdullah, H. Z.

    2015-07-01

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.

  13. Chemometrics applied to the incorporation of omega-3 in tilapia fillet feed flaxseed flour

    Directory of Open Access Journals (Sweden)

    Márcia Fernandes Nishiyama

    2014-09-01

    Full Text Available This study evaluated the effect of adding flaxseed flour to the diet of Nile tilapia on the fatty acid composition of fillets using chemometrics. A traditional and an experimental diet containing flaxseed flour were used to feed the fish for 60 days. An increase of 18:3 n-3 and 22:6 n-3 and a decrease of 18:2 n-6 were observed in the tilapia fillets fed the experimental diet. There was a reduction in the n-6:n-3 ratio. A period of 45 days of incorporation caused a significant change in tilapia chemical composition. Principal Component Analysis showed that the time periods of 45 and 60 days positively contributed to the total content of n-3, LNA, and DHA, highlighting the effect of omega-3 incorporation in the treatment containing flaxseed flour.

  14. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    Energy Technology Data Exchange (ETDEWEB)

    Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.

  15. L-proline increases survival of tilapias infected by Streptococcus agalactiae in higher water temperature.

    Science.gov (United States)

    Zhao, Xian-Liang; Han, Yi; Ren, Shi-Tong; Ma, Yan-Mei; Li, Hui; Peng, Xuan-Xian

    2015-05-01

    Streptococcosis causes massive tilapia kills, which results in heavy economic losses of tilapia farming industry. Out of the Streptococcosis, Streptococcus agalactiae is the major pathogen. The bacterium causes higher mortality of tilapias in higher than lower temperatures. However, effect of temperature on metabolic regulation which is related to the mortality is largely unknown. The present study showed 50% and 70% mortality of tilapias cultured in 25 °C and 30 °C, respectively, in comparison with no death in 20 °C following infection caused by S. agalactiae. Then, GC/MS based metabolomics was used to investigate a global metabolic response of tilapia liver to the two higher water temperatures compared to 20 °C. Thirty-six and forty-five varied abundance of metabolites were identified in livers of tilapias cultured at 25 °C and 30 °C, respectively. More decreasing abundance of amino acids and increasing abundance of carbohydrates were detected in 30 °C than 25 °C groups. On the other hand, out of the pathways enriched, the first five biggest impact pathways belong to amino acid metabolism. Decreasing abundance of l-proline was identified as a crucial biomarker for indexing higher water temperature and a potential modulator to reduce the high death. This was validated by engineering injection or oral addition of l-proline. Exogenous l-proline led to elevated amino acid metabolism, which contributes to the elevated survivals. Our findings provide a potential metabolic modulator for controlling the disease, and shed some light on host metabolic prevention to infectious diseases.

  16. The osmoregulatory effects of rearing Mozambique tilapia in a tidally changing salinity.

    Science.gov (United States)

    Moorman, Benjamin P; Inokuchi, Mayu; Yamaguchi, Yoko; Lerner, Darren T; Grau, E Gordon; Seale, Andre P

    2014-10-01

    The native distribution of Mozambique tilapia, Oreochromis mossambicus, is characterized by estuarine areas subject to salinity variations between fresh water (FW) and seawater (SW) with tidal frequency. Osmoregulation in the face of changing environmental salinity is largely mediated through the neuroendocrine system and involves the activation of ion uptake and extrusion mechanisms in osmoregulatory tissues. We compared plasma osmolality, plasma prolactin (PRL), pituitary PRL mRNA, and mRNA of branchial ion pumps, transporters, channels, and PRL receptors in tilapia reared in FW, SW, brackish water (BW) and in tidally-changing salinity, which varied between FW (TF) and SW (TS) every 6h. Plasma PRL was higher in FW tilapia than in SW, BW, TF, and TS tilapia. Unlike tilapia reared in FW or SW, fish in salinities that varied tidally showed no correlation between plasma osmolality and PRL. In FW fish, gene expression of PRL receptor 1 (PRLR1), Na(+)/Cl(-) cotransporter (NCC), aquaporin 3 (AQP3) and two isoforms of Na(+)/K(+)-ATPase (NKA α1a and NKA α1b) was higher than that of SW, BW or tidally-changing salinity fish. Gene expression of the Na(+)/K(+)/2Cl(-) cotransporter (NKCC1a), and the cystic fibrosis transmembrane conductance regulator (CFTR) were higher in fish in SW, BW or a tidally-changing salinity than in FW fish. Immunocytochemistry revealed that ionocytes of fish in tidally-changing salinities resemble ionocytes of SW fish. This study indicated that tilapia reared in a tidally-changing salinity can compensate for large changes in external osmolality while maintaining osmoregulatory parameters within a narrow range closer to that observed in SW-acclimated fish.

  17. Environmental and cortisol-mediated control of Ca(2+) uptake in tilapia (Oreochromis mossambicus).

    Science.gov (United States)

    Lin, Chia-Hao; Kuan, Wei-Chun; Liao, Bo-Kai; Deng, Ang-Ni; Tseng, Deng-Yu; Hwang, Pung-Pung

    2016-04-01

    Ca(2+) is a vital element for many physiological processes in vertebrates, including teleosts, which live in aquatic environments and acquire Ca(2+) from their surroundings. Ionocytes within the adult gills or larval skin are critical sites for transcellular Ca(2+) uptake in teleosts. The ionocytes of zebrafish were found to contain transcellular Ca(2+) transporters, epithelial Ca(2+) channel (ECaC), plasma membrane Ca(2+)-ATPase 2 (PMCA2), and Na(+)/Ca(2+) exchanger 1b (NCX1b), providing information about the molecular mechanism of transcellular Ca(2+) transports mediated by ionocytes in fish. However, more evidence is required to establish whether or not a similar mechanism of transcellular Ca(2+) transport also exists in others teleosts. In the present study, ecac, pmca2, and ncx1 were found to be expressed in the branchial ionocytes of tilapia, thereby providing further support for the mechanism of transcellular Ca(2+) transport through ionocytes previously proposed for zebrafish. In addition, we also reveal that low Ca(2+) water treatment of tilapia stimulates Ca(2+) uptake and expression of ecac and cyp11b (the latter encodes a cortisol-synthesis enzyme). Treatment of tilapia with exogenous cortisol (20 mg/l) enhanced both Ca(2+) influx and ecac expression. Therefore, increased cyp11b expression is suggested to enhance Ca(2+) uptake capacity in tilapia exposed to low Ca(2+) water. Furthermore, the application of cortisol receptor antagonists revealed that cortisol may regulate Ca(2+) uptake through glucocorticoid and/or mineralocorticoid receptor (GR and/or MR) in tilapia. Taken together, the data suggest that cortisol may activate GR and/or MR to execute its hypercalcemic action by stimulating ecac expression in tilapia.

  18. Risks for fishborne zoonotic trematodes in tilapia production systems in Guangdong province, China

    DEFF Research Database (Denmark)

    Li, Kang; Clausen, Jesper Hedegaard; Murrell, Kenneth Darwin

    2013-01-01

    Guangdong province is the most important region for tilapia culture in China. However, it is also an endemic region for fishborne zoonotic trematodes (FZT), which pose a risk to human food safety and health. A study was designed to assess the status of trematode parasite infections in tilapia...... risk of spillover of FZT from area sylvatic reservoir hosts, a survey of local wild-caught fish was conducted. Five species of FZT were discovered from a total of 271 wild-caught fish and a mean infection density of 4.0 metacercariae/100 g; FZT discovered included intestinal flukes (Haplorchis spp...

  19. Analysis of production and environmental effects of Nile tilapia and white shrimp culture in Thailand

    DEFF Research Database (Denmark)

    Ferreira, J.G.; Falconer, L.; Kittiwanich, J.

    2015-01-01

    calculated emissions of 2,105,118 and 34,904 Population Equivalents (PEQ) respectively. Only part is a negative externality, because rural agro-aqua systems in Thailand reuse discharges in holding ponds, rice culture, etc. Commercial tilapia and shrimp aquaculture have a value added share of total GDP of 0.......38, and value added of 96.24, resulting in indirect impacts of the industry on the Thai economy of $35 million, and the creation of 16,000 additional jobs. The MCE scenario analysis suggests sustainable expansion is possible for both species. The highly suitable class for tilapia would triple in the dry season...

  20. Microalgas en estanques de tilapia y su potencial biotecnológico, ambiental e industrial

    OpenAIRE

    Villalobos, Narcy; Scholz, Carola

    2013-01-01

    Las microalgas han sido ampliamente estudiadas a nivel mundial, sin embargo en el trópico hacen falta más estudios relacionados con su identificación y posibles usos biotecnológicos. Los estanques de tilapias son ecosistemas artifi­ciales con un alto potencial para la identificación de estas microalgas, debido a que sus condiciones físico-químicas son muy estables durante el año. En esta investigación se encontraron 31 especies de microalgas en los estanques de tilapia de la Estacion Biológic...

  1. Blue tilapia (Oreochromis aureus) predation on fishes in the Muddy River system, Clark County, Nevada

    Science.gov (United States)

    Scoppettone, G.G.; Salgado, J.A.; Nielsen, M.B.

    2005-01-01

    Blue tilapia (Oreochromis aureus), native to North Africa and the Middle East (Courtenay and Robins 1973, Fuller et al. 1999), has been introduced around the world as a human food source, for vegetation control, and as a game fish (Costa-Pierce and Riedel 2000). Blue tilapia has been particularly successful in establishing and spreading in North American waters where it has been reported to change fish community structure and cause native fish decline (Courtenay and Robins 1973, Fuller et al. 1999). Because of these detrimental effects, it is now generally considered an unwelcome introduction into North American waters (Dill and Cordone 1997, Fuller et al. 1999).

  2. Streptococcus agalactiae isolates of serotypes Ia, III and V from human and cow are able to infect tilapia.

    Science.gov (United States)

    Chen, Ming; Wang, Rui; Luo, Fu-Guang; Huang, Yan; Liang, Wan-Wen; Huang, Ting; Lei, Ai-Ying; Gan, Xi; Li, Li-Ping

    2015-10-22

    Recent studies have shown that group B streptococcus (GBS) may be infectious across hosts. The purpose of this study is to investigate the pathogenicity of clinical GBS isolates with serotypes Ia, III and V from human and cow to tilapia and the evolutionary relationship among these GBS strains of different sources. A total of 27 clinical GBS isolates from human (n=10), cow (n=2) and tilapia (n=15) were analyzed using serotyping, multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Among them, 15 isolates were tested for their pathogenicity to tilapia. The results showed that five human GBS strains (2 serotype III, 2 serotype Ia and 1 serotype V) infected tilapia with mortality rate ranging from 56.67% to 100%, while the other five human GBS strains tested were unable to infect tilapia. In addition, two cow GBS strains C001 and C003 of serotype III infected tilapia. However, they had significantly lower pathogenicity than the five human strains. Furthermore, human GBS strains H005 and H008, which had very strong ability to infect tilapia, had the same PFGE pattern. MLST analysis showed that the five human and the two cow GBS strains that were able to infect tilapia belonged to clonal complexes CC19, CC23 and CC103. The study for the first time confirmed that human or cow GBS clonal complexes CC19, CC23 and CC103 containing strains with serotypes Ia, III and V could infect tilapia and induce clinical signs under experimental conditions.

  3. Interaction between afternoon aeration and tilapia stocking density

    Directory of Open Access Journals (Sweden)

    Francisco Roberto dos Santos Lima

    2016-01-01

    Full Text Available The present study aimed at determining the effects of the interaction between afternoon aeration and stocking density of Nile tilapia on variables of water and soil quality, growth performance and effluent quality. The experiment was a 3 x 2 factorial randomized block design, with three stocking densities (8, 12 and 16 fish per tank or 43.5, 65.3, and 87.0 g m-3 under two mechanical aeration regimes, absence (control; three replicates and afternoon aeration (four replicates. The afternoon aeration was carried out from 12.00 a.m. up to 18.00 p.m. from the 3rd week until the end of the experiment. Except for the 16-fish tanks, the lowest concentrations of total ammonia nitrogen were found in the tanks with higher density of fish provided with afternoon aeration. Nitrite concentrations were lower in the 8-fish aerated tanks. In intensive system, the afternoon aeration of the fish culture water is an efficient management of water quality to remove gaseous ammonia and nitrite from water, but it is not appropriate to remove hydrogen sulfide from water.

  4. The Colonization Dynamics of the Gut Microbiota in Tilapia Larvae

    Science.gov (United States)

    Giatsis, Christos; Sipkema, Detmer; Smidt, Hauke; Verreth, Johan; Verdegem, Marc

    2014-01-01

    The gut microbiota of fish larvae evolves fast towards a complex community. Both host and environment affect the development of the gut microbiota; however, the relative importance of both is poorly understood. Determining specific changes in gut microbial populations in response to a change in an environmental factor is very complicated. Interactions between factors are difficult to separate and any response could be masked due to high inter-individual variation even for individuals that share a common environment. In this study we characterized and quantified the spatio-temporal variation in the gut microbiota of tilapia larvae, reared in recirculating aquaculture systems (RAS) or active suspension tanks (AS). Our results showed that variation in gut microbiota between replicate tanks was not significantly higher than within tank variation, suggesting that there is no tank effect on water and gut microbiota. However, when individuals were reared in replicate RAS, gut microbiota differed significantly. The highest variation was observed between individuals reared in different types of system (RAS vs. AS). Our data suggest that under experimental conditions in which the roles of deterministic and stochastic factors have not been precisely determined, compositional replication of the microbial communities of an ecosystem is not predictable. PMID:25072852

  5. The colonization dynamics of the gut microbiota in tilapia larvae.

    Science.gov (United States)

    Giatsis, Christos; Sipkema, Detmer; Smidt, Hauke; Verreth, Johan; Verdegem, Marc

    2014-01-01

    The gut microbiota of fish larvae evolves fast towards a complex community. Both host and environment affect the development of the gut microbiota; however, the relative importance of both is poorly understood. Determining specific changes in gut microbial populations in response to a change in an environmental factor is very complicated. Interactions between factors are difficult to separate and any response could be masked due to high inter-individual variation even for individuals that share a common environment. In this study we characterized and quantified the spatio-temporal variation in the gut microbiota of tilapia larvae, reared in recirculating aquaculture systems (RAS) or active suspension tanks (AS). Our results showed that variation in gut microbiota between replicate tanks was not significantly higher than within tank variation, suggesting that there is no tank effect on water and gut microbiota. However, when individuals were reared in replicate RAS, gut microbiota differed significantly. The highest variation was observed between individuals reared in different types of system (RAS vs. AS). Our data suggest that under experimental conditions in which the roles of deterministic and stochastic factors have not been precisely determined, compositional replication of the microbial communities of an ecosystem is not predictable.

  6. Nile tilapia culture on domestic effluent treated in stabilization ponds.

    Directory of Open Access Journals (Sweden)

    Clovis Matheus Pereira

    2009-03-01

    Full Text Available The performance and filet quality of tilapias (Oreochromis niloticus culture in effluent stabilization lagoons was tested at the densities of 3 fish/m2 (T3, 7 fish/m2 (T2 and 7 fish/m2 in clean water + diet (T1 with 3 repetitions in tanks of 2.57m2 and 0.60m of water column with supplemental aeration. Fish culture in clean water plus diet (T1 presented the highest growth. The higher density T3 (7/m2 compared to T2 (3/m2 did not result in any difference of total production (p > 0.05 but this was compensated by the increased individual fish growth rate at lower density. The conditions that sustain fish survival culture with ETE effluent were attested by the high survival (> 90% under both treatments, but only 10% of the water samples from T2 and T3 N-total ammonium was favorable for fish growth (< 2.0mg/L. The rearing system improved the effluent quality, reducing the total organic nitrogen and the solids in suspension. The faecal coliforms, Salmonella sp. and Staphylococcus aureus from the effluent and fish were verified to be within the standards laid down by the World Health Organization (WHO.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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 tilapia's ability to utilize these residues as a food source in bio-regenerative support systems.

  9. Reversion sexual de las Tilapias Roja (Oreochromis Sp), una guía básica para el acuacultor

    OpenAIRE

    Duván Andrés Arboleda Obregón

    2005-01-01

    La tilapia roja es un híbrido distribuido en todo el mundo; atractivo por su color y sus características zootécnicas lo que la convierte en una especie con gran mercado y de gran importancia para investigación, en tilapia es importante el cultivo de machos, para obtener machos se usa la 17alfametiltestosterona que es una hormona que cuando suministrada con el alimento a los alevines los transforma en machos. The red tilapia is a hybrid distribuided in all the world; it is attractive due to i...

  10. Electrotransfer of the tilapia piscidin 3 and tilapia piscidin 4 genes into skeletal muscle enhances the antibacterial and immunomodulatory functions of Oreochromis niloticus.

    Science.gov (United States)

    Lin, Wen-Chun; Chang, Hsiao-Yun; Chen, Jyh-Yih

    2016-03-01

    Tilapia piscidin 3 (TP3) and tilapia piscidin 4 (TP4) are antimicrobial peptides recently isolated from Oreochromis niloticus. We previously showed that synthetic TP3 and TP4 possessed antimicrobial activities. Here, we analyzed the bactericidal abilities and immunomodulatory properties of these AMPs following the electroporation of pCMV-GFP-TP3 or pCMV-GFP-TP4 plasmid into tilapia (O. niloticus) muscle and subsequent infection with Vibrio vulnificus or Streptococcus agalactiae. Prior overexpression of TP3 or TP4 in tilapia muscle tissues efficiently reduced bacterial numbers at 24 and 48 h after V. vulnificus infection and reduced bacterial numbers at 24 h after S. agalactiae infection compared to numbers in controls expressing pCMV-GFP (EGFP). Electroporation of pCMV-EGFP-TP3 (TP3) or pCMV-EGFP-TP4 (TP4) significantly increased expression of several immune-related genes in muscle (IL-1β (12 h, TP3), IL-8 (12 h, TP3), TGFβ (3 h, TP4), and IκB (48 h, TP3, TP4)) and decreased the expression of TLR5 (12 h and 24 h, TP3) after V. vulnificus infection. Following S. agalactiae infection, expression of the following genes was significantly decreased in muscle: IL-1β (12 h, TP3), IL-8 (12 h, TP3, TP4), TLR5 (3 h-24 h, TP3, TP4), TGFβ (3 h, TP4; 24 h, TP3, TP4), and IκB (3 h, TP3). These data suggest that TP3 and TP4 exert antimicrobial effects after overexpression in the O. niloticus muscle, and also play important roles in the regulation of immune-related gene expression.

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

    Science.gov (United States)

    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...

  12. The effect of mercury on the growth efficiency of Tilapia mossambica (Peters)

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.; Qasim, S.Z.

    Three concentrations of mercury (0.01, 0.04 and 0.4 ppm) were used for experiments on growth efficiency of Tilapia mossambica. Growth efficiencies were determined on a dry weight basis. High concentration of mercury (0.4 ppm) caused considerable...

  13. Draft Genome Sequences of Three Aeromonas hydrophila Isolates from Catfish and Tilapia

    Science.gov (United States)

    Tekedar, Hasan C.; Kumru, Salih; Kalindamar, Safak; Karsi, Attila; Waldbieser, Geoffrey C.; Sonstegard, Tad; Schroeder, Steven G.; Liles, Mark R.; Griffin, Matt J.

    2017-01-01

    ABSTRACT Aeromonas hydrophila is a Gram-negative bacterium that is particularly adapted to freshwater environments and can cause severe infections in fish and humans. Here, we report the draft genomes of three A. hydrophila catfish and tilapia isolates. PMID:28104665

  14. Influence of glyceryl guaiacolate ether on anesthetics in tilapia compared to benzocaine and eugenol

    Directory of Open Access Journals (Sweden)

    Geovana R. Cosenza

    2014-03-01

    Full Text Available Objective. The study aimed to investigate the effectiveness of glyceryl guaiacolate ether (GGE and compare the times of induction, recovery, hematological changes, total protein and glycaemia among anesthetics in Nile tilapia, Oreochromis niloticus. Materials and methods. A total of 60 tilapia distributed in 3 aquariums (N=20 were used, which formed the group benzocaine (100 mg/L, eugenol (50 mg/L and guaiacol glyceryl ether (9.000 mg/L. After the induction of anesthesia fish blood samples were collected to determine the complete hemogram and glycemia. Then the animals were placed in aquariums with running water for assessing the anesthesia recovery. Results. It was verified that GGE showed longer induction and recovery times as well a significant increase (p0.05. An increase in the number of monocytes in the group treated with benzocaine (p <0.05 was observed in the analysis of the hematological parameters with no difference between groups for other variables. Conclusions. Eugenol and benzocaine allow rapid induction and recovery in Nile tilapia, without evidence of stress during handling and GGE showed high induction and recovery times, being inadequate for anesthetic use in Nile tilapia.

  15. Feed intake, growth and metabolism of Nile tilapia (Oreochromis niloticus) in relation to dissolved oxygen concentration

    NARCIS (Netherlands)

    Tran-Duy, A.; Dam, van A.A.; Schrama, J.W.

    2012-01-01

    The objectives of the present study were to determine, for Nile tilapia of different body weights and fed to satiation, (1) the incipient dissolved oxygen (DO) concentration at which feed intake starts to level off and (2) the effect of DO on nitrogen and energy balances. Two successive experiments

  16. Draft Genome Sequences of Streptococcus agalactiae Serotype Ia and III Isolates from Tilapia Farms in Thailand.

    Science.gov (United States)

    Areechon, Nontawith; Kannika, Korntip; Hirono, Ikuo; Kondo, Hidehiro; Unajak, Sasimanas

    2016-03-24

    Streptococcus agalactiaeserotypes Ia and III were isolated from infected tilapia in cage and pond culture farms in Thailand during 2012 to 2014, in which pathogenicity analysis demonstrated that serotype III showed higher virulence than serotype Ia. Here, we report the draft genome sequencing of piscineS. agalactiaeserotypes Ia and III.

  17. The influence of ration size on energetics and nitrogen retention in tilapia (Oreochromis niloticus)

    DEFF Research Database (Denmark)

    Skov, Peter Vilhelm; Duodu, Collins Prah; Adjei-Boateng, Daniel

    2017-01-01

    of dietary nutrient intake, the effects of meal size on growth and metabolism were examined in triplicate groups of adult Nile tilapia (Oreochromis niloticus) receiving daily rations corresponding to 1, 2, 3, or 4% of their biomass. While biomass gain and specific growth rates were positively correlated...

  18. Application of Highly Purified Electrolyzed Chlorine Dioxide for Tilapia Fillet Disinfection

    Directory of Open Access Journals (Sweden)

    Chen-Hsing Yu

    2014-01-01

    Full Text Available This research aimed to develop an electrolysis method to generate high-concentration chlorine dioxide (ClO2 for tilapia fillet disinfection. The designed generator produced up to 3500 ppm of ClO2 at up to 99% purity. Tilapia fillets were soaked in a 400 ppm ClO2 solution for 5, 10, and 25 min. Results show that total plate counts of tilapia, respectively, decreased by 5.72 to 3.23, 2.10, and 1.09 log CFU/g. In addition, a 200 ppm ClO2 solution eliminated coliform bacteria and Escherichia coli in 5 min with shaking treatment. Furthermore, ClO2 and trihalomethanes (THMs residuals on tilapia fillets were analyzed by GC/MS and were nondetectable (GC-MS detection limit was 0.12 ppb. The results conform to Taiwan’s environmental protection regulations and act governing food sanitation.

  19. Apparent digestibility coefficient of duckweed (Lemna minor), fresh and dry for Nile tilapia (Oreochromis niloticus L.)

    NARCIS (Netherlands)

    El-Shafai, S.A.A.M.; El-Gohary, F.; Verreth, J.A.J.; Schrama, J.W.; Gijzen, H.J.

    2004-01-01

    Dry matter (DMD), protein (PD), ash (AD), fat (FD), gross energy (ED) and phosphorus (PhD) digestibility coefficients were determined for five different iso-N fish diets fed to Nile tilapia (Oreochromis niloticus). The control diet contained fishmeal (35%), corn (29%), wheat (20%), wheat bran (10%),

  20. Oxidative stress responses in gills of tilapia (Oreochromis niloticus) at different salinities

    Science.gov (United States)

    Handayani, Kiki Syaputri; Novianty, Zahra; Saputri, Miftahul Rohmah; Irawan, Bambang; Soegianto, Agoes

    2017-08-01

    The objective of present study is to evaluate the impact of different salinities on the levels of CAT, GSH and MDA of the gills of Nile tilapia (Oreochromis niloticus). Nile tilapia was treated by exposure to salinities concentration 0 ‰, 5 ‰ and 10 ‰. Research models were weakened and sacrificed, then took the left and right sides of the gills. The result of gills homogenity was centrifuged for supernatan, then supernatan was proceed with testing levels of CAT, GSH and MDA by ELISA assay methods. The levels of CAT in gills were significantly higher at 10 ‰ than at 5 ‰ and 0 ‰. The levels of GSH in gills were significantly higher at 0 ‰ than 5 ‰. The levels of GSH in gills at 5 ‰ and 10 ‰ salinities were not significantly different. The levels of MDA in gills at salinity 10 ‰ and 5 ‰ were higher than in control gills at 0 ‰ salinities. This occurs because the salinity of 10 ‰ salinity was optimal for live of fish tilapia. In conclusion, salinity impact the increasing of CAT, GSH, and MDA levels in gills of Nile tilapia.

  1. Water cortisol and testosterone in Nile tilapia (Oreochromis niloticus) recirculating aquaculture systems

    NARCIS (Netherlands)

    Mota, Vasco C.; Martins, Catarina I.M.; Eding, Ep H.; Canário, Adelino V.M.; Verreth, Johan A.J.

    2017-01-01

    The accumulation of steroids released by fish in recirculating aquaculture systems (RAS) may potentially influence their physiology and behavior. The present study examined the release rate of cortisol and testosterone by Nile tilapia, Oreochromis niloticus, and their accumulation in six identical

  2. Productive performance of Nile tilapia (Oreochromis niloticus fed at different frequencies and periods with automatic dispenser

    Directory of Open Access Journals (Sweden)

    R.M.R. Sousa

    2012-02-01

    Full Text Available The performance of Nile tilapia (Oreochromis niloticus raised in cages furnished with an automatic dispenser, supplied at different frequencies (once per hour and once every two hours and periods (daytime, nighttime and both was evaluated. Eighteen 1.0m³ cages were placed into a 2000m² pond, two meters deep with a 5% water exchange. One hundred and seventy tilapias, with initial weight of 16.0±4.9g, were dispersed into each 1m³ cage and the feed ration was adjusted every 21 days with biometry. Data was collected from March to July (autumn and winter. Significant difference to final weight (P<0.05 among treatments was observed. The increase in feeding frequency improves the productive performance of Nile tilapias in cages and permitted better management of the food. The better feed conversion rate for high feeding frequency (24 times day-1 can result in saving up to 360kg of food for each ton of fish produced, increasing the economic sustenance for tilapia culture and suggesting less environmental pollution.

  3. The Fish Immune System, with Particular Emphasis on Nile Tilapia (Oreochromis niloticus)

    Science.gov (United States)

    Knowledge of the immune system is important for a better understanding of disease resistance mechanisms and the development of vaccine strategies. This understanding is also relevant in the control of infectious diseases under intensive tilapia farming. The immune system first recognizes the patho...

  4. Complete Genome Sequence of Streptococcus iniae 89353, a Virulent Strain Isolated from Diseased Tilapia in Taiwan

    Science.gov (United States)

    Wu, Sheng-Han; Chen, Chun-Yao; Huang, Chang-Wen; Lu, Jenn-Kan; Chou, Hsin-Yiu

    2017-01-01

    ABSTRACT Streptococcus iniae 89353 is a virulent strain isolated from diseased tilapia in Taiwan. The full-genome sequence of S. iniae 89353 is 2,098,647 bp. The revealed genome information will be beneficial for identification and understanding of potential virulence genes of Streptococcus iniae and possible immunogens for vaccine development against streptococcosis. PMID:28126946

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

    Science.gov (United States)

    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...

  6. Optima Futura in Zwolle officieel geopend : gekoppelde teelt van tilapia en snijbloemen

    NARCIS (Netherlands)

    Heijden, van der P.G.M.

    2009-01-01

    Op 3 april is bij de AOC 'de Groene Welle' in Zwolle het project Optima Futura officieel geopend. In dit project wordt in een kas de integratie van de teelt van Tilapia met die van Gerbera's getest. Kook-entertainer Pierre Wind droeg bij aan een geslaagde middag. Behalve de opening wordt in dit stuk

  7. Enhanced susceptibility of hybrid tilapia to Flavobacterium columnare after parasitism by Ichthyophthirius multifiliis

    Science.gov (United States)

    Bacterium Flavobacterium columnare and protozoan Ichthyophthirius multifiliis are two common pathogens of cultured fish. The objective of this study was to evaluate the susceptibility of hybrid tilapia (Oreochromis spp.) to the bacterium F. columnare, including fish mortality and bacterial loads in ...

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

    Science.gov (United States)

    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...

  9. Accumulation and toxic effects of microcystin in tilapia (Oreochromis niloticus) from an eutrophic Brazilian lagoon.

    Science.gov (United States)

    Hauser-Davis, Rachel Ann; Lavradas, Raquel Teixeira; Lavandier, Ricardo Cavalcanti; Rojas, Edwin Gonzalo Azero; Guarino, Alcides Wagner Serpa; Ziolli, Roberta Lourenço

    2015-02-01

    Microcystin (MC) accumulation and depuration in environmentally exposed tilapia (Oreochromis niloticus) at a chronically contaminated eutrophic lagoon was studied. This is one of the scarce reports on microcystin accumulation in bile of environmentally exposed fish, and gonad MC accumulation in the field, in contrast to laboratory exposure experiments. Results show that preferential MC accumulation in the environment occurred in tilapia fish muscle, followed by gonads, liver and, finally, bile. Biliary MC excretion in in situ conditions indicates elimination from the body to a certain degree. High gonad MC bioaccumulation is of concern, since this could indicate potential reproductive problems in this species. This study also demonstrated that tilapia shows similar oxidative stress responses (in the form of reduced glutathione, GSH) in the environment as those observed in laboratory exposed fish. MC dietary intake values for tilapia muscle and liver were above the limits imposed by international legislations, indicating that the local human population should exercise care when ingesting this species as a part of their diet and that human ingestion of MC-contaminated samples should be carefully monitored.

  10. Physicochemical and sensory characteristics of snack made with minced Nile tilapia

    Directory of Open Access Journals (Sweden)

    João De Paula Cortez Netto

    2014-09-01

    Full Text Available Nile tilapia is one of the major fish species cultivated worldwide and in Brazil. The tilapia fillet yield is between 30-35%, thus around 70% of waste is generated. A portion of this waste can be used to obtain minced fish, and the resulting product can be used as meat raw material to prepare fish snacks. The aim of this study was to produce fish snacks containing different inclusion levels (20, 30, and 40% of minced fish obtained from Nile tilapia processing waste and evaluate their physicochemical characteristics and sensory acceptance. Protein content, ash, water activity, and hardness increased with increasing inclusion of minced fish. The scores obtained in the sensory evaluation were: flavor acceptance (from 7.2 to 5.7, texture (from 7.4 to 5.3, overall acceptance (from 7.1 to 5.9, and willingness to purchase (from 4.0 to 3.1. This study demonstrates that the inclusion of 20 to 40% of minced fish of Nile tilapia in snacks is well accepted and improves their nutritional value without affecting the physicochemical properties.

  11. Use, fate and ecological risks of antibiotics applied in tilapia cage farming in Thailand

    NARCIS (Netherlands)

    Rico, A.; Oliveira, R.; McDonough, S.; Matser, A.; Khatikarn, J.; Satapornvanit, K.; Nogueira, A.J.A.; Soares, A.M.V.M.; Domingues, I.; Brink, van den P.J.

    2014-01-01

    The use, environmental fate and ecological risks of antibiotics applied in tilapia cage farming were investigated in the Tha Chin and Mun rivers in Thailand. Information on antibiotic use was collected through interviewing 29 farmers, and the concentrations of the most commonly used antibiotics, oxy

  12. Background adaptation and water acidification affect pigmentation and stress physiology of tilapia, Oreochromis mossambicus

    NARCIS (Netherlands)

    Salm, A.L. van der; Spanings, F.A.T.; Gresnigt, R.; Wendelaar Bonga, S.E.; Flik, G.

    2005-01-01

    The ability to adjust skin darkness to the background is a common phenomenon in fish. The hormone alpha-melanophore-stimulating hormone (alphaMSH) enhances skin darkening. In Mozambique tilapia, Oreochromis mossambicus L., alphaMSH acts as a corticotropic hormone during adaptation to water with a lo

  13. Water cortisol and testosterone in Nile tilapia (Oreochromis niloticus) recirculating aquaculture systems

    NARCIS (Netherlands)

    Mota, Vasco C.; Martins, Catarina I.M.; Eding, Ep H.; Canário, Adelino V.M.; Verreth, Johan A.J.

    2017-01-01

    The accumulation of steroids released by fish in recirculating aquaculture systems (RAS) may potentially influence their physiology and behavior. The present study examined the release rate of cortisol and testosterone by Nile tilapia, Oreochromis niloticus, and their accumulation in six identical l

  14. Salinity and diet composition affect digestibility and intestinal morphology in Nile tilapia (Oreochromis niloticus)

    NARCIS (Netherlands)

    Tran, Kim; Schrama, Johan W.; Le, Mai T.T.; Nguyen, Thinh H.; Roem, Arjen J.; Verreth, Johan A.J.

    2017-01-01

    An increase in salinity of the aquatic habitat can be an environmental stress factor for fresh aquatic organism, including fish. The present study investigated the impact of salinity and diet composition on digestibility and intestinal morphology of Nile tilapia. Triplicate groups of 35 fish

  15. The role of Tilapia in food security of fishing villages in Niger state ...

    African Journals Online (AJOL)

    The role of Tilapia in food security of fishing villages in Niger state, Nigeria. ... the form of fish cooked (fresh, smoked, dried) and the source of fish (whether ... purchased in the market or caught directly by household members from local rivers).

  16. beta-adrenoceptors mediate inhibition of lipolysis in adipocytes of tilapia (Oreochromis mossambicus)

    NARCIS (Netherlands)

    Vianen, GJ; Obels, PP; Van Den Thillart, GEEJM; Zaagsma, J

    2002-01-01

    The regulation of triglyceride mobilization by catecholamines was investigated in the teleost fish Oreochromis mossambicus (tilapia) in vivo and in vitro. In vitro experiments were carried out with adipocytes that were isolated for the first time from fish adipose tissue. For the in vivo experiments

  17. Evaluation of Nile tilapia strains cultivated in cages under different feeding programmes

    Directory of Open Access Journals (Sweden)

    Thiago Archangelo Freato

    2012-06-01

    Full Text Available The objective of this study was to evaluate the performance of three Nile tilapia Oreochromis niloticus strains cultivated in cages and subjected to different feeding programmes. Initially, 31,200 Nile tilapia juveniles with an average weight of 61.15 g were distributed in 48 cages. Two genetically improved strains were used together with one from the Fish Culture Section of Universidade Federal de Lavras (UFLA. The fish were subjected to four feeding programmes, consisting of different levels of crude protein (CP in diets provided at different stages of cultivation. There was no interaction effect of the strain and feeding programme for most variables. The UFLA strain presented the highest weight gain, but with greatest lack of uniformity at the end of cultivation. The feeding programme with diets containing 36%, 32% and 28% CP, consecutively, promoted the highest weight gain and highest final biomass. The UFLA strain has great growth potential, justifying the development of a breeding programme for this strain. Crude protein levels below 36% for tilapias between 60 and 170 g and below 32% for tilapias between 170 and 700 g worsen fish performance.

  18. Complete genome sequence of a virulent Streptococcus agalactiae strain 138P isolated from diseased Nile tilapia

    Science.gov (United States)

    Streptococcus agalactiae strain 138P was isolated from the kidney of diseased Nile tilapia in Idaho during a 2007 streptococcal disease outbreak. The full genome of S. agalactiae 138P is 1,838,716 bp. The availability of this genome will allow comparative genomics to identify genes for antigen disco...

  19. Absorbed Dose Rate Due to Intake of Natural Radionuclides by Tilapia Fish (Tilapia nilotica,Linnaeus, 1758) Estimated Near Uranium Mining at Caetité, Bahia, Brazil

    Science.gov (United States)

    Pereira, Wagner de S.; Kelecom, Alphonse; Py Júnior, Delcy de Azevedo

    2008-08-01

    The uranium mining at Caetité (Uranium Concentrate Unit—URA) is in its operational phase. Aiming to estimate the radiological environmental impact of the URA, a monitoring program is underway. In order to preserve the biota of the deleterious effects from radiation and to act in a pro-active way as expected from a licensing body, the present work aims to use an environmental protection methodology based on the calculation of absorbed dose rate in biota. Thus, selected target organism was the Tilapia fish (Tilapia nilotica, Linnaeus, 1758) and the radionuclides were: uranium (U-238), thorium (Th-232), radium (Ra-226 and Ra-228) and lead (Pb-210). As, in Brazil there are no radiation exposure limits adopted for biota the value proposed by the Department of Energy (DOE) of the United States of 3.5×103 μGy y-1 has been used. The derived absorbed dose rate calculated for Tilapia was 2.51×100 μGy y-1, that is less than 0.1% of the dose limit established by DOE. The critical radionuclide was Ra-226, with 56% of the absorbed dose rate, followed by U-238 with 34% and Th-232 with 9%. This value of 0.1% of the limit allows to state that, in the operational conditions analyzed, natural radionuclides do not represent a radiological problem to biota.

  20. Absorbed dose rate due to intake of natural radionuclides by Tilapia fish (Tilapia nilotica, Linnaeus, 1758) estimated near uranium anomaly at Santa Quiteria, Ceara, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner de [Industrias Nucleares do Brasil S.A. (INB), Pocos de Caldas, MG (Brazil). Coordenacao de Protecao Radiologica. Unidade de Tratamento de Minerios], E-mail: wspereira@inb.gov.br; Kelecom, Alphonse [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Programa de Pos-graduacao em Ciencia Ambiental; Py Junior, Delcy de Azevedo [Industrias Nucleares do Brasil S.A. (INB), Caetite, BA (Brazil). Coordenacao de Protecao Radiologica. Unidade de Concentrado de Uranio], E-mail: Delcy@inb.gov.br

    2007-07-01

    The uranium mining at Santa Quiteria (Santa Quiteria Unit - USQ) is in its environmental licensing phase. Aiming to estimate the radiological environmental impact of the USQ, a monitoring program is underway. However, radioprotection of biota is not explicitly mentioned in Brazilian norms. In order to preserve the biota of the deleterious effects from radiation and to behave in a pro-active way as expected by licensing organs, the present work aims to use an environmental protection methodology, based on the calculation of absorbed dose rate in biota. Thus, selected biomarker was the fish tilapia (Tilapia nilotica, Linnaeus, 1758) and the radionuclides were: uranium (U-238), thorium (Th-232), radium (Ra-226 and Ra-228) and lead (Pb-210). Since there are no exposition limits for biota, in Brazil, the value proposed by the Department of Energy (DOE) of the United States of 3.5 x 10{sup 3} {mu}Gy/y has been used. The derived absorbed dose rate calculated for tilapia was 2.76 x 10{sup 0} {mu}Gy/y, that is less than 0.1 % of the limit established by DOE. The critical radionuclide was U-238, with 99% of the absorbed dose rate. This value of 0.1% of the limit allows to state that in pre-operational conditions analyzed natural radionuclides do not represent a radiological problem to the biota. (author)

  1. Toxicity, distribution, accumulation and cooking loss of malathion in tissues of tilapia and common carp fishes

    Directory of Open Access Journals (Sweden)

    Hassan, I. M.

    1993-12-01

    Full Text Available The acute toxicity of malathion as an organophosphorus pesticide to both of the tested fish species, i.e. Tilapia nilotica (tilapia and cyprinus carpio (Common carp was followed by estimating the LC50 at intervals from 24h up to 96h. Tilapia was much more susceptible to malathion toxicity when compared with carp and the available data proved that the LG50 of malathion to common carp fish was 5-7 times the LC50 for tilapia. Accumulation of malathion pesticide in some organs (muscles, gills, intestine and liver of both fish species was studied after application of 200, 300 and 400 ppb malathion in water for 28 days. A proportional relation was found in the two fish species between exposure time and the applied concentrations. The rate of malathion accumulation was higher in liver followed by intestine and gills whereas the lowest concentration was found in muscles. Accumulated malathion in tilapia muscles was higher than carp; while a reversible trend was observed in most other organs. Cooking of the same fish species reduced effectively malathion content in their muscles. Frying of fish in oil lead to a higher loss percent of malathion than did the other methods of cooking.

    La toxicidad aguda de malatión, pesticida organofosforado, para las dos especies de pescado analizadas, Tilapia nilotica (tilapia y Cyprinus carpio (carpa común, fue seguida por estimación de la CL50 a intervalos desde las 24h hasta las 96h. Tilapia fue mucho más susceptible a la toxicidad del malatión cuando se comparó con carpa, y los datos disponibles proporcionaron que la CL50 del malatión para carpa común fue de 5-7 veces la GL50 para tilapia. La acumulación del pesticida malatión en algunos órganos (músculos, agallas, intestino e hígado de ambas especies de pescado fue estudiada después de la aplicación de concentraciones de 200, 300 y 400 ppb de malatión en agua durante 28 días. Se encontró una relaci

  2. Differential pathogenicity of five Streptococcus agalactiae isolates of diverse geographic origin in Nile tilapia (Oreochromis niloticus L.)

    Science.gov (United States)

    Streptococcus agalactiae is an emerging pathogen of fish and has caused significant morbidity amd mortality worldwide. The work in this study assessed whether pathogenic differences exist among isolates from different geographic locations. Nile tilapia (Oreochromis niloticus L.) were administered an...

  3. Assessment of heavy metals and estimation of human health risk in Tilapia fish from Naik lake of Nagpur, India

    Digital Repository Service at National Institute of Oceanography (India)

    Giripunje, M.D.; Fulke, A.B.; Meshram, P.U.

    /g dw respectively. These levels were above the maximum permissible limits of Food and Agriculture Organization (FAO)/World Health Organisation (WHO). The results confirmed that tilapia fish from Naik lake are not safe for human consumption. Further...

  4. Reversion sexual de las Tilapias Roja (Oreochromis Sp, una guía básica para el acuacultor

    Directory of Open Access Journals (Sweden)

    Duván Andrés Arboleda Obregón

    2005-12-01

    Full Text Available La tilapia roja es un híbrido distribuido en todo el mundo; atractivo por su color y sus características zootécnicas lo que la convierte en una especie con gran mercado y de gran importancia para investigación, en tilapia es importante el cultivo de machos, para obtener machos se usa la 17alfametiltestosterona que es una hormona que cuando suministrada con el alimento a los alevines los transforma en machos. The red tilapia is a hybrid distribuided in all the world; it is attractive due to its color and its zootechnical characteristic convert in a specie with big market and of many importance for research, in tilapia is important the males culture, for obtain males is used 17alfamethyltestosterone that is an hormone when is supplied with the food to the fingerlings transform in males

  5. La Tilapia en el Perú: acuicultura, mercado, y perspectivas

    Directory of Open Access Journals (Sweden)

    Paúl M. Baltazar

    2013-05-01

    Full Text Available Tilapia es el nombre común con el cual se conocen a diversas especies de los géneros Oreochromis y Tilapia. Las Tilapias son peces de agua dulce endémicos y originarios de África y el Cercano Oriente, aprovechando sus características y adaptabilidad, a comienzos del siglo XIX se inician las investigaciones para utilizarlas en la piscicultura rural, especialmente en el Congo Belga (actualmente Zaire. A partir de 1924 se intensifica su cultivo en Kenia, sin embargo fue en el Extremo Oriente, en Malasia en donde se obtuvieron los mejores resultados y se iniciara su progresivo cultivo en diferentes partes del mundo. En Perú, en la década del 50, la Dirección General de Caza y Pesca del Ministerio de Fomento y Agricultura realizó las primeras introducciones con la especie Tilapia rendalli, utilizada como forraje para el paiche (Arapaina gigas; en la década de los 70, el IMARPE y la Universidad Nacional Agraria La Molina introdujeron las especies Oreochromis niloticus, Oreochromis hornorum y Oreochromis mossambica (Ramos y Gálvez, 2000, con fines de investigación y cultivo en las zonas de selva. La Tilapia roja, Oreochromis spp., ingresa a nuestro país entre los meses de octubre y noviembre de 1996, como parte complementaria de otro lote de reproductores grises, (con el objetivo de evitar la endogamia, procedentes de la Estación DIVISA, Panamá.

  6. Direct Ionic Regulation of the Activity of Myo-Inositol Biosynthesis Enzymes in Mozambique Tilapia.

    Directory of Open Access Journals (Sweden)

    Fernando D Villarreal

    Full Text Available Myo-inositol (Ins is a major compatible osmolyte in many cells, including those of Mozambique tilapia (Oreochromis mossambicus. Ins biosynthesis is highly up-regulated in tilapia and other euryhaline fish exposed to hyperosmotic stress. In this study, enzymatic regulation of two enzymes of Ins biosynthesis, Ins phosphate synthase (MIPS and inositol monophosphatase (IMPase, by direct ionic effects is analyzed. Specific MIPS and IMPase isoforms from Mozambique tilapia (MIPS-160 and IMPase 1 were selected based on experimental, phylogenetic, and structural evidence supporting their role for Ins biosynthesis during hyperosmotic stress. Recombinant tilapia IMPase 1 and MIPS-160 activity was assayed in vitro at ionic conditions that mimic changes in the intracellular milieu during hyperosmotic stress. The in vitro activities of MIPS-160 and IMPase 1 are highest at alkaline pH of 8.8. IMPase 1 catalytic efficiency is strongly increased during hyperosmolality (particularly for the substrate D-Ins-3-phosphate, Ins-3P, mainly as a result of [Na+] elevation. Furthermore, the substrate-specificity of IMPase 1 towards D-Ins-1-phosphate (Ins-1P is lower than towards Ins-3P. Because MIPS catalysis results in Ins-3P this results represents additional evidence for IMPase 1 being the isoform that mediates Ins biosynthesis in tilapia. Our data collectively demonstrate that the Ins biosynthesis enzymes are activated under ionic conditions that cells are exposed to during hypertonicity, resulting in Ins accumulation, which, in turn, results in restoration of intracellular ion homeostasis. We propose that the unique and direct ionic regulation of the activities of Ins biosynthesis enzymes represents an efficient biochemical feedback loop for regulation of intracellular physiological ion homeostasis during hyperosmotic stress.

  7. Dopamine inhibits somatolactin gene expression in tilapia pituitary cells through the dopamine D2 receptors.

    Science.gov (United States)

    Jiang, Quan; Lian, Anji; He, Qi

    2016-07-01

    Dopamine (DA) is an important neurotransmitter in the central nervous system of vertebrates and possesses key hypophysiotropic functions. Early studies have shown that DA has a potent inhibitory effect on somatolactin (SL) release in fish. However, the mechanisms responsible for DA inhibition of SL gene expression are largely unknown. To this end, tilapia DA type-1 (D1) and type-2 (D2) receptor transcripts were examined in the neurointermediate lobe (NIL) of the tilapia pituitary by real-time PCR. In tilapia, DA not only was effective in inhibiting SL mRNA levels in vivo and in vitro, but also could abolish pituitary adenylate cyclase-activating polypeptide (PACAP)- and salmon gonadotropin-releasing hormone (sGnRH)-stimulated SL gene expression at the pituitary level. In parallel studies, the specific D2 receptor agonists quinpirole and bromocriptine could mimic the DA-inhibited SL gene expression. Furthermore, the D2 receptor antagonists domperidone and (-)-sulpiride could abolish the SL response to DA or the D2 agonist quinpirole, whereas D1 receptor antagonists SCH23390 and SKF83566 were not effective in this respect. In primary cultures of tilapia NIL cells, D2 agonist quinpirole-inhibited cAMP production could be blocked by co-treatment with the D2 antagonist domperidone and the ability of forskolin to increase cAMP production was also inhibited by quinpirole. Using a pharmacological approach, the AC/cAMP pathway was shown to be involved in quinpirole-inhibited SL mRNA expression. These results provide evidence that DA can directly inhibit SL gene expression at the tilapia pituitary level via D2 receptor through the AC/cAMP-dependent mechanism.

  8. Direct Ionic Regulation of the Activity of Myo-Inositol Biosynthesis Enzymes in Mozambique Tilapia.

    Science.gov (United States)

    Villarreal, Fernando D; Kültz, Dietmar

    2015-01-01

    Myo-inositol (Ins) is a major compatible osmolyte in many cells, including those of Mozambique tilapia (Oreochromis mossambicus). Ins biosynthesis is highly up-regulated in tilapia and other euryhaline fish exposed to hyperosmotic stress. In this study, enzymatic regulation of two enzymes of Ins biosynthesis, Ins phosphate synthase (MIPS) and inositol monophosphatase (IMPase), by direct ionic effects is analyzed. Specific MIPS and IMPase isoforms from Mozambique tilapia (MIPS-160 and IMPase 1) were selected based on experimental, phylogenetic, and structural evidence supporting their role for Ins biosynthesis during hyperosmotic stress. Recombinant tilapia IMPase 1 and MIPS-160 activity was assayed in vitro at ionic conditions that mimic changes in the intracellular milieu during hyperosmotic stress. The in vitro activities of MIPS-160 and IMPase 1 are highest at alkaline pH of 8.8. IMPase 1 catalytic efficiency is strongly increased during hyperosmolality (particularly for the substrate D-Ins-3-phosphate, Ins-3P), mainly as a result of [Na+] elevation. Furthermore, the substrate-specificity of IMPase 1 towards D-Ins-1-phosphate (Ins-1P) is lower than towards Ins-3P. Because MIPS catalysis results in Ins-3P this results represents additional evidence for IMPase 1 being the isoform that mediates Ins biosynthesis in tilapia. Our data collectively demonstrate that the Ins biosynthesis enzymes are activated under ionic conditions that cells are exposed to during hypertonicity, resulting in Ins accumulation, which, in turn, results in restoration of intracellular ion homeostasis. We propose that the unique and direct ionic regulation of the activities of Ins biosynthesis enzymes represents an efficient biochemical feedback loop for regulation of intracellular physiological ion homeostasis during hyperosmotic stress.

  9. Derivation and osmotolerance characterization of three immortalized tilapia (Oreochromis mossambicus) cell lines.

    Science.gov (United States)

    Gardell, Alison M; Qin, Qin; Rice, Robert H; Li, Johnathan; Kültz, Dietmar

    2014-01-01

    Fish cell cultures are becoming more widely used models for investigating molecular mechanisms of physiological response to environmental challenge. In this study, we derived two immortalized Mozambique tilapia (Oreochromis mossambicus) cell lines from brain (OmB) and lip epithelium (OmL), and compared them to a previously immortalized bulbus arteriosus (TmB) cell line. The OmB and OmL cell lines were generated without or with Rho-associated kinase (ROCK) inhibitor/3T3 feeder layer supplementation. Although both approaches were successful, ROCK inhibitor/feeder layer supplementation was found to offer the advantages of selecting for epithelial-like cell type and decreasing time to immortalization. After immortalization (≥ passage 5), we characterized the proteomes of the newly derived cell lines (OmB and OmL) using LCMS and identified several unique cell markers for each line. Subsequently, osmotolerance for each of the three cell lines following acute exposure to elevated sodium chloride was evaluated. The acute maximum osmotolerance of these tilapia cell lines (>700 mOsm/kg) was markedly higher than that of any other known vertebrate cell line, but was significantly higher in the epithelial-like OmL cell line. To validate the physiological relevance of these tilapia cell lines, we quantified the effects of acute hyperosmotic challenge (450 mOsm/kg and 700 mOsm/kg) on the transcriptional regulation of two enzymes involved in biosynthesis of the compatible organic osmolyte, myo-inositol. Both enzymes were found to be robustly upregulated in all three tilapia cell lines. Therefore, the newly established tilapia cells lines represent valuable tools for studying molecular mechanisms involved in the osmotic stress response of euryhaline fish.

  10. Direct regulation of gonadotropin release by neurokinin B in tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Biran, Jakob; Golan, Matan; Mizrahi, Naama; Ogawa, Satoshi; Parhar, Ishwar S; Levavi-Sivan, Berta

    2014-12-01

    Neurokinin B (NKB) was recently identified as a key regulator of reproduction in mammals and fish. Fish were found to possess a specific novel neurokinin termed NKF. To study the role of NKB/NKF in the regulation of fish reproduction and to investigate the role of NKB/NKF and their receptors in the piscine pituitary, we have identified the NKB/tachikinin 3 receptor (tac3r) system in tilapia. Bioinformatics and phylogenetic analyses have demonstrated that the tilapia holds 1 putative tac3 gene and 2 NKB receptor genes (tac3ra and tac3rb) that clustered with other piscine Tac3 and NKB receptor lineages. Furthermore, we found that in African cichlids, NKB peptides differ from other vertebrate NKBs in their C-terminal sequence, possessing isoleucine instead of valine as the X in the NKB FXGLM-NH2-terminal consensus sequence. Signal transduction analysis demonstrated that tilapia NKB (tiNKB), tiNKF, and human NKB activated both CRE-luc and SRE-luc transcriptional activity of both tilapia and human NKB receptors. Two hours after ip injection of tiNKB, the plasma levels of both FSH and LH were increased, whereas tiNKF was more effective in increasing LH levels. However, tiNKB was more effective than tiNKF in increasing both FSH and LH from tilapia pituitary dispersed cells. Using in situ hybridization and fluorescent immunohistochemistry, we have shown that LH cells possess tac3, tac3ra, and tac3rb mRNAs, whereas FSH cells possess mainly tac3rb and tac3ra and tac3 to a much lesser extent. These results suggest that the members of the NKB/tac3r system may serve as paracrine/autocrine regulators of gonadotropin release in fish pituitary.

  11. Chemical communication in tilapia: a comparison of Oreochromis mossambicus with O. niloticus.

    Science.gov (United States)

    Hubbard, Peter C; Mota, Vasco C; Keller-Costa, Tina; da Silva, José Paulo; Canário, Adelino V M

    2014-10-01

    In allopatric speciation species differentiation generally results from different selective pressures in different environments, and identifying the traits responsible helps to understand the isolation mechanism(s) involved. Male Mozambique tilapia (Oreochromis mossambicus) use urine to signal dominance; furthermore, 5β-pregnane-3α,17,20β-triol-3α-glucuronide (and its α-epimer, 5β-pregnane-3α,17,20α-triol-3α-glucuronide), in their urine is a potent pheromone, the concentration of which is correlated with social status. The Nile tilapia (Oreochromisniloticus) is a close relative; species divergence probably resulted from geographical separation around 6 million years ago. This raises the question of whether the two species use similar urinary chemical cues during reproduction. The olfactory potency of urine, and crude extracts, from either species was assessed by the electro-olfactogram and the presence of the steroid glucuronides in urine from the Nile tilapia by liquid-chromatography/mass-spectrometry. Both species showed similar olfactory sensitivity to urine and respective extracts from either species, and similar sensitivity to the steroid glucuronides. 5β-Pregnan-3α,17α,20β-triol-3α-glucuronide was present at high concentrations (approaching 0.5mM) in urine from Nile tilapia, with 5β-pregnan-3α,17α,20α-triol-3α-glucuronide present at lower concentrations, similar to the Mozambique tilapia. Both species also had similar olfactory sensitivity to estradiol-3-glucuronide, a putative urinary cue from females. Together, these results support the idea that reproductive chemical cues have not been subjected to differing selective pressure. Whether these chemical cues have the same physiological and behavioural roles in O. niloticus as O. mossambicus remains to be investigated.

  12. Contrasting mercury accumulation patterns in tilapia (Oreochromis niloticus) and implications on somatic growth dilution.

    Science.gov (United States)

    Wang, Rui; Wang, Wen-Xiong

    2012-06-15

    Dietary ingestion constitutes a major pathway for mercury (Hg) accumulation in freshwater fish, thus the ingestion rate (IR) may greatly influence the Hg bioaccumulation through its effect on Hg influx and other biokinetic processes. To explore the complex influence of IR, we conducted long-term bioaccumulation experiments by accurately controlling the IRs in the freshwater tilapia (Oreochromis niloticus). The dietary accumulation of both inorganic mercury (Hg[II]) and methylmercury (MeHg) in tilapia under different IRs was monitored over a period of 30 days by feeding the fish with uniformly radiolabeled crustaceans. The biokinetic parameters under various IRs were concurrently determined. With the increase of IR from 0.01 g g⁻¹ d⁻¹ to 0.12 g g⁻¹ d⁻¹, the dietary assimilation efficiency of Hg(II) in the tilapia decreased by 43% while the elimination rate increased by a factor of 1.8; both biokinetic changes slowed down the overall Hg(II) bioaccumulation at high IRs. In contrast to Hg(II), the biokinetics of MeHg was not significantly influenced, but its bioaccumulation increased disproportionally with increasing IR, showing slower increase at higher IR. We then employed a biokinetic model to simulate the long-term mercury bioaccumulation patterns in tilapia at various IRs. The modeling results indicated that the growth effect could not be ignored in long-term accumulation process. A rapid growth of fish driven by food availability could significantly reduce the MeHg concentrations in the tilapia. Our results demonstrated for the first time the contrasting influences of dietary ingestion on the long-term bioaccumulation of Hg(II) and MeHg. The somatic growth dilution was much more likely to occur for MeHg than for Hg(II).

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

    Science.gov (United States)

    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.

  14. Influence of environmental color on zootechnical performance and feeding behavior during masculinization of Nile tilapia

    Directory of Open Access Journals (Sweden)

    Perila Maciel Rebouças

    2014-10-01

    Full Text Available The rise of tilapia in Brazil and the world increasingly needs the best growing conditions. Despite the Nile tilapia has diurnal, your vision is considered a strong sensory stimulus, and as the perception of the color contrast of medium, production losses may be evidence due to stress caused too. Thus, an experiment was conducted at Biotechnology Aquaculture Applied Center (CEBIAQUA, The Fishing Engineering Department, Federal University of Ceará, with the aim of evaluating the influence of the background color translucent on zootechnical performance and feeding behavior of Nile tilapia during masculinization. We used 200 post-larvae (average weight = 0:02 ± 0.01g; mean initial length = 1.10 ± 0.01 cm of Nile tilapia, packed in 40 L aquarium, covered with cellophane, for 28 days. Fish were distributed in a completely randomized in two treatments (blue and green and five replications. Environmental variables analyzed were dissolved oxygen, temperature, pH and photoperiod and productive performance was evaluated weight, total length, condition factor and lot uniformity. Behavioral observations occurred twice daily, immediately before the first feeding and 2 minutes after each feeding treatment. We found no significant difference in water parameters in two treatments. The weight, length and condition factor did not differ between treatments. There was a higher survival rate, more lot uniformity, and an obvious grouped behavior during feeding in aquaria translucent greens than blues. So for the masculinization of Nile tilapia, it is recommended to translucent green, because the results were most satisfactory.

  15. Morphometric Characters of Nile Tilapia (Oreochromis niloticus in Thailand

    Directory of Open Access Journals (Sweden)

    Piya KOSAI

    2014-02-01

    Full Text Available The present study is conducted to describe the morphometric characteristics of a Thailand strain of Oreochromis niloticus. The total length of the observed fish ranged from 7.96 - 17.36 cm. Body measurement and proportions are extensively used for identification of this species. The following 18 measurements are determined for each fish: Total length (TL; Standard length (SL; Body depth (BD; Pre-dorsal length (PDL; Pre-pectoral length (PPCL; Pre-pelvic length (PPVL; Pre-anal length (PAL; Depth of caudal peduncle (DCP; Length of caudal peduncle (LCP; Head length (HL; Eye diameter (ED; Snout length (SNL; Upper jaw length (UJL; Lower jaw length (LJL; Caudal fin length (CFL; Pectoral fin length (PFL; Length of dorsal fin base (LDFB; Length of anal fin base (LAFB. The rate of growth of different morphological body parts of the fish in relation to its total length is studied. Additionally, the total length and body weight relationship is found to be a straight line in logarithmic scale expressed as Log BW = 3.026 Log TL - 1.839. The value of regression co-efficient obtained for the length-weight relationship is 3.026. This finding suggests that selection for growth using this equation is a good alternative for measuring weight in the field, when accurate weighing balances are not available. Hence, the present study provides the information of the various body parts measurements of Tilapia and establishes mathematical equations relating to these various morphometric relationships which can be utilized for the conversion of one measurement into another.doi:10.14456/WJST.2014.76

  16. Tilapia rendalli increases phytoplankton biomass of a shallow tropical lake

    Directory of Open Access Journals (Sweden)

    Lúcia Helena Sampaio da Silva

    2014-12-01

    Full Text Available AIM: This study aimed to experimentally test the influence of a planktivorous filter-feeding fish (Tilapia rendalli on the phytoplankton dynamics of a small and shallow tropical reservoir (Lake Monte Alegre, Brazil. Adults of T. rendalli of this lake feed preferentially on phytoplankton, and we hypothesize that: I adults of T. rendalli will decrease the phytoplankton biomass and composition through direct herbivory, and II as it is a eutrophic system, fish would not have strong influence on phytoplankton through nutrient cycling. METHODS: To evaluate these different effects on algae, a field experiment was performed in the summer period for 15 days, in mesocosms isolated from the sediment, using a control group (no fish and a treatment group (with one fish in each mesocosm. Physical and chemical variables and phyto- and zooplankton were evaluated at the start, middle, and end of the experiment. RESULTS: At the end of the experiment, it was observed a significant increase in ammonium concentrations and total phytoplankton biomass, Cyanobacteria and Zygnemaphyceae and all size classes except class II (20-30 µm in the treatment group (with fish. The biomass increase of the potentially toxic cyanobacterium Cylindrospermospsis raciborskii was also observed in the fish treatment at the end of the experimental period. CONCLUSION: This study did not support both initial hypotheses. It supports the assertion that in tropical water bodies, with similar characteristics to the environment studied, planktivorous filter-feeding fish, such as T. rendalli, are not effective in reducing phytoplankton biomass through direct grazing, even when phytoplankton is one of their main food items. T. rendalli can contribute to the increase of phytoplankton biomass and can promote or increase the eutrophication of aquatic systems.

  17. Management measures to control diseases reported by tilapia (Oreochromis spp.) and whiteleg shrimp (Litopenaeus vannamei) farmers in Guangdong, China

    OpenAIRE

    2016-01-01

    Culture of tilapia (Oreochromis spp.) and whiteleg shrimp (Litopenaeus vannamei) has intensified during the last decade in China with increased production, meanwhile it has also brought some problems, including diseases, increased use of antimicrobials and other chemicals for disease control and pond water quality management. This study investigated the knowledge, practices and challenges of tilapia and whiteleg shrimp farmers when preventing and controlling diseases through the use of antimi...

  18. Development of research tool to evaluate the potential of using chlorella sorokiniana as bio-filter in recycled tilapia production

    OpenAIRE

    Latif, Muhammad Saqib

    2016-01-01

    The current study was attempted to develop the research tools in order to evaluate if Chlorella sorokiniana has a potential to perform as a bio-filter in recycle water tilapia production. The overall objective was to test the hypothesis that C. sorokiniana will effectively remove nitrogenous catabolites from the water and benefit the tilapia with oxygen and nutrients by photosynthesis. Removal of ammonia and nitrite from the water is improved by fertilization with phosphate, th...

  19. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs.

    OpenAIRE

    Guyon Richard; Rakotomanga Michaelle; Azzouzi Naoual; Coutanceau Jean Pierre; Bonillo Celine; D’Cotta Helena; Pepey Elodie; Soler Lucile; Rodier-Goud Marguerite; D’Hont Angelique; Conte Matthew A; van Bers Nikkie EM; Penman David J; Hitte Christophe; Crooijmans Richard PMA

    2012-01-01

    Abstract Background The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic ma...

  20. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs

    OpenAIRE

    Guyon, Richard; Rakotomanga, Michaelle; Azzouzi, Naoual; Coutanceau, Jean Pierre; Bonillo, Celine; D’Cotta, Helena; Pepey, Elodie; Soler, Lucile; Rodier-Goud, Marguerite; D’Hont, Angelique; Conte, Matthew A; van Bers, Nikkie EM; Penman, David J.; Hitte, Christophe; Crooijmans, Richard Pma

    2012-01-01

    Background The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic map, BAC en...

  1. COMPARACIÓN SENSORIAL DE TRES FORMULACIONES DE HAMBURGUESAS ELABORADAS A BASE DE TILAPIA ROJA (Oreochromis sp..

    Directory of Open Access Journals (Sweden)

    JOSÉ IGOR HLEAP ZAPATA

    2013-12-01

    Full Text Available Se evaluaron sensorialmente hamburguesas elaboradas a base de tilapia roja y dos formulaciones adicionales, en las cuales se sustituyó un porcentaje de tilapia roja por carne de res, en una, y de cerdo, en la otra. Se plantearon tres formulaciones diferentes: solo de carne de tilapia roja codificada con la cifra aleatoria 8204 y carne de tilapia adicionadas con carne de res y carne de cerdo, identificadas con las cifras 6271 y 3522 respectivamente. Las hamburguesas se sometieron a degustaciones realizadas por un panel de 100 consumidores no entrenados, utilizando una escala hedónica de siete puntos. Se valoró estadísticamente la aprobación de los productos y se determinó que hubo buen agrado y buena aceptación. Los resultados indicaron una conformidad del 75% para la muestra 8204, mientras que para las muestras 6271 y 3522, ésta fue respectivamente de 78% y 82%. A pesar de que se presentaron algunas diferencias entre el porcentaje de aceptación de las tres formulaciones, el intervalo de varianza no es significativo, lo cual permitió concluir que los tres productos analizados fueron de completa satisfacción. Se concluyó que las diferencias entre las hamburguesas elaboradas solo a base de tilapia versus las elaboradas a base de tilapia con adición de otras carnes no influyeron en la aceptación por los consumidores.

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

    Science.gov (United States)

    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.

  3. Study of the Antimicrobial Activity of Tilapia Piscidin 3 (TP3) and TP4 and Their Effects on Immune Functions in Hybrid Tilapia (Oreochromis spp.)

    Science.gov (United States)

    Pan, Chieh-Yu; Tsai, Tsung-Yu; Su, Bor-Chyuan; Hui, Cho-Fat; Chen, Jyh-Yih

    2017-01-01

    To address the growing concern over antibiotic-resistant microbial infections in aquatic animals, we tested several promising alternative agents that have emerged as new drug candidates. Specifically, the tilapia piscidins are a group of peptides that possess antimicrobial, wound-healing, and antitumor functions. In this study, we focused on tilapia piscidin 3 (TP3) and TP4, which are peptides derived from Oreochromis niloticus, and investigated their inhibition of acute bacterial infections by infecting hybrid tilapia (Oreochromis spp.) with Vibrio vulnificus and evaluating the protective effects of pre-treating, co-treating, and post-treating fish with TP3 and TP4. In vivo experiments showed that co-treatment with V. vulnificus and TP3 (20 μg/fish) or TP4 (20 μg/fish) achieved 95.3% and 88.9% survival rates, respectively, after seven days. When we co-injected TP3 or TP4 and V. vulnificus into tilapia and then re-challenged the fish with V. vulnificus after 28 days, the tilapia exhibited survival rates of 35.6% and 42.2%, respectively. Pre-treatment with TP3 (30 μg/fish) or TP4 (20 μg/fish) for 30 minutes prior to V. vulnificus infection resulted in high survival rates of 28.9% and 37.8%, respectively, while post-treatment with TP3 (20 μg/fish or 30 μg/fish) or TP4 (20 μg/fish) 30 minutes after V. vulnificus infection yielded high survival rates of 33.3% and 48.9%. In summary, pre-treating, co-treating, and post-treating fish with TP3 or TP4 all effectively decreased the number of V. vulnificus bacteria and promoted significantly lower mortality rates in tilapia. The minimum inhibitory concentrations (MICs) of TP3 and TP4 that were effective for treating fish infected with V. vulnificus were 7.8 and 62.5 μg/ml, respectively, whereas the MICs of kanamycin and ampicillin were 31.2 and 3.91 μg/ml. The antimicrobial activity of these peptides was confirmed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), both of which showed

  4. Bioenergetics-based matrix population modeling enhances life-cycle toxicity assessment of tilapia Oreochromis mossambicus exposed to arsenic.

    Science.gov (United States)

    Liao, Chung-Min; Chiang, Kuo-Chih; Tsai, Jeng-Wei

    2006-04-01

    The objective of this study was to integrate a bioenergetics-based modeling approach into a population stage structure to enhance life-cycle toxicity assessments of the effects of waterborne arsenic (As) on the population dynamics of the tilapia Oreochromis mossambicus. The proposed mathematical model links a Leslie matrix population model and a universal ontogenetic growth model embedding the population-level growth rate and stage-specific modes of toxic action. We present data analyses of key parameters and distributions and discuss the processes of data capture and analysis and the impact of acute/chronic As toxicity responses on population-level effects. We employed a three-parameter Hill equation model to describe the relationship between tilapia whole-body burden and mortality in order to estimate the probability of stage-specific vital rate of survival. Using the DEBtox theory, we distinguished three modes of toxic action (MOA): direct effects on growth and indirect effects via maintenance and food consumption on inhibition by arsenic of the growth of a tilapia population. The asymptotic population growth rate decreased from lambda = 1.0027 for the control group to lambda = 0.9935 for tilapia population exposed to 4 microg mL(-1) As, indicating a potential risk of population intrinsic growth rates for tilapia exposed to higher levels of waterborne As. Our results estimated that an As concentration of 1.02 microg mL(-1) would cause a 50% reduction in the tilapia population. We found that the interplay between external stressors of waterborne As concentration and internally generated modes of action decreasing feeding in the juvenile stage and increasing the maintenance cost in the adult stage had a pronounced influence on the population stage structure of tilapia.

  5. Diseases and treatment reported by shrimp and tilapia farmers in Guangdong Province, China

    DEFF Research Database (Denmark)

    Li, Kang; Liu, Liping; Clausen, Jesper Hedegaard

    Guangdong province is the most important region for tilapia (Oreochromis niloticus) and shrimp (Litopenaeus vannamei) culture in China that meet demands from both national consumers and export markets. However, the intensified production has brought increased disease problems, antibiotics and other......) and exophthalmia disease (9) which were often treated with sulfadiazine, but also other compounds. Shrimp farmers (30) mainly experienced outbreaks of red body disease, white spot syndrome disease and secretly death disease and used a variety of compounds like antibiotics, disinfectants, vitamins and probiotics...... for disease treatment. Tilapia and shrimp farmers obtained more and more technical service from staff in chemical shops, chemical and feed companies on diagnosing and treatment of diseases, and acquired information about prudent and safe application practices of chemicals more easily from different pathways...

  6. Confinement during field studies may jeopardize antioxidant and physiological responses of Nile tilapia to contaminants.

    Science.gov (United States)

    Trevisan, Rafael; Uliano-Silva, Marcela; Franco, Jeferson Luis; Posser, Thais; Hoppe, Roberto; Farina, Marcelo; Bainy, Afonso Celso Dias; Dafre, Alcir Luiz

    2013-10-01

    This work evaluates the effects of caging, a known confinement stress, in Nile tilapia (Oreochromis niloticus) during an environmental study in Cubatão river, southern Brazil. Caging animals for 7 days, regardless of being at the reference or at a contaminated site, resulted in lower levels of antioxidant-related defenses (glutathione, glutathione S-transferase, glucose-6-phosphate dehydrogenase) in liver and physiological parameters (blood glucose and lactate) as compared with free-swimming animals. Higher hepatic glutathione reductase activity and elevated Hb content could be associated to contaminant exposure. In conclusion, the confinement stress in caged Nile tilapia biochemical and physiological disturbances, acting as a confounding factor in field studies.

  7. Immunotoxicity and hepatic function evaluation in Nile tilapia (Oreochromis niloticus) exposed to diazinon.

    Science.gov (United States)

    Girón-Pérez, Manuel Iván; Santerre, Anne; Gonzalez-Jaime, Fabiola; Casas-Solis, Josefina; Hernández-Coronado, Marcela; Peregrina-Sandoval, Jorge; Takemura, Akiro; Zaitseva, Galina

    2007-10-01

    The LC(50) of the organophosphorus pesticides (OPs) diazinon to Nile tilapia (Oreochromis niloticus) was determined, thereafter, hepatic activity, phagocytic index, percentages of active cells, relative spleen weight, total IgM concentration and lymphoproliferation rates were compared between diazinon exposed groups (LC(50) and (1/2)LC(50)) and non-exposed control group. Experimental data show that diazinon is highly toxic for juvenile Nile tilapia (LC(50)=7.830 ppm) and presents immunotoxic properties which affect both the innate and cellular adaptive immune responses of this fish, as revealed by the fact that splenocyte proliferation and phagocytic indices were significantly decreased after acute exposure to the pesticide. However, the hepatic biochemical parameters and the total circulating IgM concentrations were not affected in this experimental model.

  8. Hematology and productive performance of nile tilapia (Oreochromis niloticus naturally infected with Flavobacterium columnare

    Directory of Open Access Journals (Sweden)

    F. A Sebastião

    2011-03-01

    Full Text Available Columnaris disease is one of the main causes of mortality in tilapia rearing and is responsible for large economic losses worldwide. Hematology is a tool that makes it possible to study organisms' physiological responses to pathogens. It may assist in making diagnoses and prognoses on diseases in fish populations. The hematological variables of nile tilapia were studied in specimens with a clinical diagnosis of columnaris disease and in specimens that were disease-free. The total erythrocyte count, hemoglobin rate, hematocrit percentage, mean corpuscular hemoglobin (MCH, mean corpuscular hemoglobin concentration (MCHC, mean corpuscular volume (MCV, organic defense blood cell percentages (leukocytes and thrombocytes and hepatosomatic and splenosomatic index were determined. The results showed that there were changes in the erythrocytic series and in organic defense blood cells, in the fish infected with the bacterium, with reductions in erythrocytic variables and significant increases in the numbers of circulating lymphocytes and neutrophils.

  9. Pathophysiological changes associated with dietary melamine and cyanuric acid toxicity in red tilapia.

    Science.gov (United States)

    Phromkunthong, W; Choochuay, P; Kiron, V; Nuntapong, N; Boonyaratpalin, M

    2015-02-01

    This study examined the adverse effects of feed-delivered melamine (MEL) and cyanuric acid (CYA) in red tilapia. Diet 1 (without MEL and CYA), diets 2-4 (with MEL and CYA at 2.5, 5 and 7.5 g kg(-1) diet, respectively) and diets 5 and 6 (with either MEL or CYA at 10 g kg(-1) diet) were examined. MEL alone lowered both growth and FCR (P tilapia. Protein efficiency ratio and apparent net utilization of fish on diets 2-6 were poor (P 5 g kg(-1) diet induced the activity of catalase in liver and the activity of glutathione peroxidase in liver and kidneys. Therefore, these adulterants should not be included in fish feeds.

  10. Essential oil of Lippia alba in the transport of Nile tilapia

    Directory of Open Access Journals (Sweden)

    Janis Cumming Hohlenwerger

    Full Text Available ABSTRACT: This study aimed to examine the action of the essential oil of Lippia alba (EOLA in the stress response for transport of Nile tilapia Oreochromis niloticus . The fish were transported into three treatments (in triplicate: control, 10 and 20 µL L-1 EOLA, with loading density of 15 fish/plastic bags for 8h. Plasma glucose levels were significantly decreased in fish exposed to 20µL L-1 EOLA in comparison with the control group and fish exposed to 10µL L-1 EOLA, but the plasma cortisol, lactate and paraoxonase levels were similar. Un-ionized ammonia and ventilatory rate demonstrated a significant reduction in the treatments with the use of EOLA. In conclusion the use of 20µL L-1 EOLA is indicated for Nile tilapia transport.

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

    Science.gov (United States)

    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.

  12. Potencial Productivo de una Laguna artificial en el desarrollo del cultivo de tilapia (Potencial Productive of artificial lagoon on development of tilapia

    Directory of Open Access Journals (Sweden)

    Ruiz Velazco Arce Javier Marcial de Jesús

    2007-03-01

    Full Text Available El estudio se realizó en la laguna de Mora,ubicada, a 4 km de la ciudad Tepic, capitaldel estado de Nayarit, en México. El objetivofue generar conocimiento acerca delpotencial acuícola de esta laguna, a partirdel análisis de las variables que explican elcomportamiento de su metabolismoproductivo en un ciclo anual. Con ello,identificar las estrategias de explotación másadecuadas para el desarrollo de laproducción acuícola de tilapia, en coherenciacon sus características de productividadnatural y las posibilidades de intensificaciónde la actividad, sin perjuicio de sumetabolismo productivo. Se partió de unaprimera fase de análisis cartográfico, seguidadel estudio de factibilidad ambiental,productividad natural y las condicioneshidrológicas mínimas para la subsistencia deorganismos cultivables. Después de esto, setuvieron elementos suficientes paradescartar alguna dificultad ambiental ohidrológica limitante para elaprovechamiento acuícola. Los resultados deltrabajo mostraron características deproductividad que ubican a este sistema enun nivel mesotrófico con variableshidrológicas consideradas de aptitud para unciclo del cultivo de tilapias en las estacionesde primavera, verano y parte de otoño.Estos resultados servirán de base para eldiseño, proyección y ejecuci��n de proyectosde inversión acuícola particulares para elsistema, cuyo plan de manejo se percibenecesario a fin de garantizar lasustentabilidad ambiental de suaprovechamiento. La tilapia es una especieque cuenta con buena aceptación en elmercado, sobre todo en el ámbito mundial,donde su cultivo genera empleo y divisas.Este estudio pretende contribuir al desarrollotecnológico del cultivo de tilapia para lasespecies Oreochomis aureus y Oreocchomisniloticus, en condiciones de cultivo extensivoen la laguna de Mora en Nayarit, México.

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

    Science.gov (United States)

    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...

  14. Effects of addition of tilapia Oreochromis niloticus and substrates for periphyton developments on pond ecology and production in C/N-controlled freshwater prawn Macrobrachium rosenbergii farming systems

    NARCIS (Netherlands)

    Asaduzzaman, M.; Wahab, M.A.; Verdegem, M.C.J.; Benerjee, S.; Akter, T.; Hasan, M.M.; Azim, M.E.

    2009-01-01

    The present research investigated the effect of addition of tilapia and substrates for periphyton development on pond ecology, production and economic performances in C/N controlled freshwater prawn farming system. The absence and presence (0 and 0.5 individual m- 2) of tilapia were investigated in

  15. Effects of stocking density on production and economics of Nile tilapia (Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) polyculture in periphyton-based systems

    NARCIS (Netherlands)

    Uddin, S.; Rahman, S.M.S.; Azim, M.E.; Wahab, M.A.; Verdegem, M.C.J.; Verreth, J.A.J.

    2007-01-01

    The present research investigated the effect of stocking density on pond (75 m2, depth 1.2 m) production of Nile tilapia (Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) stocked at a fixed 3:1 tilapia:prawn ratio. Three stocking densities were tried in triplicate: 20 000 ha¿1

  16. Effect of probiotic and sand filtration treatments on water quality and growth of tilapia (Oreochromis niloticus) and pangas (Pangasianodon hypophthalmus) in earthen ponds of southern Bangladesh

    DEFF Research Database (Denmark)

    Mahmud, Sultan; Ali, Mohammad Lokman; Alam, Md Ariful

    2016-01-01

    Effects of water treatment by two probiotic products (PondPlus® and AquaPhoto®) and sand filtration were studied on growth performance of tilapia (Oreochromis niloticus) and pangas (Pangasianodon hypophthalmus) stocked at tilapia:pangas ratio of 5:3 in traditional earthen ponds in Bangladesh...

  17. Evaluation of the dairy/yeast prebiotic, GroBiotic-A, in the diet of the juvenile Nile tilapia, Oreochromis niloticus

    Science.gov (United States)

    Tilapia production ranks among the highest worldwide due to their fast growth and ability to thrive under various culture conditions. However, tilapias are still susceptible to outbreaks of systemic disease caused by opportunistic bacterial pathogens such as Streptococcus inaie. These epizootic ev...

  18. Comparative proteome analysis of two Streptococcus agalactiae strains from cultured tilapia with different virulence.

    Science.gov (United States)

    Li, Wei; Su, You-Lu; Mai, Yong-Zhan; Li, Yan-Wei; Mo, Ze-Quan; Li, An-Xing

    2014-05-14

    Streptococcus agalactiae is a major piscine pathogen, which causes significant morbidity and mortality among numerous fish species, and results in huge economic losses to aquaculture. Many S. agalactiae strains showing different virulence characteristics have been isolated from infected tilapia in different geographical regions throughout South China in the recent years, including natural attenuated S. agalactiae strain TFJ0901 and virulent S. agalactiae strain THN0901. In the present study, survival of tilapia challenged with S. agalactiae strain TFJ0901 and THN0901 (10(7)CFU/fish) were 93.3% and 13.3%, respectively. Moreover, there are severe lesions of the examined tissues in tilapia infected with strain THN0901, but no significant histopathological changes were observed in tilapia infected with the strain TFJ0901. In order to elucidate the factors responsible for the invasive potential of S. agalactiae between two strains TFJ0901 and THN0901, a comparative proteome analysis was applied to identify the different protein expression profiles between the two strains. 506 and 508 cellular protein spots of S. agalactiae TFJ0901 and THN0901 were separated by two dimensional electrophoresis, respectively. And 34 strain-specific spots, corresponding to 27 proteins, were identified successfully by MALDI-TOF mass spectrometry. Among them, 23 proteins presented exclusively in S. agalactiae TFJ0901 or THN0901, and the other 4 proteins presented in different isomeric forms between TFJ0901 and THN0901. Most of the strain-specific proteins were just involved in metabolic pathways, while 7 of them were presumed to be responsible for the virulence differences of S. agalactiae strain TFJ0901 and THN0901, including molecular chaperone DnaJ, dihydrolipoamide dehydrogenase, thioredoxin, manganese-dependent inorganic pyrophosphatase, elongation factor Tu, bleomycin resistance protein and cell division protein DivIVA. These virulence-associated proteins may contribute to identify new

  19. Selection for growth of Nile tilapia (Oreochromis niloticus L.) in low-input environments

    NARCIS (Netherlands)

    Charo-Karisa, H.

    2006-01-01

    Nile tilapia,Oreochromis niloticus,is one of the most important species farmed in the world and is the mainstay of many

  20. Quantification of intestinal bacteria, operating cost and performance of fingerlings Nile tilapia subjected to probiotics

    Directory of Open Access Journals (Sweden)

    Nilton Garcia-Marengoni

    2015-05-01

    Full Text Available The use of microorganisms of the genus Bacillus in aquaculture is a nutritional management practice that is rapidly expanding in regions with intensive fish farming. This study aimed to quantify the total bacteria and total coliforms from the intestinal microbiota and estimate the partial operating costs and growth performance of Nile tilapia (Oreochromis niloticus of the GIFT strain. A total of 1,200 post-larvae (24.7 ± 0.50 mg were distributed into 24 aquaria (0.03-m³ capacity within a completely randomized design in 2 x 3 factorial (phase x bacteria, with four replications. Each aquarium, containing 50 post-larvae (sex reversal phase or 30 fish (fingerlings phase, it was considered to be an experimental unit, consisting of three treatments (diet+Bacillus subtilis C-3102, diet+Bacillus cereus var. toyoi and diet without probiotic addition. The quantification of the total bacteria and total coliforms of the intestinal microbiota of tilapia were influenced (P 0.05 by adding probiotics in the diets and no effect of the interaction between phase and bacteria was observed. The weight gain, average daily weight gain, specific growth rate and apparent feed conversion were not affected (P > 0.05 by inclusion of probiotics as part of the diets. The inclusion of B. subtilis and B. cereus as part of diets for Nile tilapia promotes intestinal colonization and improves the survival rate without negatively influencing the feed intake, total biomass, gross revenue and partial operating costs and net revenue. Therefore it recommends the use of these probiotics to growth of tilapia fingerlings Nile, GIFT strain.

  1. The role of NPY in reproductive and metabolic signalling in a mouthbrooding female tilapia, Oreochromis niloticus

    OpenAIRE

    Das, Kalpana

    2017-01-01

    Appetite is regulated by a balance between excitatory (drive) and inhibitory (satiety) processes. Dysregulation of this balance leads to eating disorders. However, the neuronal mechanism of control of appetite has not been clearly understood. A cichlid fish, the Nile tilapia(Oreochromis niloticus) is a maternal mouthbrooder in which the female churns the eggs in her mouth for 10-14 days. During mouthbrooding, female fish stops feeding and minimizes energy expenditure to maintain energy homeos...

  2. Coupled dynamics of energy budget and population growth of tilapia in response to pulsed waterborne copper.

    Science.gov (United States)

    Chen, Wei-Yu; Lin, Chia-Jung; Ju, Yun-Ru; Tsai, Jeng-Wei; Liao, Chung-Min

    2012-11-01

    The impact of environmentally pulsed metal exposure on population dynamics of aquatic organisms remains poorly understood and highly unpredictable. The purpose of our study was to link a dynamic energy budget model to a toxicokinetic/toxicodynamic (TK/TD). We used the model to investigate tilapia population dynamics in response to pulsed waterborne copper (Cu) assessed with available empirical data. We mechanistically linked the acute and chronic bioassays of pulsed waterborne Cu at the scale of individuals to tilapia populations to capture the interaction between environment and population growth and reproduction. A three-stage matrix population model of larva-juvenile-adult was used to project offspring production through two generations. The estimated median population growth rate (λ) decreased from 1.0419 to 0.9991 under pulsed Cu activities ranging from 1.6 to 2.0 μg L(-1). Our results revealed that the influence on λ was predominately due to changes in the adult survival and larval survival and growth functions. We found that pulsed timing has potential impacts on physiological responses and population abundance. Our study indicated that increasing time intervals between first and second pulses decreased mortality and growth inhibition of tilapia populations, indicating that during long pulsed intervals tilapia may have enough time to recover. Our study concluded that the bioenergetics-based matrix population methodology could be employed in a life-cycle toxicity assessment framework to explore the effect of stage-specific mode-of-actions in population response to pulsed contaminants.

  3. Lake Victoria wetlands and the ecology of the Nile tilapia, oreochromis niloticus linn,.

    OpenAIRE

    Balirwa, J.S.

    1998-01-01

    An ecological study of wetlands was undertaken in northern Lake Victoria (East Africa) between 1993 and 1996 with a major aim of characterising shallow vegetation-dominated interface habitats, and evaluating their importance for fish, in particular, for the stocked and socio-economically important Oreochromis niloticus LINNÉ (the Nile tilapia). From field and laboratory experiments, five major habitat types could be defined by the type of the dominant emergent macrophyte at the shore from the...

  4. Salmonella Weltevreden in integrated and non-integrated tilapia aquaculture systems in Guangdong, China.

    Science.gov (United States)

    Li, Kang; Petersen, Gitte; Barco, Lisa; Hvidtfeldt, Kristian; Liu, Liping; Dalsgaard, Anders

    2017-08-01

    Integrated tilapia-pig farming, which uses manure from pigs as fertilizers in fish pond, is a traditional and common production system practised by small-scale farmers in South-east Asia. Although such systems may be environmentally sustainable, they also pose potential food safety hazards including transmission of faecal zoonotic pathogens and accumulation of antimicrobial and other chemical residues. This study aimed to determine differences in occurrence and characteristics of Salmonella spp. isolated from tilapia-pig and non-integrated aquaculture systems in Guangdong province, China. A total of 77 samples (9 pig feed, 19 fish feed, 9 pig faeces, 20 fish mucus and 20 fish intestine) from 10 tilapia-pig ponds and 10 non-integrated ponds were analysed. Salmonella spp. was found in fish mucus (20.0%), fish intestine (40.0%) and pig faeces (11.1%) from integrated ponds, and from fish mucus (40.0%) and fish intestine (40.0%) from non-integrated ponds. S. Weltevreden (76.5%) was by far the most common serovar showing limited antimicrobial resistance. One pig faeces sample contained S. Typhimurium whereas feed samples were found free of Salmonella spp.. DNA fingerprinting by the PFGE method showed a clonal relationship of S. Weltevreden which was supported by similar antimicrobial resistance patterns (sulfamethoxazole and trimethoprim resistance) as well as most isolates harbouring a 147-kb sized plasmid. The common finding of S. Weltevreden in both tilapia production systems indicates that this serovar may have a different ecology and increased survival in aquaculture environments in comparison with other Salmonella serovars. Further in vivo studies of the ecology of S. Weltevreden in aquaculture environments are needed.

  5. Tilapia (Oreochromis mossambicus) brain cells respond to hyperosmotic challenge by inducing myo-inositol biosynthesis.

    Science.gov (United States)

    Gardell, Alison M; Yang, Jun; Sacchi, Romina; Fangue, Nann A; Hammock, Bruce D; Kültz, Dietmar

    2013-12-15

    This study aimed to determine the regulation of the de novo myo-inositol biosynthetic (MIB) pathway in Mozambique tilapia (Oreochromis mossambicus) brain following acute (25 ppt) and chronic (30, 60 and 90 ppt) salinity acclimations. The MIB pathway plays an important role in accumulating the compatible osmolyte, myo-inositol, in cells in response to hyperosmotic challenge and consists of two enzymes, myo-inositol phosphate synthase and inositol monophosphatase. In tilapia brain, MIB enzyme transcriptional regulation was found to robustly increase in a time (acute acclimation) or dose (chronic acclimation) dependent manner. Blood plasma osmolality and Na(+) and Cl(-) concentrations were also measured and significantly increased in response to both acute and chronic salinity challenges. Interestingly, highly significant positive correlations were found between MIB enzyme mRNA and blood plasma osmolality in both acute and chronic salinity acclimations. Additionally, a mass spectrometry assay was established and used to quantify total myo-inositol concentration in tilapia brain, which closely mirrored the hyperosmotic MIB pathway induction. Thus, myo-inositol is a major compatible osmolyte that is accumulated in brain cells when exposed to acute and chronic hyperosmotic challenge. These data show that the MIB pathway is highly induced in response to environmental salinity challenge in tilapia brain and that this induction is likely prompted by increases in blood plasma osmolality. Because the MIB pathway uses glucose-6-phosphate as a substrate and large amounts of myo-inositol are being synthesized, our data also illustrate that the MIB pathway likely contributes to the high energetic demand posed by salinity challenge.

  6. Effects of acclimation salinity on the expression of selenoproteins in the tilapia, Oreochromis mossambicus.

    Science.gov (United States)

    Seale, Lucia A; Gilman, Christy L; Moorman, Benjamin P; Berry, Marla J; Grau, E Gordon; Seale, Andre P

    2014-07-01

    Selenoproteins are ubiquitously expressed, act on a variety of physiological redox-related processes, and are mostly regulated by selenium levels in animals. To date, the expression of most selenoproteins has not been verified in euryhaline fish models. The Mozambique tilapia, Oreochromis mossambicus, a euryhaline cichlid fish, has a high tolerance for changes in salinity and survives in fresh water (FW) and seawater (SW) environments which differ greatly in selenium availability. In the present study, we searched EST databases for cichlid selenoprotein mRNAs and screened for their differential expression in FW and SW-acclimated tilapia. The expression of mRNAs encoding iodothyronine deiodinases 1, 2 and 3 (Dio1, Dio2, Dio3), Fep15, glutathione peroxidase 2, selenoproteins J, K, L, M, P, S, and W, was measured in the brain, eye, gill, kidney, liver, pituitary, muscle, and intraperitoneal white adipose tissue. Gene expression of selenophosphate synthetase 1, Secp43, and selenocysteine lyase, factors involved in selenoprotein synthesis or in selenium metabolism, were also measured. The highest variation in selenoprotein and synthesis factor mRNA expression between FW- and SW-acclimated fish was found in gill and kidney. While the branchial expression of Dio3 was increased upon transferring tilapia from SW to FW, the inverse effect was observed when fish were transferred from FW to SW. Protein content of Dio3 was higher in fish acclimated to FW than in those acclimated to SW. Together, these results outline tissue distribution of selenoproteins in FW and SW-acclimated tilapia, and indicate that at least Dio3 expression is regulated by environmental salinity.

  7. Growth of Mixed-Sex and Monosex Nile Tilapia in Different Culture Systems.

    OpenAIRE

    Chakraborty, Suman Bhusan; , Debasis Mazumdar; , Urmi Chatterji; , Samir Banerjee

    2011-01-01

    Growth of 17α-methyltestosterone treated monosex Nile tilapia, Oreochromis niloticus was compared with hormone untreated mixed-sex fish in four different culture systems. The experiment had 2 X 4 factorial design: the first factor was presence or absence of hormone treatment (monosex and mixed-sex fish), the second factor was related to culture system (cistern, flow-through, pen and pond). Fish were cultured under similar feeding regime and stock...

  8. Background adaptation and water acidification affect pigmentation and stress physiology of tilapia, Oreochromis mossambicus

    OpenAIRE

    Salm, A.L. van der; Spanings, F.A.T.; Gresnigt, R.; Wendelaar Bonga, S.E.; Flik, G

    2005-01-01

    The ability to adjust skin darkness to the background is a common phenomenon in fish. The hormone alpha-melanophore-stimulating hormone (alphaMSH) enhances skin darkening. In Mozambique tilapia, Oreochromis mossambicus L., alphaMSH acts as a corticotropic hormone during adaptation to water with a low pH, in addition to its role in skin colouration. In the current study, we investigated the responses of this fish to these two environmental challenges when it is exposed to both simultaneously. ...

  9. Background adaptation and water acidification affect pigmentation and stress physiology of tilapia, Oreochromis mossambicus.

    Science.gov (United States)

    van der Salm, A L; Spanings, F A T; Gresnigt, R; Bonga, S E Wendelaar; Flik, G

    2005-10-01

    The ability to adjust skin darkness to the background is a common phenomenon in fish. The hormone alpha-melanophore-stimulating hormone (alphaMSH) enhances skin darkening. In Mozambique tilapia, Oreochromis mossambicus L., alphaMSH acts as a corticotropic hormone during adaptation to water with a low pH, in addition to its role in skin colouration. In the current study, we investigated the responses of this fish to these two environmental challenges when it is exposed to both simultaneously. The skin darkening of tilapia on a black background and the lightening on grey and white backgrounds are compromised in water with a low pH, indicating that the two vastly different processes both rely on alphaMSH-regulatory mechanisms. If the water is acidified after 25 days of undisturbed background adaptation, fish showed a transient pigmentation change but recovered after two days and continued the adaptation of their skin darkness to match the background. Black backgrounds are experienced by tilapia as more stressful than grey or white backgrounds both in neutral and in low pH water. A decrease of water pH from 7.8 to 4.5 applied over a two-day period was not experienced as stressful when combined with background adaptation, based on unchanged plasma pH and plasma alphaMSH, and Na levels. However, when water pH was lowered after 25 days of undisturbed background adaptation, particularly alphaMSH levels increased chronically. In these fish, plasma pH and Na levels had decreased, indicating a reduced capacity to maintain ion-homeostasis, implicating that the fish indeed experience stress. We conclude that simultaneous exposure to these two types of stressor has a lower impact on the physiology of tilapia than subsequent exposure to the stressors.

  10. Developmental Biology of the Supermale YY Tilapia (Oreochromis niloticus: Histogenesis of the Reproductive System

    Directory of Open Access Journals (Sweden)

    Annabelle Herrera

    2001-06-01

    Full Text Available Histogenesis of the reproductive system of supermale (YY tilapia and XY tilapia reared at the Central Luzon State University was analyzed with the use of paraffin sections. In the course of development, the primordial germ cells appeared at the same age in YY and XY males, i.e., at 8 days posthatch. These cells which were larger in the YY (1.85 µm than in the XY male (0.9 µm later established themselves in the gonadal anlage by days 9-22. The lobules appeared earlier in the YY at day 15. Blastema of the reproductive duct appeared in the YY at day 23 and in the XY at day 27. By day 79, meiotically active cells were abundant in both groups. By day 95, the YY fish showed mature sperm cells in the fully differentiated testis while it was at day 105 in the XY fish. The supermale consistently demonstrated bigger testis, with thicker somantic tissues, more spermatogenic cells, and more advanced developmental stage than XY fish of the same age. Germ cell and nuclear size in the YY and XY fish were not statistically significantly different, although the general trend was that spermatogenic cells were bigger in the supermale tilapia. A NOVA (a = 05 showed significant difference in size of the testis, spermatocysts, and vas deferens. The study showed that with the same rearing conditions and same age, the larger supermale tilapia has superior reproductive capacity with its larger testis and ducts, faster histogenesis and spermatogenesis, and higher gonadosomatic index (GSI.

  11. Effect of Feeding Frequency on the Growth of Tilapia (Oreochromis niloticus in Earthen Ponds

    Directory of Open Access Journals (Sweden)

    Pouomogne, V.

    2001-01-01

    Full Text Available Duplicate groups of Nile tilapia fingerlings (30.9 g were fed at three different frequencies, i. e. 2, 3 and 6 meals a day, in six 400 m2 earthen ponds. Fish stocked at 22.4 g/m2 (about 60 ind./are was thus fed an experimental diet containing 25 % protein from vegetal origin. The feed was daily distributed, by hand, at equal time intervals between 8 a. m. and 3 p. m. After fifteen weeks trials, significantly (p <0.05 best growth was obtained in the 6 times a day treatment (daily growth rate 1.3 g/day as compared to 0.9 g/day for each of the two other treatments. It could be noticed that increase in the feeding frequency was associated with increase in growth rate and decrease in FGR (from 1.6 to 1.3. In term of fish production, there was an estimated extra tilapia production of 8.7 kg/are/year with the 6 times a day frequency, comparatively to the two other treatments. In an environment where labour is not actually limiting, the study suggests that Nile tilapia in production ponds should be fed six times a day.

  12. Seasonal influence on the hematological parameters in cultured Nile tilapia from southern Brazil

    Directory of Open Access Journals (Sweden)

    GT. Jerônimo

    Full Text Available This study evaluated seasonality in hematological parameters of Nile tilapia cultured in the state of Santa Catarina, southern Brazil. A total of 240 fish were examined during four seasons between April 2007 and March 2008 in three different fish farms. After being anesthetised in a benzocaine solution, blood samples were withdrawn into syringes containing a drop of 10% EDTA for hematological analysis. The results were compared between fish farms and seasons, which are well delimited in southern Brazil. In a traditional fish farm in Joinville in the summer, there was an increase in the percentage of hematocrit and in the red blood cell count. The highest values of total leukocytes were found in fish from fee-fishing in Blumenau in the autumn while the lowest values occurred in those from swine consorted system in Ituporanga in the summer. Thrombocytosis was observed in the autumn, and lymphocytosis was found in both the autumn and winter in tilapia from all fish farms investigated. Neutrophilia was only observed in winter and autumn in fish from Blumenau and Ituporanga. This work demonstrated the influence of seasonality and the handling characteristics of each fish farm on certain hematological parameters in Nile tilapia.

  13. Phosphoglycerate kinase enhanced immunity of the whole cell of Streptococcus agalactiae in tilapia, Oreochromis niloticus.

    Science.gov (United States)

    Wang, Yi-Ting; Huang, Hsing-Yen; Tsai, Ming-An; Wang, Pei-Chi; Jiang, Bo-Huang; Chen, Shih-Chu

    2014-12-01

    Streptococcus agalactiae is a Gram-positive bacterium and a severe aquaculture pathogen that can infect a wide range of warmwater fish species. The outer-surface proteins in bacterial pathogens play an important role in pathogenesis. We evaluated the immunogenicity of two of the identified surface proteins namely phosphoglycerate kinase (PGK) and ornithine carbamoyl-transferase (OCT). PGK and OCT were over-expressed and purified from Escherichia coli and used as the subunit vaccines in tilapia. Tilapia immunized with the S. agalactiae modified bacteria vaccine (whole cell preparations with recombinant PGK and OCT proteins) individually were tested for the efficacy. OCT and PGK combined with WC had a higher survival rate. A high-level protection and significant specific antibody responses against S. agalactiae challenge was observed upon the vaccinated tilapia with the purified PGK protein and S. agalactiae whole cells. The specific antibody titer against S. agalactiae antigen suggested that increased antibody titers were correlated with post-challenge survival rate. Il-1β expression profile was higher in PGK + WC-treated group. Tnf-α expression in the PGK + WC group was significantly increased. Taken together, our results suggested the combinations of recombinant protein and whole cell may elicit immune responses that reach greater protection than that of individual S. agalactiae components.

  14. Tilapia africana en el Lago de Nicaragua: ecosistema en transición.

    Directory of Open Access Journals (Sweden)

    Jeffrey K. McCrary

    1998-10-01

    Full Text Available Los grandes lagos de Nicaragua, son comparables con el sistema de grandes lagos africanos. Contienen una gran diversidad de peces, incluyendo varios peces endémicos de la familia Cichlidae. La captura de peces en el Lago de Cocibolca, estandarizada en 100 metros de red, promedió 4.34 kilogramos en el área de Ometepe, en donde la tilapia constituyó el 1.5 % del peso total de la captura. Este promedio fue de 0.80 kilogramos en la costa septentrional, donde la tilapia constituyó 54% del peso total de la captura. Un estudio ruso efectuado en 1983 y desarrollado en todo el Lago, demostró que el promedio era de 4.66 kilogramos. Los autores del presente artículo recomiendan que en el Lago Cocibolca se implemente un plan de manejo adecuado para controlar la población de tilapia y rescatar un ecosistema en peligro de colapso

  15. ISOLATION AND DETERMINATION OF TYPE I COLLAGEN FROM TILAPIA (Oreochromis niloticus WASTE

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    S.Sujithra

    2013-06-01

    Full Text Available Tilapia are one of the most widely introduced fish globally that has clearly emerged as a promising group in aquaculture. Oreochromis niloticus was the first Tilapia species to be taken up for large Scaleaquaculture. It is consumed widely due to its deliciousness and rich source of protein. During its processing, the scales, Fins, Skins etc are expelled out as waste Acid solubilized collagen (ASC and Pepsin Solubilizedcollagen (PSC were extracted from these processing wastes. Initial extraction by acid yielded 22% of collagen and subsequent digestion with pepsin yielded 56% on dry weight basis. The total protein of ASC and PSC was determined by Bradford method which contains 68.34mg/ml,23.24 mg/ml respectively. The FT-IR Spectrumshowed that ASC and PSC are helpful in prediction and confirmation of Secondary structure of proteins. The denaturation temperature of ASC was 32⁰C while for PSC it is 29⁰C.SEM micrograph showed the fibrousnature of Collagen. This report indicates that Tilapia waste might be useful as a new source of collagen apart from usual bovine and pig skin.

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

    Directory of Open Access Journals (Sweden)

    Paula A.P. Ribeiro

    2015-03-01

    Full Text Available 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. Assessing exposure risks for freshwater tilapia species posed by mercury and methylmercury.

    Science.gov (United States)

    Cheng, Yi-Hsien; Lin, Yi-Jun; You, Shu-Han; Yang, Ying-Fei; How, Chun Ming; Tseng, Yi-Ting; Chen, Wei-Yu; Liao, Chung-Min

    2016-08-01

    Waterborne and dietborne exposures of freshwater fish to mercury (Hg) in the forms of inorganic (Hg(II)) and organic (methylmercury or MeHg) affect their growth, development, and reproduction. However, an integrated mechanistic risk model framework to predict the impact of Hg(II)/MeHg on freshwater fish is lacking. Here, we integrated biokinetic, physiological and biogeographic data to calibrate and then establish key risk indices-hazardous quotient and exceedance risk-for freshwater tilapia species across geographic ranges of several major rivers in Taiwan. We found that Hg(II) burden was highest in kidney followed by gill, intestine, liver, blood, and muscle. Our results showed that Hg was less likely to pose mortality risk (mortality rate less than 5 %) for freshwater tilapia species. However, Hg is likely to pose the potential hazard to aquatic environments constrained by safety levels for aquatic organisms. Sensitivity analysis showed that amount of Hg accumulated in tilapia was most influenced by sediment uptake rate. Our approach opens up new possibilities for predicting future fish population health with the impacts of continued Hg exposure to provide information on which fish are deemed safe for human consumption.

  18. Francisella Infection in Cultured Tilapia in Thailand and the Inflammatory Cytokine Response.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  20. Electrospun tilapia collagen nanofibers accelerating wound healing via inducing keratinocytes proliferation and differentiation.

    Science.gov (United States)

    Zhou, Tian; Wang, Nanping; Xue, Yang; Ding, Tingting; Liu, Xin; Mo, Xiumei; Sun, Jiao

    2016-07-01

    The development of biomaterials with the ability to induce skin wound healing is a great challenge in biomedicine. In this study, tilapia skin collagen sponge and electrospun nanofibers were developed for wound dressing. The collagen sponge was composed of at least two α-peptides. It did not change the number of spleen-derived lymphocytes in BALB/c mice, the ratio of CD4(+)/CD8(+) lymphocytes, and the level of IgG or IgM in Sprague-Dawley rats. The tensile strength and contact angle of collagen nanofibers were 6.72±0.44MPa and 26.71±4.88°, respectively. They also had good thermal stability and swelling property. Furthermore, the nanofibers could significantly promote the proliferation of human keratinocytes (HaCaTs) and stimulate epidermal differentiation through the up-regulated gene expression of involucrin, filaggrin, and type I transglutaminase in HaCaTs. The collagen nanofibers could also facilitate rat skin regeneration. In the present study, electrospun biomimetic tilapia skin collagen nanofibers were succesfully prepared, were proved to have good bioactivity and could accelerate rat wound healing rapidly and effectively. These biological effects might be attributed to the biomimic extracellular matrix structure and the multiple amino acids of the collagen nanofibers. Therefore, the cost-efficient tilapia collagen nanofibers could be used as novel wound dressing, meanwhile effectively avoiding the risk of transmitting animal disease in the future clinical apllication.

  1. Antioxidant activities of red tilapia (Oreochromis niloticus) protein hydrolysates as influenced by thermolysin and alcalase

    Science.gov (United States)

    Daud, Nur'Aliah; Babji, Abdul Salam; Yusop, Salma Mohamad

    2013-11-01

    The hydrolysis process was performed on fish meat from Red Tilapia (Oreochromis niloticus) by enzymes thermolysin and alcalase under optimum conditions. The hydrolysis was performed from 0 - 4 hours at 37°C. Hydrolysates after 2 hours incubation with thermolysin and alcalase had degree of hydrolysis of 76.29 % and 63.49 %, respectively. The freeze dried protein hydrolysate was tested for peptide content and characterized with respect to amino acid composition. The result of increased peptide content in Red Tilapia (O. Niloticus) hydrolysates obtained was directly proportional to the increase activities of different proteolytic enzymes. The result of amino acid composition showed that the sample used contained abundant Gly, Ala, Asp, Glu, Lys and Leu in residues or peptide sequences. Both enzymatic hydrolysates were tested for anti-oxidant activity with DPPH and ABTS assay. Alcalase yielded higher anti-oxidative activity than Thermolysin hydrolysates after 1 hour incubation, but both enzymes hydrolysates showed a significant decrease of anti-oxidant activity after 2 hours of incubation. Hydrolysates from Red Tilapia may contribute as a health promoting ingredient in functional foods to reduce oxidation stress caused by accumulated free radicals.

  2. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    Science.gov (United States)

    Sockalingam, K.; Abdullah, H. Z.

    2015-07-01

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties.

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

    Science.gov (United States)

    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).

  4. An optimized group mating design and determination of the admixture rate in Nile tilapia families

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    2016-05-01

    Full Text Available The Nile tilapia is the most productive and internationally traded food fish in the world. Many Nile tilapia families are needed to develop breeding programs for this species. The aim of this study was to develop Nile tilapia families using the Oreochromis species unique breeding characteristics (male territory establisher and female mouth brooders and determine the mixing rate within each family. Both male and female fish were cultured in one pond in the reproductive season and the female mouths were checked every 5–8 days. When embryos were present, they were removed and cultivated independently as a family. As a result, 45 families were developed from the 60 female fish sampled. The embryo survival rate in aerated water varied from 85.5 to 100.0%. Seven polymorphic microsatellite loci were selected from a set of 31 for paternity identification. The CPE (combined paternity exclusion probability of two microsatellite loci was higher than 0.93 and the CPE for the seven loci used in this study was as high as 0.9999. There were no unrelated individuals in five of the seven families analyzed and only one mixed individual in F29 and F30. The overall admixture rate was very low (2.2%. In this study, we developed an optimized group mating system. Furthermore, we verified that for group mating systems there were no mixed individuals in most families and the admixture rate of some families was very low according to the paternity analysis.

  5. Induced alkoxyresorufin-O-dealkylases in tilapias (Oreochromis niloticus) from Guandu river, Rio de Janeiro, Brazil.

    Science.gov (United States)

    Parente, Thiago E M; De-Oliveira, Ana C A X; Silva, Igor B; Araujo, Francisco G; Paumgartten, Francisco J R

    2004-03-01

    The activity of fish monooxygenases has been extensively used as a monitoring tool to detect contamination of water bodies by cytochrome P450-inducing agents. In this study we evaluated the activities of ethoxy- (EROD), methoxy- (MROD) and pentoxy- (PROD) resorufin-O-dealkylases in the liver of Nile tilapias (Oreochromis niloticus) collected at the Guandu river, at a reference clean site (Lake 1) and at two other sampling sites (Lakes 2 and 3) in Rio de Janeiro state, Brazil. Alkoxyresorufin-O-dealkylases were measured fluorimetrically in the hepatic S9 fraction. EROD (17.7-fold), MROD (14.2-fold) as well as PROD activities were considerably higher in tilapias from Guandu river. A moderate increase of EROD (5.0-fold) and MROD (5.4-fold) was also found in tilapias from Lake 3. These findings suggest that Guandu river watershed, the main source of urban drinking water supply in Rio de Janeiro, is polluted with CYP1A-inducing xenobiotics. Furthermore, we also found a good linear relationship between EROD and MROD, a finding that agrees with the hypothesis that the two reactions are catalysed by the same CYP1A isoform in O. niloticus.

  6. Characterization of the Fatty Acids Present in Wastewaters from Production of Biodiesel Tilapia

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    Erika de A. S. Braga

    2015-01-01

    Full Text Available Biodiesel obtained from oil extracted from the viscera of tilapia is a viable alternative in the replacement of petroleum fuels. However, during the purification step is performed biodiesel washing water is performed, which generates high effluent pollutant loads due to the reagents used and the very composition of the raw material. This study aims to characterize the fatty acids present in water from washing of the process of purifying biodiesel tilapia (Oreochromis niloticus. Fatty acid compositions were determined using gas chromatography (GC-FID. The results showed that the fatty acids present in greater quantities in the effluent were lauric (C12: 0, followed by myristic (C14: 0, palmitic (C16: 0, oleic (C18: 1, stearic (C18: 0, linolenic (C18: 3, and linoleic (C18: 2 acids. Therefore, the levels of oil and grease found in the rinse water from washing of the oil biodiesel tilapia are far above the allowed values above; thus they do not comply with Brazilian federal regulations.

  7. Production of hydrolysate from processed Nile tilapia (Oreochromis niloticus residues and assessment of its antioxidant activity

    Directory of Open Access Journals (Sweden)

    Daniela Miotto BERNARDI

    2016-01-01

    Full Text Available Abstract The objective of this work was to produce protein hydrolysates from by-products of the Nile tilapia fileting process, and to assess the effects of different hydrolysis times on the antioxidant activity of the hydrolysed animal-based protein, in free form and incorporated into a food matrix. Gutted tilapia heads and carcasses were hydrolysed by Alcalase® for different hydrolysis times producing six hydrolysates. The protein content, degree of hydrolysis, reverse-phase high-performance liquid chromatography, and antioxidant activity by the ORAC, FRAP and TEAC methods were analysed. Three mini-hamburger formulations were produced and the lipidic oxidation of mini-hamburger was determined by TBARS. The protein contained in the residue was completely recovered in the process. The hydrolysates varied in their degree of hydrolysis, but presented similar levels of antioxidant activity. In the mini-hamburgers the hydrolysate was capable of delaying oxidation after 7 days of storage. Hydrolysis of tilapia processing by-products produced peptides may be used in the formulation of functional foods.

  8. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    Energy Technology Data Exchange (ETDEWEB)

    Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties.

  9. The effect of different cooking methods on fatty acid composition and antioxidant activity of n-3 fatty acids fortified tilapia meat with or without clove essential oil.

    Science.gov (United States)

    Ramezani-Fard, Ehsan; Romano, Nicholas; Goh, Yong-Meng; Oskoueian, Ehsan; Ehteshami, Fariborz; Ebrahimi, Mahdi

    2016-07-01

    Tilapia farmers are increasingly relying on dietary fish oil alternatives which substantially reduces health beneficial n-3 polyunsaturated fatty acids (PUFA) in tilapia products.? This may be further exacerbated depending on the cooking method.? This study aimed to evaluate the effects of different cooking methods on the fatty acid composition and oxidative stability of tilapia minced meat after prior fish oil fortifications with or without clove essential oil. Results showed that frying tilapia in either sunflower or palm oil significantly increased the saturated fatty acid and linoleic acid content, respectively, of tilapia. However, fish oil fortifications significantly increased the n-3 PUFA content, but tended to decrease oxidative stability, particularly when microwaving. This was mitigated by clove essential oil, which significantly improved oxidative stability after cooking. Results indicate that n-3 PUFA and clove essential oil fortifications is an effective method to deliver and protect these beneficial fatty acids for human consumers. ?

  10. The use of crude extracts from traditional medicinal plants to eliminate Trichodina sp. in tilapia (Oreochromis niloticus fingerlings

    Directory of Open Access Journals (Sweden)

    Chanagun Chitmanat

    2005-02-01

    Full Text Available The treatment for ectoparasitic diseases in freshwater fish with formalin seems at present to be ineffective. For this reason it is evidently a useless cost. In addition, formalin possibly leaves toxic residues in fish flesh and in the environment which are eventually harmful to consumers. The alternative way to solve this problem is to use traditional medicinal plants instead. The purpose of this research is to determine the possibility of using garlic (Allium sativum and Indian almond (Terminalia catappa as optional chemicals to treat fish ectoparasites, Trichodina sp. The results showed that crude extracts of either garlic or Indian almond at 800 mg/l significantly (P < 0.05 eliminated Trichodina sp. infections in tilapia (average weight 3.62±0.06 g each. To evaluate the acute toxicity of these products to the host fish, groups of 20 tilapia (same size as abovewere exposed to 3 concentrations of each product for 96 h. Mortality was then determined. The 2 h LC50 for tilapia exposed to crude extract of garlic was 2,259.44 mg/L while the 16 h LC50 for tilapia exposed to Indian almond extract was 46,665.94 mg/L. This information is the beneficial and fundamental knowledge to develop guidelines to reduce the use of chemicals and antibiotics in freshwater fish culture businesses. The research is underway to determine the long-term effect of Indian almond and garlic to tilapia, if any.

  11. Effects of fatty acid provision during severe hypoxia on routine and maximal performance of the in situ tilapia heart.

    Science.gov (United States)

    Speers-Roesch, Ben; Lague, Sabine L; Farrell, Anthony P; Richards, Jeffrey G

    2013-08-01

    The ability to maintain stable cardiac function during environmental hypoxia exposure is crucial for hypoxia tolerance in animals and depends upon the maintenance of cardiac energy balance as well as the state of the heart's extracellular environment (e.g., availability of metabolic fuels). Hypoxic depression of plasma [non-esterified fatty acids] (NEFA), an important cardiac aerobic fuel, is a common response in many species of hypoxia-tolerant fishes, including tilapia. We tested the hypothesis that decreased plasma [NEFA] is important for maintaining stable cardiac function during and following hypoxia exposure, based on the premise that continued reliance upon cardiac fatty acid metabolism under such conditions could impair cardiac function. We examined the effect of severe hypoxia exposure (PO2 tilapia heart under conditions of routine (400 μmol L(-1)) and low (75 μmol L(-1)) [palmitate], which mimicked the in vivo levels of plasma [NEFA] found in normoxic and hypoxic tilapia, respectively. Under both concentrations of palmitate, the in situ tilapia heart showed exceptional hypoxic performance as a result of a high maximum glycolytic potential, confirming our previous results using a perfusate without fatty acids. We additionally provide evidence suggesting that non-contractile ATP demand is depressed in tilapia heart during hypoxia exposure. Cardiac performance during and following severe hypoxia exposure was unaffected by the level of palmitate. Thus, we conclude that hypoxic depression of plasma [NEFA] in fishes does not play a role in cardiac hypoxia tolerance.

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

    Science.gov (United States)

    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.

  13. Pituitary control of branchial NCC, NKCC and Na(+), K (+)-ATPase α-subunit gene expression in Nile tilapia, Oreochromis niloticus.

    Science.gov (United States)

    Breves, Jason P; Seale, Andre P; Moorman, Benjamin P; Lerner, Darren T; Moriyama, Shunsuke; Hopkins, Kevin D; Grau, E Gordon

    2014-05-01

    This study investigated endocrine control of branchial ionoregulatory function in Nile tilapia (Oreochromis niloticus) by prolactin (Prl188 and Prl177), growth hormone (Gh) and cortisol. Branchial expression of Na(+)/Cl(-) cotransporter (ncc) and Na(+)/K(+)/2Cl(-) cotransporter (nkcc) genes were employed as specific markers for freshwater- and seawater-type ionocytes, respectively. We further investigated whether Prl, Gh and cortisol direct expression of two Na(+), K(+)-ATPase (nka)-α1 subunit genes, denoted nka-α1a and nka-α1b. Tilapia transferred to fresh water following hypophysectomy failed to adequately activate gill ncc expression; ncc expression was subsequently restored by Prl replacement. Prl188 and Prl177 stimulated ncc expression in cultured gill filaments in a concentration-related manner, suggesting that ncc is regulated by Prl in a gill-autonomous fashion. Tilapia transferred to brackish water (23 ‰) following hypophysectomy exhibited a reduced capacity to up-regulate nka-α1b expression. However, Gh and cortisol failed to affect nka-α1b expression in vivo. Similarly, we found no clear effects of Gh or cortisol on nkcc expression both in vivo and in vitro. When considered with patterns previously described in euryhaline Mozambique tilapia (O. mossambicus), the current study suggests that ncc is a conserved target of Prl in tilapiine cichlids. In addition, we revealed contrasting dependencies upon the pituitary to direct nka-α1b expression in hyperosmotic environments between Nile and Mozambique tilapia.

  14. Nile Tilapia Neu3 sialidases: molecular cloning, functional characterization and expression in Oreochromis niloticus.

    Science.gov (United States)

    Chigwechokha, Petros Kingstone; Komatsu, Masaharu; Itakura, Takao; Shiozaki, Kazuhiro

    2014-11-15

    Mammalian Neu3 is a ganglioside specific sialidase. Gangliosides are involved in various physiological events such as cell growth, differentiation and diseases. Significance of Neu3 and gangliosides is still unclear in aquaculture fish species. To gain more insights of fish Neu3 sialidases, molecular cloning and characterization were carried out in tilapia (Oreochromis niloticus). A tilapia genome-wide search for orthologues of human NEU1, NEU2, NEU3 and NEU4 yielded eight putative tilapia sialidases, five of which were neu3-like and designated as neu3a, neu3b, neu3c, neu3d and neu3e. Among five neu3 genes, neu3a, neu3d and neu3e were amplified by PCR from adult fish brain cDNA with consensus sequences of 1227bp, 1194bp and 1155bp, respectively. Multiple alignments showed conserved three Asp-boxes (SXDXGXTW), YRIP and VGPG motifs. The molecular weights for Neu3a, Neu3d and Neu3e were confirmed using immunoblotting analysis as 45.9kDa, 44.4kDa and 43.6kDa, respectively. Lysate from neu3 genes transfected HEK293 cells showed sialidase activity in Neu3a towards ganglioside mix optimally at pH4.6. Using pure gangliosides as substrates, highest sialidase activity for Neu3a was observed towards GD3 followed by GD1a and GM3, but not GM1. On the other hand, sialidase activities were not observed in Neu3d and Neu3e towards various sialoglycoconjugates. Indirect immunofluorescence showed that tilapia Neu3a and Neu3d are localized at the plasma membrane, while most Neu3e showed a cytosolic localization. RT-PCR analyses for neu3a showed significant expression in the brain, liver, and spleen tissues, while neu3d and neu3e showed different expression patterns. Based on these results, tilapia Neu3 exploration is an important step towards full understanding of a more comprehensive picture of Neu3 sub-family of proteins in fish.

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

    Science.gov (United States)

    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.

  16. Detection of Clostridium botulinum type C cells in the gastrointestinal tracts of Mozambique tilapia (Oreochromis mossambicus) by polymerase chain reaction

    Science.gov (United States)

    Nol, P.; Williamson, J.L.; Rocke, T.E.; Yuill, Thomas M.

    2004-01-01

    We established a method of directly detecting Clostridium botulinum type C cells, while minimizing spore detection, in the intestinal contents of Mozambique tilapia (Oreochromis mossambicus). This technique involved extraction of predominantly cellular DNA from tilapia intestinal tracts and used a polymerase chain reaction assay to detect presence of type C1 toxin gene. We consistently detected C. botulinum type C cells in tilapia gastrointestinal contents at a level of 7.5×104 cells per 0.25 g material or 1.9×103 cells. This technique is useful for determining prevalence of the potentially active organisms within a given population of fish and may be adapted to other types of C. botulinum and vertebrate populations as well.

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

    Science.gov (United States)

    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.

  18. Fishborne trematodes in cultured Nile tilapia (Oreochromis niloticus) and wild-caught fish from Thailand

    DEFF Research Database (Denmark)

    Wiriya, Benjamaporn; Clausen, Jesper Hedegaard; Inpankaew, Tawin

    2013-01-01

    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...... 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...

  19. Systems-level modeling the effects of arsenic exposure with sequential pulsed and fluctuating patterns for tilapia and freshwater clam

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.-Y. [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Tsai, J.-W. [Institute of Ecology and Evolutionary Ecology, China Medical University, Taichung 40402, Taiwan (China); Ju, Y.-R. [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Liao, C.-M., E-mail: cmliao@ntu.edu.t [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2010-05-15

    The purpose of this paper was to use quantitative systems-level approach employing biotic ligand model based threshold damage model to examine physiological responses of tilapia and freshwater clam to sequential pulsed and fluctuating arsenic concentrations. We tested present model and triggering mechanisms by carrying out a series of modeling experiments where we used periodic pulses and sine-wave as featured exposures. Our results indicate that changes in the dominant frequencies and pulse timing can shift the safe rate distributions for tilapia, but not for that of freshwater clam. We found that tilapia increase bioenergetic costs to maintain the acclimation during pulsed and sine-wave exposures. Our ability to predict the consequences of physiological variation under time-varying exposure patterns has also implications for optimizing species growing, cultivation strategies, and risk assessment in realistic situations. - Systems-level modeling the pulsed and fluctuating arsenic exposures.

  20. Differences in sexual size dimorphism among farmed tilapia species and strains undergoing genetic improvement for body weight

    Directory of Open Access Journals (Sweden)

    C.E. Lind

    2015-05-01

    Full Text Available Many tilapia (Oreochromis spp. farmers produce all-male populations because of the superior growth rate of males compared to females. To investigate differences in body weight at harvest of males and females among different tilapia strains, we analyzed data from 62,787 individuals collected from pedigreed breeding programs of O. niloticus (GIFT from Malaysia, the Abbassa line from Egypt, and the Akosombo line from Ghana, O. shiranus (the Bunda College-Domasi selection line, O. aureus (a selection line under development in Abbassa, Egypt, and a selection line from Israel and a synthetic selection line of Red tilapia under development in Jitra, Malaysia, derived from stock from Malaysia, Taiwan and Thailand (O. sp.. Mixed models were separately fitted to the data from each selection line. There was a significant sex effect in all strains (P < 0.001. A significant (P < 0.001 sex by generation interaction was observed in all strains (scale effect, not reversal of rankings, except Red tilapia and O. shiranus. Least squares means showed a large range in the magnitude of body weight differences between sexes across the seven strains. The largest percentage difference between females and males was in O. aureus from Egypt (female body weight was 52.2% that of males at harvest, whereas the smallest difference was observed in the GIFT strain of O. niloticus (female body weight 84.7% that of males. Female to male body weight percentages for Red tilapia, O. shiranus, Egypt O. niloticus, Israeli O. aureus and Ghana O. niloticus were 81.3, 81.0, 69.1, 61.7 and 61.0, respectively. We discuss the results in relation to the potential productivity improvements due to superior growth rates of all-male culture compared to mixed-sex culture in tilapia populations differing in the female to male body weight ratio.

  1. Bioavailability links mode of action can improve the long-term field risk assessment for tilapia exposed to arsenic.

    Science.gov (United States)

    Tsai, Jeng-Wei; Chen, Wei-Yu; Ju, Yun-Ru; Liao, Chung-Min

    2009-05-01

    The objective of this paper was to develop a mechanistic-based framework to explicitly incorporate the factors controlling the bioavailability, toxicodynamics and mode of action to enhance predictive ability of arsenic (As) toxicity to protect the health of farmed tilapia Oreochromis mossambicus. We linked the biotic ligand model and damage assessment model to develop a toxicokinetic model for elucidating the site-specific temporal changes of As bioavailability and to characterize how the fish regulate the metal toxicity. We built a bioavailability-mode of action-based growth toxicity model by linking a bioenergetic growth model and damage assessment model to predict how the As affects on the tilapia growth in the entire life span in site-specific field ecosystems. Here we show that the proposed model well describes the water-chemistry-dependent toxicokinetics and toxicodynamics variations of As to tilapia. We selected two local tilapia farms with different water chemistries located at southwestern Taiwan coast region to implement the proposed algorithm to predict the risk of As exposure. Results indicate that the growth toxicity of O. mossambicus in Taihsi is more sensitive than that in Peimen. We found that the effect of ion competition on the As bioavailability and their ecotoxicological effects on tilapia are more obvious in Taihsi comparing with that in Peimen. We suggested that the proposed bioavailability- and mode of action-based framework can be used to capture the biological response and regulation of tilapia to As exposures. It is applicable for a site-specific and long-term ecotoxicological risk assessment.

  2. Isolation, Identification and Drug Sensitive Test of Aeromonas jandaei from Tilapia (Tilapia nilotica)%罗非鱼(Tilapia nilotica)简达气单胞菌病的病原分离鉴定及药敏试验

    Institute of Scientific and Technical Information of China (English)

    杨宁; 姜芳燕; 黄海; 焦健

    2015-01-01

    Tilapia is a very important freshwater aquacultural species in China; however, bacterial disease caused huge economic losses in recent years with the continous expansion of tilapia aquaculture. The aim of this research was to isolate, identify, and test drug sensitivity of bacteria pathogen found in diseased Tilapia nilotica. Six bacteria were isolated from diseased T. nilotica as suspected pathogenic bacteria. The bacteria (NL05) isolated from intestine of diseased T. nilotica was determined as pathogenic bacteria by infection experiment. The LD50 was 1×103 CFU/g. Bacteria NL05 was identified as Aeromonas jandaei. Morphology observation indicated that NL05 was gram-negative, rod-shaped. Thirteen physiological and biochemical indexes were positive including maltose, mannitol, glucose, salicin, and hydrogen sulfide. Ten indexes were negative including saccharum, arabinose, xylose, inositol, and dulcitol. There was 1442 bp in the sequence of 16S rRNA, which was submitted into GenBank (Accession number: KC916744). The phylogenetic tree based on 16S rRNA showed that NL05 was A. jandaei. Drug sensitivity test indicated that NL05 was sensitive to 13 antibiotics including ofloxacin, ciprofloxacin, amikacin, polymyxin B, norfloxacin, rifampicin, and lincomycin, and intermediate sensitive to 5 antibiotics including azithromycin, ceftriaxone, kanamycin, streptomycin and minocycline, and resistant to 13 antibiotics including ampicillin, amoxicillin, enrofloxacin, sulfamethoxazole, and trimethoprim. The results will provide references for the prevention and treatment of diseases caused by T. nilotica.%从患病罗非鱼(Tilapia nilotica)体内分离得到细菌 NL05,通过回归感染试验确定 NL05为致病菌,并测出 NL05对罗非鱼的半致死量(LD50)为1×103 CFU/g。结合细菌形态学特征、生理生化指标和16S rRNA 基因同源分析,鉴定 NL05为简达气单胞菌(Aeromonas jandaei)。形态学观察发现, NL05为革兰氏阴性、短杆状;

  3. Prevalence and diversity of fish-borne zoonotic trematodes in tilapia (Oreochromis niloticus) culture in Guangdong, China

    DEFF Research Database (Denmark)

    Li, Kang; Murrell, Kenneth Darwin; Clausen, Jesper Hedegaard

    ), and Carassius auratus (4).The FZT species recovered were mainly Haplorchis taichui, and H. pumilio along with some unknown species whose identifications are still being determined. Subsequently a cross-sectional survey for the prevalence and diversity of FZT in tilapia culture systems was conducted in Guangdong...... Province during August-October 2011. A total of 389 tilapias sized 2.33-1450.00 g were collected from 30 farms, and examined for FZT metacercariae by the pepsin digestion method. Ten percent of the farms surveyed had fish with FZT infections. The overall FZT prevalence in fish was 1.5% and the infection...

  4. Effects of socking [sic] density on ammonia excretion and the growth of Nile tilapia (Oreochromis niloticus L.)

    OpenAIRE

    Ali, M.S.; Stead, S. M.; Houlihan, D F

    2006-01-01

    The effects of stocking density (10, 15, 50 & 75 fish in 65L tank) and ammonia excretion on the growth of Nile tilapia, Oreochromis niloticus (12.19 ± 1.21 g) were investigated. Increasing stocking density of Nile tilapia from 15 fish/tank (2.81 g fish/L) to 75 fish/tank (14.07 g fish/L) resulted in associated increase in ammonia level (1.48 ± 0.87 mg/L to 26.44 ± 11.4 mg/L) and significantly lower growth rates. Significantly better feed conversion ratios were found for fish reared at lower (...

  5. Quantification of essential fatty acids in the heads of nile tilapia (Oreochromis niloticus) fed with linseed oil

    OpenAIRE

    Aguiar,Ana C.; Cottica,Solange M.; Boroski,Marcela; Oliveira,Cláudio C.; Bonafé,Elton G.; França,Polyana B.; Souza,Nilson E.; Visentainer,Jesui V.

    2011-01-01

    The objective of this study was to examine the effects of linseed oil on n-6 and n-3 polyunsaturated (PUFA) fatty acid content in the heads of Nile tilapia (Oreochromis niloticus), these are normally discarded during the filleting process. The quantification of PUFA was carried out in absolute weights through the use of methyl ester (23:0), as an internal standard, and TCFx (theoretical FID correction factor) by GC gas chromatography. Tilapias were given diets with increasing levels (0.00, 1....

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

    Science.gov (United States)

    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

  7. Evidence of vertical transmission and tissue tropism of Streptococcosis from naturally infected red tilapia (Oreochromis spp.

    Directory of Open Access Journals (Sweden)

    Padmaja Jayaprasad Pradeep

    2016-05-01

    Full Text Available Streptococcosis is a highly problematic disease in the aquaculture of freshwater fishes, especially for tilapia. The possibility of vertical transmission of streptococcosis and the pattern of tissue tropism of this pathogen in various organs was examined in red tilapia (Oreochromis sp.. Healthy broodstock without any clinical signs of Streptococcus spp. were selected from a farm earlier reported to have the disease and a total of 10 pairs were forced spawned to provide samples of gametes and progeny for pathogen testing. A colorimetric LAMP assay was used to confirm whether the bacterial pathogens Streptococcus. agalactiae and Streptococcus. iniae was present in samples of milt, unfertilized eggs, fertilized eggs, and offspring at various stages of development, as well as internal organs of broodstock (reproductive organs, gill, liver, spleen, kidney and brain as well as samples of water from culture systems. The majority of samples of milt (9/10 and unfertilized eggs (7/10 collected from the broodstock were infected with S. iniae at the time of spawning and was transmitted to all of their offspring. Nevertheless, when the same samples of gametes were analyzed for S. agalactiae, they were all found to be negative but the pathogen was found to be present in some 10-day-old larval offspring (4/10. However, when the pathogenic presence was analyzed from the reproductive organs of the parents, both S. agalactiae (11/20 and S. iniae (18/20 bacterium were common. Although, all broodstock were asymptomatic, almost all broodstock harboured the bacteria in many organs. Confirmation of vertical transmission of streptococcosis in tilapia means that intergenerational break cannot be used as a reliable and simple means of reducing or eliminating the prevalence of these difficult pathogens in aquaculture stock.

  8. Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China.

    Science.gov (United States)

    Li, Liping; Wang, Rui; Liang, Wanwen; Gan, Xi; Huang, Ting; Huang, Yan; Li, Jian; Shi, Yunliang; Chen, Ming; Luo, Honglin

    2013-12-27

    Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae (GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the first time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in five provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding 36.9% (62/168), 37.5% (63/168) and 19.6% (33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia (95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010, but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during 2007-2011, III only occurred in 2012. 14 different PFGE types, including 4 new types (N, O, P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9% (141/168) of the total GBS strains. Ia corresponded to 11 PFGE types (A-H, N-P), in which type D predominated (51%). Ib represented 3 genotypes (I, J and Q) and III harbored only 2 genotypes (N and F). Type N and F synchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years. Although Ia still predominated, new rare serotype III already occurred in China.

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

    Science.gov (United States)

    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.

  10. Masculinization of red tilapia Oreochromis SPP. With steroid trenbolone acetate (TBA provided in the food

    Directory of Open Access Journals (Sweden)

    Apolinar Santamaría Miranda

    2012-09-01

    Full Text Available The tilapia culture in our country has presented in recent years a significant rise and diversification, this due to the food shortage in our country and in the rest of the world, there are some alternatives to increase the profitability of their crop and is also an activity important in the state of Sinaloa, mainly in the communities adjacent to the dams and reservoirs of water. Inthe present study we present the results obtained in the process of sex reversal of red tilapia fingerlings Oreochromis sp., held at the premises of CIIDIR-IPN, Guasave, Sinaloa. The experiment used a total population of 4000 organisms, which were distributed in three hormonal treatment ponds by integrating them into the food (ATB and three controls (C, were concrete ponds with a capacity of 500 L. water was applied to the food hormone to be administered orally. The percent change of sex was determined by the technique "Squash". In the treatment hormonado food supply. The physicochemical parameters were not significantly different because they are within the limits allowed in growing tilapia. Survival in the treatment of hormonedelivery was the result was 89.6 ± 2.5% and 78.0 ± 3.2% control. In her final weight (g application in the treatment of hormone was 0.52 ± 0.02 g and the control was 0.50 ± 0.04 g. The percentage reversal of the sexual hormone treatment (TBAwas 89.7 ± 3.0% in the control (C was 57.0 ± 2.3%. This allowed to know which is more effective use of the hormone in the food.

  11. SANITARY-HYGIENIC QUALITY OF FRESH AND FROZEN TILAPIA (Oreochromis spp. IN PUBLIC MARKETS

    Directory of Open Access Journals (Sweden)

    Renata Xavier Silva

    2016-10-01

    Full Text Available This study aimed to verify the sanitary quality of tilapia (Oreochromis spp. sold in public markets in the city of Mossoro-RN. For such we made use of a checklist and an observational study to evaluate good handling practices in 10 establishments that commercialize fish. We obtained 30 samples of tilapia and evaluated them as to their sensory and microbiological aspects (Salmonella spp., coliforms at 45 ºC, Staphylococcus ssp. count, psychrotrophic bacteria and enterobacteria, as well as to their pH and internal and external temperature. We observed that none of the studied establishments were in accordance with the standards recommended by the legislation. Regarding the sensory evaluation, 83.3% of the samples showed compliance with the requirements of the legislation. As for the coliforms at 45 °C essay, the results ranged from 0.477 to 1.509 log10 CFU/g; in the Staphylococcus spp. essay we found results from 4.854 to 5.397 log10 CFU/g; and further, we found values from 3.884 to 4.937 and from 4.707 to 5.463 log10 CFU/g for enterobacteria and psychrotrophic bacteria, respectively. All the samples were within the requirements for contamination by Salmonella spp. (absence. The pH ranged from 5.99 to 6.18 and temperatures indicated non-compliance with the recommendations. Thus, we can infer that the sanitary quality of tilapia sold in public markets in Mossoro-RN was impaired, presenting a risk to consumer health due to unsatisfactory handling conditions. Keywords: best practices; microbiology; physio-chemistry.

  12. Performance and economic analysis of the production of Nile tilapia submitted to different feeding management

    Directory of Open Access Journals (Sweden)

    Érica Bevitorio Passinato

    2015-12-01

    Full Text Available The productive performance and the variable cost of production were evaluated for different feeding strategies for tilapia during the production cycle. A sample of 2,000 juvenile tilapia was distributed (23.55 ± 2.38 g into five treatments and with four repetitions as follows: C (feed consumption to apparent satiety, R20 (beginning feed restriction when fish reached an average weight of 20 g, R200 (beginning feed restriction when fish reached an average weight of 200 g, R400 (beginning feed restriction when fish reached an average weight of 400 g and R600 (beginning feed restriction when fish reached an average weight of 600 g. The fish were given extruded commercial feed containing 34% crude protein until they reached a weight of 200 g, at which time they received feed containing 32% crude protein. Monthly biometrics were performed in order to determine the food restriction starting point, which was one day of restriction followed by six feeding days. The following parameters were evaluated: water quality, productive performance variables, the variable costs of production and excreted nitrogen. The results were subjected to analysis of variance, and the means were compared using Tukey’s test (5% significance. No statistical differences were observed in final weight, weight gain, feed consumption, feed conversion or survival. The fish from the R20 treatment had the lowest variable cost of production (g fish-1 and the lowest nitrogen excretion into the water. This suggests that feed restriction from the early stages of life does not compromise the productive performance and contributes to reducing the variable costs and the quantity of nitrogen excreted into the environment. Thus, a one-day per week feed restriction strategy can be applied from the earliest stages of life without compromising the productive performance or body composition of Nile tilapia. This strategy can also reduce variable costs of production by means of reducing relative

  13. Salinity-induced regulation of the myo-inositol biosynthesis pathway in tilapia gill epithelium.

    Science.gov (United States)

    Sacchi, Romina; Li, Johnathon; Villarreal, Fernando; Gardell, Alison M; Kültz, Dietmar

    2013-12-15

    The myo-inositol biosynthesis (MIB) pathway converts glucose-6-phosphate to the compatible osmolyte myo-inositol that protects cells from osmotic stress. Using proteomics, the enzymes that constitute the MIB pathway, myo-inositol phosphate synthase (MIPS) and inositol monophosphatase 1 (IMPA1), are identified in tilapia (Oreochromis mossambicus) gill epithelium. Targeted, quantitative, label-free proteomics reveals that they are both upregulated during salinity stress. Upregulation is stronger when fish are exposed to severe (34 ppt acute and 90 ppt gradual) relative to moderate (70 ppt gradual) salinity stress. IMPA1 always responds more strongly than MIPS, suggesting that MIPS is more stable during salinity stress. MIPS is N-terminally acetylated and the corresponding peptide increases proportionally to MIPS protein, while non-acetylated N-terminal peptide is not detectable, indicating that MIPS acetylation is constitutive and may serve to stabilize the protein. Hyperosmotic induction of MIPS and IMPA1 is confirmed using western blot and real-time qPCR and is much higher at the mRNA than at the protein level. Two distinct MIPS mRNA variants are expressed in the gill, but one is more strongly regulated by salinity than the other. A single MIPS gene is encoded in the tilapia genome whereas the zebrafish genome lacks MIPS entirely. The genome of euryhaline tilapia contains four IMPA genes, two of which are expressed, but only one is salinity regulated in gill epithelium. The genome of stenohaline zebrafish contains a single IMPA gene. We conclude that the MIB pathway represents a major salinity stress coping mechanism that is regulated at multiple levels in euryhaline fish but absent in stenohaline zebrafish.

  14. Characterization and localization of metal-responsive-element-binding transcription factors from tilapia

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Andrew Pok-Lap; Au, Candy Yee-Man; Chan, William Wai-Lun [Department of Biochemistry, Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong (Hong Kong); Chan, King Ming, E-mail: kingchan@cuhk.edu.hk [Department of Biochemistry, Chinese University of Hong Kong, Sha Tin, N.T., Hong Kong (Hong Kong)

    2010-08-01

    Two isoforms of MTF-1, MTF-1L (long form) and MTF-1S (short form), were cloned in tilapia (Ti) and characterized in a tilapia liver cell line, Hepa-T1. The cloned tiMTF-1L has the characteristics of all of the tiMTF-1S identified so far with the zinc finger domain having six fingers, the acidic-rich, proline-rich, and serine/threonine-rich domains; however, the short form encodes for the zinc finger domain with five zinc fingers only and no other domains. The transient transfection of tiMTF-1L into human HepG2 cells showed both constitutive and zinc-induced metal-responsive-element (MRE)-driven reporter gene expression. However, the transfection of tiMTF-1S (which lacks all three transactivation domains) into a human cell line showed reduced transcriptional activities compared with an endogenous control in both basal- and Zn{sup 2+}-induced conditions. The tiMTF-1 isoforms were tagged with GFP and transfected into Hepa-T1 cells (tilapia hepatocytes). The nuclear translocation of tiMTF-1L was observed when the cells were exposed to a sufficient concentration of metals for 6 h. However, tiMTF-1S, was localized in the nucleus with or without metal treatment. Electrophoretic mobility shift assay (EMSA) confirmed that both of the isoforms were able to bind to the MRE specifically in vitro. Tissue distribution studies showed that tiMTF-1L was more abundant than tiMTF-1S in all of the tissues tested.

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

    Science.gov (United States)

    Pridgeon, Julia W; Aksoy, Mediha; Klesius, Phillip H; Li, Yuehong; Mu, Xingjiang; Srivastava, Kunwar; Reddy, Gopal

    2011-11-15

    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 hydrophila. A total of 31 unique expressed sequence tags (ESTs) were identified from 192 clones of the subtractive cDNA library. Quantitative PCR revealed that nine of the 31 ESTs were significantly (ptilapia at 6h post infection with A. hydrophila at an injection dose of 10(5)CFU per fish (≈ 20% mortality). Of the nine upregulated genes, four were also significantly (ptilapia at 6h post infection with A. hydrophila at an injection dose of 10(6)CFU per fish (≈ 60% mortality). Of the four genes induced by A. hydrophila at both injection doses, three were also significantly (ptilapia at 6h post infection with Streptococcus iniae at doses of 10(6) and at 10(5)CFU per fish (≈ 70% and ≈ 30% mortality, respectively). The three genes induced by both bacteria included EST 2A05 (similar to adenylate kinase domain containing protein 1), EST 2G11 (unknown protein, shared similarity with Salmo salar IgH locus B genomic sequence with e value of 0.02), and EST 2H04 (unknown protein). Significant upregulation of these genes in Nile tilapia following bacterial infections suggested that they might play important roles in host response to infections of A. hydrophila and S. iniae.

  16. Pharmacokinetics of cefquinome in tilapia (Oreochromis niloticus) after a single intramuscular or intraperitoneal administration.

    Science.gov (United States)

    Shan, Q; Zhu, X; Liu, S; Bai, Y; Ma, L; Yin, Y; Zheng, G

    2015-12-01

    The pharmacokinetics of cefquinome was studied in plasma after a single dose (10 mg/kg) of intramuscular (i.m.) or intraperitoneal (i.p.) administration to tilapia (Oreochromis niloticus) in freshwater at 30 °C. Ten fish per sampling point were examined after treatment. The data were fitted to two-compartment open models following both routes of administration. The estimates of total body clearance (CL/F), volume of distribution (Vd/F), and absorption half-life (T1/2ka ) were 0.049 and 0.037 L/h/kg, 0.41 and 0.33 L/kg, and 0.028 and 0.035 h following i.m. and i.p. administration, respectively. After i.m. injection, the elimination half-life (T1⁄2β ) was calculated to be 5.81 h, the maximum plasma concentration (Cmax ) to be 49.40 μg/mL, the time to peak plasma cefquinome concentration (Tmax ) to be 0.14 h, and the area under the plasma concentration-time curve (AUC) to be 204.6 μg h/mL. Following i.p. administration, the corresponding estimates were 6.05 h, 44.39 μg/mL, 0.17 h and 267.8 μg h/mL. The minimum inhibitory concentrations of cefquinome, determined for 30 strains of Streptococcus agalactiae isolated from diseased tilapia, ranged from 0.015 to 0.12 μg/mL. Results from these studies support that 10 mg cefquinome/kg body weight daily could be expected to control tilapia bacterial pathogens inhibited in vitro by a minimal inhibitory concentration value of ≤2 μg/mL.

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

    Science.gov (United States)

    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

  18. Five different piscidins from Nile tilapia, Oreochromis niloticus: analysis of their expressions and biological functions.

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    Kuan-Chieh Peng

    Full Text Available Piscidins are antimicrobial peptides (AMPs that play important roles in helping fish resist pathogenic infections. Through comparisons of tilapia EST clones, the coding sequences of five piscidin-like AMPs (named TP1∼5 of Nile tilapia, Oreochromis niloticus, were determined. The complete piscidin coding sequences of TP1, -2, -3, -4, and -5 were respectively composed of 207, 234, 231, 270, and 195 bases, and each contained a translated region of 68, 77, 76, 89, and 64 amino acids. The tissue-specific, Vibrio vulnificus stimulation-specific, and Streptococcus agalactiae stimulation-specific expressions of TP2, -3, and -4 mRNA were determined by a comparative RT-PCR. Results of the tissue distribution analysis revealed high expression levels of TP2 mRNA in the skin, head kidneys, liver, and spleen. To study bacterial stimulation, S. agalactiae (SA47 was injected, and the TP4 transcript was upregulated by >13-fold (compared to the wild-type (WT control, without injection and was 60-fold upregulated (compared to the WT control, without injection 24 h after the S. agalactiae (SA47 injection in the spleen and gills. Synthesized TP3 and TP4 peptides showed antimicrobial activities against several bacteria in this study, while the synthesized TP1, -2, and -5 peptides did not. The synthesized TP2, -3, and -4 peptides showed hemolytic activities and synthesized TP3 and TP4 peptides inhibited tilapia ovary cell proliferation with a dose-dependent effect. In summary, the amphiphilic α-helical cationic peptides of TP3 and TP4 may represent novel and potential antimicrobial agents for further peptide drug development.

  19. Riesgos de la introducción de tilapias (Oreochromis sp. (Perciformes: Cichlidae en ecosistemas acuáticos de Chile Risks of the introduction of tilapia (Oreochromis sp. (Perciformes: Cichlidae in aquatic ecosystems of Chile

    Directory of Open Access Journals (Sweden)

    2004-03-01

    Full Text Available Se hace un llamado de alerta ante la posible introducción de la tilapia roja (Oreochromis sp. a Chile, con fines de cultivo. Se analizan los llamados cultivos monosexuales (solo machos, señalados como la solución para impedir la reproducción no deseada, que evitaría riesgos para la biodiversidad y se demuestra la falsedad de este argumento. Énfasis especial se da a los cultivos de tilapia en áreas marinas. Los peligros para la biodiversidad, son resaltadosA call of attention is made over the possible introduction of red tilapia (Oreochromis sp. for aquaculture in Chile. The so-called monosex (all male culture, considered by some as the solution for unwanted reproduction and for avoiding risks for biodiversity, are analyzed, and the falsehood of this argument is demonstrated. Special emphasis is given to the tilapia culture in marine areas. Threats to biodiversity are stressed

  20. Reduced growth in hybrid tilapia ( Oreochromis mossambicus ×O. Niloticus) at intermediate stocking density

    Science.gov (United States)

    Wang, Yan; Cui, Yi-Bo; Yang, Yun-Xia; Cai, Fa-Sheng

    2002-12-01

    Hybrid tilapia were reared at densities of 1, 5 or 10 fish per tank for four weeks. Mortality was 0 at 1 and 10 fish per tank, but was 25% at 5 fish per tank. Specific growth rate was highest at 1 fish per tank, and lowest at 5 fish per tank. The lower growth rate at the intermediate stocking density was associated with reduced feed efficiency, but there was no reduction in feed intake or digestibility. The results suggested increased metabolic cost caused by aggressive behaviour at intermediate stocking density, which can be suppressed by a further increase in density.

  1. REDUCED GROWTH IN HYBRID TILAPIA (OREOCHROMIS MOSSAMBICUS×O. NILOTICUS) AT INTERMEDIATE STOCKING DENSITY

    Institute of Scientific and Technical Information of China (English)

    王岩; 崔奕波; 杨云霞; 蔡发盛

    2002-01-01

    Hybrid tilapia were reared at densities of 1, 5 or 10 fish per tank for four weeks. Mortality was 0 at 1 and 10 fish per tank, but was 25% at 5 fish per tank. Specific growth rate was highest at 1 fish per tank, and lowest at 5 fish per tank. The lower growth rate at the intermediate stocking density was associated with reduced feed efficiency, but there was no reduction in feed intake or digestibility. The results suggested increased metabolic cost caused by aggressive behaviour at intermediate stocking density, which can be suppressed by a further increase in density.

  2. EFFECTS OF THE HEAVY METAL, ZINC, ON THE FRESHWATER FISH TILAPIA NILOTICA L.

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    VIRGINIA S. CARING

    1992-01-01

    Full Text Available Gills, gonads, and blood of Tilapia nilotica exposed to different concentrations of zinc sulfate (ZnSO4. 7H2O exhibited histological effects. Gills of posthatch larvae exposed chronically for 21 days to 2 ppm zinc sulfate and fingerlings to 10 ppm sublethal zinc concentrations exhibited hyperplasia that resulted in fusion of adjacent secondary gill lamellae. The same effects were observed in 4-hour short-term exposure to 30 ppm lethal dose. Posthatch larvae subjected to 2 and 5 ppm sublethal levels of zinc for 30 days retained undifferentiated gonads with differentiation with oogonial proliferation. Ovaries of control fish demonstrated healthy oocyte growth and other normal histological features after 57 days. In contrast, ovaries in treated groups exhibited excessive amounts of connective tissue, hyperemia and markedly reduced oocyte number. Oocytes had wavy irregular surface outlines. Deviation from normal was observed to be dose dependent. In juvenile tilapia, spermatogenesis was observed in control testes. Testes of zinc-exposed fish, on the other hand, remained immature. Hyperemia was markedly pronounced in both testes and ovary after 90 days exposure to zinc. Blood of Tilapia nilotica fingerlings exposed to sublethal concentrations of 2, 5, and 10 ppm zinc for 30, 60, and 90 days exhibited anisocytosis and poikilocytosis. There was an increase in hematocrit values in zinc-reared fish which, however, reverted to control/near control levels at day 90. Hemoglobin values were inversely proportional to the level of zinc in the rearing water. The marked reduction in hemoglobin values in fish reared at the higher zinc concentrations of 5 and 10 ppm suggests the development of some degree of anemia which is also supported by the observations of anisocytosis and poikilocytosis. INTRODUCTION Heavy metal contamination of aquatic environments has become a current serious problem because of increased industrialization. In the Philippines, data gathered

  3. Development of live attenuated Streptococcus agalactiae vaccine for tilapia via continuous passage in vitro.

    Science.gov (United States)

    Li, L P; Wang, R; Liang, W W; Huang, T; Huang, Y; Luo, F G; Lei, A Y; Chen, M; Gan, X

    2015-08-01

    Fish Streptococcus agalactiae (S. agalactiae) seriously harms the world's aquaculture industry and causes huge economic losses. This study aimed to develop a potential live attenuated vaccine of S. agalactiae. Pre-screened vaccine candidate strain S. agalactiae HN016 was used as starting material to generate an attenuated strain S. agalactiae YM001 by continuous passage in vitro. The biological characteristics, virulence, and stability of YM001 were detected, and the protective efficacy of YM001 immunization in tilapia was also determined. Our results indicated that the growth, staining, characteristics of pulsed-field gel electrophoresis (PFGE) genotype, and virulence of YM001 were changed significantly as compared to the parental strain HN016. High doses of YM001 by intraperitoneal (IP) injection (1.0 × 10(9) CFU/fish) and oral gavage (1.0 × 10(10) CFU/fish) respectively did not cause any mortality and morbidity in tilapia. The relative percent survivals (RPSs) of fishes immunized with YM001 (1.0 × 10(8) CFU/fish, one time) via injection, immersion, and oral administration were 96.88, 67.22, and 71.81%, respectively, at 15 days, and 93.61, 60.56, and 53.16%, respectively, at 30 days. In all tests with 1-3 times of immunization in tilapia, the dosages at 1 × 10(8) and 1 × 10(9) CFU/fish displayed the similar best results, whereas the immunoprotection of the dosages at 1 × 10(6) and 1 × 10(7) CFU/fish declined significantly (P 0.05). The level of protective antibody elicited by oral immunization was significantly higher compared to that of the control group (P < 0.01), and the antibody reached their maximum levels 14-21 days after the immunization but decreased significantly after 28 days of vaccination. YM001 bacteria were isolated from the brain, liver, kidney, and spleen tissues of fish after oral immunization and the bacteria existed for the longest time in the spleen (up to 15 days). Taken together, this study obtained a safe, stable, and highly

  4. Small crumbled diet versus powdered diet in restricted feeding management of juvenile Nile tilapia

    OpenAIRE

    Oliveira-Segundo,José Nacélio; Lima,Francisco Roberto dos Santos; Akao,Michael Masaki Freitas; Marcelo Vinícius do Carmo e Sá

    2013-01-01

    The pellet size of the diet can affect both fish growth performance and the water quality of the rearing units. The present work assessed the effects of feeding juvenile Nile tilapia, Oreochromis niloticus (L.) a small crumbled diet (SCD; 0.8 mm) on water quality and growth performance. Fish were reared for six weeks in twenty 250-L polyethylene outdoor tanks at a density of 10 juveniles tank-1 (40 fish m-3). There were two feeding rates (standard and restricted) and two types of artificial f...

  5. Immunological enhancement action of endotoxin-free tilapia heat shock protein 70 against Streptococcus iniae.

    Science.gov (United States)

    Chen, Ming; Wang, Rui; Li, Liping; Liang, Wanwen; Wang, Qiuhua; Huang, Ting; Li, Chao; Li, Jian; Gan, Xi; Lei, Aiying; Huang, Weiyi; Luo, Honglin

    2014-07-01

    The immunological effects of heat shock proteins (HSPs) had been found in humans and mice, but scarce data of endotoxin-free Hsp70 were reported in tilapia. In the current study, we reported that tHsp70 alone and antigen-tHsp70 compound increased the proliferations of lymphocytes and macrophages, significantly increased the NO release and phagocytotic ability of macrophages (ptilapia lymphocytes and macrophages post S. iniae exposure and its up-regulation effects on vaccine-induced protection. Our research highlights the immunological enhancement action of Hsp70 in teleost immunity.

  6. Evaluation of Radioactivity Concentration in Tilapia Nilotica and Radiation Dose to Egyptian Population

    Science.gov (United States)

    Amer, Hannan H.; El-Khawas, Enas H.

    2013-03-01

    One of the three goals of the United Nations for sustainable food security is to ensure that all people have access to sufficient, nutritionally adequate, and safe food. The study was carried out to evaluate the Uranium (238U) and thorium (232Th) concentration in the Bolti (Tilapia nilotica) fish collected from Nasser Lake by using two different types of detectors CR-39 SSNTDs and gamma spectroscopy. The annual intake of Bolti fish was estimated on the basis of their average annual consumption. Calculations were also made to determine the effective dose to an individual consuming such diet.

  7. Mianserin affects alarm reaction to conspecific chemical alarm cues in Nile tilapia.

    Science.gov (United States)

    Barreto, Rodrigo Egydio

    2017-02-01

    In this study, I show that mianserin, a chemical with serotonin and adrenoceptor antagonist activities, increases fish vulnerability to a potential predator threat, when prey fish must deal with this threat based on conspecific chemical alarm cues. For that, I evaluated whether mianserin, diluted in the water, influences the behavioral responses of Nile tilapia (Oreochromis niloticus) to conspecific skin extract (chemical alarm cues). I found that, while mianserin did not abolished antipredator responses, this drug mitigates some components of this defensive reaction. Thus, a potential decrease in serotonin and adrenergic activities reduces the ability of dealing with predators when perceiving conspecific chemical alarm cues.

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

    Science.gov (United States)

    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.

  9. Preliminary Studies on Bioconcentration of Heavy Metals in Nile Tilapia from Tono Irrigation Facility

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    Apori Ntiforo Sam-Quarcoo Dotse

    2012-12-01

    Full Text Available The present study has identified and measured the concentrations of heavy metals in the body tissue of Nile Tilapia from the Tono Irrigation facility located in the Kassena-Nankana East District of the Upper East Region of Ghana. Using Neutron Activation Analysis (NAA, Arsenic, Cadmium, Chromium, Copper, Iron, Manganese, Nickel, Vanadium and Zinc were identified and their mean concentrations were 0.23, 0.02, 0.2, 1.03, 45.95, 19, 0.21, 0.27 and 12.76 :g/g, respectively. The order of mean concentration of heavy metals in fish samples was Cd

  10. Composición del mercado nacional de alimentos balanceados para tilapia en Costa Rica

    OpenAIRE

    Ruth Vargas

    2003-01-01

    Se evaluó el origen y proceso de fabricación de los alimentos balanceados para tilapias comercializados en el país e inscritos en el Programa de Registro y Control de Calidad de Alimentos Balanceados para Animales del Ministerio de Agricultura y Ganadería. Además, se determinaron las prescripciones según la fase fisiol ógica y su composición química, así como las relaciones proteína cruda versus energía metabolizable y calcio – fósforo para compararlos contra los ...

  11. Effects of Low Levels of Zinc on the Ovarian Development of Tilapia nilotica Linnaeus

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    Virginia Cariño

    1990-12-01

    Full Text Available Eight to ten days posthatch fry of Tilapia nilotica Linn. were exposed to sublethal levels of zinc, 2 mg/l and 5 mg/l. After 30 days, ovarian differentiation occurred in the unexposed fry while gonadal anlage of zinc-exposed fry contained still undifferentiated primordial germ cells (PGC. Normal oogenesis was exhibited by the unexposed ovaries after 57 days. Zinc caused alterations in the egg membrane layers. Histopathological changes as degeneration and hyperemia in treated ovaries were observed under the light and electron microscope.

  12. Evaluation of production performance and profitability of hybrid red tilapia and genetically improved farmed tilapia (GIFT strains in the carbon/nitrogen controlled periphyton-based (C/N- CP on-farm prawn culture system in Bangladesh

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    M. Rezoanul Haque

    2016-11-01

    Full Text Available Performance of hybrid red tilapia (Mutant, Oreochromis niloticus × Oreochromis mossambicus and GIFT tilapia strain (Oreochromis niloticus in C/N-CP prawn (Macrobrachium rosenbergii farming system was evaluated at the farmers' pond at Bailor union under Trishal upazilla of Mymensingh district, Bangladesh. The on-farm trial had two treatments: TR and TG (named according to the tilapia strains with three replications. Six rectangular ponds of varying sizes (400–880 m2 were used for this experiment. Hybrid red and GIFT tilapia stains were stocked with prawn at the stocking densities of 1 tilapia fingerlings (either red or GIFT strain and 3 prawn juveniles m-2 in both treatments. Bamboo side shoot were posted vertically as periphyton substrate. This resulted in an additional substrate surface area of 1067 m2 for periphyton development equaling 147% of the pond surface area. Considering the body weight of freshwater prawn only, feeding rates were 10% of body weight at the beginning of the study (up to 30 days, and feeding application was gradually reduced to 3% in the last month assuming 80% survival. The abundance of total benthos and periphyton as well as total periphytic biomass were significantly higher (P < 0.05 in TR than TG treatment and they were also differed significantly (P < 0.05 among different months with a decreasing trends (exception to some extent over the experimental period. The individual harvesting weight, individual weight gain, specific growth rate, Food Conversion Ratio (FCR, survival (%, gross and net yields of prawn were similar in two treatments. In contrast, the GIFT tilapia strain showed a higher (P < 0.05 individual harvesting weight, individual weight gain, specific growth rate ((SGR, % bw d-1, survival, gross and net yields (1935 and 1825 kg ha-1, respectively combined gross and net yields (2952 and 2784 kg ha-1, respectively, and economic return (3755 US$ with BCR 0.82 than the hybrid Red tilapia.

  13. Genetic and environmental factors affecting growth of Nile tilapia (Oreochromis niloticus) juveniles: modelling spatial correlations between hapas

    NARCIS (Netherlands)

    Charo-Karisa, H.; Komen, J.; Rezk, M.A.; Reynolds, S.; Ponzoni, R.W.; Bovenhuis, H.

    2006-01-01

    The aim of this study was to quantify the environmental and genetic effects on early growth of Nile tilapia, Oreochromis niloticus, in hapa-in-earthen pond systems. In a pilot study, we grew swim-up fry with or without supplementary feed in hapas suspended in fertilized ponds at 5, 10, 15, and 20 fr

  14. Heritability estimates and response to selection for growth of Nile tilapia (Oreochromis niloticus ) in low-input earthen ponds

    NARCIS (Netherlands)

    Charo-Karisa, H.; Komen, J.; Rezk, M.A.; Ponzoni, R.W.; Arendonk, van J.A.M.; Bovenhuis, H.

    2006-01-01

    This study presents results of two generations of selection (G1 and G2) for growth of Nile tilapia. The selection environment consisted of earthen ponds which were fertilized daily with 50 kg dry matter (dm)/ha chicken manure. No supplementary feeds were provided. In total, 6429 fully pedigreed expe

  15. Aqueous extract ofOcimum tenuiflorum decreases levels of blood glucose in induced hyperglycemic tilapia (Oreochromis niloticus)

    Institute of Scientific and Technical Information of China (English)

    Amilcar Arenal; Leonardo Martn; Nestor M Castillo; Dainier de la Torre; Ubaldo Torres; Reinaldo Gonzlez

    2012-01-01

    Objective:To evaluate, in hyperglycemic tilapia [Oreochromis niloticus (O. niloticus)], the effect of this aqueous extract on blood glucose levels.Methods:The hyperglycemia inO. niloticus was induced by adding glucose to fish pond water.An aqueous extract ofOcimum tenuiflorum (O. tenuiflorum) was prepared by boiling fresh leaves and the doses of0,40,80,200 and400 mg per liter of pond water were tested.Results:The blood sugar concentration for tilapia with hyperglycemic induced was an average of50% higher than the control group.The blood glucose levels in tilapia after the induction of hyperglycemia were higher than the control group for 90 min after the treatment.The treatment with the aqueous extract ofO. tenuiflorum dropped the serum glucose level of hyperglycemic tilapia until it was similar to that of the control group and was dose dependent.Conclusions:The results indicated that O. tenuiflorum was endowed with anti-hyperglycemic activity.To our knowledge, this is the first report on the use of fish as a diabetes model to test natural extracts from plants.

  16. Use of tuna industry waste in diets for Nile tilapia, Oreochromis niloticus, fingerlings: effect on digestibility and growth performance

    Directory of Open Access Journals (Sweden)

    Crisantema Hernández

    2013-07-01

    Full Text Available During the tuna canning process, about 52~54% of the total weight of the fish is discarded as waste, which can be processed in order to obtain tuna byproducts meal (TBM, or stabilized as tuna silage hydrolysates (TSH. Both products were tested as replacements of soybean meal (SBM, in diets for fingerling male Nile tilapia Oreochromis niloticus. Seven test diets were isonitrogenous (35% CP and isoenergetic (19 kJ g-1: a basal diet contained SBM as main protein source (TSH0; four experimental diets had increasing inclusion levels of TSH replacing 25, 50, 75 and 100% of the SBM protein. The sixth diet contained TBM as sole protein source, and a commercial feed for tilapia was used as reference diet (RD. The diets were fed for eight weeks to triplicate tanks, each with 15 fry tilapia (initial weight of 0.89 ± 0.29 g. Tilapia fed the TBM diet had greater weight gain and feed intake, and lower feed conversion ratios than those fed diets containing with TSH. The RD, TSH25 and TSH50 diets gave the similar growth response. Fish fed diets TSH0, TSH75% and TSH100% showed reduced growth performance.

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

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    Julia W. Pridgeon

    2014-05-01

    Full Text Available Objective: To identify bacteria isolated from diseased Southern flounder and determine whether they are virulent to channel catfish and Nile tilapia. Methods: Gram-negative bacteria isolates were recovered from five tissues of diseased Southern flounder (Paralichthys lethostigma. The isolates were subjected to biochemical and molecular identification followed by virulence study in fish. Results: Based on biochemical analysis, the 25 isolates were found to share homologies with either Edwardsiella tarda (E. tarda or Aeromonas hydrophila (A. hydrophila. Based on sequencing results of partial 16S rRNA gene, 15 isolates shared 100% identities with the 16S rRNA sequence of previously identified E. tarda strain TX1, whereas the other 10 isolates shared 100% identities with the 16S rRNA sequence of previously identified A. hydrophila strain An4. When healthy fish were exposed to flounder isolate by intracoelomic injection, the LD50 values of flounder isolate E. tarda to channel catfish or Nile tilapia [(10±2 g] were 6.1×10 4 and 1.1×10 7 CFU/fish, respectively, whereas that of flounder isolate A. hydrophila to channel catfish and Nile tilapia were 1.4×10 7 and 5.6×10 7 CFU/fish, respectively. Conclusions: This is the first report that E. tarda and A. hydrophila isolated from diseased Southern flounder are virulent to catfish and tilapia.

  18. Quantitative and qualitative analyses of the bacterial microbiota of tilapia (Oreochromis niloticus) cultured in earthen ponds in the Philippines.

    Science.gov (United States)

    Pakingking, Rolando; Palma, Peter; Usero, Roselyn

    2015-02-01

    The quantity and composition of the bacterial microbiota in the rearing water, sediment, gills and intestines of tilapia Oreochromis niloticus collected every 2 weeks from Day 30 to Day 120 after stocking for grow-out culture in 6 earthen brackish water ponds in the Philippines were examined. The total heterotrophic aerobic bacterial counts obtained in the water, sediment, gills and intestines of tilapia ranged from 10(3) to 10(4) c.f.u. ml(-1), 10(3)-10(5), 10(5)-10(7) and 10(4)-10(7) c.f.u. g(-1), respectively. In terms of composition, a total of 20 bacterial genera and 31 species were identified with the preponderance of gram-negative bacteria constituting 84 % of all bacterial isolates examined. Aeromonas hydrophila, Bacillus spp., Plesiomonas shigelloides, Shewanella putrefaciens, Pseudomonas fluorescens, Staphylococcus spp. and Vibrio cholerae were the dominant bacteria identified in the gills and intestine of tilapia. These bacteria also dominated in the pond sediment and rearing water, except for the nil isolation of S. putrefaciens and V. cholerae in the water samples examined, indicating that resident bacteria in the pond water and sediment congruently typify the composition of bacterial microbiota in the gills and intestine of tilapia which under stressful conditions may propel the ascendance of disease epizootics.

  19. Lack of association between Flavobacterium columnare genomovar and virulence in hybrid tilapia Oreochromis niloticus (L.) x Oreochromis aureus (Steindachner)

    Science.gov (United States)

    Columnaris disease can be problematic in tilapia (Oreochromis spp.) production. An understanding of the pathogenesis and virulence of F. columnare is needed for the development of prevention strategies. The objective of this study was to determine the virulence of genetically defined isolates of Fl...

  20. Effects of dietary starch and energy levels on maximum feed intake, growth and metabolism of Nile tilapia, Oreochromis niloticus

    NARCIS (Netherlands)

    Tran Duy, A.; Smit, B.; Dam, van A.A.; Schrama, J.W.

    2008-01-01

    The aim of this study was to gain insight into how Nile tilapia (Oreochromis niloticus) regulate feed and energy intake in response to diets low and high in starch and cellulose. It was hypothesized that high-starch diets would reduce feed intake due to the effect of high blood glucose level, and th

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

    Institute of Scientific and Technical Information of China (English)

    Julia W Pridgeon; Phillip H Klesius; Gregory A Lewbart; Harry V Daniels; Megan Jacob

    2014-01-01

    Objective:To identify bacteria isolated from diseased Southern flounder and determine whether they are virulent to channel catfish and Nile tilapia. Methods:Gram-negative bacteria isolates were recovered from five tissues of diseased Southern flounder (Paralichthys lethostigma). The isolates were subjected to biochemical and molecular identification followed by virulence study in fish. Results: Based on biochemical analysis, the 25 isolates were found to share homologies with either Edwardsiella tarda (E. tarda) or Aeromonas hydrophila (A. hydrophila). Based on sequencing results of partial 16S rRNA gene, 15 isolates shared 100%identities with the 16S rRNA sequence of previously identified E. tarda strain TX1, whereas the other 10 isolates shared 100%identities with the 16S rRNA sequence of previously identified A. hydrophila strain An4. When healthy fish were exposed to flounder isolate by intracoelomic injection, the LD50 values of flounder isolate E. tarda to channel catfish or Nile tilapia [(10±2) g] were 6.1í104 and 1.1í107 CFU/fish, respectively, whereas that of flounder isolate A. hydrophila to channel catfish and Nile tilapia were 1.4í107 and 5.6í107 CFU/fish, respectively. Conclusions: This is the first report that E. tarda and A. hydrophila isolated from diseased Southern flounder are virulent to catfish and tilapia.

  2. Genotype by environment interaction for harvest weight, growth rate and shape between monosex and mixed sex Nile tilapia (Oreochromis niloticus)

    NARCIS (Netherlands)

    Omasaki, S.K.; Charo-Karisa, H.; Kahi, A.K.; Komen, H.

    2016-01-01

    In Kenya, Nile tilapia (Oreochromis niloticus) is mostly grown in ponds. To avoid excessive reproduction and stunted growth, fingerlings are treated with methyl-testosterone to make all-male populations (monosex). For a national breeding programme that aims to provide genetically improved broodst

  3. Characteristics of Bone Gelatin Tilapia (Oreochromis niloticus Processed by Using Hydrolysis With Phosphoric Acid and Papain Enzyme

    Directory of Open Access Journals (Sweden)

    Gugun Hidayat

    2016-04-01

    Full Text Available Phosphoric acid and papain enzyme able to hydrolyzing collagen from Tilapia into gelatin . Thepurpose of this research was to determine the best concentration of phosphoric acid and papain enzymeand to determine the physicochemical characteristic gelatin to from Tilapia fish bone which processedwith phosphoric acid and papain enzyme. The first research phase was making bone gelatin tilapia usingphosphoric acid at concentration of 4%, 5% and 6%, and the papain enzyme 0.5%, 1% and 1.5%. Thesecond phase was characterize the physicochemical gelatin from the best concentration of phosphoric acidconcentration (6% and papain enzyme (1.5%, all treatment done with three repetitions. Analysis of thedata using ANOVA with completely randomized (CRD design If there was difference between treatmentthen continued with Honestly Significant Difference Test (HSDT. The results of the first research phasefound the best concentration were 6% of phosphoric acid and 1.5% papain enzyme, its shows by the valuegel strength 325,95 and 373,32 g.bloom. The second research phase shows that the the best results obtainedin this study was gelatin from 1.5% papain enzyme as hydrolysis agent, the physicochemical characteristicwere: 376.21 g.bloom gel strength; viscosity of 7.57 cP; yield 6.30%; protein content of 86.46%; water contentof 7.12%; and the pH value of 5.11.Keywords : gelatin, hydrolysis, papain enzyme, phosphoric acid, tilapia bones

  4. Exploring the trophic structure in organically fertilized and feed-driven tilapia culture environments using multivariate analyses

    NARCIS (Netherlands)

    Muendo, P.N.; Milstein, A.; Dam, A.; Gamal, N.E.; Stoorvogel, J.J.; Verdegem, M.C.J.

    2006-01-01

    Reports of similar yields in manure and feed-driven tilapia culture environments raise questions on food utilization in these environments. The possibility that similar production rates are because of utilization of different foods was investigated using exploratory techniques of multivariate analys

  5. Characterization of the duodenase-1 gene and its associations with resistance to Streptococuus agalactiae in hybrid tilapia (Oreochromis spp.).

    Science.gov (United States)

    Shen, Yubang; Fu, Gui Hong; Liu, Feng; Yue, Gen Hua

    2015-08-01

    Tilapia is a group of cultured teleost fishes whose production is threatened by some diseases. Identification of DNA markers associated with disease resistance in candidate genes may facilitate to accelerate the selection of disease resistance. The gene encoding a duodenase, which can trigger immune response, has not been studied in fish. We characterized the cDNA of duodenase-1 gene of hybrid tilapia. Its ORF is 759 bp, encoding a serine protease of 252 amino acids. This gene consisted of five exons and four introns. Its expression was detected in all 10 tissues examined, and it was highly expressed in the intestine and kidney. After a challenge with the bacterial pathogen, Streptococcus agalactiae, its expression was up-regulated significantly in the intestine, liver and spleen. We identified seven SNPs in the gene and found that four of them were significantly associated with the resistance to S. agalactiae (P tilapia. The SNP markers in the duodenase-1 gene associated with resistance to the bacterial pathogen, may facilitate the selection of tilapia resistant to the bacterial disease.

  6. Complete genome sequence of an Edwardsiella piscicida-like species recovered from tilapia in the United States

    Science.gov (United States)

    Edwardsiella piscicida-like sp. is a Gram-negative, facultative anaerobe that causes disease in some fish species. In this report we present the complete and annotated genome of isolate LADL05-105, recovered from cultured tilapia reared in Louisiana, which contains a chromosome of 4,142,037 bp and n...

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

    Science.gov (United States)

    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. Genetic parameters for reproductive traits in female Nile tilapia (Oreochromis niloticus): I. Spawning success and time to spawn

    NARCIS (Netherlands)

    Trong, T.Q.; Arendonk, van J.A.M.; Komen, J.

    2013-01-01

    Breeding programmes for Nile tilapia typically use nested mating designs with 2 females mated to 1 male to produce paternal half-sib families. This mating design can take up to 3 months or longer to produce the desired number of half-sib family groups. Prolonged family production increases common en

  9. Interaction between dissolved oxygen concentration and diet composition on growth, digestibility and intestinal health of Nile tilapia (Oreochromis niloticus)

    NARCIS (Netherlands)

    Tran, N.T.K.; Dinh, Ngu T.; Tin, Nguyen Hong; Roem, A.J.; Schrama, J.W.; Verreth, J.A.J.

    2016-01-01

    The present study was undertaken to evaluate the individual and combined effects of oxygen concentration and
    diet composition on the growth, nutrient utilization and intestinal morphology of Nile tilapia (Oreochromis
    niloticus). Two recirculating aquaculture systems were used to create the

  10. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs

    NARCIS (Netherlands)

    Guyon, R.; Rakotomanga, M.; Azzouzi, N.; Coutanceau, J.P.; Bonillo, C.; Cotta, D' H.; Pepey, E.; Soler, L.; Rodier-Goud, M.; Hont, D' A.; Conte, M.A.; Bers, van N.E.M.; Penman, D.J.; Hitte, C.; Crooijmans, R.P.M.A.; Kocher, T.D.; Ozouf-Costaz, C.; Baroiller, J.F.; Galibert, F.

    2012-01-01

    Background: The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebr

  11. Effects of replacing fishmeal with wastes derived from local fisheries on the growth of juvenile tilapia, Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Chanagun Chitmanat

    2009-01-01

    Full Text Available A feeding trial was conducted to investigate the effects of partially and totally replacing fishmeal with by-product derived from local fisheries on growth performances of tilapia (Oreochromis niloticus. Tilapia fingerlings (average initialweight 0.38±0.05 g were fed with 5 different diet formulas composing of fish meal protein replacement levels of 0%, 25%,50%, 75, and 100%. Tilapia were raised in 80 x 80 x 80 cm3 hapa in an earthen pond for 8 weeks. Each treatment contained3 replications. No feeding trial was applied as negative control. The result showed that fish by-product powder could substitute for fishmeal on a crude protein basis at a level of not more than 25%. As a result, feed cost can only be cut down approximately 3 US cents/kg. Specific growth rate, weight gain, survival rate and feed conversion ratio were not significantly different between the fish fed with the 75% and 100% fishmeal containing diets (P>0.05. The outcome would beapplied to reduce the solid wastes from fish processing and partially replace the imported fishmeal. This can also be used as guideline for farmers in small communities to produce their own tilapia feed.

  12. 橙色莫桑比克罗非鱼和荷那龙罗非鱼的染色体核型分析%The karyotypes of Mozambique tilapia and Zanzibar tilapia

    Institute of Scientific and Technical Information of China (English)

    朱华平; 卢迈新; 黄樟翰; 高风英; 杨丽萍; 陈昆慈

    2009-01-01

    Chromosome numbers, forms and karyotype of Mozambique tilapia (Oreochromis mossambicus) and Zanzibar ti-lapia {Oreochromis homorum) were analyzed and compared by using PHA-injection air drying method. Both of the two species of Tilapia had a diploid chromosome number of 44 with a large and long chromosome pairs. No metacentric chromosome pairs and heteromorphic chromosomes were found. The two fishes had similar karyotype and the conventional karyotype formula is 2n =44, 6sm +24st + 14t, NF =50. It was difficult to distinguish the karyotype of the two tilapia species using the conventional technique. The result showed that the difference of karyotypes between the two tilapia species was not significant, indicating that they were quite close to each other in terms of classification status.%采用体腔注射PHA-空气干燥法对橙色莫桑比克罗非鱼(Oreochromis mossambicus)和荷那龙罗非鱼(O.hornorum)染色体数量、形态和核型进行了分析和比较.结果显示:两种罗非鱼的二倍体染色体数目均为2n=44,都具有1对特大的染色体,未发现中部着丝粒染色体对和异型染色体.两种罗非鱼的染色体组型形态基本相似,它们的核型公式为2n=44,6sm+24st+14t,NF=50,用常规染色体染色的方法难以区分.研究结果表明,这两种罗非鱼的常规核型差异不显著,在分类地位上非常接近.

  13. Effects of substrate addition and supplemental feeding on plankton composition and production in tilapia (Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) polyculture

    NARCIS (Netherlands)

    Uddin, M.S.; Azim, M.E.; Wahab, M.A.; Verdegem, M.C.J.

    2009-01-01

    This study investigated the effects of substrates and supplemental feeding on growth and production of tilapia (Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) in a polyculture system. On actual farms, four treatments were evaluated in triplicate: substrate plus feed (herein

  14. A qualitative ecological risk assessment of the invasive Nile tilapia, Oreochromis niloticus in a sub-tropical African river system (Limpopo River, South Africa)

    CSIR Research Space (South Africa)

    Zengeya, TA

    2013-01-01

    Full Text Available This study outlines the development of a qualitative risk assessment method and its application as a screening tool for determining the risk of establishment and spread of the invasive Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), within...

  15. Effects of dietary inclusions of oilseed meals on physical characteristics and feed intake of diets for the Nile Tilapia, Oreochromis niloticus

    DEFF Research Database (Denmark)

    Obirikorang, Kwasi Adu; Amisah, Stephen; Fialor, Simon Cudjoe;

    2015-01-01

    The present study investigated the effects of the inclusion of three oilseed by-products (soybean, copra and palm kernel meals) on some physical characteristics of pelletized feeds as well as on voluntary feed intake and faecal matter production by the Nile tilapia, Oreochromis niloticus. The die......The present study investigated the effects of the inclusion of three oilseed by-products (soybean, copra and palm kernel meals) on some physical characteristics of pelletized feeds as well as on voluntary feed intake and faecal matter production by the Nile tilapia, Oreochromis niloticus......) was significantly higher in the tilapia groups fed the copra and palm kernel meals. The results obtained from this study show that 30% inclusions of unrefined forms of copra and palm kernel meal in Nile tilapia diets is possible, without adversely affecting feed intake or pellet nutrient losses prior to ingestion....

  16. Effects of bamboo substrate and supplemental feeding on growth and production of hybrid red tilapia fingerlings (Oreochromis mossambicusxOrechromis niloticus)

    NARCIS (Netherlands)

    Keshavanath, P.; Gangadhar, B.; Ramesh, T.J.; Dam, van A.A.; Beveridge, M.C.M.; Verdegem, M.C.J.

    2004-01-01

    Periphyton growing on artificial substrates can increase the production of herbivorous fish in aquaculture ponds. Periphyton may be an alternative or a complement for supplemental feed in fingerling production. Growth and production of hybrid red tilapia (Oreochromis mossambicus x Oreochromis

  17. THE OPTIMAL RATIO OF NILE TILAPIA (Oreochromis niloticus AND COMMON CARP (Cyprinus carpio FOR IMPROVING PRODUCTIVITY ON DEEP WATER POND

    Directory of Open Access Journals (Sweden)

    Imam Taufik

    2013-06-01

    Full Text Available Pond productivity can be increased by applied polyculture system in the deep pond. The purpose of this experiment is to examine the optimal ratio between nile tilapia and common carp, in order to increase the productivity. Nine concrete tanks (15 m2 with water depth of 2.2 m and were completed by water inlet, water outlet, and aeration. Both of nile tilapia and common carp with size ranging of 5-8 cm in total length were used. Stock density was 150 ind./m2. The difference ratio of both fish tilapia and carp of fish stocked as a treatment. The fish ratio this experiment were as followed: A 100%; B 80%:20%; C 60%:40%. Fish fed by pellet until at ad libitum. The duration of experiment was 100 days. Parameters such as survival, growth, and productivity were observed every ten days during the experiment period. Water quality parameters were also periodically observed. The results showed that survival of nile tilapia among the treatments were not significantly different (P>0.05 where survival of common carp at B treatment was better than C treatment (P<0.05. The highest of growth of absolute weight (94.86±2.85 g and total length (14.71±1 cm of nile tilapia at B treatment was found (P<0.05 where the best of growth of absolute weight (106.52±10.47 g and total length (11.57±1.78 cm of common carp was also found at B treatment (P<0.05. Biomass productivity at B treatment was the highest compared with A treatment (P<0.05. Combination between polyculture and the deep water pond technology could increase productivity. The polyculture system and the deep water pond technology would be able to keep constant water quality within in the threshold accordance with the regulation for fish culture.

  18. Mapping QTL for Sex and Growth Traits in Salt-Tolerant Tilapia (Oreochromis spp. X O. mossambicus)

    Science.gov (United States)

    Lin, Grace; Chua, Elaine; Orban, Laszlo; Yue, Gen Hua

    2016-01-01

    In aquaculture, growth and sex are economically important traits. To accelerate genetic improvement in increasing growth in salt-tolerant tilapia, we conducted QTL mapping for growth traits and sex with an F2 family, including 522 offspring and two parents. We used 144 polymorphic microsatellites evenly covering the genome of tilapia to genotype the family. QTL analyses were carried out using interval mapping for all individuals, males and females in the family, respectively. Using all individuals, three suggestive QTL for body weight, body length and body thickness respectively were detected in LG20, LG22 and LG12 and explained 2.4% to 3.1% of phenotypic variance (PV). When considering only males, five QTL for body weight were detected on five LGs, and explained 4.1 to 6.3% of PV. Using only females from the F2 family, three QTL for body weight were detected on LG1, LG6 and LG8, and explained 7.9–14.3% of PV. The QTL for body weight in males and females were located in different LGs, suggesting that in salt-tolerant tilapia, different set of genes ‘switches’ control the growth in males and females. QTL for sex were mapped on LG1 and LG22, indicating multigene sex determination in the salt-tolerant tilapia. This study provides new insights on the locations and effects of QTL for growth traits and sex, and sets the foundation for fine mapping for future marker-assisted selection for growth and sex in salt-tolerant tilapia aquaculture. PMID:27870905

  19. Protective effect of clove oil-supplemented fish diets on experimental Lactococcus garvieae infection in tilapia.

    Science.gov (United States)

    Rattanachaikunsopon, Pongsak; Phumkhachorn, Parichat

    2009-09-01

    The essential oils extracted from the four herbs, cinnamon (Cinnamomum verum), clove (Syzygium aromaticum), ginger (Zingiber officinale) and holy basil (Ocimum sanctum), were investigated for their antimicrobial activity and mode of action against Lactococcus garvieae, a fish pathogenic bacteria causing lactococcosis. Of all the tested oils, clove oil had the strongest inhibitory effect and exhibited a bactericidal mode of action against the pathogenic bacterium. When an intraperitoneal infection of tilapia (Oreochromis niloticus) with L. garvieae was performed, the median lethal dose (LD(50)) was determined to be 1.78x10(2) CFU/fish. For an in vivo trial, no mortality was apparent in fish fed on the fish diets supplemented with 3% (w/w) of clove oil and with 0.5% (w/w) of oxytetracycline 5 d prior to the infection with L. garvieae. These results indicate that clove oil had a protective effect on experimental L. garvieae infection in tilapia and the potential to replace antibiotics for controlling the disease.

  20. Behavioral response of tilapia (Oreochromis niloticus) to acute ammonia stress monitored by computer vision

    Institute of Scientific and Technical Information of China (English)

    XU Jian-yu; MIAO Xiang-wen; LIU Ying; CUI Shao-rong

    2005-01-01

    The behavioral responses of a tilapia (Oreochromis niloticus) school to low (0.13 mg/L), moderate (0.79 mg/L) and high (2.65 mg/L) levels of unionized ammonia (UIA) concentration were monitored using a computer vision system. The swimming activity and geometrical parameters such as location of the gravity center and distribution of the fish school were calculated continuously. These behavioral parameters of tilapia school responded sensitively to moderate and high UIA concentration. Under high UIA concentration the fish activity showed a significant increase (P<0.05), exhibiting an avoidance reaction to high ammonia condition, and then decreased gradually. Under moderate and high UIA concentration the school's vertical location had significantly large fluctuation (P<0.05) with the school moving up to the water surface then down to the bottom of the aquarium alternately and tending to crowd together. After several hours' exposure to high UIA level, the school finally stayed at the aquarium bottom. These observations indicate that alterations in fish behavior under acute stress can provide important information useful in predicting the stress.

  1. Biocompatibility of Novel Type I Collagen Purified from Tilapia Fish Scale: An In Vitro Comparative Study

    Directory of Open Access Journals (Sweden)

    Jia Tang

    2015-01-01

    Full Text Available Type I collagen (COL-1 is the prevailing component of the extracellular matrix in a number of tissues including skin, ligament, cartilage, bone, and dentin. It is the most widely used tissue-derived natural polymer. Currently, mammalian animals, including pig, cow, and rat, are the three major sources for purification of COL-1. To reduce the risk of zoonotic infectious diseases transmission, minimize the possibility of immunogenic reaction, and avoid problems related to religious issues, exploration of new sources (other than mammalian animals for the purification of type I collagen is highly desirable. Hence, the purpose of the current study was to investigate the in vitro responses of MDPC-23 to type I collagen isolated from tilapia scale in terms of cellular proliferation, differentiation, and mineralization. The results suggested that tilapia scale collagen exhibited comparable biocompatibility to porcine skin collagen, indicating it might be a potential alternative to type I collagen from mammals in the application for tissue regeneration in oral-maxillofacial area.

  2. Effects of photoperiod on somatic growth and gonadal development in male nile tilapia

    Directory of Open Access Journals (Sweden)

    Rodrigo Diana Navarro

    2015-10-01

    Full Text Available Rotation and translation of the Earth subject the living organisms to cyclic changes of environmental factors. This study evaluated the effects of photoperiod on growth and gonadal development in Nile tilapia (Oreochromis niloticus. In a completely randomized design experiment, juvenile males were distributed into nine tanks (10 fish per tank and maintained for 60 days under three different light treatments with three repetitions each. The treatments were: T1 - 0 h photoperiod (tanks covered with lids and black plastic; T2 - 12 hours photoperiod (tanks uncovered during photoperiod to provide natural light; and T3 - 24 hours photoperiod (tanks covered with lids equipped with lamps. No significant differences were found between treatments for body length, gonad weight or gonadosomatic index, but body weight was higher in fish subjected to T3 compared with other treatments. Furthermore, significant increases in tubular lumen and germinal epithelium were observed in fish exposed to T1 and T3, respectively. Thus, the manipulation of photoperiod in Nile tilapia culture systems can improve production and consequently increase the economic return on investment.

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

    Science.gov (United States)

    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.

  4. Dietary mannan oligosaccharide and Bacillus subtilis in diets for Nile tilapia (Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Rafael Vieira de Azevedo

    2016-11-01

    Full Text Available A six week study was conducted to investigate the supplementation of prebiotic (Mannan oligosaccharide – MOS, from yeast Saccharomyces cerevisiae, probiotic (Bacillus subtilis – BS, C-3102 strain and their combination in diets for Nile tilapia. 192 fishes (4.03 ± 0.28 g were distributed into 16 tanks (40-L, in a completely randomized design (n=4. The following treatments were evaluated: control; prebiotic - 2 g MOS kg-1; probiotic - 2 g BS kg-1 and synbiotic - 1 g MOS kg-1 plus 1 g BS kg-1. Fishes fed diets pre-, pro- and synbiotic supplemented performed better in average daily gain, feed conversion rate, specific growth rate, protein efficiency ratio, carcass yield, total and standard length and body height than those maintained on control diets. The probiotic supplementation resulted in higher villus height and intestinal perimeter ratio than the control diet while the pre- and synbiotic supplementation in diets resulted in higher intestinal perimeter ratio. Carcass protein and ether extract were, respectively, higher and lower in fish fed synbiotic diets than other fish. The results of this study indicated that the mannan oligosaccharide and Bacillus subtilis supplementation, isolated or combined (synbiotic, could improve growth, body index, intestine morphometry and carcass composition in Nile tilapia.

  5. Identification of immunoreactive proteins of Streptococcus agalactiae isolated from cultured tilapia in China.

    Science.gov (United States)

    Liu, Guangjin; Zhang, Wei; Lu, Chengping

    2013-12-01

    Streptococcus agalactiae (Group B streptococcus, GBS) is an important zoonotic pathogen that can cause lethal infections in humans and animals, including aquatic species. Immunoreactive proteins of the S. agalactiae strain, GD201008-001, isolated from cultured tilapia in China, were screened by immunoproteomics using hyperimmune sera, convalescent guinea pig sera and GD201008-001-infected tilapia antisera as primary detection antibodies. A total of 16 different proteins were identified including 13 novel immunoreactive proteins of S. agalactiae. Four proteins, serine-rich repeat glycoprotein 1, branched-chain alpha-keto acid dehydrogenase (BKD) subunit E2, 5'-nucleotidase family protein and ornithine carbamoyltransferase, were shown to react with the three types of sera and thus were considered to represent novel S. agalactiae vaccine candidate antigens. Our findings represent the basis for vaccine development for piscine S. agalactiae and are necessary for understanding virulence factors and immunogenicity of S. agalactiae with different hosts.

  6. Application of Lactic Acid Bacteria (LAB) in freshness keeping of tilapia fillets as sashimi

    Science.gov (United States)

    Cao, Rong; Liu, Qi; Chen, Shengjun; Yang, Xianqing; Li, Laihao

    2015-08-01

    Aquatic products are extremely perishable food commodities. Developing methods to keep the freshness of fish represents a major task of the fishery processing industry. Application of Lactic Acid Bacteria (LAB) as food preservative is a novel approach. In the present study, the possibility of using lactic acid bacteria in freshness keeping of tilapia fillets as sashimi was examined. Fish fillets were dipped in Lactobacillus plantarum 1.19 (obtained from China General Microbiological Culture Collection Center) suspension as LAB-treated group. Changes in K-value, APC, sensory properties and microbial flora were analyzed. Results showed that LAB treatment slowed the increase of K-value and APC in the earlier storage, and caused a smooth decrease in sensory score. Gram-negative bacteria dominated during refrigerated storage, with Pseudomonas and Aeromonas being relatively abundant. Lactobacillus plantarum 1.19 had no obvious inhibitory effect against these Gram-negatives. However, Lactobacillus plantarum 1.19 changed the composition of Gram-positive bacteria. No Micrococcus were detected and the proportion of Staphylococcus decreased in the spoiled LAB-treated samples. The period that tilapia fillets could be used as sashimi material extended from 24 h to 48 h after LAB treatment. The potential of using LAB in sashimi processing was confirmed.

  7. The LBP Gene and Its Association with Resistance to Aeromonas hydrophila in Tilapia

    Directory of Open Access Journals (Sweden)

    Gui Hong Fu

    2014-12-01

    Full Text Available Resistance to pathogens is important for the sustainability and profitability of food fish production. In immune-related genes, the lipopolysaccharide-binding protein (LBP gene is an important mediator of the inflammatory reaction. We analyzed the cDNA and genomic structure of the LBP gene in tilapia. The full-length cDNA (1901 bp of the gene contained a 1416 bp open reading frame, encoding 471 amino acid residues. Its genomic sequence was 5577 bp, comprising 15 exons and 14 introns. Under normal conditions, the gene was constitutively expressed in all examined tissues. The highest expression was detected in intestine and kidney. We examined the responses of the gene to challenges with two bacterial pathogens Streptcoccus agalactiae and Aeromonas hydrophila. The gene was significantly upregulated in kidney and spleen post-infection with S. agalactiae and A. hydrophila, respectively. However, the expression profiles of the gene after the challenge with the two pathogens were different. Furthermore, we identified three SNPs in the gene. There were significant associations (p < 0.05 of two of the three SNPs with the resistance to A. hydrophila, but not with the resistance to S. agalactiae or growth performance. These results suggest that the LBP gene is involved in the acute-phase immunologic response to the bacterial infections, and the responses to the two bacterial pathogens are different. The two SNPs associated with the resistance to A. hydrophila may be useful in the selection of tilapia resistant to A. hydrophila.

  8. Association between periphyton and bioflocs systems in intensive culture of juvenile Nile tilapia

    Directory of Open Access Journals (Sweden)

    Davi de Holanda Cavalcante

    2016-05-01

    Full Text Available The present work aimed at determining the effects of the association between the periphyton-based system with the bioflocs-based system in the intensive culture of juvenile Nile tilapia (1.56 ± 0.07 g; 72 fish m-3, on variables of water quality, growth performance and effluent quality after 10 weeks. The experiment was arranged in a 2 x 2 factorial randomized block design with four treatments and five repetitions each. The factors tested were the following: ‘underwater structure’ (absence and presence and ‘adjustment of the C: N ratio of water’ (no and yes. The final fish body weight, specific growth rate and yield were higher (p < 0.05 in the C: N-adjusted tanks. The presence of submerged structures in the tanks had no significant influence on those same variables. It was concluded that the periphyton-based system is not indicated for intensive farming of Nile tilapia, in which there is a high allowance of artificial feed to fish.

  9. Use, fate and ecological risks of antibiotics applied in tilapia cage farming in Thailand.

    Science.gov (United States)

    Rico, Andreu; Oliveira, Rhaul; McDonough, Sakchai; Matser, Arrienne; Khatikarn, Jidapa; Satapornvanit, Kriengkrai; Nogueira, António J A; Soares, Amadeu M V M; Domingues, Inês; Van den Brink, Paul J

    2014-08-01

    The use, environmental fate and ecological risks of antibiotics applied in tilapia cage farming were investigated in the Tha Chin and Mun rivers in Thailand. Information on antibiotic use was collected through interviewing 29 farmers, and the concentrations of the most commonly used antibiotics, oxytetracycline (OTC) and enrofloxacin (ENR), were monitored in river water and sediment samples. Moreover, we assessed the toxicity of OTC and ENR on tropical freshwater invertebrates and performed a risk assessment for aquatic ecosystems. All interviewed tilapia farmers reported to routinely use antibiotics. Peak water concentrations for OTC and ENR were 49 and 1.6 μg/L, respectively. Antibiotics were most frequently detected in sediments with concentrations up to 6908 μg/kg d.w. for OTC, and 2339 μg/kg d.w. for ENR. The results of this study indicate insignificant short-term risks for primary producers and invertebrates, but suggest that the studied aquaculture farms constitute an important source of antibiotic pollution.

  10. COMPENSATORY GROWTH IN MOZAMBIQUE TILAPIA (Oreochromis mossambicus, FED A SUB-OPTIMAL DIET

    Directory of Open Access Journals (Sweden)

    Ewen McLean

    1998-04-01

    Full Text Available Mozambique tilapia, Oreochromis mossambicus, held in 30%o seawater and at 29-30 °C, were divided into four groups (n = 50/group in replicate, and given one of four feed cycles: 1 control, with continuous feedind, 2 5:5, 3 10:10 and 4 15:15, wherein fish were subjected to starvation and subsequent refeeding cycles of 5, 10 and 15 days respectively. All animals were fed a commercial diet containing 18.4% protein, 6.7% lipid, 58.6% carbohydrate and 7.2% ash, over a 60 day trial period. Growth compensation was observed in the feed cycled groups as increased (P < 0.03 weight specific growth rates during refeeding. However, feed cycled groups were unable to achieve the weghts of control fish. Starvation reduced (P<0.01 haematocrit values when compared to control levels and, in the 15:15 cycled groups, elevated the testicular index (P < 0.02. The results are considered with respect to the commercial application of compensatory growth during production of tilapia.

  11. Application of Probiotic, Prebiotic and Synbiotic for the Control of Streptococcosis in Tilapia Oreochromis niloticus.

    Science.gov (United States)

    Widanarni; Tanbiyaskur

    2015-02-01

    One of the fish diseases that is becoming the main problem in tilapia culture is streptococcosis caused by Streptococcus agalactiae. Application of probiotic, prebiotic and synbiotic are expected to be an alternative for controlling the disease. The purpose of this study was to examine the effectiveness of the administration of probiotic, prebiotic and synbiotic through artificial feed to control streptococcosis in tilapia. This study consisted of five treatments with three replications, namely positive control, negative control; 1% probiotic treatment; 2% prebiotic treatment and synbiotic treatment (1% probiotic and 2% prebiotic). Results showed that fish survival rate before the challenge test for all treatments was between 95 and 100%. Growth and feed conversion ratios in probiotic, prebiotic and synbiotic treatments were better than that of the controls. After the challenge test, the fish survival rate in probiotic, prebiotic and synbiotic treatments were 74.08, 74.08 and 85.19%, respectively; whereas, in the positive control it was only 18.52%. Results showed that S. agalactiae bacteria could be found in the brain, kidney, liver and eyes. The number of S. agalactiae bacteria and the damage level of various target organs in probiotic, prebiotic and synbiotic treatments were lower than that of positive control.

  12. MICRONUCLEI PROFILE: AN INDEX OF CHROMOSOMAL ABERRATIONS IN FRESHWATER FISHES (SYNODONTIS CLARIAS AND TILAPIA NILOTICA

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    J.C. OKONKWO

    2011-01-01

    Full Text Available Incidence of chromosomal aberrations in Synodontis clarias and Tilapia nilotica (Linnaeus 1757 were measured using the conventional micronucleus assay in fish erythrocytes. The species showed varying degree of micronuclei frequencies in their respective genomes of sampled gill and kidney blood. Cytological examinations showed bi-nucleated cells, deformed nuclei including the main aberrations, micronucleus formations in various genomes of the fish from different locations considered in this study. Comparison of the micronucleus rates in peripheral and kidney blood of the two species revealed no statistical difference (P> 0.05. On species occurrence of the measured chromosomal aberrations, averages of micronucleus frequencies recorded in Synodontis clarias showed visible variation and to be 2.2 folds higher than the values obtained in the corresponding Tilapia sp. but there was no statistical difference (P>0.01 among the two breeds. The work recommends that micronuclei tests in fish erythrocytes be carried out at various times, thus making it possible to follow-up the changing micronuclei frequencies and concludes that gills and kidney erythrocytes can be used in studies concerning chromosomal aberrations since the sampling of the peripheral blood is appropriate as it allows collecting several samples from the same individuals, without having to sacrifice it.

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

    Science.gov (United States)

    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.

  14. Effects of high-voltage electrostatic fields on the quality of tilapia meat during refrigeration.

    Science.gov (United States)

    Hsieh, Chang-Wei; Lai, Cheng-Hung; Lee, Chia-Hsin; Ko, Wen-Ching

    2011-08-01

    Fresh fish is typically brought to market refrigerated at approximately 4 °C, R-storage. A storage method has been devised that combines refrigeration with a high-voltage electrostatic field (100 kV/m; E-storage). It was developed to improve the quality and prolong the shelf life of foods. This study investigated changes in the freshness of tilapia meat under E-storage conditions. The total viable count of tilapia reached 10⁷ CFU/g on the 7th d of refrigeration in R-storage. By the 6th d, K-value had increased from 20% to 61.7% for E-storage and to 94.7% for R-storage. Volatile basic nitrogen had increased from 12.54 mg/100 g to about 24.34 and 25.03 mg/100 g for R- and E-storage (on the 7th and 10th d), respectively. The sensory assessment also indicated that E-storage yielded an improvement in quality over that of R-storage. Practical application of the study model has the potential to prolong the freshness of fish.

  15. Digestible methionine + cystine requirement for Nile tilapia from 550 to 700 g

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    Mariana Michelato

    2013-01-01

    Full Text Available This trial was conducted to determine the dietary digestible methionine + cystine requirement of Nile tilapia (550 to 700 g based on the ideal protein concept. Six hundred fish were distributed in a completely randomized design with five treatments and four replicates, with 30 fish per experimental unit. The fish were fed diets containing approximately 262 g of digestible protein/kg, 3,040 kcal of digestible energy/kg and 7.90, 9.40, 10.90, 12.40 or 13.90 g of methionine + cystine/kg. The fish were hand-fed three times a day until apparent satiation for 30 days. No effects of dietary methionine + cystine on feed conversion ratio, daily protein deposition, whole body moisture, fillet moisture, crude protein, ether extract and ash, plasmatic HDL and LDL cholesterol were observed. Dietary methionine resulted in a linear increase in whole body protein and linear reduction in lipid deposition rate, hepatosomatic index, whole body ether extract and ash, plasmatic total cholesterol, plasmatic total lipids and plasmatic triglycerides. According to the Linear Response Plateau, the daily weight gain and fillet yield increased up to a level of 9.00 and 9.90 g methionine + cystine/kg of diet, respectively. The digestible methionine + cystine requirement of Nile tilapia is 9.00 g/kg for weight gain and 9.90 g/kg for fillet yield, corresponding to methionine + cystine:lysine ratios of 0.60 and 0.66, respectively.

  16. Transmission and pathology of Streptococcus inane in monosex Nile tilapia (Oreochromis niloticus in aquaculture of Bangladesh

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    Md. Mer Mosharraf Hossain

    2014-04-01

    Full Text Available Streptococcus iniae is a major fish pathogen, recently emergent outbreaks were recorded in commercially cultured monosex Nile tilapia (Oreochromis niloticus result in significant losses termed “streptococcosis”-causes unusual appearances with multi-focal pin-point haemorrhages, abscesses, necrosis and ascites in skin, fin, muscle, liver, spleen, kidney, blood, interstitial fluid specially in central nervous system and brain. This disease was more prevalent (>26% at summer when the water temperature was approximately >25oC, percentage of mortality was higher >41% during the overcrowding and improper water chemistry. Raised levels of glucose and ammonium in blood serum causes reduced number of free blood cells released into the haemolymph to stomach and gut, result in refrain from eating in diseased tilapia. Stocking density (200 fish/decimal; class IV had significant effect (P<0.01 on the total production (5,000 to 5,500 kg/ha. S. iniae in the circulating blood cells, extra-tubular haemal spaces containing blood vessels, fixed phagocytes in the hepatopancreas (gastrointestinal tract, bacteria-like particles in the brain tissue, vacuum and necrosis in hepatocytes revealed with histopathology. In vitro study revealed that cohabitation of dead or infected fish with healthy fish resulted infection (horizontal transmission mechanism to the healthy fish.

  17. Effects of Dietary Yeast (Saccharomyces cerevisia Supplementation in Practical Diets of Tilapia (Oreochromis niloticus

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    José E. P. Cyrino

    2012-01-01

    Full Text Available A 51-day feeding trial was carried out to determine the effects of various dietary levels of brewer’s yeast, Saccharomyces cerevisiae, in the growth performance, body composition and nutrient utilization in Nile tilapia, Oreochromis niloticus, juveniles. Fish (7.6 ± 0.3 g were stocked into eighteen 1,000-L tanks (100 fish per tank; n = 3 and fed to apparent satiation six isonitrogenous (27% crude protein and isoenergetic (19 kJ/g diets, formulated to contain different dried yeast levels (0%, 10%, 15%, 20%, 30% or 40% diet in substitution to fishmeal. Body weight tripled at the end of the feeding trial for fish fed up to 20% dietary yeast incorporation. Daily growth coefficient (DGC, % body weight/day decreased with increasing dietary yeast level (P < 0.0001. Voluntary feed intake (VFI, %BW/day did not vary significantly with increasing yeast level. Fish fed 40% yeast showed significant reduction in protein efficiency rate, protein retention and nitrogen gain. Increasing levels of dietary yeast did not significantly affect protein or lipid digestibility. Dietary dried yeast was seemingly palatable to tilapia juveniles and was suitable up to 15% inclusion to promote growth and efficient diet utilization, without affecting body composition.

  18. The aquaculture potential of Tilapia rendalli in relation to its feeding habits and digestive capabilities

    Science.gov (United States)

    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). 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.

  19. The LBP gene and its association with resistance to Aeromonas hydrophila in tilapia.

    Science.gov (United States)

    Fu, Gui Hong; Liu, Feng; Xia, Jun Hong; Yue, Gen Hua

    2014-12-01

    Resistance to pathogens is important for the sustainability and profitability of food fish production. In immune-related genes, the lipopolysaccharide-binding protein (LBP) gene is an important mediator of the inflammatory reaction. We analyzed the cDNA and genomic structure of the LBP gene in tilapia. The full-length cDNA (1901 bp) of the gene contained a 1416 bp open reading frame, encoding 471 amino acid residues. Its genomic sequence was 5577 bp, comprising 15 exons and 14 introns. Under normal conditions, the gene was constitutively expressed in all examined tissues. The highest expression was detected in intestine and kidney. We examined the responses of the gene to challenges with two bacterial pathogens Streptcoccus agalactiae and Aeromonas hydrophila. The gene was significantly upregulated in kidney and spleen post-infection with S. agalactiae and A. hydrophila, respectively. However, the expression profiles of the gene after the challenge with the two pathogens were different. Furthermore, we identified three SNPs in the gene. There were significant associations (p tilapia resistant to A. hydrophila.

  20. Role of miR-21 in alkalinity stress tolerance in tilapia.

    Science.gov (United States)

    Zhao, Yan; Wu, Jun-Wei; Wang, Yan; Zhao, Jin-Liang

    2016-02-26

    MicroRNAs (miRNAs) are a class of short, evolutionary conserved non-coding RNA molecules, which are shown as the key regulators of many biological functions. External stress can alter miRNA expression levels, thereby changing the expression of mRNA target genes. Here, we show that miR-21 is involved in the regulation of alkalinity tolerance in Nile tilapia. Alkalinity stress results in a marked reduction in miR-21 levels. miR-21 loss of function could affect ion balance regulation, ROS production, and antioxidant enzyme activity in vivo. Moreover, miR-21 knockdown protects cell against alkalinity stress-induced injury in vitro. miR-21 directly regulates VEGFB and VEGFC expression by targeting the 3'-untranslated regions (UTRs) of their mRNAs, and inhibition of miR-21 significantly increases the levels of VEGFB and VEGFC expression in vivo. Taken together, our study reveals that miR-21 knockdown plays a protective role in alkalinity tolerance in tilapia.

  1. Bacterioplankton community analysis in tilapia ponds by Illumina high-throughput sequencing.

    Science.gov (United States)

    Fan, Li Min; Barry, Kamira; Hu, Geng Dong; Meng, Shun long; Song, Chao; Wu, Wei; Chen, Jia Zhang; Xu, Pao

    2016-01-01

    The changes of microbial community in aquaculture systems under the effects of stocking densities and seasonality were investigated in tilapia ponds. Total DNAs were extracted from the water samples, 16S rRNA gene was amplified and the bacterial community analyzed by Illumina high-throughput sequencing obtaining 3486 OTUs, from a total read of 715,842 sequences. Basing on the analysis of bacterial compositions, richness, diversity, bacterial 16S rRNA gene abundance, water sample comparisons and existence of specific bacterial taxa within three fish ponds in a 4 months period, the study conclusively observed that the dominant phylum in all water samples were similar, and they included; Proteobacteria, Cyanobacteria, Bacteroidetes, Actinobacteria, Planctomycetes and Chlorobi, distributed in different proportions in the different months and ponds. The seasonal changes had a more pronounced effect on the bacterioplankton community than the stocking densities; however some differences between the ponds were more likely caused by feed coefficient than by stocking densities. At the same time, most bacterial communities were affected by the nutrient input except phylum Cyanobacteria that was also affected by the feed control of tilapia.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  4. Digestible lysine requirement of Nile tilapia fingerlings fed arginine-tolysine-balanced diets

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    Wilson Massamitu Furuya

    2012-03-01

    Full Text Available This study was conducted to determine the digestible lysine requirements of Nile tilapia fingerlings. Fish (n = 300; average initial weight = 1.44 g were distributed 15 300-L aquariums, in a completely randomized design with five treatments and three replicates, and fed extruded diets containing 11.3, 13.7, 16.1, 18.4 or 20.8 g/kg of digestible lysine. The arginine:lysine ratio was maintained at 1.3:1. All fish were fed diets containing 281 g/kg of digestible protein and 3,372 kcal digestible energy/kg, hand-fed until apparent satiation. There was no effect of the dietary lysine levels on survival rate, or protein and ash body rates. With increasing levels of lysine in the diet, a quadratic effect on weight gain, feed conversion, protein efficiency ratio, protein deposition rate, deposition rate of fat, body moisture and body lipids was observed, where the best values of the variables were estimated at 15.96, 16.4, 14.35, 15.21, 15.87, 15.21 and 16.29 g/kg of lysine, respectively. The digestible lysine requirement of Nile tilapia fingerlings is 15.21 g/kg (5.41 g/100 g of digestible protein, in diets balanced for the arginine:lysine ratio.

  5. Haematology and melanoma crophage centers of Nile tilapia fed supplemented diet with propolis

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    Jerko Ledic-Neto

    2014-05-01

    Full Text Available The objective of this study was to investigate the influence of dietary supplementation with propolis on hematology and number and area of melanomacrophage centers in spleen and kidney of tilapia. After acclimation, fish (24.7 ± 7.4 gmean weight were distributed in 6 tanks 100 L, 6 fish per tank, in triplicate, at a temperature 24.0 ± 2.8oC, with two treatments: Fish fed 2% propolis supplemented diet and fish fed non-supplemented diet. To monitor the evolution of the effects, two samples were collected: half of the fish from each treatment were used after 15 days and the other half after 21, composing two feeding times. After each feeding time, blood, spleen and kidney were collected. After twenty one days feeding on 2% propolis supplemented diet, fish showed a lower number of total leukocytes and lymphocytes and an increase in the total erythrocytes number. Fish fed supplemented diet presented an increased number of melanomacrophage centers. We observed hemosiderin in all spleen samples. Kidney showed no significant difference on the presence of melanomacrophage centers containing hemosiderin. Despite these changes, the fish health status was not affected. The results showed that propolis supplementation in the diet ofNile tilapia may be physiologically feasible.

  6. MICROBIOLOGICAL QUALITY AND SHELF LIFE OF FRESH PACKAGED TILAPIA FILLETS STORED UNDER DIFFERENT CHILL TEMPERATURES

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    Odoli Cyprian

    2013-02-01

    Full Text Available Nile tilapia (Oreochromis niloticus farmed in recirculation aquaculture system (RAS was filleted and packaged in 100% air and 50% CO2: 50% N2 modified atmosphere (MA prior to storage at 1˚C and -1˚C for up to 27 days. Fillets were sampled regularly and analysed for headspace gas composition, sensory and microbial changes. Shelf life varied with apparent relation to storage temperature, package atmosphere and microflora. Pseudomonads were reported as the main spoilage organisms in tilapia fillets during chilled storage conditions. Sensory analysis of cooked samples as well as microbial growth indicated fillets packaged in 100% air had a shelf life of 13-15 days during storage at 1˚C and 20 days at -1˚C. At the end of shelf life in 100% air packaged groups, TVC and pseudomonads counts reached log 7 colony-forming units g-1 in flesh. Whereas in 50% CO2: 50% N2 packaged fillets, the lag phase and generation time of bacteria was extended and recorded counts of < log 4 colony-forming units g-1 up to 27 days of storage at both 1˚C and -1˚C. However, 50% CO2 : 50% N2 conditions restricted fillets shelf life to 23 days based on sensorial changes mainly fillets colour characteristics.

  7. Limit growth of ice crystals under different temperature oscillations levels in nile Tilapia

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    Mirko Salomon Chávez GUTIÉRREZ

    Full Text Available Abstract The degenerative effect of temperature fluctuations during storage time is a critical condition that needs to be quantitatively characterized in products where drip losses are appreciable. In this work, real storage conditions were reproduced using freezers modified to cause 3 levels of temperature fluctuation (± 0, ± 3, ± 5; ± 7 during storage of Tilapia (Oreochromis sp, at temperature of –18 °C. The fast frozen tilapia muscle (freezing cabinet was chosen to quantify the growth of ice crystals according to temperature fluctuations. The identification of crystals in the optical microscope as well as histological treatments and measurements using specific software has shown that the growth of ice crystals in the first days of storage follows an asymptote, whose final value is conditioned only by the level of temperature fluctuations regardless of initial diameter, which begins storage. It has also been found that the growth of crystals formed during rapid freezing rapidly develops according to temperature fluctuations to which the product has been subjected. This work also identified statistically significant differences in the equivalent diameter of crystals formed at the four proposed levels of temperature fluctuation with significance level of p < 0.05.

  8. Cymothoa indica (Isopoda; Cymothoidae and Alitropus typus (Isopoda; Aegidae on freshwater fish Tilapia mossambica (Cichlidae in Vellar estuary, Southeast coast of India

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    G. Rameshkumar

    2010-09-01

    Full Text Available The study was carried out to establish the extent of double parasitation of two species of isopods Cymothoa indica and Alitropus typus on Tilapia mossambica. Cymothoa indica, a typical Indo-Pacific genus, and A. typus, a common crustacean parasite of fish in Southeast Asia, which feeds by sucking blood species, are reported by the first time in the freshwater fish Tilapia from Vellar estuary.

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

    OpenAIRE

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

    2014-01-01

    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.

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

    Science.gov (United States)

    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.

  11. The supplementation of phytase RONOZYME P on the growth and the utilisation of phosphorus by sex-reversed red tilapia (Oreochromis niloticus Linn.)

    OpenAIRE

    Jirawat Tudkaew,; Jacques Gabaudan; Wutiporn Phromkunthong

    2008-01-01

    The effect of phytase supplementation to a low fish meal based diet on growth performance and phosphorus utilisation was investigated in sex-reversed red tilapia. Diets were prepared without phytase or inorganic phosphorus supplementation, with phytase, with supplemented inorganic phosphorus and with both phytase and supplemental inorganic phosphorus. Available phosphorus was set below requirement and the total phosphorus set to meet requirement for tilapia. After 8 weeks, there were signific...

  12. 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)

    Science.gov (United States)

    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

  13. Determining the cleavage site for the mature antimicrobial peptide of Nile tilapia β-defensin using 2D electrophoresis, western blot, and mass spectrometry analysis.

    Science.gov (United States)

    Chang, Chin-I; Chen, Li-Hao; Hu, Yeh-Fang; Wu, Chia-Che; Tsai, Jyh-Ming

    2017-03-01

    Several proteomic techniques were used to determine the cleavage site of the mature antimicrobial peptide of Nile tilapia β-defensin. The computer-predicted Nile tilapia β-defensin ((25)ASFPWSCLSLSGVCRKVCLPTELFFGPLGCGKGSLCCVSHFL(66)) composed of 42 amino acids was chemically synthesized and prepared to produce an antibody for Western blotting. Total proteins from the skin of the Nile tilapia were separated on two-dimensional electrophoresis, and the spot of Nile tilapia β-defensin was recognized using Western blot analysis. It was then excised and extracted from the gel. The precise molecular mass of this spot was determined by LC-MS/MS spectrometry. Four major peptides were discovered, with molecular weights of 4293.2 Da, 4306.5 Da, 4678.9 Da, and 4715.0 Da. The calculated mass of the 40-amino-acid sequence ((27)FPWSCLSLSGVCRKVCLPTELFFGPLGCGKGSLCCVSHFL(66)) of Nile tilapia β-defensin starting from Phe27 and ending with Leu66 was 4293.18 Da, which completely matched the 4293.2 Da peptide that was obtained from the mass spectrometry analysis. This result confirmed that the cleavage site for the mature C-terminal Nile tilapia β-defensin is at residue Ser26-Phe27, not at Ala24-25 as predicted by computer analysis. This study provides a simple but reliable model to determine the cleavage site for a mature antimicrobial peptide. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Increasing of temperature induces pathogenicity of Streptococcus agalactiae and the up-regulation of inflammatory related genes in infected Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Kayansamruaj, Pattanapon; Pirarat, Nopadon; Hirono, Ikuo; Rodkhum, Channarong

    2014-08-06

    Temperature strongly affects the health of aquatic poikilotherms. In Nile tilapia (Oreochromis niloticus), elevated water temperatures increase the severity of streptococcosis. Here we investigated the effects of temperature on the vulnerability and inflammatory response of Nile tilapia to Streptococcus agalactiae (Group B streptococci; GBS). At 35 and 28 °C, GBS took 4 and 7h, respectively to reach the log-phase and, when incubated with tilapia whole blood, experienced survival rates of 97% and 2%, respectively. The hemolysis activity of GBS grown at 35 °C was five times higher than that of GBS grown at 28 °C. GBS expressed cylE (β-hemolysin/cytolysin), cfb (CAMP factor) and PI-2b (pili-backbone) much more strongly at 35 °C than at 28 °C. Challenging Nile tilapia reared at 35 and 28 °C with GBS resulted in accumulated mortalities of about 85% and 45%, respectively. At 35 °C, infected tilapia exhibited tremendous inflammatory responses due to a dramatic up-regulation (30-40-fold) of inflammatory-related genes (cyclooxygenase-2, IL-1β and TNF-α) between 6 and 96 h-post infection. These results suggest that the increase of GBS pathogenicity to Nile tilapia induced by elevated temperature is associated with massive inflammatory responses, which may lead to acute mortality.

  15. Colorimetric Method of Loop-Mediated Isothermal Amplification with the Pre-Addition of Calcein for Detecting Flavobacterium columnare and its Assessment in Tilapia Farms.

    Science.gov (United States)

    Suebsing, Rungkarn; Kampeera, Jantana; Sirithammajak, Sarawut; Withyachumnarnkul, Boonsirm; Turner, Warren; Kiatpathomchai, Wansika

    2015-03-01

    Flavobacterium columnare, the causative agent of columnaris disease in fish, affects many economically important freshwater fish species. A colorimetric method of loop-mediated isothermal amplification with the pre-addition of calcein (LAMP-calcein) was developed and used to detect the presence of F. columnare in farmed tilapia (Nile Tilapia Oreochromis niloticus and red tilapia [Nile Tilapia × Mozambique Tilapia O. mossambicus]) and rearing water. The detection method, based on a change in color from orange to green, could be performed within 45 min at 63°C. The method was highly specific, as it had no cross-detections with 14 other bacterial species, including other fish pathogens and two Flavobacterium species. The method has a minimum detection limit of 2.2 × 10(2) F. columnare CFU; thus, it is about 10 times more sensitive than conventional PCR. With this method, F. columnare was detected in gonad, gill, and blood samples from apparently healthy tilapia broodstock as well as in samples of fertilized eggs, newly hatched fry, and rearing water. The bacteria isolated from the blood were further characterized biochemically and found to be phenotypically identical to F. columnare. The amplified products from the LAMP-calcein method had 97% homology with the DNA sequence of F. columnare.

  16. 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).

    Science.gov (United States)

    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.

  17. 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.

    Directory of Open Access Journals (Sweden)

    Pallab K Sarker

    Full Text Available 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.

  18. Caracterización de tilapia roja (Oreochromis sp. con marcadores moleculares RAPD Characterization of the red tilapia Oreochromis sp. through molecular markers RAPD

    Directory of Open Access Journals (Sweden)

    Julieta Torres Jaramillo

    2010-04-01

    Full Text Available Se utilizó la técnica RAPD (amplificación al azar de ADN polimórfico para el estudio de la diversidad genética de Oreochromis sp. (tilapia roja en cinco piscícolas del Valle del Cauca (Colombia y en la determinación del nivel de introgresión de las especies parentales Oreochromis mosambicus, O. niloticus y O. aureus. Se evaluaron 25 cebadores, ocho fueron polimórficos y se obtuvieron 109 bandas. Los valores de heterocigosidad esperada (0.196 a 0.256 y la estructura genética (Gst = 0.22 para Oreochromis sp. indicaron un elevado grado de polimorfismo y alta estructuración genética. Estos resultados fueron consistente con el Fst = 0.268 (P Random amplified polymorphic DNA (RAPD markers were used to study genetic diversity on red Tilapia (Oreochromis sp. species collected from five fish farms located in the Valle del Cauca, Colombia and to determine the level of introgression from three parental species O. mosambicus, O. niloticus and O. aureus into local Oreochromis populations. from the 25 RAPD primers evaluated, eight were polymorphic and 109 banding patterns were observed, any of them were specific. The expected levels of heterozygosis (0.1964 to 0.2561 and genetic structure (Gst = 0.22 funded for Oreochrosmis sp. indicate high grade of polymorphism and genetic structuring. This results were observed following the analysis of molecular variance [AMOVA] (Fst = 0.268 (P <0.0001 and Multiple correspondence analysis (Gst = 0.040. The values of genetic similarity, the analysis of group, the analysis of multiple correspondence and the level of introgression, indicated that the differences in the introgression levels(P=0.0001 were significant. The low level of observed genetic differentiation among populations, could be the result of fish with the same genetic origin, whereas the high variation within populations can be displayed by handling practices and the pressure of selection to favor commercial phenotypes. The level of introgression

  19. Assessment of heavy metals in tilapia fish (Oreochromis niloticus) from the Langat River and Engineering Lake in Bangi, Malaysia, and evaluation of the health risk from tilapia consumption.

    Science.gov (United States)

    Taweel, Abdulali; Shuhaimi-Othman, M; Ahmad, A K

    2013-07-01

    Concentrations of the heavy metals copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb) and nickel (Ni) were determined in the liver, gills and muscles of tilapia fish from the Langat River and Engineering Lake, Bangi, Selangor, Malaysia. There were differences in the concentrations of the studied heavy metals between different organs and between sites. In the liver samples, Cu>Zn>Ni>Pb>Cd, and in the gills and muscle, Zn>Ni>Cu>Pb>Cd. Levels of Cu, Cd, Zn and Pb in the liver samples from Engineering Lake were higher than in those from the Langat River, whereas the Ni levels in the liver samples from the Langat River were greater than in those from Engineering Lake. Cd levels in the fish muscle from Engineering Lake were lower than in that from the Langat River. Meanwhile, the Cd, Zn and Pb levels in the fish muscle from the Langat River were lower than in that from Engineering Lake, and the Ni levels were almost the same in the fish muscle samples from the two sites. The health risks associated with Cu, Cd, Zn, Pb and Ni were assessed based on the target hazard quotients. In the Langat River, the risk from Cu is minimal compared to the other studied elements, and the concentrations of Pb and Ni were determined to pose the greatest risk. The maximum allowable fish consumption rates (kg/d) based on Cu in Engineering Lake and the Langat River were 2.27 and 1.51 in December and 2.53 and 1.75 in February, respectively. The Cu concentrations resulted in the highest maximum allowable fish consumption rates compared with the other studied heavy metals, whereas those based on Pb were the lowest. A health risk analysis of the heavy metals measured in the fish muscle samples indicated that the fish can be classified at one of the safest levels for the general population and that there are no possible risks pertaining to tilapia fish consumption.

  20. Selección masal por peso y coloración en tilapia roja Mass selection by weight and coloration in red tilapia

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    María Alejandra Ruiz Peña

    2009-04-01

    Full Text Available Para evaluar la efectividad de la selección masal por color y peso se analizaron dos generaciones (G1 y G2 de alevinos de tilapia roja Oreochromis sp. De 40.000 larvas a la sexta semana se eliminaron los alevinos manchados y blancos y a las 14 semanas se separaron por sexos. Se midió el peso (g, la longitud total (cm, la altura (cm y el ancho (cm de 150 individuos a las 6, 14 y 24 semanas de edad. En la semana 24 se escogieron 150 machos y 450 hembras con las coloraciones deseables y mayor peso. La selección resultó efectiva para coloración en G2, puesto que la proporción de individuos rojos se incrementó en 15% con respecto a los testigos. Entre generaciones (G1 y G2 el efecto de la selección fue positivo, debido a que la proporción de rojos se incrementó de 64% a 84% y se redujo la de manchados de 31% a 13%. En ambas generaciones los machos fueron significativamente más pesados que las hembras. Se encontraron notables diferencias entre generaciones para peso y talla, puesto que los selectos superaron al control en 27% y 8% (G1 y en 22% y 11% (G2 para el peso y la talla, respectivamente.In order to evaluate the effectiveness of mass selection by color and weight, two generations (G1 y G2 of red tilapia Oreochromis sp. were analyzed. 40000 larvae were used, at the sixth week fries with black spots and white were eliminated, and at week 14, the fishes were separated by sex. The weight (g, length, height and width (cm were measured in a sample of 150 individuals at 6, 14 and 24 weeks. At week 24, the best 150 males and 450 females with desirable colorations and higher weight were chosen. The selection was effective for coloration in G2, because proportion of red individuals increased in 15% compared to the control. The effect of the selection between generations (G1 y G2 was positive because proportion of red fries increased from 64% to 84%, and the spotted ones were reduced from 31% to 13%. In both generations males were significantly

  1. Expression of endogenous and exogenous growth hormone (GH) messenger (m) RNA in a GH-transgenic tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Caelers, Antje; Maclean, Norman; Hwang, Gyulin; Eppler, Elisabeth; Reinecke, Manfred

    2005-02-01

    We have previously produced transgenic fish from crosses between a wild-type female tilapia (Oreochromis niloticus) and a G transgenic male. This line of growth-enhanced tilapia carries a single copy of a chinook salmon (s) growth hormone (GH) gene spliced to an ocean pout antifreeze promoter (OPA-FPcsGH) co-ligated to a carp beta-actin/lacZ reporter gene construct, integrated into the tilapia genome. Because little is known about the expression sites of transgenes, we have characterised the gene expression patterns of sGH and tilapia (t)GH in transgenic tilapia using a newly established real-time PCR to measure the absolute mRNA amounts of both hormones. The sGH gene, which was expected to be expressed mainly in liver, was also found to be expressed in other organs, such as gills, heart, brain, skeletal muscle, kidney, spleen, intestine and testes. However, in pituitary no sGH mRNA but only tGH mRNA was found. Tilapia GH mRNA in wild-type pituitary amounted to 226 +/- 30 pg/microg total RNA but in transgenics only to 187 +/- 43 pg/microg total RNA. Liver exhibited the highest level of sGH mRNA (8.3 +/- 2.5 pg/microg total RNA) but the extrahepatic sites expressed considerable amounts of sGH mRNA ranging from 4.1 +/- 2.0 pg/microg total RNA in gills to 0.2 +/- 0.08 pg/microg total RNA in kidney. The widespread expression of the sGH gene is assumed to be due to the tissue specificity of the type III AFP gene promoter. It is assumed that our transgenic experiments, which in contrast to some other approaches caused no obvious organ abnormalities, mimick the GH expression during ontogeny. Because sGH mRNA is expressed both in liver and in extrahepatic sites it may not only promote secretion and release of liver-derived (endocrine) IGF-I leading to an overall growth enhancement but also stimulate IGF-I expression within the different organs in a paracrine/autocrine manner and, thus, further promote organ growth.

  2. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs

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    Guyon Richard

    2012-06-01

    Full Text Available Abstract Background The Nile tilapia (Oreochromis niloticus is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic map, BAC end sequences and ESTs, but comparative genome analysis and maps of quantitative trait loci (QTL are still limited. Results We have constructed a high-resolution radiation hybrid (RH panel for the Nile tilapia and genotyped 1358 markers consisting of 850 genes, 82 markers corresponding to BAC end sequences, 154 microsatellites and 272 single nucleotide polymorphisms (SNPs. From these, 1296 markers could be associated in 81 RH groups, while 62 were not linked. The total size of the RH map is 34,084 cR3500 and 937,310 kb. It covers 88% of the entire genome with an estimated inter-marker distance of 742 Kb. Mapping of microsatellites enabled integration to the genetic map. We have merged LG8 and LG24 into a single linkage group, and confirmed that LG16-LG21 are also merged. The orientation and association of RH groups to each chromosome and LG was confirmed by chromosomal in situ hybridizations (FISH of 55 BACs. Fifty RH groups were localized on the 22 chromosomes while 31 remained small orphan groups. Synteny relationships were determined between Nile tilapia, stickleback, medaka and pufferfish. Conclusion The RH map and associated FISH map provide a valuable gene-ordered resource for gene mapping and QTL studies. All genetic linkage groups with their corresponding RH groups now have a corresponding chromosome which can be identified in the karyotype. Placement of conserved segments indicated that multiple inter-chromosomal rearrangements have occurred

  3. Prebiotic (Mannanoligosaccharide- MOS in fish nutrition: effects on nile-tilapia Oreochromis niloticus performance

    Directory of Open Access Journals (Sweden)

    Flávio Endrigo Cechim

    2012-12-01

    Full Text Available World fish production are growing about 10% a year and Brazil presents potential to be the first one in fish production until 2030. However, intensification of aquaculture production systems expose fish to numerous stressors such as poor water quality, crowding, handling and transport which may negatively affect their growth and and limit profitability of aquaculture systems. This current setup favors the use of dietary prebiotics for management of farmed fish as environmentally friendly practice. This study was set out to determine de effects of increasing levels of mannanoligosccharides (MOS on growth of juvenile Nile tilapia (Oreochromis niloticus. Fish (12.62 ± 0.38 were randomly distributed into 16 cages (0.25m3 polyvinyl chloride; 20 fish per cage, inside four 5m3 net-cage at Salto Caxias Hydroeletric water reservoir (Boa Vista da Aparecida, PR. Fish were fed during 60 days with a commercial diet (32%CP supplemented with 0.0 (control; 0.2; 0.4 and 0.8% dietary MOS (n=4. Water quality parameters (temperature, pH and dissolved oxygen were monitored during trial. After 60 days feeding trial, fish were fasted for 24 hours and sedated for biometrical parameters to evaluate growth parameters. It was observed no influence (p>0.05 of MOS supplementation on Nile tilapia growth parameters (weight gain, feed conversion rate, specific growth rate as well as for hepatosomatic index. Fish fed 0.4% dietary MOS showed increased (p<0.05 feed consumption (76.74 ± 3.98 when compared to fish fed control (unsupplemented diet (69.31 ± 1.11. MOS are indigestible glucomannoproteins, which provide mannose substrate upon which pathogenic gut bacteria selectively attach and prevents formation of mixed colonies leading to better gut health by increasing regularity, height and integrity of the gut villi and consequent better utilization and absorption of nutrients. Several authors found positive effects of MOS supplementation on fish growth and at same time, others

  4. Dietary levels of Mannanoligosaccharide (MOS for nile-tilapia (Oreochromis niloticus: Intestinal Morphology

    Directory of Open Access Journals (Sweden)

    Flavio Endrigo Cechim

    2012-12-01

    Full Text Available Intensification of aquaculture production systems exposes fish to numerous stressors, which may negatively affect their growth and limit profitability of aquaculture systems. In addition, fish farmers are now obliged to conform to Best Management Practices (BPMs regulations. This current setup favors the use of dietary prebiotics for management of farmed fish as environmentally friendly practice. Mannanoligosaccharides (MOS are complex carbohydrates derived from yeast (Saccharomyces cerevisiae cell walls. This study was set out to evaluate the effects of increasing levels of dietary MOS on intestinal morphology of Nile-tilapia. Fish (12.62 ± 0.38 were randomly distributed into 16 cages (0.25m3 polyvinyl chloride; 20 fish per cage, inside four 5m3 net-cage at Salto Caxias Hydroeletric water reservoir (Boa Vista da Aparecida, PR and fed diets containing increasing levels of MOS (0.0; 0.2; 0.4 and 0.8% during 30 days (n=4. The proximal intestine fragment of two specimens from each replicate was taken for histological observations. The histological sections (5 μm were stained with haematoxylin and eosin (H & E and documented photographically with a digital camera (DCM 130E digital camera for microscope 1.3 pixels, CMOS chip Software Scopephoto connected to a light microscope (EDUTEC 502 AC. The images were analyzed by using (BEL Eurisko software for intestinal villi measures. Water quality parameters (temperature, pH and dissolved oxygen were monitored during trial. It was observed influence (p<0.05 of MOS supplementation on Nile tilapia intestinal morphology. Fish fed diet containing 0.4% MOS supplementation showed increased (p<0.05 villi height (436.98±66.81 μm when compared to fish fed unsupplemented control diet (401.01±70.73 μm, 0.2% (364.59±61.68 μm and 0.8% (404.08±61.62 μm. Mannanoligosaccharides (MOS are complex carbohydrates derived from yeast (Saccharomyces cerevisiae cell walls and present mannose as primary carbohydrate

  5. Mechanical and thermal properties of irradiated films based on Tilapia (Oreochromis niloticus) proteins

    Energy Technology Data Exchange (ETDEWEB)

    Sabato, S.F. [Radiation Technology Center, IPEN-CNEN/SP, Av. Lineu Prestes 2242, 05508 900 Sao Paulo, SP (Brazil)], E-mail: sfsabato@ipen.br; Nakamurakare, N.; Sobral, P.J.A. [Food Engineering Department, ZEA/FZEA/USP, Av. Duque de Caxias Norte 225, 13635 900 Pirassununga, SP (Brazil)

    2007-11-15

    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.

  6. Impacto de los metales contaminantes en la calidad de la tilapia ( oreocromis aureus) cultivada en Cuba

    OpenAIRE

    Pis Ramírez, M.A.

    1999-01-01

    Se evaluó el impacto producido por los metales traza sobre ecosistemas acuáticos dedicados al cultivo de peces para la alimentación de la población, a través de la realización de estudios de determinación de los niveles de Pb; Cd; Hg; Fe; Cu; y Zn en el agua, sedimento y tilapias de tres presas de interés comercial para el país; dos situadas en la Ciudad de la Habana (Paso Seco y Niña Bonita) y una en Villa Clara (Palmarito). Los resultados obtenidos mostraron niveles de Pb en agua y de Hg...

  7. Influence of emulsion composition and spray-drying conditions on microencapsulation of tilapia oil.

    Science.gov (United States)

    Huang, Hui; Hao, Shuxian; Li, Laihao; Yang, Xianqing; Cen, Jianwei; Lin, Wanling; Wei, Ya

    2014-09-01

    The influence of processing conditions on the microencapsulation of tilapia oil by spray drying was studied. Trehalose, gelatin, sucrose and xanthan were used as emulsion composition. The experimental parameters of spray drying such as inlet air temperature, solid content, drying air flow rate and atomizing pressure were optimized using a central composite design. Encapsulation efficiency and lipid oxidation were determined. Bulk density, powder morphology and particle size were also analyzed. Trehalose improved the glass transition temperature of wall material significantly and prevented the oxidation of the fish oil. Encapsulation efficiency reached a maximum of 90 % under optimum conditions with an inlet air temperature of 121 °C, a drying air flow rate of 0.65 m(3)/min and a spray pressure of 100 kPa.

  8. Erythrocytes alterations of monosex tilapia (Oreochromis niloticus, Linnaeus, 1758 produced using methyltestosterone

    Directory of Open Access Journals (Sweden)

    Alaa El-Din H. Sayed

    2016-03-01

    Full Text Available The present study aims to investigate the effects of methyltestosterone on monosex farmed tilapia, Oreochromis niloticus by detection of apoptosis, micronucleus and alterations of erythrocytes. Fishes were obtained from four localities (Assiut as a control and Beheira, Alexandria and Kafr EL-Sheikh; three farms from each governorate as farmed monosex produced using methyltestosterone. Blood smears were processed for Hematoxylin and eosin technique. The major alterations recorded in the red blood cells were as swelled cells (Sc, tear drop-like cells (Tr, and sickle cells (Sk. Also, a significant difference (P ⩽ 0.001 between three governorates and Assiut was recorded in the micronucleus test, apoptosis and altered erythrocytes. These alterations are considered as an indication for performance and health of fish in the monosex culture medium indicating the side effects of overdose induction of MT.

  9. Histopathological studies and oxidative stress of synthesized silver nanoparticles in Mozambique tilapia (Oreochromis mossambicus)

    Institute of Scientific and Technical Information of China (English)

    Rajakumar Govindasamy; Abdul Abdul Rahuman

    2012-01-01

    To evaluate the potential environmental effects of engineered nano metals,it is important to determine the adverse effects of various nanomaterials on aquatic species.Adult tilapia (Oreochromis mossambicus) were maintained in 10 L glass aquaria,and exposed to a graded series of synthesized silver nanoparticles (Ag-NPs) at 25,50 and 75 mg/L for eight days.The LC50 value was 12.6 mg/L.Reduced activities of antioxidant enzymes and the contents of antioxidants were lowered in the gills and liver of fishes treated with Ag-NPs,which resulted in heavy accumulation of free radicals.Histopathological results imply that the balance between the oxidative and antioxidant system in the fish was broken down during Ag-NPs exposure.The principal coneern related with the release of nanomaterials and their smaller particle may change the materials transport and potential toxicity to aquatic organisms compared to larger particles.

  10. Immunologic parameters evaluations in Nile tilapia (Oreochromis niloticus) exposed to sublethal concentrations of diazinon.

    Science.gov (United States)

    Girón-Pérez, M I; Velázquez-Fernández, J; Díaz-Resendiz, K; Díaz-Salas, F; Canto-Montero, C; Medina-Díaz, I; Robledo-Marenco, M; Rojas-García, A; Zaitseva, G

    2009-08-01

    Fish resistance to microorganisms depends basically on the immune response. Although there are several studies on the diazinon mammalian immunotoxicity, in the case of fish there are only few. The aim of present study was to evaluate the effect of diazinon on immunological parameters (relative spleen weight, splenocytes count, lysozyme activity, respiratory burst and IgM concentration) in Nile tilapia. Diazinon at sublethal concentrations (0.39 and 0.78 mg/L) did not alter RSW, splenocytes count or lysozyme activity. However, at the highest concentration tested (1.96 mg/L) diazinon significantly increased respiratory burst and IgM concentration. In summary, diazinon (and perhaps other pesticides) could alter immunological response and induce oxidative stress.

  11. The utilization of Vallisneria aethiopica, Brassica oleracea and Pennisetum clandestinum by Tilapia rendalli

    Science.gov (United States)

    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.

  12. Mechanical and thermal properties of irradiated films based on Tilapia ( Oreochromis niloticus) proteins

    Science.gov (United States)

    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.

  13. Population dynamics of Enterogyrus cichlidarum (Monogenea: Ancyrocephalinae) from the stomach of Tilapia spp. in Egypt.

    Science.gov (United States)

    Khidr, A A

    1990-10-01

    In a 1-year seasonal study of the numbers of the stomach-inhabiting monogenean Enterogyrus cichlidarum in Tilapia nilotica in the River Nile, Egypt, prevalence and intensity reached a height in spring and infection levels were surprisingly high in winter. T. zillii harboured fewer parasites but seasonal changes were similar. No parasites were found in T. galilaea. The prevalence and intensity of the infection with E. cichlidarum rose significantly with increasing size of the host. Some of the possible reasons for these fluctuations are discussed. Immature enterogyrids were more abundant in the posterior sector of the stomach and adult enterogyrids showed a preference for the anterior sector. No significant difference was found in the numbers of enterogyrids in male and female hosts.

  14. Effect of the hydrostatic pressure on otolith growth of early juveniles of Nile tilapia Oreochromis niloticus.

    Science.gov (United States)

    Correia, A T; Coimbra, A M; Damasceno-Oliveira, A

    2012-07-01

    Nile tilapia Oreochromis niloticus early juveniles were maintained for 2 weeks in a pressurized system under a controlled photoperiod, at constant salinity and temperature. Groups of fish were exposed to one of three absolute hydrostatic pressure (HP) regimes: (1) a constant normal atmospheric pressure (100 kPa), (2) a constant 40 m pressure (500 kPa) or (3) a semi-diurnal cyclic vertical migration (100-500 kPa). No significant differences were detected in otolith size and incremental periodicity among the three HP treatments, suggesting that HP does not affect otolith growth of early juveniles O. niloticus. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  15. TOXICOLOGICAL STUDY OF SINGLE ACTION OF ZINC ON TILAPIA SPECIES (Oreochromis Niloticus

    Directory of Open Access Journals (Sweden)

    C.D EZEONYEJIAKU

    2011-07-01

    Full Text Available Lethal effects of zinc sulphate (ZnSO4.H2O, a widespread environmental pollutant was evaluated following exposure at different concentrations of the toxicant to Tilapia species, Oreochromis niloticus based on toxicity index of 96 hrs LC50 values. The obtained results were analyzed by the Finney’s Probit Analysis LC50 Method and 96 hrs LC50 value for Oreochromis niloticus was found to be 72.431 mg/l. The work further documented the lower and upper confidence limits for the LC50 to be 77.288 mg/l and 67.682 mg/l, respectively. The research showed zinc to be lethal to the test organism and recommends proactive control measures to be put in place to avert possible disaster of zinc poisoning.

  16. Oxygen Consumption of Tilapia and Preliminary Mass Flows through a Prototype Closed Aquaculture System

    Science.gov (United States)

    Muller, Matthew S.; Bauer, Clarence F.

    1994-01-01

    Performance of NASA's prototype CELSS Breadboard Project Closed Aquaculture System was evaluated by estimating gas exchange quantification and preliminary carbon and nitrogen balances. The total system oxygen consumption rate was 535 mg/hr kg/fish (cv = 30%) when stocked with Tilapia aurea populations (fresh weights of 97 +/- 19 to 147 +/- 36 g/fish for various trials). Oxygen consumption by T. aurea (260 mg/hr kg/fish) contributed to approximately one-half of total system demand. Continuous carbon dioxide quantification methods were analyzed using the,relation of carbon dioxide to oxygen consumption. Overall food conversion rates averaged 18.2 +/- 3.2%. Major pathways for nitrogen and carbon in the system were described with preliminary mass closure of 60-80% and 60% for nitrogen and carbon.

  17. Influence of salinity on PAH Uptake from water soluble fraction of crude oil in Tilapia mossambica.

    Science.gov (United States)

    Shukla, P; Gopalani, M; Ramteke, D S; Wate, S R

    2007-12-01

    Accidents during marine transport and offshore production facilities often are responsible for oil spills in the open sea. In few cases, these oil slicks drift towards the shore and further into the estuaries, which serve as an important spawning and nursing grounds for many fish species. This study examined the role of salinity in the uptake and accumulation of toxic PAH from crude oil in select somatic and reproductive organs of Tilapia mossambica. Our results showed significantly (ANOVA, p waters and its uptake by fish. The differences were largest with the low molecular weight (LMW) two (naphthalenes) and three (phenanthrene) ring compounds as compared with higher molecular weight (HMW) compounds such as pyrene (four ringed).

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  2. Prolactin is a major inhibitor of hepatic Leptin A synthesis and secretion: studies utilizing a homologous Leptin A ELISA in the tilapia.

    Science.gov (United States)

    Douros, Jonathan D; Baltzegar, David A; Breves, Jason P; Lerner, Darren T; Seale, Andre P; Gordon Grau, E; Borski, Russell J

    2014-10-01

    The present study identifies regulatory interactions between leptin A (LepA) and the pituitary hormone prolactin (PRL). In order to measure tilapia (Oreochromis mossambicus) LepA, an enzyme-linked immunosorbent assay (ELISA) utilizing a rabbit polyclonal antibody specific to tilapia LepA was first developed. The antibody shows strong cross reactivity to recombinant tilapia LepA (rtLepA), and a corresponding 16kDa protein in both tilapia and striped bass plasma, but not to recombinant human leptin (rhLep). The assay has a linear detection range of 0.25-1000nM, with intra- and interassay variability of 9% and 16%, respectively. Plasma LepA levels measured in tilapia ranged from 0.8 to 3.9nM, similar to that found for other vertebrates. Hypophysectomy (Hx) increased circulating LepA and lepa mRNA levels in the liver, the dominant source of hormone production. Adminstration of ovine PRL (oPRL, 5μg/g BW) to Hx fish restored circulating LepA and hepatic lepa mRNA levels to those of control fish. Additionally, oPRL reduced lepa mRNA levels in a dose-dependent fashion in cultured hepatocytes following an 18h incubation. Previous work in our lab indicates that rhLep stimulates PRL release in vitro from tilapia pituitaries. Here, both rtLepA and rhLep (0.5μg/g BW) increased mRNA expression of tilapia prolactin mRNAs (prl1, prl2) in the pituitary in vivo. These results demonstrate that LepA enhances pituitary prolactin synthesis and release, while PRL in turn inhibits hepatic leptin secretion and synthesis in teleosts. We postulate this regulatory interaction may be necessary for mobilizing energy reserves during acute hyperosmotic adaptation.

  3. Thyroid Hormone Upregulates Hypothalamic kiss2 Gene in the Male Nile Tilapia, Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Satoshi eOgawa

    2013-11-01

    Full Text Available Kisspeptin has recently been recognized as a critical regulator of reproductive function in vertebrates. During the sexual development, kisspeptin neurons receive sex steroids feedback to trigger gonadotropin-releasing hormone (GnRH neurons. In teleosts, a positive correlation has been found between the thyroid status and the reproductive status. However, the role of thyroid hormone in the regulation of kisspeptin system remains unknown. We cloned and characterized a gene encoding kisspeptin (kiss2 in a cichlid fish, the Nile tilapia (Oreochromis niloticus. Expression of kiss2 mRNA in the brain was analyzed by in situ hybridization. The effect of thyroid hormone (triiodothyronine, T3 and hypothyroidism with methimazole (MMI on kiss2 and the three GnRH types (gnrh1, gnrh2 and gnrh3 mRNA expression was analyzed by real-time PCR. Expression of thyroid hormone receptor mRNAs were analyzed in laser-captured kisspeptin and GnRH neurons by RT-PCR. The kiss2 mRNA expressing cells were seen in the nucleus of the lateral recess in the hypothalamus. Intraperitoneal administration of T3 (5µg/g body weight to sexually mature male tilapia significantly increased kiss2 and gnrh1 mRNA levels at 24 hr post injection (P < 0.001, while the treatment with an anti-thyroid, MMI (100 ppm for 6 days significantly reduced kiss2 and gnrh1 mRNA levels (P < 0.05. gnrh2, gnrh3 and thyrotropin-releasing hormone mRNA levels were insensitive to the thyroid hormone manipulations. Furthermore, RT-PCR showed expression of thyroid hormone receptor mRNAs in laser-captured GnRH neurons but not in kiss2 neurons. This study shows that GnRH1 may be directly regulated through thyroid hormone, while the regulation of Kiss2 by T3 is more likely to be indirect.

  4. PERFORMANCE OF NILE TILAPIA (OREOCHROMIS NILOTICUS FED FISH MEAL AND POULTRY BY-PRODUCT

    Directory of Open Access Journals (Sweden)

    H.M. ADAM SULIEMAN

    2011-11-01

    Full Text Available This study was conducted at the Department of Fisheries and Wild life Science, College of Science and Technology of Animal Production, Sudan University of Science and Technology, to determine the feed efficiency of two locally formulated diets (A and B on performance of Nile Tilapia (Oreochromis niloticus. Two iso-caloric iso-nitrogenus diets were formulated by adding 60% wheat bran, 30% cotton seed cake and 10% poultry by-product (offal+intestine, while the diet (B contained 60% wheat bran, 30% cotton seed cake and 10% fish meal. The fish were fed twice a day at affixed feeding rate of 5% body weight of fish per day for 90 days. The total body weight, total length and standard length were measured every 10 days throughout the experimental period. The growth response and performance data of the studied fish (Oreochromis niloticus fed with diet (B containing fishmeal recorded a better growth response than that fish fed poultry by- product meal (diet A. The final weight increment, specific growth rate (SGR, feed conversion ratio (FCR and protein efficiency ratio (PER over the experimental period showed lowest value for the group fed the diet with poultry by-product (Diet A compared to those fed with the fishmeal (Diet B. Except the apparent protein utilization (APU was recorded higher for those fed with Diet A (23.31 than Diet B (11.99. The groups fed diet (A attained SGR 0.24, FCR 1.9, PER 0.75, APU 23.31, while it recorded in group (B, SGR 0.34, FCR 1.2, PER 1.06, APU 11.99. Therefore, fish meal is better as compared to poultry by-products for Nile Tilapia (Oreochromis niloticus nutrition.

  5. Hematology of Nile tilapia (Oreochromis niloticus subjected to anesthesia and anticoagulation protocols

    Directory of Open Access Journals (Sweden)

    Nadia Cristine Weinert

    2015-12-01

    Full Text Available Clinical hematology facilitates the diagnosis of disease and can act as a prognostic indicator of pathological conditions in fish. The aim of the present study was to evaluate hematological parameters of Nile tilapia (Oreochromis niloticus subjected to different anesthetics and anticoagulants. Thirty apparently healthy fishes (average weight of 473 ± 35. 50 g and mean total length of 29. 33 ± 0. 37 cm, were selected from the local commercial fish farm in the Lages municipality (Santa Catarina, Brazil. The animals were randomly divided into three groups of 10. In two groups, anesthesia was induced with eugenol (70 mg·L- 1 (EG and Benzocaine hydrochloride (100 mg·L-1 (BG, respectively. Anesthesia was not administered to fish of the third group (CG/control group. Blood samples were obtained by venipuncture of the caudal vessels and placed into microtubes containing sodium heparin or Na2EDTA for further analysis. The results were analyzed by Sigma Stat for Windows, the paired t-test for significant differences between anticoagulants of the same group, and analysis of variance followed by the Tukey test for comparison of means between groups (p ? 0. 05. Most of the observed changes in the erythrogram were significantly higher for the anticoagulant heparin and benzocaine group in comparison to the control group. However, the values obtained for the leukogram were significantly higher for all groups subjected to the Na2EDTA anticoagulant, suggesting that heparin may cause cell clumping. The results suggest that the anesthetics under investigation effectively minimizes the effects of stress caused by handling and invasive procedures, and that the anticoagulant heparin causes less hemolysis in comparison to Na2EDTA for Nile tilapia. Thus, the hematological variations attributed to different anesthetic protocols and/or different anticoagulants should be considered for the species Oreochromis niloticus.

  6. Molecular cloning and bioinformatic analysis of the Streptococcus agalactiae neuA gene isolated from tilapia.

    Science.gov (United States)

    Wang, E L; Wang, K Y; Chen, D F; Geng, Y; Huang, L Y; Wang, J; He, Y

    2015-06-01

    Cytidine monophosphate (CMP) N-acetylneuraminic acid (NeuNAc) synthetase, which is encoded by the neuA gene, can catalyze the activation of sialic acid with CMP, and plays an important role in Streptococcus agalactiae infection pathogenesis. To study the structure and function of the S. agalactiae neuA gene, we isolated it from diseased tilapia, amplified it using polymerase chain reaction (PCR) with specific primers, and cloned it into a pMD19-T vector. The recombinant plasmid was confirmed by PCR and restriction enzyme digestion, and identified by sequencing. Molecular characterization analyses of the neuA nucleotide amino acid sequence were performed using bioinformatic tools and an online server. The results showed that the neuA nucleotide sequence contained a complete coding region, which comprised 1242 bp, encoding 413 amino acids (aa). The aa sequence was highly conserved and contained a Glyco_tranf_GTA_type superfamily and an SGNH_hydrolase superfamily conserved domain, which are related to sialic acid activation catalysis. The NeuA protein possessed many important sites related to post-translational modification, including 28 potential phosphorylation sites and 2 potential N-glycosylation sites, had no signal peptides or transmembrane regions, and was predicted to reside in the cytoplasm. Moreover, the protein had some B-cell epitopes, which suggests its potential in development of a vaccine against S. agalactiae infection. The codon usage frequency of neuA differed greatly in Escherichia coli and Homo sapiens genes, and neuA may be more efficiently expressed in eukaryotes (yeast). S. agalactiae neuA from tilapia maintains high structural homology and sequence identity with CMP-NeuNAc synthetases from other bacteria.

  7. In vitro screening for estrogenic endocrine disrupting compounds using Mozambique tilapia and sea bass scales.

    Science.gov (United States)

    Pinto, Patrícia I S; Estêvão, M Dulce; Santos, Soraia; Andrade, André; Power, Deborah M

    2017-09-01

    A wide range of estrogenic endocrine disruptors (EDCs) are accumulating in the environment and may disrupt the physiology of aquatic organisms. The effects of EDCs on fish have mainly been assessed using reproductive endpoints and in vivo animal experiments. We used a simple non-invasive assay to evaluate the impact of estrogens and EDCs on sea bass (Dicentrarchus labrax) and tilapia (Oreochromis mossambicus) scales. These were exposed to estradiol (E2), two phytoestrogens and six anthropogenic estrogenic/anti-estrogenic EDCs and activities of enzymes related to mineralized tissue turnover (TRAP, tartrate-resistant acid phosphatase and ALP, alkaline phosphatase) were measured. Semi-quantitative RT-PCR detected the expression of both membrane and nuclear estrogen receptors in the scales of both species, confirming scales as a target for E2 and EDCs through different mechanisms. Changes in TRAP or ALP activities after 30minute and 24h exposure were detected in sea bass and tilapia scales treated with E2 and three EDCs, although compound-, time- and dose-specific responses were observed for the two species. These results support again that the mineralized tissue turnover of fish is regulated by estrogens and reveals that the scales are a mineralized estrogen-responsive tissue that may be affected by some EDCs. The significance of these effects for whole animal physiology needs to be further explored. The in vitro fish scale bioassay is a promising non-invasive screening tool for E2 and EDCs effects, although the low sensitivity of TRAP/ALP quantification limits their utility and indicates that alternative endpoints are required. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The effect of titanium dioxide nanoparticles on antioxidant gene expression in tilapia ( Oreochromis niloticus)

    Science.gov (United States)

    Varela-Valencia, Ruth; Gómez-Ortiz, Nikte; Oskam, Gerko; de Coss, Romeo; Rubio-Piña, Jorge; del Río-García, Marcela; Albores-Medina, Arnulfo; Zapata-Perez, Omar

    2014-04-01

    The reactivity of nanoparticles (NPs) in biological systems is well recognized, but there are huge gaps in our understanding of NP toxicity in fish, despite a number of recent ecotoxicity studies. Therefore, the aim of this research was to evaluate the effect of titanium dioxide NPs (TiO2-NPs) on antioxidant gene expression in the tilapia, Oreochromis niloticus. First, different sizes, shapes, and phases of TiO2-NPs were synthesized and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS). Fish were injected intraperitoneally with different concentrations (0.1, 1.0, 10.0 mg/L), sizes (7, 14, and 21 nm), and phases (anatase and rutile) of TiO2-NPs, and sacrificed 3, 6, 12, and 24 h after injection, when their livers were removed. Total RNA was extracted, and expression of the catalase ( CAT), glutathione- S-transferase ( GST), and superoxide dismutase ( SOD) genes was assessed by real-time polymerase chain reaction (RT-PCR). The results showed that injection of 1.0 mg/L TiO2-NPs induced an initial mild increase in CAT, GST, and SOD gene expression in tilapia, after which transcript levels decreased. Fish injected with 7 and 14 nm TiO2-NPs showed an increase in antioxidant transcript levels 6 h after treatment. Finally, the rutile form generated stronger induction of the GST gene than anatase TiO2-NPs during the first 6 h after injection, which suggests that exposure to rutile causes higher levels of reactive oxygen species to be produced.

  9. Characterization of derived natural hydroxyapatite (HAp) obtained from different types of tilapia fish bones and scales

    Science.gov (United States)

    Fara, A. N. K. A.; Abdullah, H. Z.

    2015-07-01

    Hydroxyapatite, (HAp), Ca10(PO4)6(OH)2, is recognised as a biomaterial that is widely used for bone implant due to its chemical and structural similarity to the mineral components in human bone and enamel. The elements of HAp are primarily composed of calcium and phosphorus molar ratio of calcium to phosphorous is 1.67 capable to promote bone in-growth into prosthetic implant. Enormous amounts of by-product waste produced from fish factories generated an undesirable environmental impact. Thus, this study was conducted to obtain natural biological HAp from different types of tilapia fish bones and scales from fishery waste. Therefore, fish bones and scales can be as cheap source to produce biological HAp for medical applications. For this purpose, fish bones and scales of tilapia fish were boiled at 100°C to remove adhering meat and other impurities. Later, fish bones and scales were separated into several groups and subjected to different calcination temperatures of 800° C and 900° C for 3h respectively. Afterward, all calcined samples were crushed to form a fine powder. The XRD result revealed the presence of derived Hapfrom the samples powder and were identical with standard Hap. Thermo Gravimetric Analysis was carried out to show the thermal stability of the HAp powder from different types of fish bones and scales. SEM results show porous structure appeared in calcined samples compared to raw samples. The findings are the promising alternative to produce calcium and phosphorus from fishery wastes that beneficial to medical applications.

  10. Available phosphorus requirement of sex-reversed red tilapia fed all-plant diets

    Directory of Open Access Journals (Sweden)

    Udomnan Udom

    2008-01-01

    Full Text Available A feeding trial was conducted to estimate the optimum requirement of dietary phoshporus (P for sex-reversed red tilapia in glass aquaria (50x100x47cm. Six practical diets were formulated to contain graded levels (0.58, 0.66, 0.72, 0.75 and 0.82% of available P from all-plant raw ingredients and dicalcium phosphate (DCP. Each diet was randomly assigned to triplicate groups of fish, and each group was stocked with 20 fish (initial body weight, 25.16g 0.13. Fish were fed twice daily (08:00 and 16:00 ad libitum for 8 weeks. Average body weight and weight gain significantly increased with increasing available P (P<0.05. The whole body composition analysis showed that lipid and protein as well as P contents in whole body, vertebrae ash and vertebrae p, were significantly affected by available P (P<0.05. The blood biochemistry analysis showed that serum P and serum alkaline phosphatase activity increased with the increase of dietary available P levels (P<0.05. Data for weight gain, FCR, whole body P, vertebrae ash, vertebrae P, muscle protein, muscle fat and visceral fat were subjected to regression analysis to determine effects of the dietary levels of available P on these responses. Employing quadratic non-linear regression model of the relationship between available dietary P and P in vertebrae and whole body to study the P requirement, it was found that available dietary P requirement for sex-reversed red tilapia from the current study were of 0.76 and 0.79%, respectively. Increasing the dietary available P to higher concentration appears to reduce muscle fat while muscle protein increases.

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

    Science.gov (United States)

    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.

  12. WY型罗非鱼的性别鉴定%Sex identification of tilapia of WY type

    Institute of Scientific and Technical Information of China (English)

    杨永铨; 张海明; 陈远生

    2012-01-01

    以尼罗罗非鱼(Oreochromis niloticus)和奥利亚罗非鱼(O.aurea)为材料,进行WZ♀×XY ♂、WZ♀ ×YY♂、WY×ZY ♂、WY×YY ♂杂交实验及其子代分析,确认WY型罗非鱼的性别为雌性.%Hybridizations between tilapias, Oreochromis niloticus and 0. Aurea, were conducted in the groups WZ♀× XY 6 , WZ♀ ×YY(δ) , WY×ZY(δ) and WY×YY(δ), and the offsprings were analyzed. From the results, it could be deduced that the tilapia of genotype WY was female.

  13. Apparent digestibility of nutrients, energy, and amino acid of nontoxic and detoxified physic nut cakes for Nile tilapia

    Directory of Open Access Journals (Sweden)

    Hamilton Hisano

    2015-09-01

    Full Text Available Abstract:The objective of this work was to evaluate the apparent digestibility coefficients of nutrients, energy, and amino acids of nontoxic and detoxified physic nut cakes treated with solvent plus posterior extrusion, for Nile tilapia. The apparent digestibility coefficients of crude protein and gross energy were higher for detoxified than for nontoxic physic nut cake. However, the apparent digestibility coefficient of ether extract of the nontoxic physic nut cake was higher than that of the detoxified one. The apparent digestibility coefficient of amino acids of both feed ingredients was superior to 80%, except for glycine, for the nontoxic psychic nut cake, and for threonine, for the detoxified one. Nontoxic and detoxified physic nut cakes show apparent digestibility coefficient values equivalent to those of the other evaluated oilseeds and potential for inclusion in Nile tilapia diets.

  14. Anaerobic bio-digestion of concentrate obtained in the process of ultra filtration of effluents from tilapia processing unit

    Directory of Open Access Journals (Sweden)

    Milena Alves de Souza

    2012-02-01

    Full Text Available The objective of the present study was to evaluate the efficiency of the process of biodigestion of the protein concentrate resulting from the ultrafiltration of the effluent from a slaughterhouse freezer of Nile tilapia. Bench digesters were used with excrements and water (control in comparison with a mixture of cattle manure and effluent from the stages of filleting and bleeding of tilapias. The effluent obtained in the continuous process (bleeding + filleting was the one with highest accumulated population from the 37th day, as well as greatest daily production. Gases composition did not differ between the protein concentrates, but the gas obtained with the use of the effluent from the filleting stage presented highest methane gas average (78.05% in comparison with those obtained in the bleeding stage (69.95% and in the continuous process (70.02% or by the control method (68.59%.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    exposed at ZT15. Taken together, this study shows that several key components of humoral immunity in tilapia exhibit circadian rhythms and adapt to photoperiodic changes. Further, results of the bacterial endotoxin challenge suggest that responsiveness of serum humoral factors to a biological insult......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...

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

    Science.gov (United States)

    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. Life Cycle Assessment for environmentally sustainable aquaculture management : a case study of combined aquaculture systems for carp and tilapia

    OpenAIRE

    2013-01-01

    Life Cycle Assessment (LCA) was applied to evaluate the potential environmental impacts associated with two-net cage aquaculture systems of common carp (Cyprinus carpio carpio) and tilapia (Oreochromis niloticus) in the Cirata reservoir, Indonesia. The studied system included fingerling production in hatcheries, fish rearing in cages, and transport of fry and feed as well as that of harvested fish to markets. The environmental impact indicators were calculated based on the annual production i...

  18. Nutritional status and growth hormone regulate insulin-like growth factor binding protein (igfbp) transcripts in Mozambique tilapia.

    Science.gov (United States)

    Breves, Jason P; Tipsmark, Christian K; Stough, Beth A; Seale, Andre P; Flack, Brenda R; Moorman, Benjamin P; Lerner, Darren T; Grau, E Gordon

    2014-10-01

    Growth in teleosts is controlled in large part by the activities of the growth hormone (Gh)/insulin-like growth factor (Igf) system. In this study, we initially identified igf-binding protein (bp)1b, -2b, -4, -5a and -6b transcripts in a tilapia EST library. In Mozambique tilapia (Oreochromis mossambicus), tissue expression profiling of igfbps revealed that igfbp1b and -2b had the highest levels of expression in liver while igfbp4, -5a and -6b were expressed at comparable levels in most other tissues. We compared changes in hepatic igfbp1b, -2b and -5a expression during catabolic conditions (28days of fasting) along with key components of the Gh/Igf system, including plasma Gh and Igf1 and hepatic gh receptor (ghr2), igf1 and igf2 expression. In parallel with elevated plasma Gh and decreased Igf1 levels, we found that hepatic igfbp1b increased substantially in fasted animals. We then tested whether systemic Gh could direct the expression of igfbps in liver. A single intraperitoneal injection of ovine Gh into hypophysectomized tilapia specifically stimulated liver igfbp2b expression along with plasma Igf1 and hepatic ghr2 levels. Our collective data suggest that hepatic endocrine signaling during fasting may involve post-translational regulation of plasma Igf1 via a shift towards the expression of igfbp1b. Thus, Igfbp1b may operate as a molecular switch to restrict Igf1 signaling in tilapia; furthermore, we provide new details regarding isoform-specific regulation of igfbp expression by Gh.

  19. Osmotic regulation and tissue localization of the myo-inositol biosynthesis pathway in tilapia (Oreochromis mossambicus) larvae.

    Science.gov (United States)

    Sacchi, Romina; Gardell, Alison M; Chang, Nicole; Kültz, Dietmar

    2014-10-01

    The myo-inositol biosynthesis (MIB) pathway converts glucose-6-phosphate to the compatible osmolyte myo-inositol, which protects cells from salinity stress. We exposed tilapia larvae just after yolk sac resorption to various hypersaline environments and recorded robust induction of the enzymes that constitute the MIB pathway, myo-inositol-phosphate synthase (MIPS), and inositol monophosphatase 1 (IMPA1). Strong up-regulation of these enzymes is evident at both mRNA (quantitative real-time PCR) and protein (densitometric analysis of Western blots) levels. The highest level of induction of these enzymes occurs at the highest salinity that larvae were exposed to (90 ppt). Less severe salinity stress causes a proportionately reduced induction of the MIB pathway. Two distinct MIPS mRNA variants are present in tilapia larvae and both are induced at comparable levels for all the salinity challenges tested (34, 70, and 90 ppt). Immunohistochemical localization of IMPA1 protein in sagittal sections of salinity stressed and control larvae identified tissues that are particularly potent in inducing the MIB pathway. These tissues include the skin (epidermis), gills, eye (ciliary epithelium) and heart. In particular, the epidermis directly facing the external milieu showed a very strong induction of IMPA1 immunoreactivity. IMPA1 induction in response to salinity stress was not observed in other tissues suggesting that tilapia larvae may also utilize compatible organic osmolytes other than solely myo-inositol for osmoprotection. We conclude that the MIB pathway plays an important role in protecting multiple (but not all) tissues of tilapia larvae from hyperosmotic salinity stress.

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

    Science.gov (United States)

    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.

  1. Phenolic acids identified in sorghum distillery residue demonstrated antioxidative and anti-cold-stress properties in cultured tilapia, Oreochromis mossambicus.

    Science.gov (United States)

    Lee, Shin-Mei; Lin, Jing-Jen; Liao, Chih-Yuan; Cheng, Hui-Ling; Pan, Bonnie Sun

    2014-05-21

    This study aimed to identify the bioactive compounds and evaluate the anti-cold-stress function of the sorghum distillery residue (SDR) using tilapia as an alternative animal model. The highest contents of water-soluble bioactive compounds in SDR were polyphenols, followed by tannins, anthocyanins, and flavonoids. SDR was extracted with double-distilled water, 95% ethanol, and ethyl acetate, separately. The ethanol extract (SDR-E) yielded the highest polyphenol content [15.03 mg/g of SDR dry weight (dw)], of which the EC50 value of R,R-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging efficiency was 0.56 ± 0.04 mg/mL. The SDR-E suppressed the oxidation of low-density lipoproteins (LDLs) more efficiently than that of other extracts. Tilapia fed a diet containing 3.6% SDR-E decreased accumulative mortality during cold stress, of 46.2%. The accumulative morality of the control was 92.9%. The phenolic acids identified in SDR included gallic acid (0.36 ± 0.08 mg/g of SDR dw), 3,4-dihydroxybenzoic acid (0.16 ± 0.12 mg/g of SDR dw), and 4-hydroxybenzoic acid (0.49 ± 0.23 mg/g of SDR dw). Diets supplemented with 0.5% 4-hydroxybenzoic acid fed to tilapia showed a lower mortality rate than that fed 1.0% 4-hydroxybenzoic acid, comparable to that of the tilapia fed 20% SDR. The latter showed lower mortality than that of the control. These results suggested that 4-hydroxybenzoic acid is one of the major anti-cold-stress compounds in SDR.

  2. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs.

    OpenAIRE

    Guyon, Richard; Rakotomanga, Michaëlle; Azzouzi, Naoual; Coutanceau, Jean-Pierre; Bonillo, Celine; D'Cotta, Helena; Pepey, Elodie; Soler, Lucile; Rodier-Goud, Marguerite; D'Hont, Angélique; Conte, Matthew,; Van Bers, Nikkie; Penman, David,; Hitte, Christophe; Crooijmans, Richard

    2012-01-01

    International audience; ABSTRACT: BACKGROUND: The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. Itis also an important model for studies of fish physiology, particularly because of its broadtolerance to an array of environments. It is a good model to study evolutionary mechanismsin vertebrates, because of its close relationship to haplochromine cichlids, which haveundergone rapid speciation in East Africa. The existing genomic resources for Nile tilapi...

  3. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs

    OpenAIRE

    Guyon, Richard; Rakotomanga, Michaëlle; Azzouzi, Naoual; Coutanceau, Jean-Pierre; Bonillo, Celine; D'Cotta, Helena; Pepey, Elodie; Soler, Lucile; Rodier-Goud, Marguerite; D'Hont, Angélique; Conte, Matthew,; Van Bers, Nikkie; Penman, David,; Hitte, Christophe; Crooijmans, Richard P M A

    2012-01-01

    BACKGROUND: The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. Itis also an important model for studies of fish physiology, particularly because of its broadtolerance to an array of environments. It is a good model to study evolutionary mechanismsin vertebrates, because of its close relationship to haplochromine cichlids, which haveundergone rapid speciation in East Africa. The existing genomic resources for Nile tilapiainclude a genetic map, BAC end se...

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

    Science.gov (United States)

    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.

  5. Spatial analysis of potential carcinogenic risks associated with ingesting arsenic in aquacultural tilapia (Oreochromis mossambicus) in blackfoot disease hyperendemic areas.

    Science.gov (United States)

    Jang, Cheng-Shin; Liu, Chen-Wuing; Lin, Kao-Hung; Huang, Feng-Mei; Wang, Sheng-Wei

    2006-03-01

    This work analyzed spatially potential carcinogenic risks associated with ingesting arsenic (As) contents in aquacultural tilapia (Oreochromis mossambicus) in coastal regions of southwestern Taiwan, where the blackfoot disease prevails. Sequential indicator simulation (SIS) was used to reproduce As exposure distributions in groundwater based on their three-dimensional variability. A target cancer risk (TR) associated with ingesting As in aquacultural tilapia was calculated to evaluate the potential risk to human health. Owing to sparse measured data, Monte Carlo simulation and SIS properly accounted for the uncertainty of assessed parameters. The probabilistic risk assessment formulated suitable strategies under various remedial stages. Aquacultural regions with high risks were mapped to elucidate the safety of groundwater use at different depths. Many TRs determined from the risks at the 75th and 95th percentiles exceed one millionth in the regions, indicating that ingesting tilapia farmed in the highly As-polluted regions poses potential cancer threats to human health. The 75th percentile of TR is considered in formulating a remedial strategy for the aquacultural use of groundwater in the preliminary stage. Additionally, this study suggests reducing the use of groundwater in aquaculture or changing the depths from which groundwater is withdrawn in the areas with high risks of cancer.

  6. Replacement of fishmeal with processed meal from knife fish Chitala ornata in diets of juvenile Nile tilapia Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Sherilyn T. Abarra

    2017-02-01

    Full Text Available A 60-day feeding trial was conducted to assess the effects of processed meal from knife fish Chitala ornata (KFM as fishmeal replacement in diets of Nile tilapia Oreochromis niloticus juveniles. Five iso-nitrogenous (36.4% in dry matter and isolipidic diets (8.6% in dry matter with 0 (D1, 25 (D2, 50 (D3, 75 (D4 and 100% (D5 KFM inclusions were prepared. With a stocking density of 15 fish (0.59 ± 0.01 g per tank, tilapia juveniles were distributed randomly in fifteen 30-L tanks. Results indicate a significant increase (P  0.05 among treatments. Results of hepatic histopathology showed absence of tumors, lesions and parenchymal inflammation in all treatments. However, mild cell membrane lysis and mild and mild to moderate apoptosis were evident in liver samples. Based on the results, KFM can partially and completely replace dietary protein from fishmeal. Moreover, D4 (75% KFM is considered the optimal KFM replacement level for Nile tilapia juveniles.

  7. Molecular and functional characterization of CD59 from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.

    Science.gov (United States)

    Gan, Zhen; Wang, Bei; Zhou, Wei; Lu, Yishan; Zhu, Weiwei; Tang, Jufen; Jian, JiChang; Wu, Zaohe

    2015-05-01

    CD59, the major inhibitor of membrane attack complex, plays a crucial role in regulation of complement activation. In this paper, a CD59 gene of Nile tilapia, Oreochromis niloticus (designated as On-CD59) was cloned and its expression pattern under the stimulation of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for complement-inhibitory activity were detected in the deduced amino acid sequence of On-CD59. In healthy Nile tilapia, the On-CD59 transcripts could be detected in all the examined tissues, with the most abundant expression in the brain. When immunized with inactivated S. agalactiae, there was a clear time-dependent expression pattern of On-CD59 in the skin, brain, head kidney, thymus and spleen, with quite different kinetic expressions. The assays for the complement-inhibitory activity suggested that recombinant On-CD59 protein had a species-selective inhibition of complement. Moreover, our works showed that recombinant On-CD59 protein may possess both binding activities to PGN and LTA and inhibiting activity of S. agalactiae. These findings indicated that On-CD59 may play important roles in the immune response to S. agalactiae in Nile tilapia.

  8. Characterization of two novel gadd45a genes in hybrid tilapia and their responses to the infection of Streptococcus agalactiae.

    Science.gov (United States)

    Shen, Yubang; Ma, Keyi; Liu, Feng; Yue, Gen Hua

    2016-07-01

    Diseases are one of the major challenges in tilapia aquaculture. Identification of DNA markers associated with disease resistance may facilitate the acceleration of the selection for disease resistance. Gadd45a (growth arrest and DNA damage 45 A), a stress-inducible gene in humans and mice, has not been studied in fish. We characterized the two prologues of Gadd45a genes in hybrid tilapia. Gadd45a1 and Gadd45a2 shared an identical gene structure and showed an amino acid sequence identity of 73.8%. Their expressions were detected in all 10 tissues examined, with the kidney and gill having high transcriptional expressions. The expression levels of Gadd45a1 were significantly lower than those of Gadd45a2 in all examined tissues. After a challenge with a bacterial pathogen Streptococcus agalactiae, the expressions of the two genes were up-regulated significantly in the spleen, kidney, liver and intestine. These findings suggest that the two Gadd45a genes play an important role in the resistance to S. agalactiae in tilapia. We identified 10 SNPs in the two genes. The SNP markers in the two Gadd45a genes could be used to examine whether they are associated with resistance to S. agalactiae.

  9. Lipolytic response of adipose tissue and metabolic adaptations to long periods of fasting in red tilapia (Oreochromis sp., Teleostei: Cichlidae

    Directory of Open Access Journals (Sweden)

    WALTER DIAS JUNIOR

    2016-01-01

    Full Text Available ABSTRACT Adaptive changes of carbohydrate and lipid metabolism induced by 7, 15, 30, 60, 90, 150 and 200 days of fasting were investigated in red tilapia (Oreochromis sp.. Plasma glucose, lactate and free fatty acids (FFA levels, liver and muscle glycogen and total lipid contents and rates of FFA release from mesenteric adipose tissue (MAT were measured. Plasma glucose levels showed significant differences only after 90 days of fasting, when glycemia was 34% lower (50±5mg.dL-1 than fed fish values (74±1mg.dL-1, remaining relatively constant until 200 days of fasting. The content of liver glycogen ("15% in fed tilapia fell 40% in 7 days of food deprivation. In 60, 90 and 150 days of fasting, plasma FFA levels increased 49%, 64% and 90%, respectively, compared to fed fish values. In agreement with the increase in plasma FFA, fasting induced a clear increase in lipolytic activity of MAT incubated in vitro. Addition of isobutylmethylxanthine (cAMP-phosphodiesterase inhibitor and isoproterenol (non selective beta adrenergic agonist to the incubation medium induced a reduction of lipolysis in fasted fish, differently to what was observed in mammal adipose tissue. This study allowed a physiological assessment of red tilapia response to starvation.

  10. Shewanella putrefaciens in cultured tilapia detected by a new calcein-loop-mediated isothermal amplification (Ca-LAMP) method.

    Science.gov (United States)

    Suebsing, Rungkarn; Kampeera, Jantana; Sirithammajak, Sarawut; Pradeep, Padmaja Jayaprasad; Jitrakorn, Sarocha; Arunrut, Narong; Sangsuriya, Pakkakul; Saksmerprome, Vanvimon; Senapin, Saengchan; Withyachumnarnkul, Boonsirm; Kiatpathomchai, Wansika

    2015-12-09

    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.

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

    Science.gov (United States)

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

    2016-03-08

    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.

  12. Involvement of redox- and phosphorylation-dependent pathways in osmotic adaptation in sperm cells of euryhaline tilapia.

    Science.gov (United States)

    Morita, Masaya; Nakajima, Ayako; Takemura, Akihiro; Okuno, Makoto

    2011-06-15

    Sperm cells involved in fertilisation must tolerate hypo-osmotic and hyper-osmotic environments. Euryhaline tilapia (Oreochromis mossambicus) can acclimatise to and reproduce in freshwater and seawater because its sperm are able to adapt to these differing osmotic environments. In this study, we found that the dephosphorylation of sperm proteins in O. mossambicus correlated with the activation of flagellar motility when sperm were exposed to hypotonic or hypertonic conditions, and that differences in phosphorylation may reflect adaptations to a given osmotic environment. Of the sperm proteins that were dephosphorylated, the phosphorylation pattern of an 18 kDa protein, identified as the superoxide anion scavenger Cu/Zn superoxide dismutase (Cu/Zn SOD), was different in freshwater- and seawater-acclimatised tilapia sperm. Cu/Zn SOD was distributed from the sperm head to the flagellum. Additionally, differences were observed between freshwater and seawater tilapia in the nitration of tyrosine residues (which might be mediated by SOD) in sperm flagellar proteins in response to osmotic shock. These results demonstrate that reactive-oxygen-species-dependent mechanisms contribute to both osmotic tolerance and the activation of flagellar motility.

  13. Distribution and health risk assessment of trace metals in freshwater tilapia from three different aquaculture sites in Jelebu Region (Malaysia).

    Science.gov (United States)

    Low, Kah Hin; Zain, Sharifuddin Md; Abas, Mhd Radzi; Md Salleh, Kaharudin; Teo, Yin Yin

    2015-06-15

    The trace metal concentrations in edible muscle of red tilapia (Oreochromis spp.) sampled from a former tin mining pool, concrete tank and earthen pond in Jelebu were analysed with microwave assisted digestion-inductively coupled plasma-mass spectrometry. Results were compared with established legal limits and the daily ingestion exposures simulated using the Monte Carlo algorithm for potential health risks. Among the metals investigated, arsenic was found to be the key contaminant, which may have arisen from the use of formulated feeding pellets. Although the risks of toxicity associated with consumption of red tilapia from the sites investigated were found to be within the tolerable range, the preliminary probabilistic estimation of As cancer risk shows that the 95th percentile risk level surpassed the benchmark level of 10(-5). In general, the probabilistic health risks associated with ingestion of red tilapia can be ranked as follows: former tin mining pool > concrete tank > earthen pond. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  15. A genome scan revealed significant associations of growth traits with a major QTL and GHR2 in tilapia.

    Science.gov (United States)

    Liu, Feng; Sun, Fei; Xia, Jun Hong; Li, Jian; Fu, Gui Hong; Lin, Grace; Tu, Rong Jian; Wan, Zi Yi; Quek, Delia; Yue, Gen Hua

    2014-12-01

    Growth is an important trait in animal breeding. However, the genetic effects underpinning fish growth variability are still poorly understood. QTL mapping and analysis of candidate genes are effective methods to address this issue. We conducted a genome-wide QTL analysis for growth in tilapia. A total of 10, 7 and 8 significant QTLs were identified for body weight, total length and standard length at 140 dph, respectively. The majority of these QTLs were sex-specific. One major QTL for growth traits was identified in the sex-determining locus in LG1, explaining 71.7%, 67.2% and 64.9% of the phenotypic variation (PV) of body weight, total length and standard length, respectively. In addition, a candidate gene GHR2 in a QTL was significantly associated with body weight, explaining 13.1% of PV. Real-time qPCR revealed that different genotypes at the GHR2 locus influenced the IGF-1 expression level. The markers located in the major QTL for growth traits could be used in marker-assisted selection of tilapia. The associations between GHR2 variants and growth traits suggest that the GHR2 gene should be an important gene that explains the difference in growth among tilapia species.

  16. Quality Evaluation Focusing on Tissue Fractal Dimension and Chemical Changes for Frozen Tilapia with Treatment by Tangerine Peel Extract

    Science.gov (United States)

    He, Qi; Yang, Zhao; Gong, Bin; Wang, Jingjing; Xiao, Kaijun; Yang, Shang-Tian

    2017-01-01

    This work aimed to establish an effective approach to evaluate the quality of frozen fish, focusing on changes in fish tissue structure and chemical composition during storage. Fresh tilapia samples were treated by coating with tangerine peel (TP) extract and then stored at −4, −8 and −18 °C, respectively, for 40 days. The frozen fish tissues were analyzed for structural and chemical changes. Fractal dimension, which quantifies the porous structure formed in the tissue samples, texture properties including hardness and springiness, and moisture content and water activity all decreased during the storage, while the extents of lipid oxidation, measured as peroxide value and thiobarbituric acid concentration, and protein degradation, monitored with total volatile basic nitrogen and trichloroacetic acid soluble peptides, increased. The change rates of these parameters decreased with decreasing the storage temperature and by applying TP extract. A model was developed for predicting fractal dimension, which indicated the quality of preserved tilapia and thus can be used to predict the shelf life under different storage temperatures. The results demonstrated that TP extract could extend the shelf life of frozen tilapia by 35–45% by inhibiting changes in tissue structure, moisture loss, lipid oxidation and protein degradation during frozen storage. PMID:28169365

  17. The effects of acute salinity challenges on osmoregulation in Mozambique tilapia reared in a tidally changing salinity.

    Science.gov (United States)

    Moorman, Benjamin P; Lerner, Darren T; Grau, E Gordon; Seale, Andre P

    2015-03-01

    This study characterizes the differences in osmoregulatory capacity among Mozambique tilapia, Oreochromis mossambicus, reared in freshwater (FW), in seawater (SW) or under tidally driven changes in salinity. This was addressed through the use of an abrupt exposure to a change in salinity. We measured changes in: (1) plasma osmolality and prolactin (PRL) levels; (2) pituitary expression of prolactin (PRL) and its receptors, PRLR1 and PRLR2; (3) branchial expression of PRLR1, PRLR2, Na(+)/Cl(-) co-transporter (NCC), Na(+)/K(+)/2Cl(-) co-transporter (NKCC), α1a and α1b isoforms of Na(+)/K(+)-ATPase (NKA), cystic fibrosis transmembrane conductance regulator (CFTR), aquaporin 3 (AQP3) and Na(+)/H(+) exchanger 3 (NHE3). Mozambique tilapia reared in a tidal environment successfully adapted to SW while fish reared in FW did not survive a transfer to SW beyond the 6 h sampling. With the exception of CFTR, the change in the expression of ion pumps, transporters and channels was more gradual in fish transferred from tidally changing salinities to SW than in fish transferred from FW to SW. Upon transfer to SW, the increase in CFTR expression was more robust in tidal fish than in FW fish. Tidal and SW fish successfully adapted when transferred to FW. These results suggest that Mozambique tilapia reared in a tidally changing salinity, a condition that more closely represents their natural history, gain an adaptive advantage compared with fish reared in FW when facing a hyperosmotic challenge.

  18. Quality Evaluation Focusing on Tissue Fractal Dimension and Chemical Changes for Frozen Tilapia with Treatment by Tangerine Peel Extract

    Science.gov (United States)

    He, Qi; Yang, Zhao; Gong, Bin; Wang, Jingjing; Xiao, Kaijun; Yang, Shang-Tian

    2017-02-01

    This work aimed to establish an effective approach to evaluate the quality of frozen fish, focusing on changes in fish tissue structure and chemical composition during storage. Fresh tilapia samples were treated by coating with tangerine peel (TP) extract and then stored at -4, -8 and -18 °C, respectively, for 40 days. The frozen fish tissues were analyzed for structural and chemical changes. Fractal dimension, which quantifies the porous structure formed in the tissue samples, texture properties including hardness and springiness, and moisture content and water activity all decreased during the storage, while the extents of lipid oxidation, measured as peroxide value and thiobarbituric acid concentration, and protein degradation, monitored with total volatile basic nitrogen and trichloroacetic acid soluble peptides, increased. The change rates of these parameters decreased with decreasing the storage temperature and by applying TP extract. A model was developed for predicting fractal dimension, which indicated the quality of preserved tilapia and thus can be used to predict the shelf life under different storage temperatures. The results demonstrated that TP extract could extend the shelf life of frozen tilapia by 35-45% by inhibiting changes in tissue structure, moisture loss, lipid oxidation and protein degradation during frozen storage.

  19. Dietary supplementation of cumin (Cuminum cyminum preventing streptococcal disease during first-feeding of Mozambique tilapia (Oreochromis mossambicus

    Directory of Open Access Journals (Sweden)

    Sevdan Yılmaz

    2013-01-01

    Full Text Available This study was conducted to investigate the effect of dietary cumin (Cuminum cyminum powder (CP as a feed additive on growth performance and disease resistance during first-feeding of Mozamique tilapia (Oreochromis mossambicus. Five isonitrogenous (40% crude protein and isocaloric (18.9 kj g-1 diets were formulated to contain 0 (control, 0.5, 1, 1.5, and 2.0% CP. In a 45-day feeding trial, 15 plastic tanks (21 L were stocked with 40 fry (0.012 ± 0.001 g each. After feeding experiment, fish were infected with Streptococcus iniae and mortalities were recorded. The second-order polynomial regression indicated that a dietary CP level of 1.14% provided the best survival rate challenge infection with S. iniae, growth performance and feed utilization. In conclusion, CP can be used as growth promoter to improve feed utilization and weight gain in tilapia fry, and it can be also used as an antimicrobial agent during first-feeding of O. mossambicus. Therefore, CP can be suggested as an alternative to antibiotics in controlling streptococcal disease in tilapia culture.

  20. CARACTERIZACIÓN DE COPRODUCTOS DE LA INDUSTRIA DEL FILETEADO DE TILAPIA NILÓTICA (Oreochromis niloticus Y TRUCHA ARCOÍRIS (Oncorhynchus mykiss EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    A. Osorio

    2013-01-01

    Full Text Available La industria del fileteado de tilapia y trucha genera cantidades significativas de coproductos de los cuales no existe suficiente información disponible sobre su composición y calidad. Esta investigación determinó algunos componentes nutricionales y microbiológicos de coproductos obtenidos en plantas exportadoras de filetes de tilapia nilótica y trucha arcoíris en Colombia. El esqueleto mostró el mayor aporte de cenizas (tilapia: 14,12 ± 0,16%; trucha: 6,18 ± 0,06%, calcio (tilapia: 5,70 ± 0,04%; trucha: 1,72 ± 0,08% y fósforo (tilapia: 1,89 ± 0,06%; trucha: 0,84 ± 0,03%, mientras que los recortes presentaron la mayor concentración de extracto etéreo (tilapia: 30,10 ± 0,58%; trucha: 17,50 ± 0,51% y la carne mecánicamente separada, los mayores contenidos de humedad (tilapia: 70,38 ± 0,18%; trucha: 72,93 ± 0,3% y proteína (tilapia: 14,32 ± 0,03%; trucha: 18,88 ± 0,05%. El mayor aporte de ácidos grasos polinsaturados (AGPI, como porcentaje del total de ácidos grasos identificados, se encontró en esqueleto de tilapia (17,27% y en recortes de trucha (38,68%, con relaciones n6/n3 de 2,67 y 0,71, respectivamente. En general, los coproductos estudiados cumplieron con los estándares microbiológicos exigidos por la normatividad colombiana (Resolución 122 de 2012 del Ministerio de Salud y Protección Social que establece los requisitos fisicoquímicos y microbiológicos que deben cumplir los productos de la pesca, en particular pescados, moluscos y crustáceos para consumo humano. Los resultados muestran que los coproductos estudiados contienen un importante aporte de proteína, cenizas, ácidos grasos poli-insaturados y adecuada calidad microbiológica, con potencial para alimentación humana o animal.

  1. Mossambicus tilapia (Oreochromis mossambicus) collected from water bodies impacted by urban waste carries extended-spectrum beta-lactamases and integron-bearing gut bacteria

    Indian Academy of Sciences (India)

    NACHIKET P MARATHE; SWAPNIL S GAIKWAD; ANKITA A VAISHAMPAYAN; MANDAR H RASANE; YOGESH S SHOUCHE; WASUDEV N GADE

    2016-09-01

    Oreochromis mossambicus (Peters 1852) (Tilapia) is one of the most consumed fish globally. Tilapia thrives well inenvironments polluted by urban waste, which invariably contain antibiotic-resistant bacteria and antibiotic resistance genes(ARGs). Thus, Tilapia surviving in such polluted environments may serve as a potential source for dissemination of ARGs.To investigate this, we isolated bacterial strains from gut of Tilapia found in polluted rivers and lakes near Pune, India, andstudied the prevalence of resistance genes bymolecularmethods. A total of 91 bacterial strains were obtained, which includefish pathogens and human pathogens such as Aeromonas hydrophila, Klebsiella pneumoniae, E. coli, Serratia marcescens,Enterobacter spp. and Shigella spp. Overall the prevalence of class 1 integrons, class 2 integrons, extended-spectrum betalactamases(ESBLs) bla_{CTX-M}, bla_{SHV} and aac(6')-Ib-cr gene was 38%, 24%, 38%, 31% and 31% respectively. Forty-twopercent of the Enterobacteriaceae strains carried bla_{CTX-M} gene, which is a common ESBL gene in clinics. The studydemonstrates that tilapia found in the polluted waters can serve as reservoirs and an alternative route for human exposure toclinically important ARG-carrying bacteria. The consumption and handling of these fish may pose a potential health risk.

  2. The ecological impact of tidal pond channelization on the distribution of tilapia species (Perciformes: Cichlidae on Buguma creek, Rivers State, Nigeria

    Directory of Open Access Journals (Sweden)

    Blessing Julius Oribhabor

    2011-12-01

    Full Text Available A study of the tilapia species (Perciformes: Cichlidae of a tidal creek in the Southeast of theNiger Delta, Nigeria was conducted to assess the ecological impact of tidal pond channelization. Therewas no significant difference (p>0.05 in the values of the physical and chemical parameters, except fortransparency, water level and salinity (pSarotherodon melanotheron and Tilapia guineensis were recorded during the studies, with S. melanotheron being the dominant species.Orthogonal comparison using Duncan’s Multiple Range test showed that S. melanotheron was the causeof the observed difference in the tilapia population. Although there was positive correlation betweensalinity and the tilapia species at all stations, there was no significant correlation between tilapia speciesand the environmental variables. The findings of this study showed that channelized water bodies havelower qualify fish assemblage when compared to natural water bodies due to a loss of heterogeneoushabitat. Although channelization is inevitable in the development of brackishwater fish ponds,amelioration measures of its adverse effects deserve high priority. However since no significantdifference (p>0.05 existed in the distribution of T. guineensis, this study indicated that not all speciesare impacted by tidal pond channelization.

  3. Determination of presence and quantification of cadmium, lead and copper in Nile tilapia (Oreochromis niloticus fillets obtained from three cold storage plants in the state of Parana, Brazil

    Directory of Open Access Journals (Sweden)

    Alexandre Nobuhiro Tajiri

    2011-06-01

    Full Text Available Pisciculture is an economic activity that is steadily growing in the state of Parana, Brazil, and Nile tilapia (Oreochromis niloticus is one of the widely cultivated species in this state. Tilapia is not only a very nutritious food, but also an important indicator of environmental contamination. This study aimed to verify contamination by cadmium, copper and lead in tilapia fillets, and to compare the found values to international legislations. Were collected 135 samples of tilapia fillets, between July 2006 and May 2007, in three fish stores located in regions west and north of Paraná State. Samples of tilapia fillet were analyzed in relation to the presence of cadmiun, lead and copper, using atomic absorption spectrophotometry. Lead has not been detected in the analyses. Cadmium has been detected in three samples, on concentrations of 0.012 µg.g-1, 0.011 µg.g-1 and 0.014 µg.g-1. Copper has been detected in all fillets, and the average concentration of each cold storage plant was of 0.122 µg.g-1, 0.106 µg.g-1 and 0.153 µg.g-1. The concentrations found in this study are within the limits allowed by both the European and the Australian legislations.

  4. Species-specific content of As, Pb, and other elements in pangas (Pangasianodon hypophthalmus) and tilapia (Oreochromis niloticus) from aquaculture ponds in southern Bangladesh

    DEFF Research Database (Denmark)

    Marcussen, Helle; Alam, Md. Ariful; Rahman, Md. Mizanur

    2014-01-01

    by different feeding habits of the two fish. The other elements had similar concentrations in both species. Content of As in tilapia and pangas was 0.37 and 0.11 μg g−1, respectively, while Pb made up 0.056 and 0.051 μg g−1, respectively. Water treatment during the farming period (sand filtration and probiotic......Content of arsenic and lead and 10 other potentially toxic elements (Ba, Ce, Cr, Cu, Fe,Mg,Mn, Se, Sr and Zn) was determined in tilapia and pangas from aquaculture ponds in southern Bangladesh. Tilapia had 1.6- to 4.3-fold higher content of Mn, As, Sr, and Ba than pangas, possibly caused...... bacteria) and final depuration in groundwater for up to 48 h had no effect on content of the elements. For As, consumption of 100 g fresh fish per day contained 1.3% (pangas) and 5% (tilapia) of the maximum tolerable daily intake according to FAO recommendations. Relative to whole tilapia froma lake near...

  5. Dynamical coupling of PBPK/PD and AUC-based toxicity models for arsenic in tilapia Oreochromis mossambicus from blackfoot disease area in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Liao, C.-M. [Ecotoxicological Modeling Center, Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan 10617 (China)]. E-mail: cmliao@ntu.edu.tw; Liang, H.-M. [Ecotoxicological Modeling Center, Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan 10617 (China); Chen, B.-C. [Department of Post-Modern Agriculture, Mingdao University, Changhua, Taiwan 52345 (China); Singh Sher [Center of Genomics Medicine, School of Medicine, National Taiwan University, Taipei, Taiwan 10617 (China); Tsai, J.-W. [Ecotoxicological Modeling Center, Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan 10617 (China); Chou, Y.-H. [Ecotoxicological Modeling Center, Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan 10617 (China); Lin, W.-T. [Environment Change Research Center, Academia Sinica, Nankang, Taipei, Taiwan 11517 (China)

    2005-05-01

    A physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) models were developed for arsenic (As) in tilapia Oreochromis mossambicus from blackfoot disease area in Taiwan. The PBPK/PD model structure consisted of muscle, gill, gut wall, alimentary canal, and liver, which were interconnected by blood circulation. We integrate the target organ concentrations and dynamic response describing uptake, metabolism, and disposition of As and the associated area-under-curve (AUC)-based toxicological dynamics following an acute exposure. The model validations were compared against the field observations from real tilapia farms and previously published uptake/depuration experimental data, indicating that predicted and measured As concentrations in major organs of tilapia were in good agreement. The model was utilized to reasonably simulate and construct a dose-dependent dynamic response between mortality effect and equilibrium target organ concentrations. Model simulations suggest that tilapia gills may serve as a surrogate sensitive biomarker of short-term exposure to As. This integrated As PBPK/PD/AUC model quantitatively estimates target organ concentration and dynamic response in tilapia and is a strong framework for future waterborne metal model development and for refining a biologically-based risk assessment for exposure of aquatic species to waterborne metals under a variety of scenarios. - Integrated toxicity models can identify dynamic responses of fish to arsenic.

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

    Science.gov (United States)

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

    2016-02-23

    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.

  7. Streptococcus agalactiae: HASTA AHORA EL ÚNICO Streptococcus PATÓGENO DE TILAPIAS CULTIVADAS EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    AP Jiménez

    2007-01-01

    Full Text Available Las estreptococosis son un conjunto de enfermedades ocasionadas por un grupo de cocos Gram positivos con similares signologías que involucran distintos órganos en los individuos afectados. La identiÀcación precisa de cada uno de estos microorganismos no se logra de manera deÀnitiva por los métodos tradicionales microbiológicos, por lo que se debe acudir a otro tipo de metodologías como las técnicas de biología molecular. En 1999 se identiÀcó por primera vez en Colombia la estreptococosis en híbridos de tilapias de cultivo. La pos-terior secuenciación del ADN de distintos aislamientos obtenidos de varias regiones del país demostró un 98,8% de aÀnidad con el Streptococcus agalactiae. El presente estudio pretende deÀnir si hasta la fecha existe solo esta especie de Streptococcus en el país causan-do infección o enfermedad en tilapias de cultivo o, por el contrario, son varias las especies que intervienen en los cuadros infecciosos. Se evaluaron aislamientos de tejidos, de agua y fango de los sitios de cultivo, así como de lugares de expendio de tilapia roja (Oreochromissp., utilizando técnicas microbiológicas, inmunoperoxidasa indirecta (IPI y PCR, espe-cíÀcas para el aislamiento e identiÀcación del S. agalactiae. Los resultados del presente estudio demostraron que hasta la fecha en el país únicamente se ha identiÀcado la especie S. agalactiae causando infección o enfermedad en tilapias. No tenemos evidencia de que otros Streptococcus reportados internacionalmente como S. iniae y otros Gram positivos causen estreptococosis en Colombia.La tilapia parece ser el principal reservorio del S. agalactiae en el país, y el riesgo zoonótico, aunque existe, es mínimo si se toman las medidas apropia-das de bioseguridad.

  8. The acute salinity changes activate the dual pathways of endocrine responses in the brain and pituitary of tilapia.

    Science.gov (United States)

    Aruna, Adimoolam; Nagarajan, Ganesan; Chang, Ching-Fong

    2015-01-15

    To analyze and compare the stress and osmoregulatory hormones and receptors in pituitary during acute salinity changes, the expression patterns of corticotropin releasing hormone (crh) in hypothalamus, prolactin (prl) releasing peptide (pRrp) in telencephalon and diencephalon, glucocorticoid receptors 2 (gr2), and mineralocorticoid receptor (mr), crh-r, pro-opiomelanocorticotropin (pomc), pRrp, prl, dopamine 2 receptor (d2-r), growth hormone (gh), gh-receptor (gh-r) and insulin-like growth hormone (igf-1) transcripts in pituitary were characterized in euryhaline tilapia. The results indicate that the crh transcripts increased in the hypothalamus and rostral pars distalis of the pituitary after the transfer of fish to SW. Similarly, the pRrp transcripts were more abundant in SW acclimated tilapia forebrain and hypothalamus. The crh-r, gr2 and mr transcripts were more expressed in rostral pars distalis and pars intermedia of pituitary at SW than FW tilapia. The data indicate that the SW acclimation stimulates these transcripts in the specific regions of the brain and pituitary which may be related to the activation of the hypothalamic-pituitary-interrenal (HPI)-axis. The results of dual in situ hybridization reveal that the transcripts of crh-r, gr2 and mr with pomc are highly co-localized in corticotrophs of pituitary. Furthermore, we demonstrate high expression of pRrp in the brain and low expression of pRrp and prl transcripts in the pituitary of SW fish. No crh-r and corticosteroid receptors were co-localized with prl transcripts in the pituitary. The gh-r and igf-1 mRNA levels were significantly increased in SW acclimated tilapia pituitary whereas there was no difference in the gh mRNA levels. The data suggest that the locally produced pRrp and d2-r may control and regulate the expression of prl mRNA in pituitary. Therefore, the dual roles of pRrp are involved in the stress (via brain-pituitary) and osmoregulatory (via pituitary) pathways in tilapia exposed to

  9. Study of the Effect of Gypsum and Rice Straw Extract on the Control of Earthy-Musty Odor in Tilapia Culture Pond

    Directory of Open Access Journals (Sweden)

    Supannee SUWANPAKDEE

    2016-07-01

    Full Text Available The effect of gypsum and rice straw extract to reduce the levels of earthy-musty odor in tilapia earthen ponds was determined. Three treatments with 3 replicates in a completely randomized design were performed as follows: T1 - control; T2 - gypsum at 200 ppm, and T3 - rice straw tannin extract at 1 ppm. The results show that rice straw tannin extract treatment in tilapia ponds was the most effective method in reducing off-flavor in pond water. The use of 200 ppm gypsum in reducing off-flavor in ponds was also more effective than the control. Both rice straw extract and gypsum-treated ponds had increased fish biomass and %FCE. These methods have potential as alternative methods for the reduction of off-flavor, as well as the control of phytoplankton, turbidity, and TSS in tilapia ponds.

  10. Identities among actin-encoding cDNAs of the Nile tilapia (Oreochromis niloticus and other eukaryote species revealed by nucleotide and amino acid sequence analyses

    Directory of Open Access Journals (Sweden)

    Andréia B. Poletto

    2008-01-01

    Full Text Available Actin-encoding cDNAs of Nile tilapia (Oreochromis niloticus were isolated by RT-PCR using total RNA samples of different tissues and further characterized by nucleotide sequencing and in silico amino acid (aa sequence analysis. Comparisons among the actin gene sequences of O. niloticus and those of other species evidenced that the isolated genes present a high similarity to other fish and other vertebrate actin genes. The highest nucleotide resemblance was observed between O. niloticus and O. mossambicus a-actin and b-actin genes. Analysis of the predicted aa sequences revealed two distinct types of cytoplasmic actins, one cardiac muscle actin type and one skeletal muscle actin type that were expressed in different tissues of Nile tilapia. The evolutionary relationships between the Nile tilapia actin genes and diverse other organisms is discussed.

  11. An outbreak of granulomatous inflammation associated with Francisella noatunensis subsp. orientalis in farmed tilapia ( Oreochromis niloticus × O. aureus) in China

    Science.gov (United States)

    Lin, Qiang; Li, Ningqiu; Fu, Xiaozhe; Hu, Qiandong; Chang, Ouqin; Liu, Lihui; Zhang, Defeng; Wang, Guangjun; San, Guibao; Wu, Shuqin

    2016-05-01

    In 2013, a novel disease was detected in tilapia ( Oreochromis niloticus × O. aureus) in Guangzhou, South China. To identify the causative pathogen, we conducted histological examination, bacteria isolation, and purification, and sequenced the 16S rRNA gene of isolates. Infected fish had a large number of white granulomas in the kidney, liver, heart, and spleen. The head kidney and spleen were markedly swollen. A bacterium strain designated as gz201301 was recovered from the spleen of infected tilapia. The 16S rRNA sequence of gz201301 revealed that it was highly similar to F. noatunensis subsp. orientalis. This is the first report of a Francisella-like infection in farmed tilapia in China.

  12. Agonistic and reproductive behaviors in males of red hybrid tilapia, Oreochromis niloticus (Linnaeus, 1758 x O. mossambicus (Peters, 1852 (Osteichthyes: Cichlidae

    Directory of Open Access Journals (Sweden)

    APT Medeiros

    Full Text Available The red hybrid tilapia, Oreochromis niloticus (Linnaeus, 1758 x O. mossambicus (Peters, 1852 is a fertile hybrid used in the semi-intensive level of fish culture in the Northeast of Brazil. It is a territorial cichlid and is highly aggressive towards conspecifics during the breeding season. The purpose of this study was to investigate and describe the aggressive behaviour displayed by the males of this hybrid in non-reproductive and reproductive contexts. Behavioural observations revealed that aggression displayed by the reproductive males of red hybrid tilapia included threatening, undulation, parallel, lateral and frontal attacks, chasing, escape and submission. Possession of a territory influenced male aggressiveness, which was more intense in their own territory than that observed in a neutral situation. The males built nests, irrespective of female presence. All the behavioural patterns were in accordance with those previously described for one parental species, the Nile tilapia, O. niloticus.

  13. Tilapia guineensis

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-22

    Mar 22, 2010 ... fication of potential toxicological effects up the food chain. (Britton ..... be used as an emergency energy supply and any change observed in the ... Toxic Metabolites in Waste Effluent Discharges: An Integrated Study. (Pristine).

  14. Levels and patterns of persistent organic pollutants (POPs) in tilapia (Oreochromis sp.) from four different lakes in Tanzania: geographical differences and implications for human health.

    Science.gov (United States)

    Polder, A; Müller, M B; Lyche, J L; Mdegela, R H; Nonga, H E; Mabiki, F P; Mbise, T J; Skaare, J U; Sandvik, M; Skjerve, E; Lie, E

    2014-08-01

    In Tanzania fish is one of the most important protein sources for the rapidly increasing population. Wild fish is threatened by overfishing and pollution from agriculture, industries, mining, household effluents and vector control. To monitor possible implications for public health, the geographical differences of the occurrence and levels of persistent organic pollutants (POPs) in tilapia fish (Oreochromis sp.) from four different Tanzanian lakes were investigated in 2011. Concentrations of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyls (PBDEs) and hexabromocyclododecane (HBCDD) were determined in pooled samples of tilapia muscle from Lake (L) Victoria, L. Tanganyika, L. Nyasa (also called L. Malawi) and L. Babati in Tanzania in 2011. Levels of Σ-DDTs (274 ng/g lipid weight (lw)) and sum of 7 indicator PCBs (Σ-7PCBs) (17 ng/g lw) were significantly higher in tilapia from L. Tanganyika compared to the other lakes. The highest levels of Σ-endosulfan (94 ng/g lw) were detected in tilapia from L. Victoria. Toxaphenes were detected in low levels in fish from L. Tanganyika and L. Babati. Results revealed a geographic difference in the use of DDT and endosulfan between L. Victoria and L. Tanganyika. Low ratios of DDE/DDT in tilapia from L. Tanganyika indicated an on-going use of DDT in the area. Median levels of ΣBDEs, including BDE-209, were highest in L. Victoria (19.4 ng/g lw) and BDE-209 was present in 68% of the samples from this lake. The presence of BDE-209 indicates increasing influence of imported products from heavy industrialized countries. The measured POP levels in the studied tilapia were all below MRLs of EU or were lower than recommended levels, and thus the fish is considered as safe for human consumption. They may, however, pose a risk to the fish species and threaten biodiversity.

  15. UPLC-MS/MS determination of florfenicol and florfenicol amine antimicrobial residues in tilapia muscle.

    Science.gov (United States)

    Orlando, Eduardo Adilson; Costa Roque, Aline Gabriela; Losekann, Marcos Eliseu; Colnaghi Simionato, Ana Valéria

    2016-11-01

    Despite the benefits to fish farmers, the use of antimicrobials in aquaculture has concerned consumers and competent authorities. The indiscriminate use of such substances promotes the emergence of resistant microorganisms, decreases the effectiveness of treatments, and causes possible toxic effects in humans. In Brazil, florfenicol is the only antimicrobial registered for use in aquaculture and is often used in tilapia in cage creation. Thus, this study aimed to develop a method for determination of florfenicol residues and its metabolite florfenicol amine in tilapia fillet by UPLC-MS/MS. Analytes were extracted with ethyl acetate, followed by liquid-liquid partition clean-up with hexane and SPE. The sorbents C18, phenyl and HLB-Oasis were evaluated by SPE. Phenyl sorbent showed the best results, and the extraction conditions were optimized in the sample matrix with fractional factorial design 2(4-1). The analytes were separated on a C18 chromatographic column (50×2.1mm×1.7μm) using water (A) and acetonitrile (B) as mobile phase at a flow rate of 0.3mLmin(-1) with a linear gradient (in% B): 0-2.0min: 20%; 2.0-2.5min: increase to 90%; 2.5-3.5min: 90%; 3.0-3.5min: decrease to 20%; 4.0-5.0min: 20%. The analytes were monitored in a MS/MS triple quadrupole system by MRM mode with transitions at m/z 356.1>336.1 (florfenicol) and m/z 248.1>130.1 (florfenicol amine). The optimized method was validated obtaining LOQ values of 3 and 25ngg(-1) for florfenicol and florfenicol amine, respectively, precision between 20 and 36%, absolute extraction efficiency between 38 and 80%, and adequate linearity. The method was applied to samples intended for human consumption, and within the 15 evaluated samples, only one showed florfenicol residue at 30ngg(-1), which is below the maximum residue limit established in Brazil.

  16. Functionality and antioxidant properties of tilapia (Oreochromis niloticus) as influenced by the degree of hydrolysis.

    Science.gov (United States)

    Foh, Mohamed Beva Kelfala; Amadou, Issoufou; Foh, Betty Mabel; Kamara, Mohamed Tabita; Xia, Wenshui

    2010-04-26

    Freeze dried protein powders (Fresh minced meat, FMM and Hot water dip, HWD) from tilapia (Oreochromis niloticus) were hydrolyzed by Alcalase 2.4 L (Alc), Flavourzyme (Flav) and Neutrase (Neut), and investigated for antioxidant activity and their functional properties. FMM and HWD hydrolysed by Alc, exhibiting superior antioxidant activity, had estimated degrees of hydrolysis (DH) of 23.40% and 25.43%, respectively. The maximum values of the 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), 3-(2-pyridyl) 5,6-bis(4-phenyl-sulphonic acid)-1,2,4-triazine (ferrozine), radical scavenging activities and metal chelating properties were 86.67%, 91.27% and 82.57%, and 84.67%, 92.60% and 78.00% for FMM and HWD, respectively, with a significant difference (P acids were above the amounts recommended by the Food and Agricultural Organization/World Health Organization (FAO/WHO/UNU) for humans. Lower molecular weight sizes 8,000 Da. At pH 2, FMM and HWD hydrolysates have varying solubilities above 85% (Alc FMM; 91.33%, Flav FMM; 79.5%, Neut FMM; 83.8% and Alc HWD; 90.45%, Flav HWD; 83.5%, and Neut HWD; 85.8%). They have 'U' shaped solubility curves, water holding capacity was in the range of 2.77 and 1.77 mL/g, while oil holding capacity ranged between 3.13 and 2.23 mL/g. FMM and HWD have the highest bulk density of 0.53 and 0.53 for Neutrase and Alcalase 2.4 L, respectively. Foam capacity and stability ranged from 125.5 to 61.4, 138.5 to 45.2, 130.0 to 62.5, and 124.5 to 55.0, 137.5 to 53.3, 129.6 to 62.7 for FMM and HWD hydrolyzed with Alcalase 2.4 L, Flavourzyme and Neutrase, respectively. Tilapia fish protein hydrolysates are thus potential functional food ingredients.

  17. Functionality and Antioxidant Properties of Tilapia (Oreochromis niloticus as Influenced by the Degree of Hydrolysis

    Directory of Open Access Journals (Sweden)

    Mohamed Tabita Kamara

    2010-04-01

    Full Text Available Freeze dried protein powders (Fresh minced meat, FMM and Hot water dip, HWD from tilapia (Oreochromis niloticus were hydrolyzed by Alcalase 2.4 L (Alc, Flavourzyme (Flav and Neutrase (Neut, and investigated for antioxidant activity and their functional properties. FMM and HWD hydrolysed by Alc, exhibiting superior antioxidant activity, had estimated degrees of hydrolysis (DH of 23.40% and 25.43%, respectively. The maximum values of the 1,1-diphenyl-2-picrylhydrazyl (DPPH, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS, 3-(2-pyridyl 5,6-bis(4-phenyl-sulphonic acid-1,2,4-triazine (ferrozine, radical scavenging activities and metal chelating properties were 86.67%, 91.27% and 82.57%, and 84.67%, 92.60% and 78.00% for FMM and HWD, respectively, with a significant difference (P < 0.05 between the samples. Essential amino acids were above the amounts recommended by the Food and Agricultural Organization/World Health Organization (FAO/WHO/UNU for humans. Lower molecular weight sizes 8,000 Da. At pH 2, FMM and HWD hydrolysates have varying solubilities above 85% (Alc FMM; 91.33%, Flav FMM; 79.5%, Neut FMM; 83.8% and Alc HWD; 90.45%, Flav HWD; 83.5%, and Neut HWD; 85.8%. They have ‘U’ shaped solubility curves, water holding capacity was in the range of 2.77 and 1.77 mL/g, while oil holding capacity ranged between 3.13 and 2.23 mL/g. FMM and HWD have the highest bulk density of 0.53 and 0.53 for Neutrase and Alcalase 2.4 L, respectively. Foam capacity and stability ranged from 125.5 to 61.4, 138.5 to 45.2, 130.0 to 62.5, and 124.5 to 55.0, 137.5 to 53.3, 129.6 to 62.7 for FMM and HWD hydrolyzed with Alcalase 2.4 L, Flavourzyme and Neutrase, respectively. Tilapia fish protein hydrolysates are thus potential functional food ingredients.

  18. Comparación de técnicas de Diagnóstico de Francisella sp. en muestras de tilapia (Oreochomis sp.)

    OpenAIRE

    Mancera Cuadros, Gerardo

    2015-01-01

    La francisellosis en tilapias (Oreochromis spp) es una enfermedad emergente causada por el cocobacilo, Gram negativo, intracelular facultativo Francisella noatunensis subsp. orientalis (FNO), que afecta a varios países donde el cultivo de peces de género tilapia es importante. Esta enfermedad de manifestación crónica se caracteriza por la ausencia de signos clínicos y baja mortalidad, lo que asociado al difícil aislamiento de la bacteria en medios de cultivo bacteriológicos convencionales, di...

  19. Evaluación nutricional de ensilajes de residuos pesqueros para la alimentación de tilapias rojas (Oreochromis mossambicus x O. niloticus)

    OpenAIRE

    Llanes, J. E.; Toledo, J.; Savón, L.; Gutiérrez, O.

    2011-01-01

    Se determinó la composición química de ensilajes químico y biológico de residuos del fileteado de tilapias, así como la digestibilidad in vitro en tilapias rojas (Oreochromis mossambicus x O. niloticus) mediante modelos de clasificación simple con tres repeticiones. Un total de 270 peces (45,43 ± 8,35 g de peso promedio) se distribuyeron en tres tratamientos (una dieta de referencia y dos experimentales con cada ensilaje de pescado); se usó óxido crómico como indicador y las heces...

  20. Determinación y prevalencia de Mycobacterium spp., en tilapia nilótica (Oreochromis niloticus) cultivada en Campeche, México

    OpenAIRE

    Maurilio Lara-Flores; Sara Balan-Zetina; Ana Zapata; Karina Sonda-Santos

    2013-01-01

    RESUMENObjetivo. Determinar la presencia y prevalencia de Mycobacterium spp., en granjas de tilapia nilótica (Oreochromis niloticus) en el Municipio de Champotón, Campeche, México. Materiales y métodos. La colecta de organismos se realizó en tres granjas de cultivo de tilapia nilótica del municipio de Champotón, Campeche, México. Los organismos se examinaron externa e internamente y se tomó una muestra de riñón la cual fue sembrada en forma de estría en medios de cultivo: Löwesntein-Jensen, T...

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

    Energy Technology Data Exchange (ETDEWEB)

    Bainy, A.C.D. [UFSC, Florianopolis (Brazil); Carvalho, P.S.M. [CETESB, Sao Paulo (Brazil); Saito, E.; Leitao, M.A.S.; Junqueira, V.B.C. [IQUSP, Sao Paulo (Brazil)

    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.

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

    Science.gov (United States)

    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.

  3. Physiological and hematological responses of Nile tilapia (Oreochromis Niloticus to different anesthetics during simulated transport conditions

    Directory of Open Access Journals (Sweden)

    Rodrigo Diana Navarro

    2016-06-01

    Full Text Available Minimization of stress during the transportation of live fish is essential in maintaining the welfare and performance of the animals. In order to test the hypothesis that stress during transport of fingerlings of Nile tilapia (Oreochromis niloticus can be reduced with the aid of the anesthetics menthol, eugenol or benzocaine, we have assessed the effects of these agents at various concentrations on the physiological parameters and survival rates of fish subjected to conditions simulating those normally used in transportation. Fingerlings (N = 1200 were fasted for 24 hours and distributed in 20 L polyethylene bags (N = 50 per bag containing 5 L of water and an anesthetic at the appropriate concentration. Fingerlings treated with menthol at 75 mg L-1, or eugenol or benzocaine at 20 mg L-1, maintained levels of plasma cortisol and glucose that were lower than those of the stressed but untreated controls and within the physiological limits of the baseline values for this species. Under these conditions, the survival rate was 100%, suggesting that stress was substantially reduced despite dense consignment. Treatments involving higher doses of the studied agents induced significant anesthetic toxicity.

  4. Predictive Blood Chemistry Parameters for Pansteatitis-Affected Mozambique Tilapia (Oreochromis mossambicus)

    Science.gov (United States)

    Chapman, Robert W.; Somerville, Stephen E.; Guillette, Matthew P.; Botha, Hannes; Hoffman, Andre; Luus-Powell, Wilmien J.; Smit, Willem J.; Lebepe, Jeffrey; Myburgh, Jan; Govender, Danny; Tucker, Jonathan; Boggs, Ashley S. P.

    2016-01-01

    One of the largest river systems in South Africa, the Olifants River, has experienced significant changes in water quality due to anthropogenic activities. Since 2005, there have been various “outbreaks” of the inflammatory disease pansteatitis in several vertebrate species. Large-scale pansteatitis-related mortality events have decimated the crocodile population at Lake Loskop and decreased the population at Kruger National Park. Most pansteatitis-related diagnoses within the region are conducted post-mortem by either gross pathology or histology. The application of a non-lethal approach to assess the prevalence and pervasiveness of pansteatitis in the Olifants River region would be of great importance for the development of a management plan for this disease. In this study, several plasma-based biomarkers accurately classified pansteatitis in Mozambique tilapia (Oreochromis mossambicus) collected from Lake Loskop using a commercially available benchtop blood chemistry analyzer combined with data interpretation via artificial neural network analysis. According to the model, four blood chemistry parameters (calcium, sodium, total protein and albumin), in combination with total length, diagnose pansteatitis to a predictive accuracy of 92 percent. In addition, several morphometric traits (total length, age, weight) were also associated with pansteatitis. On-going research will focus on further evaluating the use of blood chemistry to classify pansteatitis across different species, trophic levels, and within different sites along the Olifants River. PMID:27115488

  5. Organochlorine pesticides in lacustrine sediments and tilapias of Metztitlan, Hidalgo, Mexico.

    Science.gov (United States)

    Fernández-Bringas, Laura M; Ponce-Vélez, Guadalupe; Calva, Laura G; Salgado-Ugarte, Isaías Hazamamberth; Botello, Alfonso V; Díaz González, Gilberto

    2008-09-01

    The organochlorine pesticides (OP) are very stable molecules, due to this stability; they are very resistant in the environment and highly related to fat tissues with a wide diffusion property and an average time life higher then 10 years. We studied sediments (November 2001, April and June 2002) and organisms collected in April and July (2002) from the lacustric zone of Metzitlán, Hidalgo, Mexico. The analysis was performed according to UNEP/IAEA (1982) (sediments) and UNEP/FAO/IOC/IAEA (1986) (organisms) methods. Three chemical families of organochlorine pesticides were identified and analyzed to determine posible toxicological risk. The principal organochlorine compounds found in sediments were gamma-HCH, delta-HCH, p,p'-DDT and the endosulfan sulfate; these xenobiotics come from agriculture lands near the river and lake, used intensively, and most probably carried by the rain and rain flows into the main water body. In the tilapias tissue, p,p'-DDD y delta-HCH were detected. The average concentrations of organochlorine pesticides in sediments were within the internacional limits for freshwater benthonic fauna, although lindane (gamma-HCH) was near the limit. The fish were above the criteria established in the local legislation (NOM-027-SSA1-1993 y NOM-028-SSA1-1993).

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

    Directory of Open Access Journals (Sweden)

    Aline Cristina Zago

    Full Text Available 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. niloticusin 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 Epistylissp. 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.

  7. Inter-cohort growth for three tropical resources: tilapia, octopus and lobster.

    Science.gov (United States)

    Velázquez-Abunader, Iván; Gómez-Muñoz, Victor Manuel; Salas, Silvia; Ruiz-Velazco, Javier M J

    2015-09-01

    Growth parameters are an important component for the stock assessment of exploited aquatic species. However, it is often difficult to apply direct methods to estimate growth and to analyse the differences between males and females, particularly in tropical areas. The objective of this study was to analyse the inter-cohort growth of three tropical resources and discuss the possible fisheries management implications. A simple method was used to compare individual growth curves obtained from length frequency distribution analysis, illustrated by case studies of three tropical species from different aquatic environments: tilapia (Oreochromis aureus), red octopus (Octopus maya) and the Caribbean spiny lobster (Panulirus argus). The analysis undertaken compared the size distribution of males and females of a given cohort through modal progression analysis. The technique used proved to be useful for highlighting the differences in growth between females and males of a specific cohort. The potential effect of extrinsic and intrinsic factors on the organism's development as reflected in the size distribution of the cohorts is discussed.

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

    Science.gov (United States)

    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.

  9. Development and method validation for the determination of nitroimidazole residues in salmon, tilapia and shrimp muscle.

    Science.gov (United States)

    Watson, Lynn; Potter, Ross; MacNeil, James D; Murphy, Cory

    2014-01-01

    The use of nitroimidazoles in aquacultured fish has been banned in many countries due to the suspected mutagenic and carcinogenic effects of these compounds. In response to the need to conduct residue testing of these compounds in fish, a simple, rapid, and sensitive method was developed and validated that is suitable for regulatory monitoring of nitroimidazole residues and their hydroxy metabolites in fish muscle tissue. Following solvent extraction of homogenized tissue and clean-up using a C18 SPE cartridge, analyses were conducted by ultra-performance UPLC-MS/MS. A precursor ion and two product ions were monitored for each of the parent compounds and metabolites included in the method. The validated method has an analytical range from 1 to 50 ng/g in the representative species (tilapia, salmon, and shrimp), with an LOD and LOQ ranging from 0.07 to 1.0 nglg and 0.21 to 3.0 nglg, respectively, depending on the analyte. Recoveries ranged from 81 to 124% and repeatability was between 4 and 17%. HorRat values were within typical limits of acceptability for a single laboratory. Working standards were stable for 12 months, extracts were stable for 5 days, and tissues for 2 months under appropriate storage conditions. This method was determined to be suitable for routine use for screening, quantification, and confirmation of nitroimidazole residues in a residue monitoring program for fish with regulatory oversight.

  10. Predictive Blood Chemistry Parameters for Pansteatitis-Affected Mozambique Tilapia (Oreochromis mossambicus.

    Directory of Open Access Journals (Sweden)

    John A Bowden

    Full Text Available One of the largest river systems in South Africa, the Olifants River, has experienced significant changes in water quality due to anthropogenic activities. Since 2005, there have been various "outbreaks" of the inflammatory disease pansteatitis in several vertebrate species. Large-scale pansteatitis-related mortality events have decimated the crocodile population at Lake Loskop and decreased the population at Kruger National Park. Most pansteatitis-related diagnoses within the region are conducted post-mortem by either gross pathology or histology. The application of a non-lethal approach to assess the prevalence and pervasiveness of pansteatitis in the Olifants River region would be of great importance for the development of a management plan for this disease. In this study, several plasma-based biomarkers accurately classified pansteatitis in Mozambique tilapia (Oreochromis mossambicus collected from Lake Loskop using a commercially available benchtop blood chemistry analyzer combined with data interpretation via artificial neural network analysis. According to the model, four blood chemistry parameters (calcium, sodium, total protein and albumin, in combination with total length, diagnose pansteatitis to a predictive accuracy of 92 percent. In addition, several morphometric traits (total length, age, weight were also associated with pansteatitis. On-going research will focus on further evaluating the use of blood chemistry to classify pansteatitis across different species, trophic levels, and within different sites along the Olifants River.

  11. Effect of brining on the drying rate of tilapia in a solar tunnel dryer

    Energy Technology Data Exchange (ETDEWEB)

    Kituu, G.M.; Shitanda, D.; Kanali, C.L.; Mailutha, J.T. [Jomo Kenyatta Univ. of Agriculture and Technology, Nairobi (Kenya). BEED

    2008-07-01

    In addition to being a source of protein, fish is an important source of local and foreign currency earnings in Kenya. A substantial amount of fish production is exported. Approximately 30 per cent is exported to the European Union, the United States, and countries in the Middle East, but nearly half of the total annual fish harvest in Kenya goes to waste due to poor processing and preservation. Measures must be taken to ensure the fish industry is protected and waste is minimized, since the livelihood of over 500,000 people depends on fish as a source of proteins and employment. Therefore, it is necessary to implement appropriate and affordable processing and preservation techniques for fish at the artisanal landing sites in order to reduce the wastage and spoilage of fish during oversupply, and to enhance long storage. This paper presented studies that were conducted to determine the effect of brining on the drying rate of tilapia in a solar tunnel dryer. The paper discussed the materials and methods, including a description of the solar tunnel dryer system; the brining process of fish; the fish drying process; and data analysis. It was concluded that limiting the amount of salt used in brining, and subsequently dehydrating fish with a solar tunnel dryer achieves a more stable and suitable dried fish product than osmotic dehydration or solar drying process separately. 19 refs., 5 figs., 2 appendices.

  12. Predictive Blood Chemistry Parameters for Pansteatitis-Affected Mozambique Tilapia (Oreochromis mossambicus).

    Science.gov (United States)

    Bowden, John A; Cantu, Theresa M; Chapman, Robert W; Somerville, Stephen E; Guillette, Matthew P; Botha, Hannes; Hoffman, Andre; Luus-Powell, Wilmien J; Smit, Willem J; Lebepe, Jeffrey; Myburgh, Jan; Govender, Danny; Tucker, Jonathan; Boggs, Ashley S P; Guillette, Louis J

    2016-01-01

    One of the largest river systems in South Africa, the Olifants River, has experienced significant changes in water quality due to anthropogenic activities. Since 2005, there have been various "outbreaks" of the inflammatory disease pansteatitis in several vertebrate species. Large-scale pansteatitis-related mortality events have decimated the crocodile population at Lake Loskop and decreased the population at Kruger National Park. Most pansteatitis-related diagnoses within the region are conducted post-mortem by either gross pathology or histology. The application of a non-lethal approach to assess the prevalence and pervasiveness of pansteatitis in the Olifants River region would be of great importance for the development of a management plan for this disease. In this study, several plasma-based biomarkers accurately classified pansteatitis in Mozambique tilapia (Oreochromis mossambicus) collected from Lake Loskop using a commercially available benchtop blood chemistry analyzer combined with data interpretation via artificial neural network analysis. According to the model, four blood chemistry parameters (calcium, sodium, total protein and albumin), in combination with total length, diagnose pansteatitis to a predictive accuracy of 92 percent. In addition, several morphometric traits (total length, age, weight) were also associated with pansteatitis. On-going research will focus on further evaluating the use of blood chemistry to classify pansteatitis across different species, trophic levels, and within different sites along the Olifants River.

  13. Kinetics of chronic inflammation in Nile tilapia fed n‑3 and n‑6 essential fatty acids

    Directory of Open Access Journals (Sweden)

    Róberson Sakabe

    2013-03-01

    Full Text Available The objective of this work was to investigate the effect of dietary supplementation with essential fatty acids on the kinetics of macrophage accumulation and giant cell formation in Nile tilapia (Oreochromis niloticus. The supplementation sources were soybean oil (SO, source of omega 6, n‑6 and linseed oil (LO, source of omega 3, n‑3, in the following proportions: 100% SO; 75% SO + 25% LO; 50% SO + 50% LO; 25% SO + 75% LO; and 100% LO (four replicates per treatment. After a feeding period of three months, growth performance was evaluated, and glass coverslips were implanted into the subcutaneous connective tissue of fish, being removed for examination at 2, 4, 6, and 8 days after implantation. Growth performance did not differ between treatments. Fish fed 100% linseed oil diet had the greatest macrophage accumulation and the fastest Langhans cell formation on the sixth day. On the eighth day, Langhans cells were predominant on the coverslips implanted in the fish feed 75 and 100% linseed oil. n‑3 fatty acids may contribute to macrophage recruitment and giant cell formation in fish chronic inflammatory response to foreign body.

  14. The antioxidant effects of complexes of tilapia fish skin collagen and different marine oligosaccharides

    Science.gov (United States)

    Ren, Shuwen; Li, Jing; Guan, Huashi

    2010-12-01

    An excess of reactive oxygen species (ROS) leads to a variety of chronic health problems. As potent antioxidants, marine bioactive extracts containing oligosaccharides and peptides have been extensively studied. Recently, there is a growing interest in protein-polysaccharide complexes because of their potential uses in pharmaceutical and food industries. However, only few studies are available on the antioxidant activities of such complexes, in terms of their ROS scavenging capability. In this study, we combined different marine oligosaccharides (isolated and purified) with collagen peptides derived from tilapia fish skin, and evaluated the antioxidant activity of the marine peptide-oligosaccharide complexes vis-à-vis the activity of their original component molecules. Biochemical and cellular assays were performed to measure the scavenging effects on 1, 1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide radicals, and to evaluate the influences on the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the level of malondialdehyde (MDA) in UV-induced photoaging models. The results indicated that the antioxidant activities of all the complexes were stronger than those of their individual components. Among the 11 complexes tested, two complexes, namely MA1000+CP and κ-ca3000+CP, turned out to be highly effective antioxidants. Although the detailed mechanisms of this improved scavenging ability are not fully understood, this work provides insights into the design of highly efficient peptide-oligosaccharide complexes for potential applications in pharmaceutical, cosmetics and food industries.

  15. Effect of molecular characteristics of Konjac glucomannan on gelling and rheological properties of Tilapia myofibrillar protein.

    Science.gov (United States)

    Jian, Wenjie; Wu, Huayi; Wu, Lanlan; Wu, Yunhui; Jia, Lina; Pang, Jie; Sun, Yuan-Ming

    2016-10-05

    Konjac glucomannan (KGM) is an important gelling agent in composite gels. This study aimed to investigate the effects of KGM molecular characteristics (molecular weight, size and conformation) on gelling properties of Tilapia myofibrillar protein (TMP). In this work, TMP composite gels were prepared under neutral pH with varying KGM (native KGM, 10kGy-KGM, 20kGy-KGM, and 100kGy-KGM) of different molecular characteristics. Native KGM, 10kGy-KGM, and 20kGy-KGM exerted negative effect on gel strength or whiteness of TMP gels. Interestingly 100kGy-KGM improved gelling properties and whiteness of TMP gels. Such effects presented by varying KGM were attributed the physical filling behaviors and the interaction between KGM and TMP. These behaviors or interactions are resulted from different molecular size and conformation. Smaller molecular size (root-mean square radius, Rz 20.2nm) and approximated spherical conformation in 100kGy-KGM enhanced its interaction with TMP and maintained its compact and smooth structure, but the larger molecular size (Rz≥40.2nm) and random coil conformation in other KGMs inhibited part of actins from gelling and deteriorated the network structure. Our study provided principle knowledge to understand the structure-functions relationships of KGM-TMP composite gels. These results can be used to provide theoretical guidance for surimi gel processing. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  17. Neobenedenia melleni-Specific Antibodies Are Associated with Protection after Continuous Exposure in Mozambique Tilapia

    Directory of Open Access Journals (Sweden)

    Jennifer M. Kishimori

    2015-01-01

    Full Text Available Neobenedenia melleni is a significant monogenean pathogen of fish in aquaculture facilities and public aquaria. Immunity after exposure to live N. melleni is well established, but the mechanisms of immunity remain unclear. In this study, tilapia (Oreochromis mossambicus were continuously exposed to N. melleni over a four-month period and assessed for immunity as determined by a reduction in the number of parasites dislodged from the experimental animals during freshwater immersion. Specific mucosal and systemic antibody levels were by determined via enzyme-linked immunosorbent assay. At 45 days postexposure (DPE, fish displayed high parasite loads and baseline levels of mucosal antibodies. At 102 and 120 DPE parasite loads were significantly decreased, and antibody levels were significantly increased for mucus and plasma samples. The correlation between immunity (reduction in parasite load and an increased humoral antibody response suggests a key role of antibody in the immune response. This is the first report of immunity against N. melleni that is associated with specific mucosal or systemic antibodies.

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

    Science.gov (United States)

    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.

  19. Chemical diplomacy in male tilapia: urinary signal increases sex hormone and decreases aggression.

    Science.gov (United States)

    Saraiva, João L; Keller-Costa, Tina; Hubbard, Peter C; Rato, Ana; Canário, Adelino V M

    2017-08-09

    Androgens, namely 11-ketotestosterone (11KT), have a central role in male fish reproductive physiology and are thought to be involved in both aggression and social signalling. Aggressive encounters occur frequently in social species, and fights may cause energy depletion, injury and loss of social status. Signalling for social dominance and fighting ability in an agonistic context can minimize these costs. Here, we test the hypothesis of a 'chemical diplomacy' mechanism through urinary signals that avoids aggression and evokes an androgen response in receiver males of Mozambique tilapia (Oreochromis mossambicus). We show a decoupling between aggression and the androgen response; males fighting their mirror image experience an unresolved interaction and a severe drop in urinary 11KT. However, if concurrently exposed to dominant male urine, aggression drops but urinary 11KT levels remain high. Furthermore, 11KT increases in males exposed to dominant male urine in the absence of a visual stimulus. The use of a urinary signal to lower aggression may be an adaptive mechanism to resolve disputes and avoid the costs of fighting. As dominance is linked to nest building and mating with females, the 11KT response of subordinate males suggests chemical eavesdropping, possibly in preparation for parasitic fertilizations.

  20. Echinacea purpurea and Allium sativum as immunostimulants in fish culture using Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Aly, S M; Mohamed, M F

    2010-10-01

    The study was conducted to evaluate the efficiency of echinacea (E) and garlic (G) supplemented diets as immunostimulant for tilapia (Oreochromis niloticus). Seven treatments were designed including a control (C). Fish were fed on 35% protein diet at a rate of 3% body weight per day. Echinacea (1.0 ppt) and garlic (3%) were incorporated in the feed, which was administered for periods of 1, 2 and 3 months (summer season), followed by basal diet for 4 more months (winter season). Neutrophil adherence and haematocrit values increased in both supplemented groups with prolonging period of application. The neutrophils adherence was significantly increased in all treatments except group administered echinacea for 1 month. The lymphocytic counts were significantly (p echinacea for 1 and 2 months when compared with the control and/or other treatments. The gain in the body weight and specific growth rate was significantly increased in all supplemented groups (p 85%) in all the supplemented groups. The percentage of protection, after challenge infection using pathogenic Aeromonas hydrophila was the highest in groups supplemented with echinacea and garlic for 3 months after summer and winter seasons. It could be concluded that echinacea and garlic improve the gain in body weight, survival rate and resistance against challenge infection. Both compounds showed extended effects after withdrawal and improved resistance to cold stress during the winter season. However, a full commercial cost benefit analysis is necessary before recommending their application in aquaculture. © 2010 Blackwell Verlag GmbH.

  1. Nutritional background changes the hypolipidemic effects of fenofibrate in Nile tilapia (Oreochromis niloticus)

    Science.gov (United States)

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

    2017-01-01

    Peroxisome proliferation activated receptor α (PPARα) is an important transcriptional regulator of lipid metabolism and is activated by high-fat diet (HFD) and fibrates in mammals. However, whether nutritional background affects PPARα activation and the hypolipidemic effects of PPARα ligands have not been investigated in fish. In the present two-phase study of Nile tilapia (Oreochromis niloticus), fish were first fed a HFD (13% fat) or low-fat diet (LFD; 1% fat) diet for 10 weeks, and then fish from the first phase were fed the HFD or LFD supplemented with 200 mg/kg body weight fenofibrate for 4 weeks. The results indicated that the HFD did not activate PPARα or other lipid catabolism-related genes. Hepatic fatty acid β-oxidation increased significantly in the HFD and LFD groups after the fenofibrate treatment, when exogenous substrates were sufficiently provided. Only in the HFD group, fenofibrate significantly increased hepatic PPARα mRNA and protein expression, and decreased liver and plasma triglyceride concentrations. This is the first study to show that body fat deposition and dietary lipid content affects PPARα activation and the hypolipidemic effects of fenofibrate in fish, and this could be due to differences in substrate availability for lipid catabolism in fish fed with different diets. PMID:28139735

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

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    M. S. G. Moura e Silva

    Full Text Available Abstract 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.

  3. Coupling of methylmercury uptake with respiration and water pumping in freshwater tilapia Oreochromis niloticus.

    Science.gov (United States)

    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.

  4. Growth, immune status and intestinal morphology of Nile tilapia fed dietary prebiotics (mannan oligosaccharides-MOS

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    Ricardo Yuji-Sado

    2015-11-01

    Full Text Available Farmers must conform to Best Management Practices in fish production such as the development of non-antibiotic dietary supplements for fish growth and health management. We determined the effects of increasing levels of dietary mannan oligosaccharides on growth, immune system and intestine integrity of Nile tilapia. Fish (49.6 ± 10.8 g were randomly distributed into 12 tanks (250 L; 20 fish per tank and fed during 60 days with a practical diet supplemented with 0.0, 0.2, 0.4 and 0.6% dietary mannan oligosaccharides (n = 3. Fish growth and immune system were not affected (P > 0.05 by treatments. Fish fed 0.4% prebiotic supplementation presented increased (P < 0.05 intestinal fold height. Moreover, the intestine muscular layer thickness was increased in fish fed 0.4 and 0.6% dietary prebiotic. After 60 days, there were no effects on intestinal morphology. Studies regarding characterization of intestinal microbiota and experiment that reproduce commercial fish production systems hearing conditions are necessary to determine the effective use of this dietary supplement for the species.

  5. The influence of chromatic background on the photosensitivity of tilapia erythrophores

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    Shyh-Chi Chen

    2014-01-01

    Non-mammalian vertebrates and invertebrates use extraretinal photoreceptors to detect light and perform diverse non-image-forming functions. Compared to well-studied visual systems, the effect of ambient light conditions on photosensory systems of extraretinal photoreceptors is poorly understood. Chromatophores are photosensitive dermal pigment cells that play an important role in the formation of body color patterns to fit the surrounding environment. Here, we used tilapia erythrophores to investigate the relationship between environmental light and chromatophore photoresponses. All erythrophores from three spectral conditions aggregated their pigment granules in UV/short wavelengths and dispersed in middle/long wavelengths. Unlike retinal visual systems, environmental light did not change the usage of the primary opsins responsible for aggregation and dispersion. In addition, short wavelength-rich and red-shifted background conditions led to an inhibitory effect on erythrophore photoresponses. We suggest that, as extraretinal photoreceptors for non-image-forming functions, chromatophores directly adjust their photoresponse sensitivity via changes in opsin expression levels rather than opsin types when environmental light changes.

  6. The influence of chromatic background on the photosensitivity of tilapia erythrophores.

    Science.gov (United States)

    Chen, Shyh-Chi; Hornsby, Mark A W; Robertson, R Meldrum; Hawryshyn, Craig W

    2014-02-15

    Non-mammalian vertebrates and invertebrates use extraretinal photoreceptors to detect light and perform diverse non-image-forming functions. Compared to well-studied visual systems, the effect of ambient light conditions on photosensory systems of extraretinal photoreceptors is poorly understood. Chromatophores are photosensitive dermal pigment cells that play an important role in the formation of body color patterns to fit the surrounding environment. Here, we used tilapia erythrophores to investigate the relationship between environmental light and chromatophore photoresponses. All erythrophores from three spectral conditions aggregated their pigment granules in UV/short wavelengths and dispersed in middle/long wavelengths. Unlike retinal visual systems, environmental light did not change the usage of the primary opsins responsible for aggregation and dispersion. In addition, short wavelength-rich and red-shifted background conditions led to an inhibitory effect on erythrophore photoresponses. We suggest that, as extraretinal photoreceptors for non-image-forming functions, chromatophores directly adjust their photoresponse sensitivity via changes in opsin expression levels rather than opsin types when environmental light changes.

  7. Deposition of bodily chemical components in the carcass of tilapia (Oreochromis sp. strains

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    Ivan Bezerra Allaman

    2014-10-01

    Full Text Available The knowledge of how animals deposited chemical components as water, protein, fat and ash in the carcass is importance for the formulation of a balanced diet, allowing maximum performance with a low environmental impact. So, the study was carried out to evaluate the influence of different tilapia strains (Chitralada, Commercial, Red and Universidade Federal de Lavras [UFLA] on the deposition of bodily chemical components in the carcass. The bodily components analyzed were water, protein, fat and ash. For the determination of the bodily chemical deposition curves by age, the exponential, Brody, logistic, Gompertz and von Bertalanffy models were adjusted. The Commercial and UFLA strains deposited water at a faster speed (P0.05 for the logistic model parameter between Red, UFLA and Commercial strains for fat, which presented a maximum fat deposition (0.23 g at 310 days of age. Regarding ash deposition, the Commercial strain presented a higher maximum deposition (0.10 g at 337 days, occurring later than the other strains that presented maximum deposition (0.033g at 254 days of age. Thus, it was concluded that the genetic strains evaluated differ in chemical deposition curves of water, protein, fat and ash.

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

    Science.gov (United States)

    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).

  9. Polycyclic Aromatic Hydrocarbon Contamination in Nile Tilapia (Oreochromis Niloticus : Analysis in Liver and Bile

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    Voravit Cheevaporn

    2010-07-01

    Full Text Available Polycyclic aromatic hydrocarbons (PAHs, mainly from petroleum products, are a source of worldwide contamination, and it is in the present study, we exposed Nile Tilapia in aquaria to No-Observed-Effect-Levels (NOELs of naphthalene, phenanthrene and pyrene for periods up to 9 days in a continuous flow system. Additional studies were carried out on fish exposed to lubricating oil, gasoline and diesel oil. Two methods were used to measure the levels of these PAHs: determination of ethoxyresorufin-O-deethylase (EROD activity in liver extracts, and fixed wavelength fluorescence (FF of PAH in bile. Optimal excitation wavelengths for FF analyses were determined to 290, 260 and 341 nm for naphthalene, phenanthrene and pyrene, respectively. The optimal emission wavelengths were 335, 380 and 383 nm, respectively. EROD activity and fluorescence intensity increased with increasing PAH concentrations and increasing exposure times. Similar results were obtained after exposure to lubricating oil, gasoline, or diesel oil. There was a high and significant correlation between the two methods. In view of its higher accuracy, lower cost, and convenience FF offered better possibilities than EROD determination to monitor PAH contamination in fish.

  10. Selección masal por peso y coloración en tilapia roja

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    María Alejandra Ruiz Peña

    2009-04-01

    Full Text Available Para evaluar la efectividad de la selección masal por color y peso se analizaron dos generaciones (G1 y G2 de alevinos de tilapia roja Oreochromis sp. De 40.000 larvas a la sexta semana se eliminaron los alevinos manchados y blancos y a las 14 semanas se separaron por sexos. Se midió el peso (g, la longitud total (cm, la altura (cm y el ancho (cm de 150 individuos a las 6, 14 y 24 semanas de edad. En la semana 24 se escogieron 150 machos y 450 hembras con las coloraciones deseables y mayor peso. La selección resultó efectiva para coloración en G2, puesto que la proporción de individuos rojos se incrementó en 15% con respecto a los testigos. Entre generaciones (G1 y G2 el efecto de la selección fue positivo, debido a que la proporción de rojos se incrementó de 64% a 84% y se redujo la de manchados de 31% a 13%. En ambas generaciones los machos fueron significativamente más pesados que las hembras. Se encontraron notables diferencias entre generaciones para peso y talla, puesto que los selectos superaron al control en 27% y 8% (G1 y en 22% y 11% (G2 para el peso y la talla, respectivamente.

  11. Variation of limnological parameters in a tropical lake used for tilapia cage farming

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    Graciele P. Venturoti

    2015-11-01

    Full Text Available The aim of this study was to assess the effects of tilapia cage culture on the water quality and sediment of Palminhas Lake during both the dry and rainy seasons. Eight sites within the lake (four in fish farms and four in areas without fish farms and one site on an affluent stream were sampled monthly from February 2011 to January 2012. Dissolved oxygen and pH were significantly lower at fish farm sites than at locations without farms, while chlorophyll a was higher at fish farm sites. Moreover, large seasonal variations were observed, which were not related to the fish farms. The Secchi disc depth and ammonia nitrogen level were significantly higher during the dry season, but temperature, dissolved oxygen, pH, total phosphorus and chlorophyll a were significantly higher during the rainy season. The affluent stream contributed substantially to lake eutrophication. Palminhas Lake is mesotrophic and has exhibited a progressive worsening in water quality over the past 20 years. These changes were not caused by fish farming alone but probably by other anthropic activities in the areas surrounding the lake.

  12. Genetic parameters and trends of morphometric traits of GIFT tilapia under selection for weight gain

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    Rafael Vilhena Reis Neto

    2014-08-01

    Full Text Available The main factor considered in breeding programs for fish is growth, which can be assessed in terms of a gain in either weight or body measurements. This study was undertaken to evaluate the morphometric traits of GIFT strain tilapia (Oreochromis sp. selected for weight gain. The data set used contained information on 6,650 animals. The genetic values of 8,590 animals in a relationship matrix of five generations were predicted. The following morphometric measurements were evaluated: standard length; body depth and body width. Body area and volume were also calculated. Bi-character analyses involving morphometric traits were used to estimate (covariance components. Heritability, larval and fingerling common environmental effects were estimated for each trait, together with the genetic and phenotypic correlations between traits. Bayesian procedures were utilised by Gibbs chains, and the convergence of the chains was tested using the Heidelberger and Welch method. Genetic trends were estimated by segmented regression of the fish breeding values of the generations considered in this study. Estimates of heritability (0.28 a 0.31 had moderate to high magnitudes for all traits. Genetic correlations between traits were all above 0.8, and the genetic gains were satisfactory from the third generation onwards. From the estimates of the genetic parameters and genetic gain the morphometric traits evaluated have good potential for selection.

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

    Science.gov (United States)

    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.

  14. Isotopic and geochemical characterization of invader tilapia fishes from water bodies of West Bengal and Karnataka, India.

    Science.gov (United States)

    Chatterjee, Mousumi; Ghosh, Prosenjit; Ramdas, Leena; Chakrabarti, Ramananda

    2015-11-01

    The otoliths (N = 12) of freshwater invasive species tilapia (Tilapia mossambicus) collected from two water bodies located at Kolkata and Bangalore, India, were analyzed for stable isotopes (δ18O, δ14C) and major and trace elements in order to assess the suitability of using otoliths as a tracer of aquatic environmental changes. The stable isotope analysis was done using the dual inlet system of a Finnigan-MAT 253 isotope ratio mass spectrometer (Thermo-Fisher, Bremen, Germany). Concentrations of major and trace elements were determined using a Thermo X-Series II quadrupole mass spectrometer. The stable isotope composition in tilapia otolith samples from Bangalore and Kolkata water bodies are quite good agreeing with that of the respective lake/pond and rain water. Elemental composition revealed in a pattern of Ca>Fe>Na>Sr>K>Ba>Cr>Mg>As>Mn>Zn>Co>Cu>Cd>Pb. The otoliths from Kolkata pond water are more enriched in Ba, Zn, Pb, Mn, Se, Cu, Zn, Cd, and Ni whereas Cr and As were found to be higher in otolith samples from Bangalore lake. The enrichment factor (EF) values of Cr were higher for both the sampling location in comparison with other metals, although all the studied metals exhibited EF values>1. The PCA shows clustering of metals in the otolith which are related either with the metabolic and physiological attributes or waterborne source. The study demonstrated the potential of stable isotope techniques to distinguish otolith specimens from varied climatic zone, while elemental composition recorded the quality of water at both the locations. The role of climate driving the quality of water can be understood by detailed and continuous monitoring of otolith specimens in the future. Future method allows reconstruction of climate and water quality from old specimens from field exposures or museum collection.

  15. An Overview of Vaccination Strategies and Antigen Delivery Systems for Streptococcus agalactiae Vaccines in Nile Tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Munang'andu, Hetron Mweemba; Paul, Joydeb; Evensen, Øystein

    2016-12-13

    Streptococcus agalactiae is an emerging infectious disease adversely affecting Nile tilapia (Niloticus oreochromis) production in aquaculture. Research carried out in the last decade has focused on developing protective vaccines using different strategies, although no review has been carried out to evaluate the efficacy of these strategies. The purpose of this review is to provide a synopsis of vaccination strategies and antigen delivery systems currently used for S. agalactiae vaccines in tilapia. Furthermore, as shown herein, current vaccine designs include the use of replicative antigen delivery systems, such as attenuated virulent strains, heterologous vectors and DNA vaccines, while non-replicative vaccines include the inactivated whole cell (IWC) and subunit vaccines encoding different S. agalactiae immunogenic proteins. Intraperitoneal vaccination is the most widely used immunization strategy, although immersion, spray and oral vaccines have also been tried with variable success. Vaccine efficacy is mostly evaluated by use of the intraperitoneal challenge model aimed at evaluating the relative percent survival (RPS) of vaccinated fish. The major limitation with this approach is that it lacks the ability to elucidate the mechanism of vaccine protection at portals of bacterial entry in mucosal organs and prevention of pathology in target organs. Despite this, indications are that the correlates of vaccine protection can be established based on antibody responses and antigen dose, although these parameters require optimization before they can become an integral part of routine vaccine production. Nevertheless, this review shows that different approaches can be used to produce protective vaccines against S. agalactiae in tilapia although there is a need to optimize the measures of vaccine efficacy.

  16. Determination of cyanuric acid residues in catfish, trout, tilapia, salmon and shrimp by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Karbiwnyk, Christine M; Andersen, Wendy C; Turnipseed, Sherri B; Storey, Joseph M; Madson, Mark R; Miller, Keith E; Gieseker, Charles M; Miller, Ron A; Rummel, Nathan G; Reimschuessel, Renate

    2009-04-01

    In May 2007, investigators discovered that waste material from the pet food manufacturing process contaminated with melamine (MEL) and/or cyanuric acid (CYA) had been added to hog and chicken feeds. At this time, investigators also learned that adulterated wheat gluten had been used in the manufacture of aquaculture feeds. Concern that the contaminated feed had been used in aquaculture and could enter the human food supply prompted the development of a method for the determination of CYA residues in the edible tissues of fish and shrimp. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed as a sensitive technique for the analysis of CYA in catfish, tilapia, salmon, trout and shrimp tissue. CYA was extracted from ground fish or shrimp with an acetic acid solution, defatted with hexane, and isolated with a graphitic carbon black solid-phase extraction column. Residues were separated from matrix components using a porous graphitic carbon LC column, and then analyzed with electrospray ionization in negative ion mode on a triple quadrupole mass spectrometer. Selective reaction monitoring was performed on the [M-H](-)m/z 128 ion resulting in the product ions m/z 85 and 42. Recoveries from catfish, tilapia and trout fortified with 10-100 microgkg(-1) of CYA averaged 67% with a relative standard deviation (R.S.D.) of 18% (n=107). The average method detection limit (MDL) for catfish, tilapia and trout is 3.5 microgkg(-1). An internal standard, (13)C(3)-labeled CYA, was used in the salmon and shrimp extractions. Average recovery of CYA from salmon was 91% (R.S.D.=15%, n=18) with an MDL of 7.4 microgkg(-1). Average recovery of CYA from shrimp was 85% (R.S.D.=10%, n=13) with an MDL of 3.5 microgkg(-1).

  17. Effect of the establishment of dominance relationships on cortisol and other metabolic parameters in Nile tilapia (Oreochromis niloticus

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    Corrêa S.A.

    2003-01-01

    Full Text Available The objective of the present study was to investigate the influence of the establishment of dominance relationships and social stress on plasma cortisol and metabolite levels in Nile tilapia (Oreochromis niloticus. During the 30-day experiment, the fish weighing 236 ± 29 g were kept in individual aquaria, except for two pairings lasting 6 h each. Blood samples were taken from the animals before and after pairing. Display, approach, attack, rebuff, chase flight, and coloration were carried out on days 16 and 30. Activities and behaviors characteristic of the establishment of dominance relationships were described. It was possible to classify all experimental fish (N = 30 as dominant or subordinate. No differences were detected between dominant (N = 15 and subordinate (N = 15 fish during isolation or after pairing in cortisol (isolated: 5.76 ± 0.98 vs 5.42 ± 0.63; paired: 10.94 ± 1.62 vs 11.21 ± 2.45 µg/dl, glucose (isolated: 60.02 ± 4.9 vs 67.85 ± 16.16; paired: 110.44 ± 15.72 vs 136.26 ± 22.46 mg/dl, triglyceride (isolated: 167.87 ± 5.06 vs 185.68 ± 7.24; paired: 210.85 ± 13.40 vs 221.82 ± 12.70 mg/dl or total protein levels (isolated: 7.01 ± 0.42 vs 6.69 ± 0.59; paired: 9.21 ± 0.62 vs 9.51 ± 0.66 g/dl. However, when isolated (N = 30 and paired (N = 30 tilapia were compared, there were significant differences in cortisol and metabolite levels. The similar response presented by dominant and subordinate tilapia indicates that establishment of dominance relationships was a stressor for both groups.

  18. Expression of a novel piscine growth hormone gene results in growth enhancement in transgenic tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Rahman, M A; Mak, R; Ayad, H; Smith, A; Maclean, N

    1998-09-01

    Several lines of transgenic G1 and G2 tilapia fish (Oreochromis niloticus) have been produced following egg injection with gene constructs carrying growth hormone coding sequences of fish origin. Using a construct in which an ocean pout antifreeze promoter drives a chinook salmon growth hormone gene, dramatic growth enhancement has been demonstrated, in which the mean weight of the 7 month old G2 transgenic fish is more than three fold that of their non transgenic siblings. Somewhat surprisingly G1 fish transgenic for a construct consisting of a sockeye salmon metallothionein promoter spliced to a sockeye salmon growth hormone gene exhibited no growth enhancement, although salmon transgenic for this construct do show greatly enhanced growth. The growth enhanced transgenic lines were also strongly positive in a radio-immuno assay for the specific hormone in their serum, whereas the non growth enhanced lines were negative. Attempts to induce expression from the metallothionein promoter by exposing fish to increased levels of zinc were also unsuccessful. Homozygous transgenic fish have been produced from the ocean pout antifreeze/chinook salmon GH construct and preliminary trials suggest that their growth performance is similar to that of the hemizygous transgenics. No abnormalities were apparent in the growth enhanced fish, although minor changes to skull shape and reduced fertility were noted in some fish. There is also preliminary evidence for improved food conversion ratios when growth enhanced transgenic tilapia are compared to their non-transgenic siblings. The long term objective of this study is to produce lines of tilapia which are both growth enhanced and sterile, so offering improved strains of this important food fish for aquaculture.

  19. An Overview of Vaccination Strategies and Antigen Delivery Systems for Streptococcus agalactiae Vaccines in Nile Tilapia (Oreochromis niloticus)

    Science.gov (United States)

    Munang’andu, Hetron Mweemba; Paul, Joydeb; Evensen, Øystein

    2016-01-01

    Streptococcus agalactiae is an emerging infectious disease adversely affecting Nile tilapia (Niloticus oreochromis) production in aquaculture. Research carried out in the last decade has focused on developing protective vaccines using different strategies, although no review has been carried out to evaluate the efficacy of these strategies. The purpose of this review is to provide a synopsis of vaccination strategies and antigen delivery systems currently used for S. agalactiae vaccines in tilapia. Furthermore, as shown herein, current vaccine designs include the use of replicative antigen delivery systems, such as attenuated virulent strains, heterologous vectors and DNA vaccines, while non-replicative vaccines include the inactivated whole cell (IWC) and subunit vaccines encoding different S. agalactiae immunogenic proteins. Intraperitoneal vaccination is the most widely used immunization strategy, although immersion, spray and oral vaccines have also been tried with variable success. Vaccine efficacy is mostly evaluated by use of the intraperitoneal challenge model aimed at evaluating the relative percent survival (RPS) of vaccinated fish. The major limitation with this approach is that it lacks the ability to elucidate the mechanism of vaccine protection at portals of bacterial entry in mucosal organs and prevention of pathology in target organs. Despite this, indications are that the correlates of vaccine protection can be established based on antibody responses and antigen dose, although these parameters require optimization before they can become an integral part of routine vaccine production. Nevertheless, this review shows that different approaches can be used to produce protective vaccines against S. agalactiae in tilapia although there is a need to optimize the measures of vaccine efficacy. PMID:27983591

  20. Assessment of Heavy-Metal Pollution in Sediments and Tilapia Fish Species in Kafue River of Zambia.

    Science.gov (United States)

    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.

  1. Antagonistic roles of Dmrt1 and Foxl2 in sex differentiation via estrogen production in tilapia as demonstrated by TALENs.

    Science.gov (United States)

    Li, Ming-Hui; Yang, Hui-Hui; Li, Meng-Ru; Sun, Yun-Lv; Jiang, Xiao-Long; Xie, Qing-Ping; Wang, Ting-Ru; Shi, Hong-Juan; Sun, Li-Na; Zhou, Lin-Yan; Wang, De-Shou

    2013-12-01

    Transcription activator-like effector nucleases (TALENs) are a powerful approach for targeted genome editing and have been proved to be effective in several organisms. In this study, we reported that TALENs can induce somatic mutations in Nile tilapia, an important species for worldwide aquaculture, with reliably high efficiency. Six pairs of TALENs were constructed to target genes related to sex differentiation, including dmrt1, foxl2, cyp19a1a, gsdf, igf3, and nrob1b, and all resulted in indel mutations with maximum efficiencies of up to 81% at the targeted loci. Effects of dmrt1 and foxl2 mutation on gonadal phenotype, sex differentiation, and related gene expression were analyzed by histology, immunohistochemistry, and real-time PCR. In Dmrt1-deficient testes, phenotypes of significant testicular regression, including deformed efferent ducts, degenerated spermatogonia or even a complete loss of germ cells, and proliferation of steroidogenic cells, were observed. In addition, disruption of Dmrt1 in XY fish resulted in increased foxl2 and cyp19a1a expression and serum estradiol-17β and 11-ketotestosterone levels. On the contrary, deficiency of Foxl2 in XX fish exhibited varying degrees of oocyte degeneration and significantly decreased aromatase gene expression and serum estradiol-17β levels. Some Foxl2-deficient fish even exhibited complete sex reversal with high expression of Dmrt1 and Cyp11b2. Furthermore, disruption of Cyp19a1a in XX fish led to partial sex reversal with Dmrt1 and Cyp11b2 expression. Taken together, our data demonstrated that TALENs are an effective tool for targeted gene editing in tilapia genome. Foxl2 and Dmrt1 play antagonistic roles in sex differentiation in Nile tilapia via regulating cyp19a1a expression and estrogen production.

  2. Pharmacokinetics of doxycycline in tilapia (Oreochromis aureus × Oreochromis niloticus) after intravenous and oral administration.

    Science.gov (United States)

    Yang, F; Li, Z L; Shan, Q; Zeng, Z L

    2014-08-01

    The pharmacokinetics of doxycycline was studied in plasma after a single dose (20 mg/kg) of intravenous or oral administration to tilapia (Oreochromis aureus × Oreochromis niloticus) reared in fresh water at 24 °C. Plasma samples were collected from six fish per sampling point. Doxycycline concentrations were determined by high-performance liquid chromatography with a 0.005 μg/mL limit of detection, then were subjected to noncompartmental analysis. Following oral administration, the double-peak phenomenon was observed, and the first (Cmax1 ) and second (Cmax2) peaks were 1.99 ± 0.43 μg/mL at 2.0 h and 2.27 ± 0.38 μg/mL at 24.0 h, respectively. After the intravenous injection, a Cmax2 (12.12 ± 1.97 μg/mL) was also observed, and initial concentration of 45.76 μg/mL, apparent elimination rate constant (λz) of 0.018 per h, apparent elimination half-life (t1/2λz) of 39.0 h, systemic total body clearance (Cl) of 41.28 mL/h/kg, volume of distribution (Vz) of 2323.21 mL/kg, and volume of distribution at steady-state (Vss) of 1356.69 mL/kg were determined, respectively. While after oral administration, the λz, t1/2λz, and bioavailability of doxycycline were 0.009 per h, 77.2 h, and 23.41%, respectively. It was shown that doxycycline was relatively slowly and incompletely absorbed, extensively distributed, and slowly eliminated in tilapia, in addition, doxycycline might undergo enterohepatic recycling in tilapia.

  3. Used of microbial phytase to replace inorganic phosphorus in sex-reversed red tilapia: 1 dose response

    Directory of Open Access Journals (Sweden)

    Wutiporn Phromkunthong

    2006-07-01

    Full Text Available Sex-reversed red tilapia of average initial body weight 5.5 g were fed seven practical diets containing 0, 500, 1,000, 2,000 and 4,000 units of microbial phytase/kg and two diets containing 0.2 and 0.3% feed grade dicalcium phosphate (DCP (but no microbial phytase, respectively. The experiment was carried out in 235- l glass aquaria filled with 180 l water and attached with a closed-recirculating water system with 0.8 l/min flow rate. The experimental period was 10 weeks. All experimental diets were formulated with plant-based protein of 30% and 6% fat. Results indicated an improvement in apparent digestibility coefficient of phosphorus (ADCP in fish given phytase supplemented feed. There was no difference in ADCP when 1,000 unit phytase/kg diet or higher phytase levels (2,000 and 4,000 unit phytase/kg diet or 0.2 and 0.3% DCP were supplemented. A significant increase was noted for hemoglobin in tilapia that received 1,000 unit phytase/kg diet or higher levels compared to the control. Serum phosphorus ma kedly increased when the fish were given feeds with 1,000 unit phytase/kg diet and over, while the supplementation of 500 unit phytase/kg diet and over increased serum zinc level. Higher levels of phosphorus were retained in bone whereas lower levels of phosphorus presented in the feces of tilapia fed feeds supplemented with phytase. Growth performance was markedly influenced when the fish were given feed with 4,000 unit phytase/kg diet.

  4. Effect of pyrene on hepatic cytochrome P450 1A (CYP1A) expression in Nile Tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Zapata-Pérez, O; Gold-Bouchot, G; Ortega, A; López, T; Albores, A

    2002-05-01

    The effect of pyrene on the regulation of the gene expression of cytochrome P4501A ( CYP1A) was studied in tilapia (Oreochromis niloticus), a tropical fish of great ecological and economical importance. To evaluate CYP1A mRNA, tilapia CYP1A cDNA was cloned, sequenced, and compared with those CYP1A reported sequences in the GeneBank DNA database. The top seven matches corresponded to CYP1A from other teleosts. Hepatic CYP1A mRNA levels showed a significant increase at day 1 after pyrene injection (20 mg kg(-1) body weight [BW]), and this CYP1A mRNA levels did not return to basal levels for up to 5 days. The immunoblot analysis of CYP1A protein levels using polyclonal rabbit-anti-trout antibodies in the liver of pyrene-treated (20 mg kg(-1) BW) tilapias showed a 1.9-fold increase at day 3 after injection. Ethoxyresorufin- O-deethylase (EROD) activity increased 18-fold with respect to control fish at day 3 after injection. CYP1A protein and EROD activity remained increased for 5 days after a single pyrene IP administration. Similarly, the highest concentration of 1-hydroxypyrene (1-OH pyrene) in bile was observed in fish sacrificed at day 3 after injection. EROD activity and 1-OH pyrene concentration showed a statistically significant correlation (r = 0.85) according to the Spearman test, suggesting the participation of this cytochrome in the biotransformation of pyrene.

  5. Growth, mortality and reproduction of the blue tilapia Oreochromis aureus (Perciformes: Cichlidae) in the Aguamilpa Reservoir, Mexico.

    Science.gov (United States)

    Peña Messina, Emilio; Tapia Varela, Raul; Velázquez Abunader, José Iván; Orbe Mendoza, Alma Araceli; Velazco Arce, Javier Marcial de Jesús Ruiz

    2010-12-01

    Tilapia production has increased in Aguamilpa Reservoir, in Nayarit, Mexico, in the last few years and represents a good economic activity for rural communities and the country. We determined growth parameters, mortality and reproductive aspects for 2413 specimens of blue tilapia Oreochromis aureus in this reservoir. Samples were taken monthly from July 2000 through June 2001, of which 1 371 were males and 1 042 were females. Standard length (SL) and total weight (TW) were measured in each organism. The SL/TW relationships through power models for sexes were determined. The growth parameters L infinity k, and t0 of the von Bertalanffy equation were estimated using frequency distribution of length through ELEFAN-I computer program. Finally the reproductive cycle and size of first maturity were established using morph chromatic maturity scale. The results suggested that the males and females had negative allometric growth (b < 3). Significant differences were found between SL/TW model for the sexes, suggesting separate models for males and females. Results indicate that there are no differences in growth rates between sexes; the proposed parameters were L infinity = 43.33 cm standard length, k = 0.36/year and t0 = -0.43 years. Natural and fishing mortality coefficients were 0.83/year and 1.10/year, respectively. The estimated exploitation rate (0.57/year) suggested that during the study period the fishery showed signs of overfishing. Blue tilapia reproduces year-round; the highest activity occurs from January through May and size of first maturity was 23 cm SL. We conclude that it is necessary to establish a minimum catch size in this reservoir based on the reproductive behavior of this species.

  6. Carbohydrate utilization and digestibility by tilapia, Oreochromis niloticus x O. aureus, are affected by chromic oxide inclusion in the diet.

    Science.gov (United States)

    Shiau, S Y; Liang, H S

    1995-04-01

    A 12-wk feeding trial was conducted to study the influence of chromic oxide (Cr2O3) on carbohydrate utilization and digestibility by tilapia, Oreochromis niloticus x O. aureus. Two levels of chromic oxide (0.5 and 2%) were each incorporated into diets containing glucose or starch. Chromic oxide was added at 0 or 8 wk. The diets were fed to triplicate groups of fish weighing 1.11 +/- 0.05 g. Fish fed the starch diet had greater (P protein efficiency ratio, protein deposition and digestibility of protein, lipid, carbohydrate and dry matter than fish fed the glucose diet irrespective of the time and level of chromic oxide supplementation. Fish fed the glucose diet with 0.5% chromic oxide had higher weight gain, feed efficiency ratio, protein efficiency ratio and protein deposition than fish fed the glucose diet with 2% chromic oxide. The ingredient digestibility estimated using 0.5% chromic oxide as the marker was greater than that estimated with 2% chromic oxide. Higher phosphofructokinase and lower glucose-6-phosphatase activity was found in fish fed the starch diet than in fish fed the glucose diet regardless of the time and level of chromic oxide inclusion. Fish fed the glucose diet with 0.5% chromic oxide had higher phosphofructokinase activity and lower tissue chromium concentration than fish fed the glucose diet with 2% chromic oxide irrespective of chromic oxide inclusion time. These data suggest that the level of chromic oxide in the diet alters glucose utilization by tilapia and affects nutrient digestibility by tilapia. The time of chromic oxide inclusion had no effect on carbohydrate utilization and digestibility.

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

    Science.gov (United States)

    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.

  8. Acute acidic exposure induces p53-mediated oxidative stress and DNA damage in tilapia (Oreochromis niloticus) blood cells.

    Science.gov (United States)

    Mai, Wei-jun; Yan, Jun-lun; Wang, Lei; Zheng, Ying; Xin, Yu; Wang, Wei-na

    2010-11-01

    Acid rain and inputs of acidic effluent can result in increased acidity in aquatic ecosystems, where it is known to have a significant impact and possibly, to cause the decline of some populations of aquatic organisms. In previous studies, intracellular acid-induced oxidative stress has been shown to cause DNA damage, and cooperatively activate the expression of the p53 gene. The acute effects of acidic environments on shrimp and fish have been widely studied. However, the molecular mechanism of acid-induced injury remains largely unknown. In this study, we examined the cellular responses of tilapia to acidic exposure-induced oxidative stress and antioxidant enzyme gene expression. Furthermore, we determined how acute acid stress activates the ATM-p53 signal pathway. We measured the upregulation of reactive oxygen species (ROS) production, the intracellular Ca(2)(+) concentration ([Ca(2)(+)](i)), the tail DNA values, the malondialdehyde (MDA) level in the blood cells and the percentage of dead and damaged blood cells. Our results suggest that oxidative stress and DNA damage occurred in tilapia in conditions where the pH was 5.3. Apoptosis was detected by Hoechst staining, which was mainly associated with changes in cell viability. The parameters that we measured were related to acid-induced DNA damage, and all parameters changed in the blood cells through time. The effects of acute acid exposure (pH 5.3) on the expression of ATM, p53, p21, Bax, manganese superoxide dismutase (MnSOD), glutathione peroxidase (GPx) were investigated in tilapia blood cells. The results showed that acute acid stress induced upregulation of ATM, p53 and p21, associated with increasing of DNA damage and apoptosis in blood cells. Additionally, the expression of Bax was slightly increased. Moreover, consensus p53-binding sequences were identified in tilapia MnSOD and GPx gene promoter regions and increased levels of ROS in the blood cells coincided with increased mRNA expression of p53, Mn

  9. Physiological, biochemical and histometric responses of Nile tilapia (Oreochromis niloticus L.) by dietary organic chromium (chromium picolinate) supplementation

    OpenAIRE

    2014-01-01

    Chromium has been recognized as a new and important micro-nutrient, essential for both human and animal nutrition. This study was conducted to evaluate the appropriateness and/or the use of safety level of dietary chromium picolinate (Cr-Pic), and its effects on the physiological responses, the histometric characteristics, and the chemical analysis of dorsal muscles of mono-sex Nile tilapia, Oreochromis niloticus. A total of 420 fingerlings (28.00 ± 0.96 g) were randomly distributed into 21 f...

  10. Estudio comparativo de la influencia del empaque, en la tilapia fresca, almacenado a temperaturas de refrigeración

    OpenAIRE

    Fiallos Cardenas, Cesar; Castillo Soto, Priscila

    2009-01-01

    Este trabajo presenta el estudio comparativo de la influencia del empaque en la vida útil de filetes de tilapia almacenados a temperaturas de refrigeración. El objetivo es desarrollar un empaque capaz de mejorar las características organolépticas como el tiempo de vida útil del producto. Para el desarrollo de este estudio se optó por la utilización de atmósferas modificadas en el empaque de los filetes. Para esto se utilizó diferentes concentraciones en cada mezcla. El producto final fue some...

  11. Hepatic transcriptome analysis of juvenile GIFT tilapia (Oreochromis niloticus), fed diets supplemented with different concentrations of resveratrol.

    Science.gov (United States)

    Zheng, Yao; Wu, Wei; Hu, Gengdong; Zhao, Zhixiang; Meng, Shunlong; Fan, Limin; Song, Chao; Qiu, Liping; Chen, Jiazhang

    2017-09-08

    The GIFT (Genetically Improved Farmed Tilapia) tilapia, Oreochromis niloticus, is cultured widely for the production of freshwater fish in China. Streptococcosis, which is related to pathogenic infections, occurs frequently in juvenile and adult female GIFT individuals. Resveratrol (RES) has been used in feed to control these infections in freshwater tilapia. To address the effects of RES on tilapia, we used high-throughput RNA sequencing technology (RNA-Seq, HiSeq. 2500) to explore the global transcriptomic response and specific involvement of hepatic mRNA of juvenile O. niloticus fed with diets containing different concentrations of (0, 0.025, 0.05, and 0.1g/kg) RES. A total of > 24,513,018 clean reads were generated and then assembled into 23,244 unigenes. The unigenes were annotated by comparing them against non-redundant protein sequence (Nr), non-redundant nucleotide (Nt), Swiss-Prot, Pfam, Gene Ontology database (GO), Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, and 12,578 unigenes were annotated to the GO database. A total of 1444 (0.025g/kg RES), 1526 (0.05g/kg RES), and 3135 (0.1g/kg RES) genes were detected as significant differentially expressed genes (DEGs), when compared with the controls. A total of 6 (0.025 vs 0.05g/kg RES), 19 (0.025 vs 0.1g/kg RES), and 124 (0.05 vs 0.1g/kg RES) genes were detected as significant DEGs. Six genes, including dnah7x1, sox4, fam46a, hsp90a, ddit4, and nmrk2, were associated with an immune response. These findings provide information on the innate immunity of GIFT and might contribute to the development of strategies for the effective management of diseases and long-term sustainability of O. niloticus culture. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  14. Phenotype and genetic parameters for body measurements, reproductive traits and gut lenght of Nile tilapia (Oreochromis niloticus) selected for growth in low-input earthen ponds

    NARCIS (Netherlands)

    Charo-Karisa, H.; Bovenhuis, H.; Rezk, M.A.; Ponzoni, R.W.; Arendonk, van J.A.M.; Komen, J.

    2007-01-01

    In this study we present estimates of phenotypic and genetic parameters for body size measurements, reproductive traits, and gut length for Nile tilapia (Oreochromis niloticus) selected for growth in fertilized earthen ponds for two generations. Throughout the experiment, ponds were fertilized daily

  15. EFECTO DE LA INCLUSION DE DIFERENTES FUENTES DE LIPIDOS SOBRE PARAMETROS PRODUCTIVOS Y COMPOSICION PROXIMAL DEL FILETE DE TILAPIA NILOTICA -Oreochromis niloticus- CULTIVADA EN JAULAS FLOTANTES

    National Research Council Canada - National Science Library

    J M Moreno; A P Muñoz Ramirez; G A Wills

    2013-01-01

    ... y la composición proximal del filete de tilapia nilótica Oreochromis niloticus, se formularon cuatro dietas con aceite de pescado (AP), aceite de palma (APL), semilla de chía (SC) o semilla de lino (SL...

  16. Potential contribution of fish feed and phytoplankton to the content of volatile terpenes in cultured Pangasius (Pangasianodon hypophthalmus) and Tilapia (Oreochromis niloticus)

    DEFF Research Database (Denmark)

    Podduturi, Raju; Petersen, Mikael Agerlin; Mahmud, Sultan

    2017-01-01

    Geosmin and 2-methylisoborneol are the most recognized off-flavors in freshwater fish, but terpenes may also contribute off-flavor in fish. We identified six monoterpenes, 11 sesquiterpenes, and three terpene-related compounds in pangasius and tilapia from aquaculture farms in Bangladesh. The con...

  17. Prolactin 177, prolactin 188, and extracellular osmolality independently regulate the gene expression of ion transport effectors in gill of Mozambique tilapia.

    Science.gov (United States)

    Inokuchi, Mayu; Breves, Jason P; Moriyama, Shunsuke; Watanabe, Soichi; Kaneko, Toyoji; Lerner, Darren T; Grau, E Gordon; Seale, Andre P

    2015-11-15

    This study characterized the local effects of extracellular osmolality and prolactin (PRL) on branchial ionoregulatory function of a euryhaline teleost, Mozambique tilapia (Oreochromis mossambicus). First, gill filaments were dissected from freshwater (FW)-acclimated tilapia and incubated in four different osmolalities, 280, 330, 380, and 450 mosmol/kg H2O. The mRNA expression of Na(+)/K(+)-ATPase α1a (NKA α1a) and Na(+)/Cl(-) cotransporter (NCC) showed higher expression with decreasing media osmolalities, while Na(+)/K(+)/2Cl(-) cotransporter 1a (NKCC1a) and PRL receptor 2 (PRLR2) mRNA levels were upregulated by increases in media osmolality. We then incubated gill filaments in media containing ovine PRL (oPRL) and native tilapia PRLs (tPRL177 and tPRL188). oPRL and the two native tPRLs showed concentration-dependent effects on NCC, NKAα1a, and PRLR1 expression; Na(+)/H(+) exchanger 3 (NHE3) expression was increased by 24 h of incubation with tPRLs. Immunohistochemical observation showed that oPRL and both tPRLs maintained a high density of NCC- and NKA-immunoreactive ionocytes in cultured filaments. Furthermore, we found that tPRL177 and tPRL188 differentially induce expression of these ion transporters, according to incubation time. Together, these results provide evidence that ionocytes of Mozambique tilapia may function as osmoreceptors, as well as directly respond to PRL to modulate branchial ionoregulatory functions.

  18. Effects of stocking density of freshwater prawn Macrobrachium rosenbergii and addition of different levels of tilapia Oreochromis niloticus on production in C/N controlled periphyton based system

    NARCIS (Netherlands)

    Asaduzzaman, M.; Wahab, M.A.; Verdegem, M.C.J.; Mondal, M.N.; Azim, M.E.

    2009-01-01

    An on-station trial was conducted to evaluate the effect of stocking density of freshwater prawn and addition of different levels of tilapia on production in carbon/nitrogen (C/N) controlled periphyton based system. The experiment had a 2 × 3 factorial design, in which two levels of prawn stocking d

  19. The potential of mixed culture of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) and freshwater giant prawn (Macrobrachium rosenbergii) in periphyton-based systems

    NARCIS (Netherlands)

    Uddin, S.; Azim, M.E.; Wahab, M.A.; Verdegem, M.C.J.

    2006-01-01

    The production performance of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) in periphyton-based systems were studied in farmers' ponds at Mymensingh, Bangladesh. Fifteen ponds (200-300 m2 area and 1.0-1.5 m in depth) were used to c

  20. Effects of stocking density, periphyton substrate and supplemental feed on biological processes affecting water quality in earthen tilapia-prawn polyculture ponds

    NARCIS (Netherlands)

    Sharif Uddin, M.; Milstein, A.; Ekram Azim, M.; Abdul Wahab, M.; Verdegem, M.C.J.; Verreth, J.A.J.

    2008-01-01

    The technical and economic potentials of tilapia, Oreochromis niloticus (L.), and giant river prawn, Macrobrachium rosenbergii (de Man), polyculture in periphyton-based systems are under investigation in an extensive research programme. This article is a combined analysis of data from four experimen