| isolation and expression of tilapia (oreochromis niloticus) serine 8-type gnrh coding and regulatory sequences. | the complete serine 8-type gonadotropin releasing hormone (gnrh) coding sequence with a substantial 5-prime regulatory sequence (5 kb) has been isolated and characterised in nile tilapia (oreochromis niloticus) from a relevant genomic library. the primary structure of the protein precursor was identified for this gene. the promoter efficacy has been tested using 0.6 kb of the gnrh promoter driving a lacz reporter gene in both cultured spleen cells and transiently expressing zebrafish. in the cel ... | 2003 | 12568719 |
| isolation of complementary dnas coding for a receptor for activated c kinase (rack) from zebrafish (danio rerio) and tilapia (oreochromis niloticus): constitutive developmental and tissue expression. | : we have cloned and sequenced complementary dnas coding for a receptor for activated c kinase (rack) from two species of teleost fishes, zebrafish (danio rerio) and tilapia (oreochromis niloticus). the tilapia clone is 1063 nucleotides long, and the zebrafish clone is 1069 nucleotides long. both clones contain an open reading frame coding for the complete rack protein of 317 amino acids. northern hybridization analysis using these clones as probes detected a 1.2-kb band, indicating that these a ... | 1999 | 10384002 |
| potential of the microbial assay for risk assessment (mara) for assessing ecotoxicological effects of herbicides to non-target organisms. | many microbiotests that have been proposed for use in the risk assessment of environmental pollutants have the drawback of lacking relevant published data on various aspects of their test application possibilities and therefore do not receive the regulatory recognition which they may deserve. the mara bioassay lacks published data for many relevant environmental pollutants, particularly pesticides and this may limit its use in regulatory framework. the present study has assessed the sensitivity ... | 2015 | 26362569 |
| cholinesterase inhibition and behavioral toxicity of carbofuran on oreochromis niloticus early life stages. | nile tilapia oreochromis niloticus at 9 days post-hatch were exposed in semi-static experiments to the carbamate insecticide carbofuran, which is applied in agricultural systems in brazil. although the molecular mechanism of carbofuran toxicity is well known, a detailed understanding of the ecological mechanisms through which carbofuran effects can propagate towards higher levels of biological organization in fish is incomplete. mortality rates were quantified for larvae exposed for 96 h to 8.3, ... | 2011 | 21794226 |
| exploring a nonmodel teleost genome through rad sequencing-linkage mapping in common pandora, pagellus erythrinus and comparative genomic analysis. | common pandora (pagellus erythrinus) is a benthopelagic marine fish belonging to the teleost family sparidae, and a newly recruited species in mediterranean aquaculture. the paucity of genetic information relating to sparids, despite their growing economic value for aquaculture, provides the impetus for exploring the genomics of this fish group. genomic tool development, such as genetic linkage maps provision, lays the groundwork for linking genotype to phenotype, allowing fine-mapping of loci r ... | 2015 | 26715088 |
| accumulation of metals in three fish species from the yaounde municipal lake in cameroon. | metals are dangerous to aquatic organisms and they can bioaccumulate in the food chain and represent risk for humans. in order to appraise their levels in fish species, concentrations of various elements including na, mg, k, ca, al, fe, mn, cr, ni, co, cd, cu, pb, zn, ba, and sr were determined in the muscles and gills of three fish species (oreochromis niloticus, sarotherodon galilaeus, and clarias sp.) which are more fished and consumed in the yaounde municipal lake, cameroon. according to che ... | 2015 | 26251061 |
| fish genomes provide novel insights into the evolution of vertebrate secretin receptors and their ligand. | the secretin receptor (sctr) is a member of class 2 subfamily b1 gpcrs and part of the pac1/vpac receptor subfamily. this receptor has long been known in mammals but has only recently been identified in other vertebrates including teleosts, from which it was previously considered to be absent. the ligand for sctr in mammals is secretin (sct), an important gastrointestinal peptide, which in teleosts has not yet been isolated, or the gene identified. this study revises the evolutionary model previ ... | 2014 | 24906176 |
| environment and sex determination in farmed fish. | a plasticity of gonadal sex differentiation was reported in the 1930s following exogenous steroid treatments in fish, but demonstration that environmental factors (temperature, ph, density and social interactions) could influence the sex ratio in gonochoristic species has been relatively recent. in fish, as in reptiles and amphibians displaying environmental sex determination, the main environmental factor influencing sex seems to be temperature (tsd=temperature sex determination). in most therm ... | 2001 | 11738628 |
| orange-spotted grouper epinephelus coioides tak1: molecular identification, expression analysis and functional study. | in this study, the complementary (c)dna sequence encoding orange-spotted grouper epinephelus coioides tak1 (ectak1) was cloned, which has an open reading frame of 1728 bp that encodes 575 amino acids (aa). sequence analysis indicated that ectak1 contains two characteristic conserved domains, i.e. an n-terminal serine-threonine protein kinase catalytic domain (27-275 aa) and a c-terminal coiled-coil region (499-562 aa). ectak1 shares high sequence identity with tak1 from other fish species, espec ... | 2015 | 25677752 |
| construction of a microsatellites-based linkage map for the white grouper (epinephelus aeneus). | the white grouper (epinephelus aeneus) is a promising candidate for domestication and aquaculture due to its fast growth, excellent taste, and high market price. a linkage map is an essential framework for mapping quantitative trait loci for economic traits and the study of genome evolution. dna of a single individual was deep-sequenced, and microsatellite markers were identified in 177 of the largest scaffolds of the sequence assembly. the success rate of developing polymorphic homologous marke ... | 2014 | 24902605 |
| conservation of a satellite dna sequence (satb) in the tilapiine and haplochromine genome (pisces: cichlidae). | we have cloned and sequenced a 1900-bp ecori fragment (satb) from the tilapiine fish oreochromis niloticus. the satb sequence is highly reiterated in the tilapiine genome and organized in long tandem arrays. a 760-bp hindiii fragment, an internal component of satb, has also been cloned and sequenced from the related tilapiine species oreochromis hornorum. hybridization of the radiolabelled 760-bp hindiii repeat detected the presence of the satb repeat in the genomes of several tilapiine species ... | 1993 | 8458567 |
| molecular cloning, characterisation and expression analysis of melanoma differentiation associated gene 5 (mda5) of green chromide, etroplus suratensis. | innate immune system recognises pathogen-associated molecular patterns (pamps) by limited number of germline encoded and non-clonally developed pathogen recognition receptors (prrs). retinoic acid-inducible gene i (rig-i)-like receptors (rlrs) are important cytosolic prrs for sensing viral rnas. the receptor encoded by melanoma differentiation associated gene 5 (mda5), an rlr, recognises viral rna and enhances antiviral response in host cells. the full-length mda5 cdna in etroplus suratensis was ... | 2015 | 25523097 |
| bioactivity of crude ethanol extract and fractions of eugenia uniflora (myrtaceae) in the hepatopancreas of oreochromis niloticus l. | this study evaluates the bioactivity of the crude ethanol extract and ethyl acetate, hexane and chloroform fractions obtained from eugenia uniflora leaves using the hepatopancreas of oreochromis niloticus l. as an experimental model. the ethanol extract and fractions were administered to the fish orally with their feed. twenty-four hours later, the fish were sacrificed and their livers dissected, fixed in neutral formalin, embedded in paraffin and sectioned. histological analyses were performed ... | 2009 | 20140296 |
| concentrations and profiles of polycyclic aromatic hydrocarbons in some popular fish species in nigeria. | the concentrations and profiles of polycyclic aromatic hydrocarbons (pahs) in 10 popular fish species in the nigerian market were determined with a view to providing information on the health hazards associated with the consumption of these fish species. the concentrations of pahs were measured by gas chromatography-mass spectrometry after extraction by ultrasonication with acetone-dichloromethane and clean up. the concentration ranges of the σ16 pahs were 20 to 39.6 μg kg(-1) for parachanna obs ... | 2015 | 25719880 |
| pharmacodynamic interaction of spirulina platensis and deltamethrin in freshwater fish nile tilapia, oreochromis niloticus: impact on lipid peroxidation and oxidative stress. | spirulina platensis (sp) is one of the most commonly used dietary supplements in human and many animal species, including fish. recently, it has gained more attention in fish not only for its growth-promoting and immunomodulatory effects but also for its antioxidant potential. the present study was conducted to investigate the protective role of two different dietary levels of sp on freshwater nile tilapia; oreochromis niloticus exposed to subacute deltamethrin (dlm) intoxication. spirulina was ... | 2015 | 25231739 |
| toxicological effects of the herbicide oxyfluorfen on acetylcholinesterase in two fish species: oreochromis niloticus and gambusia affinis. | the alterations of the ache activity in the brains of two fresh water fishes; oreochromis niloticus and gambusia affinis were measured after exposure to acute, sub-acute and chronic concentrations from the widely used herbicide; oxyfluorfen. bioassays were conducted under controlled laboratory conditions. the used concentrations were acute: lc50 for 6 days, sub-acute 1/3 lc50 for 15 days and chronic 1/10 lc50 for 30 days. the obtained results showed marked inhibitory effects of the herbicide on ... | 2002 | 12046652 |
| a genetic linkage map of sole (solea solea): a tool for evolutionary and comparative analyses of exploited (flat)fishes. | linkage maps based on markers derived from genes are essential evolutionary tools for commercial marine fish to help identify genomic regions associated with complex traits and subject to selective forces at play during exploitation or selective breeding. additionally, they allow the use of genomic information from other related species for which more detailed information is available. sole (solea solea l.) is a commercially important flatfish species in the north sea, subject to overexploitatio ... | 2014 | 25541971 |
| comet assay and micronucleus tests on oreochromis niloticus (perciforme: cichlidae) exposed to raw sugarcane vinasse and to phisicochemical treated vinasse by ph adjustment with lime (cao). | in brazil vinasse, a main sugarcane distillery residue, stands out because every liter of alcohol generates 10-15 l of vinasse as waste. an alternative for the disposal of this waste is the fertirrigation of the sugarcane culture itself. however, the high amount released can saturate the soil and through leaching/percolation contaminate water resources. the aim of this study is verifying the toxic potential of vinasse in tilapias and effectiveness of the physicalchemical treatment of this waste ... | 2017 | 28131919 |
| dietary probiotic supplementation improves growth and the intestinal morphology of nile tilapia. | probiotic administration can be a nutritional strategy to improve the immune response and growth performance of fish. the current study aimed to evaluate the effects of a probiotic blend (bacillus sp., pediococcus sp., enterococcus sp., lactobacillus sp.) as a dietary supplement on growth performance, feed utilization, innate immune and oxidative stress responses and intestinal morphology in juvenile nile tilapia (oreochromis niloticus). the probiotic was incorporated into a basal diet at three ... | 2017 | 28077192 |
| histopathological analysis of tilapia gills (oreochromis niloticus linnaeus, 1758) exposed to sugarcane vinasse. | sugarcane vinasse is one of the main residues generated by the transformation of cane into ethanol. because of the high organic content (cod), high biochemical oxygen demand (bod), low ph, the large amount that this residue is generated (15l for every liter of ethanol produced) and their use as fertilizer on the sugarcane crop, this residue is potentially polluting to the soil ecossystem and by percolation to water ecossystem too. thus, this study aimed to assess the toxicity of vinasse by analy ... | 2017 | 27770647 |
| effects of a homeopathic complex on the performance and cortisol levels in nile tilapia (oreochromis niloticus). | intensive fish farming results in stress adversely effecting the performance of farmed fish. plasma cortisol is a validated measure of stress in fish. we evaluated the effect of a homeopathic complex on the cortisol level of nile tilapias (oreochromis niloticus). | 2014 | 24685419 |
| species of gyrodactylus von nordmann, 1832 (platyhelminthes: monogenea) from cichlids from zambezi and limpopo river basins in zimbabwe and south africa: evidence for unexplored species richness. | new findings on gyrodactylus spp. parasitising african cichlids in southern africa are presented, comprising data from zimbabwe and south africa. morphometry of opisthaptoral hard parts in combination with nuclear ribosomal dna sequences confirmed the presence of six species of gyrodactylus von nordmann, 1832. three new species are described from fishes in zimbabwe: gyrodactylus chitandiri n. sp. from the gill arches of coptodon rendalli (boulenger) and pseudocrenilabrus philander (weber); gyrod ... | 2016 | 27522367 |
| sinuolinea niloticus n. sp., a myxozoan parasite that causes disease in nile tilapia (oreochromis niloticus). | sinuolinea species are myxozoans of the order bivalvulida, suborder variisporina, and family sinuolineidae, which can be parasites for freshwater and marine fish. the aim of this study was to describe the occurrence of sinuolinea niloticus n. sp. infecting nile tilapia (oreochromis niloticus) from aquaculture and from river sources with morphological and molecular analyses. between march 2010 and november 2012, 116 nile tilapia were randomly sampled from aquaculture net fishing (n = 56) in mira ... | 2016 | 27492198 |
| 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). | 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 ( ... | 2016 | 27258552 |
| effects of dietary exposure to sulfamethazine on the hematological parameters and hepatic oxidative stress biomarkers in nile tilapia (oreochromis niloticus). | 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- ... | 2016 | 27225508 |
| assessment of benthic macroinvertebrates at nile tilapia production using artificial substrate samplers. | 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 nilotic ... | 2016 | 27191461 |
| acanthocephalan parasites (acanthogyrus sp.) of nile tilapia (oreochromis niloticus) as biosink of lead (pb) contamination in a philippine freshwater lake. | the potential use of acanthocephalans as bioindicators of lead (pb) pollution in sampaloc lake, laguna, philippines was investigated. nile tilapias (oreochromis niloticus) were collected and pb concentrations were determined in fish tissues and in their acanthocephalan parasites, acanthogyrus sp. significantly higher levels of pb were detected in the parasites relative to the fish host tissues (p = 0.001). bioaccumulation capacity of the parasites against fish tissues were 102, 119, and 147 time ... | 2016 | 27052033 |
| digestive enzyme activity in the intestine of nile tilapia (oreochromis niloticus l.) under pond and cage farming systems. | the effect of different farming systems (cage, pond) upon digestive enzyme activities of nile tilapia was evaluated. juvenile nile tilapia (87.61 ± 1.52 g) were simultaneously cultured in pond and cage systems during 90 days. cages used nutritional biphasic plan (35 and 32 % crude protein-cp feeds) and ponds used nutritional triphasic plan (35, 32 and 28 % cp feeds). biometric measurements were monthly performed for adjustments in feeding regimes and removal of intestine tissues to evaluate the ... | 2016 | 27021899 |
| integrated cytogenetics and genomics analysis of transposable elements in the nile tilapia, oreochromis niloticus. | 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 ... | 2016 | 26860923 |
| correlated changes in body shape after five generations of selection to improve growth rate in a breeding program for nile tilapia oreochromis niloticus in brazil. | body shape is a commercial trait of great interest as it impacts profit and productivity of aquaculture enterprises. in the present study, we examined correlated changes in two measures of body shape (depth to length ratio, dl-r and ellipticity of mid sagittal plane, el-h) from a selection program for high daily weight gain in a nile tilapia population reared in freshwater cages in brazil. genetic parameters for body shape and its genetic association with growth traits (body weight and daily gai ... | 2016 | 26810351 |
| estrogenic activities of diuron metabolites in female nile tilapia (oreochromis niloticus). | 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 ... | 2016 | 26741556 |
| arsenic-induced genotoxicity in nile tilapia (orechromis niloticus); the role of spirulina platensis extract. | 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 prop ... | 2015 | 26573688 |
| anti-androgenic activities of diuron and its metabolites in male nile tilapia (oreochromis niloticus). | diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a widely used herbicide which has been frequently detected in surface waters throughout the world. in vivo bioassay guided fractionation studies indicated that diuron may have estrogenic activity augmented by biotransformation. this study evaluated the effects of diuron and three of its metabolites on plasma hormone concentrations and spermatogenesis of the freshwater fish nile tilapia (oreochromis niloticus). sexually mature male fish were exp ... | 2015 | 25930013 |
| teflubenzuron as a tool for control of trichodinids in freshwater fish: acute toxicity and in vivo efficacy. | in this study we describe the anti-trichodina effects of teflubenzuron (tfb) for oreochromis niloticus and for piaractus mesopotamicus. we also evaluated the acute toxicity, for both species, by using tfb in the concentrations of 700.0, 800.0, 900.0 and 1000.0 mg l(-1) and a control, without the drug. to assess the efficacy of tfb against trichodina spp., we used the concentrations of 30.0 or 50.0 mg l(-1) for one hour exposure in tilapia, and the concentration of 30.0, 50.0 and 80.0 mg l(-1) fo ... | 2015 | 25913667 |
| the potential effects of spirulina platensis (arthrospira platensis) on tissue protection of nile tilapia (oreochromis niloticus) through estimation of p53 level. | the current study was designed to investigate the potential effect of spirulina platensis, arthrospira platensis, (sp) on tissue protection of nile tilapia (oreochromis niloticus) through estimation of p53 level. five isonitrogenous and isocaloric rations containing graded levels of dried sp 5, 7.5,10, 15, and 20 g/kg diet were fed separately to five equal groups of o. niloticus fingerlings, additional control group was assigned for 3 months. liver samples were separately collected from each gro ... | 2014 | 25685480 |
| first records of ambiphrya and vorticella spp. (protozoa, ciliophora) in cultured nile tilapia (oreochromis niloticus) in the central region of saudi arabia. | 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. | 2014 | 25473359 |
| in vitro mucus transportability, cytogenotoxicity, and hematological changes as non-destructive physiological biomarkers in fish chronically exposed to metals. | the biomonitoring of fish using biomarkers represents a useful tool for the assessment of aquatic pollution. this study evaluated the sublethal toxic effects of aquatic pollution on fish collected from a site contaminated by metals. water and fish (oreochromis niloticus) samples were collected from a pond in the parque ecológico do tietê (pet) that lies along the tietê river (são paulo, brazil), and from a control site (an experimental fish farm). the metal content of the water was evaluated, an ... | 2015 | 25463867 |
| ecotoxicological effects of carbofuran and oxidised multiwalled carbon nanotubes on the freshwater fish nile tilapia: nanotubes enhance pesticide ecotoxicity. | 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 carb ... | 2015 | 25450925 |
| e2 potentializes benzo(a)pyrene-induced hepatic cytochrome p450 enzyme activities in nile tilapia at high concentrations. | in the aquatic environment, biotransformation enzymes are established biomarkers for assessing pah exposure in fish, but little is known about the effect of 17β-estradiol (e2) on these enzymes during exposure to benzo(a)pyrene (bap). in this study, nile tilapia (oreochromis niloticus) were exposed for 3, 5, and 10 days to bap (300 μg l(-1)) and e2 (5 μg l(-1)). these substances were applied isolated or mixed. in the mixture experiment, fish were analyzed pre- and postexposure in order to better ... | 2015 | 25280508 |
| sugar cane vinasse in water bodies: impact assessed by liver histopathology in tilapia. | aquatic ecosystems are the main receptors of toxic substances from human activities. with the increase in sugar cane production, vinasse - the main residue of ethanol production - is a potential contaminant of water resources, due to its high organic matter content. this study was aimed at evaluating the toxicity of vinasse by examining the liver of the fish oreochromis niloticus exposed to different dilutions of sugar cane vinasse (1%, 2%, 5%, 5% and 10%) in laboratory bioassays. portions of li ... | 2014 | 25265025 |
| hematological changes and cytogenotoxicity in the tilapia oreochromis niloticus caused by sub-chronic exposures to mercury and selenium. | fish bioassays are valuable tools that can be used to elucidate the toxicological potential of numerous substances that are present in the aquatic environment. in this study, we assessed the antagonistic action of selenium (se) against the toxicity of mercury (hg) in fish (oreochromis niloticus). six experimental groups with six fish each were defined as follows: (1) control, (2) mercury (hgcl(2)), (3) sodium selenite (na(2)se(4)o(3)), (4) sodium selenate (na(2)se(6)o(4)), (5) mercury + sodium s ... | 2015 | 25216806 |
| biomarker responses as indication of contaminant effects in oreochromis niloticus. | the current study investigated oxidative stress parameters (enzymes activities, metallothionein content and lipid peroxidation) in freshwater fish, oreochromis niloticus, tilapia exposure to monjolinho river (in 4 months of year: january, april, july and november). one critical site in monjolinho river (site b) was assessed in comparison to a reference site (site a). water ph and oxygen concentration was lower than that recommended by conama (brazilian national environmental committee), resoluti ... | 2012 | 22583787 |
| parasite community of wild and cultured oreochromis niloticus from lake manzalah, egypt. | a total of 323 o. niloticus (168 wild fishes and 155 cultured fishes) were collected from lake manzala, egypt from july to september 2010. the fish samples were examined for both ectoparasites and endoparasites. the parasite community of wild and cultured, o. niloticus consisted of ten parasitic species, one protozoon (trichodina spp.), six monogenea (cichlidogyrus sclerosus, c. thurstonae, c. halli typicus, c. tilapiae, c. ergensi, c. tiberianus), one acanthocephalan (acanthogyrus (acanthosenti ... | 2011 | 22435161 |
| ecological risk assessment of the antibiotic enrofloxacin applied to pangasius catfish farms in the mekong delta, vietnam. | antibiotics applied in aquaculture production may be released into the environment and contribute to the deterioration of surrounding aquatic ecosystems. in the present study, we assessed the ecological risks posed by the use of the antibiotic enrofloxacin (enr), and its main metabolite ciprofloxacin (cip), in a pangasius catfish farm in the mekong delta region, vietnam. water and sediment samples were collected in a stream receiving effluents from a pangasius catfish farm that had applied enr. ... | 2015 | 25063964 |
| nickel exposure promotes osmoregulatory disturbances in oreochromis niloticus gills: histopathological and energy dispersive spectrometry analysis. | water is an essential factor for maintaining the vital functions of living beings. nickel is the 24th most abundant element on earth; it is a heavy metal that is genotoxic and mutagenic in its chloride form. due to industrial use, its concentration in surface sediments increased considerably. fish develop characteristics that make them excellent experimental models for studying aquatic toxicology. they are particularly useful because they can alert of the potential danger of chemical substances ... | 2014 | 24996943 |
| the influence of fish cage culture on δ13c and δ15n of filter-feeding bivalvia (mollusca). | the objective of this study was to evaluate the effect of oreochromis niloticus cage culture promoted variations in the δ13c and δ15n in corbicula fluminea (mollusca; bivalvia) and in the sediment of an aquatic food web. samples were taken before and after net cage installation in the rosana reservoir (paranapanema river, pr-sp). samples of specimens of the bivalve filterer c. fluminea and samples of sediment were collected using a modified petersen grab. all samples were dried in an oven (60 °c ... | 2013 | 24789389 |
| eye darkening as a reliable, easy and inexpensive indicator of stress in fish. | we expand the use of eye darkening (ed) to indicate non-social stress in the fish nile tilapia oreochromis niloticus (l.). ed is easily estimated, not requiring any sophisticated equipment, and is non-invasive, facilitating the collection of several measures of stress over time. in the current study, we showed the following: (i) high- and low-ed occur spontaneously, indicating different fish reactions to adjustments to a novel environment; (ii) fish confinement or air exposure clearly increases ... | 2014 | 24783997 |
| bile and liver metallothionein behavior in copper-exposed fish. | the present study analyzed metallothionein (mt) excretion from liver to bile in nile tilapia (oreochromis niloticus) exposed to sub-lethal copper concentrations (2mgl(-1)) in a laboratory setting. mts in liver and bile were quantified by spectrophotometry after thermal incubation and mt metal-binding profiles were characterized by size exclusion high performance liquid chromatography coupled to icp-ms (sec-hplc-icp-ms). results show that liver mt is present in approximately 250-fold higher conce ... | 2014 | 24210855 |
| impact of introduced nile tilapia (oreochromis niloticus) on non-native aquatic ecosystems. | the global invasion of non-native aquatic ecosystems by nile tilapia (oreochromis niloticus) is well documented and coincides with their increased use as an aquaculture species. aquaculture can be defined as the farming of fish or other aquatic organisms and it varies considerably in terms of production practices. generally, freshwater finfish, such as nile tilapia, are reared in inland ponds (closed systems). however, in several countries, floating cages are increasingly used to rear nile tilap ... | 2013 | 24171273 |
| a simple method for the determination of fluoroquinolone residues in tilapia (oreochromis niloticus) and pacu (piaractus mesopotamicus) employing lc-ms/ms qtof. | the use of antimicrobials in livestock production is a powerful resource applied throughout the world to guarantee high yield and control bacterial diseases in aquaculture. however, residues of these substances in animal products represent a potential risk to consumer health when residue levels are above the established maximum residue limits (mrls). fluoroquinolones (fqs) are antimicrobials commonly used worldwide in aquaculture. the aim of this work was to develop and validate a simple analyti ... | 2013 | 23731191 |
| branchial o(2) chemoreceptors in nile tilapia oreochromis niloticus: control of cardiorespiratory function in response to hypoxia. | this study examined the distribution and orientation of gill o(2) chemoreceptors in oreochromis niloticus and their role in cardiorespiratory responses to graded hypoxia. intact fish, and a group with the first gill arch excised (operated), were submitted to graded hypoxia and their cardiorespiratory responses (oxygen uptake - v˙o(2) , breathing frequency - fr, ventilatory stroke volume - vt, gill ventilation - v˙g, o(2) extraction from the ventilatory current - eo(2) , and heart rate - fh) were ... | 2013 | 23651928 |
| short periods of fasting followed by refeeding change the expression of muscle growth-related genes in juvenile nile tilapia (oreochromis niloticus). | muscle growth mechanisms are controlled by molecular pathways that can be affected by fasting and refeeding. in this study, we hypothesized that short period of fasting followed by refeeding would change the expression of muscle growth-related genes in juvenile nile tilapia (oreochromis niloticus). the aim of this study was to analyze the expression of myod, myogenin and myostatin and the muscle growth characteristics in the white muscle of juvenile nile tilapia during short period of fasting fo ... | 2013 | 23416085 |
| expanded description of lamproglena monodi (copepoda: lernaeidae), parasitizing native and introduced fishes in brazil. | an occurrence of the copepod lamproglena monodi capart, 1944, parasitizing freshwater fishes in brazil is presented, along with new morphological data. this crustacean was originally described parasitizing several cichlids in africa. in the present study, the crustaceans were collected from the body surface and gills of two fish species native to brazil [astronotus ocellatus (agassiz, 1831) and cichla ocellaris bloch and schneider, 1801] and two introduced species [oreochromis niloticus (linnaeu ... | 2012 | 23070437 |
| environmental and physiological conditions affecting tetrahymena sp. infection in guppies, poecilia reticulata peters. | parasitic infections caused by tetrahymena sp. constitute a serious problem in guppies, poecilia reticulata. tetrahymena was isolated from skin lesions of naturally infected guppies in a commercial aquaculture farm, cultured in vitro and used in subsequent experimental infections. in addition to guppies, angelfish, pterophyllum scalare, platyfish, xiphophorus maculates, and neontetra, paracheirodon innesi, were susceptible, whereas tilapia (oreochromis niloticus xo. aureus) was resistant. the ci ... | 2005 | 16266327 |
| evolutionary dynamics of rrna gene clusters in cichlid fish. | among multigene families, ribosomal rna (rrna) genes are the most frequently studied and have been explored as cytogenetic markers to study the evolutionary history of karyotypes among animals and plants. in this report, we applied cytogenetic and genomic methods to investigate the organization of rrna genes among cichlid fishes. cichlids are a group of fishes that are of increasing scientific interest due to their rapid and convergent adaptive radiation, which has led to extensive ecological di ... | 2012 | 23035959 |
| ancyrocephalidae (monogenea) of lake tanganyika: iii: cichlidogyrus infecting the world's biggest cichlid and the non-endemic tribes haplochromini, oreochromini and tylochromini (teleostei, cichlidae). | lake tanganyika is the deepest and oldest african great lake and of economic importance. while the diversity of its endemic cichlid radiations yielded scientific interest, a number of cichlid tribes have few representatives in the lake. some of those, namely oreochromini (ex-tilapiini), haplochromini and tylochromini, reach higher species numbers in riverine systems. conversely, the phylogenetic position of the monospecific and endemic boulengerochromini is unclear. the oreochromines oreochromis ... | 2012 | 22983218 |
| environmental color affects nile tilapia reproduction. | 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 rep ... | 2004 | 15064810 |
| analysis of diflubenzuron in tilapia filet by hplc-dad. | a simple and efficient new procedure is presented for the analysis of diflubenzuron (dfb) accumulation in tilapia (oreochromis niloticus) filet. a liquid-chromatography (lc) with diode array detection method with c(18) solid-phase extraction clean-up was employed. the methods exhibit no significant matrix effect as verified by the recovery efficiency. the limits of detection and quantification were 32 microg/kg and 110 microg/kg, respectively. lc-tandem mass spectrometry analysis confirmed the p ... | 2009 | 19835689 |
| comparative cytogenetics of cichlid fishes through genomic in-situ hybridization (gish) with emphasis on oreochromis niloticus. | cichlidae is the most species-rich freshwater family of perciformes and has attracted the attention of aquarium hobbyists, aquaculturists, and sport fisherman. oreochromis niloticus is very important in aquaculture today and is currently used in varied areas of study as an 'experimental model'. oreochromis niloticus has been characterized using classical and molecular cytogenetic techniques, with special attention paid to heterochromatin structure and the identification of sex chromosomes. in th ... | 2009 | 19685270 |
| genomic content and new insights on the origin of the b chromosome of the cichlid fish astatotilapia latifasciata. | b chromosomes are additional chromosomes widely studied in a diversity of eukaryotic groups, including fungi, plants and animals, but their origin, evolution and possible functions are not clearly understood. to further understand the genomic content and the evolutionary history of b chromosomes, classical and molecular cytogenetic analyses were conducted in the cichlid fish astatotilapia latifasciata, which harbor 1–2 b chromosomes. through cytogenetic mapping of several probes, including trans ... | 2011 | 22286964 |
| copper sulfate affects nile tilapia (oreochromis niloticus) cardiomyocytes structure and contractile function. | copper sulfate (cuso(4))is an inorganic chemical product worldwide used as an algaecide and a fungicide in aquaculture and agriculture and being discharged into freshwater environments where it can affect the freshwater fauna, especially fishes. the impact of copper on fish cardiac function was analyzed in two groups of nile tilapias, oreochromis niloticus (control group and group exposed to 1 mg l(-1) of cuso(4) for 96 h). structural and ultra-structural changes were studied and related to pert ... | 2012 | 22160950 |
| levels of copper in nile tilapia from brazil. | the purpose of this work was to determine the concentration of copper in samples of farmed nile tilapia (oreochromis niloticus l.) fillets purchased in the city of botucatu (são paulo, brazil) and in fillet and liver samples of tilapia fed diets supplemented with different concentrations of cu from the laboratory of aquatic organism nutrition/fmvz-unesp (botucatu, brazil). the fillet samples were prepared by lyophilisation and cryogenic grinding into particles smaller than 60 µm, and copper was ... | 2011 | 24786245 |
| infection patterns of nile tilapia (oreochromis niloticus l.) by two helminth species with contrasting life styles. | the larval stages of bolbophorus sp. (digenean) and amirthalingamia macracantha (cestode) are frequently reported in oreochromis niloticus in uganda. little, however, is known about their infection patterns. this study examined the influence of habitat type, host size, and sex and weather patterns on the parasite populations in uganda. a total of 650 fish were collected between january and november 2008 from a reservoir, cages, fishponds and a stream. the prevalence and intensity of a. macracant ... | 2012 | 21972071 |
| positive darwinian selection drives the evolution of the morphology-related gene, epcam, in particularly species-rich lineages of african cichlid fishes. | the study of genetic evolution within the context of adaptive radiations offers insights to genes and selection pressures that result in rapid morphological change. cichlid fishes are very species-rich and variable in coloration, behavior, and morphology, and so provide a classical model system for studying the genetics of adaptive radiation. in this study, we researched the evolution of the epithelial cell adhesion molecule (epcam), a candidate gene for the adaptive evolution of morphology broa ... | 2011 | 21811860 |
| biochemical biomarkers in nile tilapia (oreochromis niloticus) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends. | fossil fuels such as diesel are being gradually replaced by biodiesel, a renewable energy source, cheaper and less polluting. however, little is known about the toxic effects of this new energy source on aquatic organisms. thus, we evaluated biochemical biomarkers related to oxidative stress in nile tilapia (oreochromis niloticus) after two and seven exposure days to diesel and pure biodiesel (b100) and blends b5 and b20 at concentrations of 0.01 and 0.1 ml l(-1). the hepatic ethoxyresorufin-o-d ... | 2011 | 21683976 |
| comparative susceptibility of two different genetic types of tilapia to neobenedenia sp. (monogenea). | two different genetic types of tilapia, mozambique tilapia oreochromis mossambicus (mt), and pargo-unam (pu; a synthetic hybrid whose genetic composition is 50% florida red tilapia, 25% rocky mountain tilapia, and 25% red variant oreochromis niloticus), were acclimatized to salinity and exposed to seawater from the gulf of mexico off the port of veracruz, mexico. both fish types were infected by the monogenean ectoparasite neobenedenia sp. and were killed within 2 to 3 wk. a crude worm extract w ... | 2011 | 21381523 |
| seasonal and ontogenetic variations in the diet of cichla kelberi kullander and ferreira, 2006 introduced in an artificial lake in southeastern brazil. | the diet of cichla kelberi introduced in an artificial lake in leme-sp was predominantly composed of common fish species (oreochromis niloticus and c. kelberi). in the spring and summer, the most consumed item was o. niloticus. however, cannibalism was very common for this species. the high frequencies of o. niloticus and c. kelberi reveal that this species is adapted to a seasonal cycle, feeding on the most common prey in each period of the year, with a reduction of foraging activity during the ... | 2010 | 21180910 |
| substratum choice for nesting in male nile tilapia oreochromis niloticus. | four substrata were offered to groups of adult nile tilapia oreochromis niloticus (one male and two females) simultaneously: pure sand, a mixture of sand and shells, stones and no substratum. the results showed that males chose to dig nests in a lighter and more homogeneous substratum. | 2010 | 21039515 |
| aluminum as an endocrine disruptor in female nile tilapia (oreochromis niloticus). | the effects of aluminum on plasma ion, lipid, protein and steroid hormone concentration were evaluated in oreochromis niloticus broodstock females. lipid and protein concentrations from the gonads and liver were also measured. experiments were performed at neutral and acidic water ph. four groups of fish were tested for 96h: 1) control conditions at neutral water ph; 2) control conditions at acidic water ph (ctr-ac); 3) aluminum at neutral water ph (al-n); and 4) aluminum at acidic water ph (al- ... | 2010 | 20167288 |
| biochemical biomarkers in oreochromis niloticus exposed to mixtures of benzo[a]pyrene and diazinon. | biochemical biomarkers (the activities of acetylcholinesterase, 7-ethoxyresorufin-o-deetilase, carboxylesterase, catalase, glutathione peroxidase and glutathione s-transferase) were evaluated in nile tilapia (oreochromis niloticus) that had been exposed to benzo[a]pyrene (bap) and the organophosphate pesticide diazinon (dz), at 0.5mg/l. the animals were pre-exposed to bap for three days, and dz was then added to both non-exposed and pre-exposed groups, being exposed for 2 and 7 additional days. ... | 2010 | 20149458 |
| the use of histological, histochemical and ultramorphological techniques to detect gill alterations in oreochromis niloticus reared in treated polluted waters. | fish gills are constituted by primary filaments and secondary lamellae, which are formed, basically, by three different cell types: pillar cells, respiratory cells and erythrocytes that circulate in the lamellae interior. this respiratory organ is very appreciated in environmental studies since it is constantly in contact with the water, accomplishing exchanges; besides this, it presents a high adaptation capacity. in this work, some fishes were reared in polluted waters treated by the flotation ... | 2009 | 19656687 |
| sex group composition, social interaction, and metabolism in the fish nile tilapia. | we tested whether the fish nile tilapia (oreochromis niloticus) in a monosex male group spends more energy and displays an agonistic profile, differently from males in male-female groups. such differences are expected because males and females should compete for different reproductive resources. an intruder male (mm) or female (mf) was paired with a resident male and agonistic interaction was quantified during 20 minutes, 10 minutes after pairing and another 10 minutes period 30 minutes later. e ... | 2008 | 19197498 |
| application of the comet assay in erythrocytes of oreochromis niloticus (pisces): a methodological comparison. | the present study applied the comet assay to erythrocytes of oreochromis niloticus with the aim of improving protocols to detect dna damage in these cells, by using two distinct phs (ph = 12.1 and ph > 13) and evaluating whether there is a correspondence between silver and ethidium bromide staining. comets were visually examined and, the frequency of cells with and without damage was obtained, as well as the distribution of classes and scores. by using the kruskal-wallis test, our results reveal ... | 2009 | 21637662 |
| selenite and selenate effects on mercury (hg(2+)) uptake and distribution in tilapia, oreochromis niloticus l., assessed by chronic bioassay. | aquatic organisms are considered excellent biomarkers of mercury (hg) occurrence in the environment. selenium (se) acts in antagonism to this metal, stimulating its elimination, and reducing its toxicity. in this paper, tilapia (oreochromis niloticus) were chronically acclimated in sub-lethal hg(2+), hg(2+) + se(4+) and hg(2+) + se(6+) concentrations. distribution and bioaccumulation of both elements were evaluated in fish tissues. the kidney was the main target of the hg and se uptake, and the ... | 2009 | 19034371 |
| induction of micronucleus and nuclear alterations in fish (oreochromis niloticus) by a petroleum refinery effluent. | in this study, micronucleus and nuclear alterations tests were performed on erythrocytes of oreochromis niloticus (perciformes, cichlidae) in order to evaluate the water quality of the atibaia river, in an area that receives effluents discharge of a petroleum refinery and also to evaluate the effectiveness of the treatments used by the refinery. water samples were collected in five different sites related with a refinery from são paulo state, brazil. for the micronucleus and nuclear alterations ... | 2008 | 18692593 |
| comparison of gastropod mollusc (apogastropoda: hydrobiidae) habitats in two crater lakes in nicaragua. | the aquatic gastropod mollusc, pyrgophorus coronatus, may perform an important role in the transmission of an emergent ocular pathology among fishes in lake apoyo, nicaragua. this disease emerged after an introduction of tilapia (oreochromis niloticus) and the subsequent loss of chara sp. beds in the lake. we compared the mollusc population densities in three habitats (sandy/muddy substrates, rocks, and chara vegetation) at varying depths (1.5, 10, 20, and 30 m) in two volcanic crater lakes in n ... | 2008 | 18624230 |
| physical chromosome mapping of repetitive dna sequences in nile tilapia oreochromis niloticus: evidences for a differential distribution of repetitive elements in the sex chromosomes. | repetitive dnas have been extensively applied as physical chromosome markers on comparative studies, identification of chromosome rearrangements and sex chromosomes, chromosome evolution analysis, and applied genetics. here we report the characterization of repetitive dna sequences from the nile tilapia (oreochromis niloticus) genome by construction and screening of plasmid library enriched with repetitive dnas, analysis of a bac-based physical map, and hybridization to chromosomes. the physical ... | 2008 | 17395473 |
| genomic organization and evolution of the 5s ribosomal dna in tilapiini fishes. | 5s rdna sequences present an intense dynamism and have proved to be valuable as genetic markers to distinguish closed related species and also in the understanding of the evolutionary dynamic of repetitive sequences in the genomes. in order to identify patterns of 5s rdna organization and their evolution in the genome of fish species, such genomic segment was investigated in the tilapias oreochromis niloticus and tilapia rendalli, and in the hybrid o. urolepis hornorum x o. mossambicus. a dual 5 ... | 2006 | 16850228 |
| micronucleus test and observation of nuclear alterations in erythrocytes of nile tilapia exposed to waters affected by refinery effluent. | micronuclei and nuclear alterations tests were performed on erythrocytes of oreochromis niloticus (perciformes, cichlidae) in order to evaluate the water quality from paraíba do sul river, in an area affected by effluents from an oil shale processing plant, located in the city of são josé dos campos, brazil-sp. water samples were collected on 2004 may and august (dry season) and on 2004 november and 2005 january (rain season), in three distinct sites, comprising 12 samples. it was possible to de ... | 2006 | 16678473 |
| morphological aspects of muscle regeneration in the nile tilapia (oreochromis niloticus). | the aim of our study was to analyze the morphological events in the skeletal muscle of the nile tilapia (oreochromis niloticus) after a traumatic lesion. thirty-two fish were used, on which a small longitudinal incision was made in the muscle. the fish were sacrificed after 7, 14, 21, and 42 days and muscle samples were collected from the lesion and processed for morphological analysis. muscle regeneration in the tilapia occurred gradually through the analyzed period, possibly due to the prolife ... | 2005 | 15906608 |
| the ultrastructure of the intestinal epithelium in oreochromis niloticus on a diet with different concentrations of zinc. | the effects of diets with variable zinc levels on the midgut epithelial cells were studied in oreochromis niloticus l. one hundred and twenty fry of tilapia were apportioned into 4 experimental groups (i, ii, iii and iv groups), with 30 fish in each treatment, 5 replicate aquaria per treatment containing 6 fish each. the animals of the 4 groups were fed with isonitrogenous (30% crude protein) and isoenergetic (3000 kcal/kg of digestible energy) diets with increasing quantities of zinc (44.59; 14 ... | 2004 | 15311680 |
| caution for using ventilatory frequency as an indicator of stress in fish. | this study tested the use of ventilatory frequency (vf) as an indicator of stress in the nile tilapia, oreochromis niloticus (l.). firstly, we tested the relationship between vf and plasma cortisol after confinement. confined fish showed higher vf and plasma cortisol levels, but the latter continued to increase significantly for longer time than vf. secondly, we conducted another experiment to test the use of vf as indicator of fish stress. in four out of six treatment, we confined the fish for ... | 2004 | 15062970 |
| four new species of cichlidogyrus paperna, 1960 (monogenea, ancyrocephalidae), all gill parasites from african mouthbreeder tilapias of the genera sarotherodon and oreochromis (pisces, cichlidae), with a redescription of c. thurstonae ergens, 1981. | a study of oreochromis niloticus (linnaeus), o. aureus (steindachner), sarotherodon caudomarginatus (boulenger), s. galilaeus (linnaeus) and s. galilaeus sanagaensis (thys van den audenaerde) (teleostei, cichlidae) from different locations in africa (burkina faso, cameroon, guinea, niger and senegal) revealed the presence of 11 species of monogenean gill parasites. four, belonging to cichlidogyrus paperna, 1960 and considered as new species, are described: c. rognoni n. sp., c. douellouae n. sp. ... | 2003 | 14707506 |
| effect of the establishment of dominance relationships on cortisol and other metabolic parameters in nile tilapia (oreochromis niloticus). | 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 ... | 2003 | 14666258 |
| eye color as an indicator of social rank in the fish nile tilapia. | we investigated the association of eye color with the dominant-subordinate relationship in the fish nile tilapia, oreochromis niloticus. eye color pattern was also examined in relation to the intensity of attacks. we paired 20 size-matched fish (intruder: 73.69 11.49 g; resident: 75.42 8.83 g) and evaluated eye color and fights. these fish were isolated in individual aquaria for 10 days and then their eye color was measured 5 min before pairing (basal values). twenty minutes after pairing, eye c ... | 2003 | 14666250 |
| dynamics of 5s rdna in the tilapia (oreochromis niloticus) genome: repeat units, inverted sequences, pseudogenes and chromosome loci. | in higher eukaryotes, the 5s ribosomal dna (5s rdna) is organized in tandem arrays with repeat units composed of a coding region and a non-transcribed spacer sequence (nts). these tandem arrays can be found on either one or more chromosome pairs. 5s rdna copies from the tilapia fish, oreochromis niloticus, were cloned and the nucleotide sequences of the coding region and of the non-transcribed spacer were determined. moreover, the genomic organization of the 5s rdna tandem repeats was investigat ... | 2002 | 12584446 |
| ventilatory frequency indicates visual recognition of an allopatric predator in nai;ve nile tilapia. | perceiving a possible predator may promote physiological changes to support prey 'fight or flight'. in this case, an increase in ventilatory frequency (vf) may be expected, because this is a way to improve oxygen uptake for escape tasks. therefore, changes in vf may be used as a behavioral tool to evaluate visual recognition of a predator threat. thus, we tested the effects of predator visual exposure on vf in the fish nile tilapia, oreochromis niloticus. for this, we measured tilapia vf before ... | 2003 | 12505177 |
| melanophore appearance in wild and red tilapia embryos. | red tilapia has aroused interest in many countries for its commercial potential. this tilapia strain combines a desirable coloration and appearance with other advantageous farming characteristics. to study the early appearance of melanophore pigmentation in tilapia, a red tilapia strain originating from thailand and a wild type coloration of oreochromis niloticus were used as broodstock to produce artificially wild x wild and red x red progenies. the larvae were assessed periodically up to the f ... | 2002 | 11837457 |
| histoenzymological and ultrastructural changes in lateral muscle fibers of oreochromis niloticus (teleostei: cichlidae) after local injection of veratrine. | the effects of veratrine have been investigated in mammalian, amphibian, and crustacean muscle, but not in fish. in this work, the action of veratrine was studied in the lateral muscle of the freshwater teleost oreochromis niloticus after intramuscular injection. histoenzymological typing and electron microscopy of muscle fibers before and 15, 30, and 60 min after veratrine injection (10 ng/kg fish) were used to indirectly assess the morphological changes and the oxidative and m-atpase activitie ... | 2001 | 11810194 |
| environmental blue light prevents stress in the fish nile tilapia. | the present study aimed to test the effects of blue, green or white light on the stress response of the nile tilapia, oreochromis niloticus (l.). each color was tested on two groups of isolated adult nile tilapia (8 replicates each): one being subjected to confinement stress, and the other not (control). a different environmental color was imposed on each compartment by covering the light source with cellophane of the respective color (green or blue; no cellophane was used for white light). the ... | 2001 | 11471044 |
| cardiac tissue function of the teleost fish oreochromis niloticus under different thermal conditions. | the cardiac responses of oreochromis niloticus acclimated to 25 degrees c were assessed using ventricle strips mounted for isometric force recording (fc) and in vivo heart rate (f(h)). f(h) increased progressively from 25 to 40 degrees c. at extracellular ca(2+) concentrations of 1.25 and 9.25 mm, a transition from 25 to 40 degrees c resulted in a decreased fc. at both 25 and 40 degrees c, fc rose when [ca(2+)] was increased from 1.25 to 9.25 mm. fc remained constant at 72 and 120 contractions.m ... | 2000 | 10838176 |
| systemic zygomycosis in farmed tilapia fish. | decreased feed intake and persistent low-level mortality in a production tank of hybrid tilapia (oreochromis niloticus x oreochromis mossambicus x oreochromis aureus) prompted the submission of three affected fish for diagnosis. consistent macrosopical findings included multifocal dermal haemorrhage, excess abdominal fluid and an enlarged friable liver. on microscopical examination, broad non-septate fungal hyphae and chlamydospores were identified within numerous internal organs, often within a ... | 1999 | 10486168 |
| chemical communication, aggression, and conspecific recognition in the fish nile tilapia. | the chemical modulation of agonistic behavior and conspecific recognition were tested in juveniles of the fish nile tilapia, oreochromis niloticus (l.). after a 7-day isolation period, the fish were grouped (four individuals per aquarium) for 7 days. then fish of alpha and beta ranks (previously matched for similar size) were paired in a neutral territory for analysis of their agonistic interaction. pairs composed of alpha and beta fish were established with either fish from the same group (fami ... | 1997 | 9383122 |
| [larval clinostomum infection of cichlid fish in the lake of kompienga in burkina faso: a menace to haleutic exploitation and public health]. | clinostomum sp. is a trematode, a parasitic worm, of which the larva infest a number of species of wild fish. in intertropical africa and particularly in artificial lakes in the east of burkina faso, the infestation is especially observed in the cichlids fish. because cichlids constitute 80 to 90% of the fish catches, enzootic infestation could infringe upon the fisheries, and also adversely affect public health. for this epidemiological study conducted during the first three quarters of 1994, w ... | 2006 | 7640902 |
| heterogeneous growth in the nile tilapia: social stress and carbohydrate metabolism. | increase in heterogeneous growth as a result of grouping in the nile tilapia, oreochromis niloticus (l.), is presumed to be partially promoted by the social stress imposed by the dominant fish on the subordinates. such stress may decrease the energy available for growth. in this study, the effect of social stress on carbohydrate metabolism was studied in adult, growing males. all animals were deprived of food during the experimentation period and pairing was imposed for either 2 or 4 days. glyce ... | 1993 | 8372127 |
| 2-deoxyglucose-induced food intake by nile tilapia, oreochromis niloticus (l.). | the alimentary and glycemic responses to cytoglycopenia were studied in thirty-one nile tilapia alevins of indeterminate sex and age, measuring on average 10.67 +/- 0.82 cm. the cytoglycopenia was provoked by ip injection of 60 mg/kg 2-deoxy-d-glucose (2-dg, n = 16). the control group (n = 15) was submitted to ip injection of 0.2 ml saline. blood samples for glucose determination were obtained before and three hours after drug administration by cardiac puncture. food was then offered ad libitum. ... | 1993 | 8257932 |
| loma camerounensis sp. nov. (protozoa:microsporida) a parasite of oreochromis niloticus linnaeus, 1757 (teleost:cichlidae) in fish-rearing ponds in melen, yaoundé, cameroon. | a new microsporidian, loma camerounensis, was found in the cichlidae oreochromis niloticus from the melen fish-rearing station in yaoundé, cameroon. xenomas were located in the gut from the oesophagus to the intestine, but preferentially in the duodenum. dimensions of the fresh spores were 3.96 x 2.16 microns. the ultrastructural study indicated the following characteristics: parasite stages arranged in a random, unstratified manner in the xenoma; merogony by multiple fission; sporogonic stages ... | 1992 | 1589428 |
| does snatching frequency really indicate food ingestion in the nile tilapia? | the fitness of the snatching frequency as an indicator of food intake in nile tilapia fingerlings, oreochromis niloticus (l), was studied. five groups of four individuals each were used after a two-day starvation period. the hierarchical rank among individuals in the same group was registered. food in the form of tiny pellets (ranging from 1.30 to 1.95 mm in diameter) was offered, and the individual snatching frequency was observed during a 20-min period. the animals were then sacrificed for eva ... | 1991 | 1800999 |