Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| effect of fasting on glucose turnover in a carnivorous fish (hoplias sp). | intravenous glucose tolerance tests and measurements with [6-3h]glucose of rate of glucose replacement, transit time, and body glucose mass were performed in fed and fasted hoplias malabaricus. both glycemia levels and the rate of decline of blood glucose following intravenous administration of 500 mg/kg glucose were significantly lower in 60-day-fasted than in fed fish. changes in plasma free fatty acids were opposite to those in blood glucose. the rate of glucose replacement, calculated graphi ... | 1989 | 2923251 |
| [nutritional and sensory evaluation of macaroni supplemented with fish protein concentrate]. | the present work consisted of the supplementation of macaroni with fish protein concentrate (fpc) at the levels of 5, 10, 15, and 20% in relation to wheat flour. the fpc was obtained from eviscerated and deboned trairas (hoplias malabaricus), using boiling ethanol as a solvent at a ph range of 5.5 to 6.0. the fpc showed desirable aspects such as bright color, no off-flavor, high levels of protein (84.3 g/100 g) and lysine (484 mg/g n) and low levels of fat (0.4 mg/100 g) and moisture (8.6 g/100 ... | 1990 | 2133183 |
| dependence on body size of respiratory function in hoplias malabaricus (teleostei, erythrinidae) during graded hypoxia. | oxygen uptake and ventilatory responses to environmental hypoxia were assessed for two groups of hoplias malabaricus of nearly tenfold different body weights (mean weights, group i = 39 g; group ii = 365 g). the main purpose of the study was to evaluate the relationships between body weight and the critical o2 tension (pco2) for maintenance of normal resting o2 uptake. the smaller specimens had a threefold larger weight-specific o2 uptake compared to that of the larger specimens. moreover, small ... | 1993 | 24202624 |
| henneguya malabarica sp. nov. (myxozoa, myxobolidae) in the amazonian fish hoplias malabaricus. | henneguya malabarica sp. nov. is described from the amazonian teleost fish hoplias malabaricus boch, 1794, collected from the estuarine region of the amazon river near belém, brazil. plasmodia were represented by several vegetative nuclei, generative cells, and sporogony stages contained in cyst-like plasmodia. the spore body was ellipsoidal (12.6 microns in length and 4.8 x 3.6 microns in width) and each valve presented a tapering tail (17.1 microns in length). thin valves surrounded the binucl ... | 1996 | 8801553 |
| light and electron microscopic study of a myxosporean, tetrauronema desaequalis n. sp. (fam. tetrauronematidae), from an amazonian fish. | tetrauronema desaequalis n. sp. described from the bases of the ventral fins of the teleost hoplias malabaricus boch, 1794, was collected in an estuarine region of the amazon river near belem, brazil. this myxosporean produces large cysts (1-2 mm in diameter) that represent plasmodia containing all life cycle stages, including spores. spores averaged 22.5 microns in total length and possess 2 pairs of posterolateral unequal projections extending from beside the sutural ridges near the terminus o ... | 1996 | 8604098 |
| the x1x2y sex chromosome system in the fish hoplias malabaricus. i. g-, c- and chromosome replication banding. | hoplias malabaricus, a widely distributed neotropical fish (central america to argentina), may represent a group of distinct species showing diversified cytotypes with respect to chromosome number, morphology and sex systems. one of these karyotypic forms is characterized by an x1x1x2x2/x1x2y sex chromosome system, with 2n = 40 and 39 chromosomes in females and males respectively. analyses with g-, c- and chromosome replication banding permitted a better characterization of the sex chromosomes i ... | 1997 | 9421268 |
| metabolic responses of the teleost hoplias malabaricus to high levels of environmental nitrite. | the metabolic responses of hoplias malabaricus to hypoxia caused by nitrite exposure was studied and compared to previous data of hypoxia caused by low environmental oxygen concentrations. these metabolic responses were analyzed from the contents of glycogen, glucose, lactate and pyruvate in liver, red and white muscle, heart and plasma. glycogen mobilization provided clues to explain the metabolic behavior of the organism against internal hypoxia. the ratio of closely related metabolic intermed ... | 1998 | 9699320 |
| the x1x2y sex chromosome system in the fish hoplias malabaricus. ii. meiotic analyses. | the neotropical fish hoplias malabaricus shows diversified cytotypes and may represent a group of distinct species. one of these cytotypes is characterized by 2n = 40 and 2n = 39 chromosomes in females and males, respectively, with a multiple sex chromosome system of the x1x1x2x2/x1x2y type. the y, representing a large chromosome in male karyotype, is derived from a translocation event between two biarmed chromosomes: one of them similar to x1 chromosome (no. 6) and another one similar to x2 chr ... | 1998 | 9543017 |
| epitheliocystis disease in cultured pacu (piaractus mesopotamicus) in brazil. | epitheliocystis disease was diagnosed in a cultured pacu (piaractus mesopotamicus holmberg, 1893) stock on the basis of gross pathological (greyish-white, pinpoint- or pinhead-sized focal areas, connected strongly to the gill lamellae) and histopathological examinations (hypertrophic cells 10-40 microns in size, having a well-defined wall and a central inclusion or characteristic granular content stained with giemsa). the disease did not occur among fishes (cyprinus carpio l., ctenopharyngodon i ... | 1999 | 10497824 |
| characterization of the fishes and of subsistence fishing in the pantanal of mato grosso, brazil. | fishing is one of the oldest human activities in the pantanal of mato grosso in central brazil. in the of bento gomes river basin (pantanal of poconé) the presence of fishermen is very common. the objective of this study is to describe the fishing activity in the basin in view of the elaboration of proposals for the sustainable use of this natural resource. of the 256 fishermen that were registered most are fishing for their subsistence (92%) and the rest (8%) are occasional fishermen (locally c ... | 2000 | 11188869 |
| a biodiversity approach in the neotropical erythrinidae fish, hoplias malabaricus. karyotypic survey, geographic distribution of cytotypes and cytotaxonomic considerations. | hoplias malabaricus, a widely distributed neotropical freshwater fish, shows a conspicuous karyotypic diversification. an overview of this diversity is presented here comprising several brazilian populations, and some others from argentina, uruguay and surinam. seven general cytotypes are clearly identified on the basis of their diploid number (2n = 39 to 2n = 42), chromosomal morphology and sex chromosome systems, which can be clustered into two major karyotypic groups. this clustering suggests ... | 2000 | 11117356 |
| mercury contamination in freshwater, estuarine, and marine fishes in relation to small-scale gold mining in suriname, south america. | the extent of mercury contamination in surinamese food fishes due to small-scale gold mining was investigated by determination of the total mercury concentration in 318 freshwater fishes, 109 estuarine fishes, and 110 fishes from the atlantic ocean. high background levels were found in the piranha serrasalmus rhombeus (0.35 microg hg x g(-1) muscle tissue, wet mass basis) and the peacock cichlid cichla ocellaris (0.39 microg x g(-1)) from the central suriname nature reserve. average mercury leve ... | 2001 | 11437465 |
| distribution pattern of two fish species in a coastal stream in southeast brazil. | longitudinal distribution of mimagoniates microlepis and hoplias malabaricus was analyzed in a coastal stream system in southeast brazil. six sites were sampled by electrofishing in seven months, from july 94 to july 95. densities of m. microlepis, and h. malabaricus and its prey (poecilia vivipara, deuterodon sp. and astyanax janeiroensis) were estimated by the zippin method; environmental variables of: (i) kind of substratum; (ii) percentage of pools, runs, riffles, instream vegetation, and ca ... | 2002 | 12185917 |
| genetic variability in hoplias malabaricus (osteichthyes: erythrinidae) in fluvial and lacustrine environments in the upper paraná river floodplain (paraná state, brazil). | genetic variability in hoplias malabaricus, from two localities in the upper paraná riverfloodplain, was investigated by starch and polyacrylamide gel electrophoresis. a total of 52 specimens were analyzed for 14 enzymatic systems. twenty-three gene loci of 13 enzymatic systems (aat, acp, adh, gdh, g6pdh, gpi, idh, ldh, mdh, mep, pgm, per, and sod) were analyzed by starch gel electrophoresis (penetrose-30). the est system was analyzed by polyacrylamide gel electrophoresis, and one polymorphic lo ... | 2002 | 12296625 |
| the life cycle of clinostomum complanatum rudolphi, 1814 (digenea, clinostomidae) on the floodplain of the high paraná river, brazil. | the life cycle of the digenetic trematode clinostomum complanatum was studied on the floodplain of the high paraná river, brazil. sampling was done between june 1999 and june 2000. the mollusc biomphalaria peregrina was the first intermediate host with a prevalence of infection of 0.75%. the fish loricariichthys platymetopon, hoplosternum littorale, parauchenipterus galeatus, hoplias malabaricus and loricaria sp. were second intermediate hosts, with the prevalence varying from 2.45% ( h. malabar ... | 2003 | 12658465 |
| the fish fauna in tropical rivers: the case of the sorocaba river basin, são paulo, brazil. | a survey was carried out on the fish species in the sorocaba river basin, the main tributary of the left margin of the tietê river, located in the state of são paulo, brazil. the species were collected with gill nets. after identification of the specimens, their relative abundance, weight and standard length were determined. up to the present moment there are not any studies that focus this subject in this hydrographic basin. fifty-three species, distributed in eighteen families and six orders w ... | 2003 | 15162785 |
| heterochromatin polymorphism associated with 18s rdna: a differential pathway among hoplias malabaricus fish populations. | the distribution of constitutive heterochromatin has showed a relevant association with karyotypic evolution in several animal groups. in the present paper, a polymorphic condition for a heterochromatic segment overlapping a nucleolar organizer region in the fish species hoplias malabaricus from the iguaçu river, southern brazil, was analyzed. in accordance with previous studies, this population belongs to cytotype a, showing 2n = 42 meta-submetacentric chromosomes, without differentiation of se ... | 2003 | 14571132 |
| isoform expression in the multiple soluble malate dehydrogenase of hoplias malabaricus (erythrinidae, characiformes). | kinetic properties and thermal stabilities of hoplias malabaricus liver and skeletal muscle unfractionated malate dehydrogenase (mdh, ec 1.1.1.37) and its isolated isoforms were analyzed to further study the possible smdh-a* locus duplication evolved from a recent tandem duplication. both a (a1 and a2) and b isoforms had similar optima ph (7.5-8.0). while hoplias a isoform could not be characterized as thermostable, b could as thermolabile. a isoforms differed from b isoform in having higher km ... | 2003 | 12914410 |
| chloride cell responses to ion challenge in two tropical freshwater fish, the erythrinids hoplias malabaricus and hoplerythrinus unitaeniatus. | chloride cell (cc) responses to ion challenge and plasma ion concentration were evaluated in two ecologically distinct erythrinids, hoplias malabaricus, an exclusively water-breathing species, and hoplerythrinus unitaeniatus, a facultative air-breathing fish, at one, two, seven, and 15 days of exposure to deionized water and to ion-rich water. h. malabaricus displayed high cc proliferation on filament and lamellar epithelium during exposure to deionized water and significant cc proliferation in ... | 2003 | 12884271 |
| gill chloride cell proliferation and respiratory responses to hypoxia of the neotropical erythrinid fish hoplias malabaricus. | the effect of chloride cell proliferation on the respiratory function was evaluated by measuring oxygen consumption (vo2) and ventilatory parameters during normoxia and gradual hypoxia in the tropical fish hoplias malabaricus. chloride cell proliferation was induced by keeping fish in deionized water, and the effect on the respiratory function was measured on the 1st, 2nd, and 7th day in this water using a flow-through respirometry system. plasma osmolarity and the partial pressure of arterial o ... | 2003 | 12677459 |
| different biochemical strategies of two neotropical fish to cope with the impairment of nitrogen excretion during air exposure. | the exposure of fish to air is normally expected to interfere with the nitrogen excretion process. hoplias malabaricus and hoplerythrinus unitaeniatus, two teleost species, display distinct behaviors in response to decreases in natural reservoir water levels, although they may employ similar biochemical strategies. to investigate this point, plasma levels of ammonia, urea, uric acid, and the two urea cycle enzymes, ornithine carbamoyl transferase (oct) and arginase (arg), as well as glutamine sy ... | 2003 | 12563532 |
| a comparison of adrenergic stress responses in three tropical teleosts exposed to acute hypoxia. | experiments were performed to assess the afferent and efferent limbs of the hypoxia-mediated humoral adrenergic stress response in selected hypoxia-tolerant tropical fishes that routinely experience environmental o(2) depletion. plasma catecholamine (cat) levels and blood respiratory status were measured during acute aquatic hypoxia [water po(2) (pw(o(2))) = 10-60 mmhg] in three teleost species, the obligate water breathers hoplias malabaricus (traira) and piaractus mesopotamicus (pacu) and the ... | 2004 | 15044187 |
| larval contracaecum sp. (nematoda: anisakidae) in hoplias malabaricus and hoplerythrinus unitaeniatus (osteichthyes: erythrinidae) of economic importance in occidental marshlands of maranhão, brazil. | this work describes the presence of contracaecum sp. larvae (nematoda: anisakidae) found in food fish of economic importance captured in occidental marshlands in the state of maranhão, brazil. hoplias malabaricus (erythrinidae) and hoplerythrinus unitaeniatus (erythrinidae), commonly called "traíra" and "jejú", respectively, were examined. all h. malabaricus were infected with a mean intensity of 24.6+/-38.3 (1-137 parasites per host) while eighty percent of h. unitaeniatus showed a mean intensi ... | 2004 | 15619375 |
| ureotelism is inducible in the neotropical freshwater hoplias malabaricus (teleostei, erythrinidae). | increased environmental ph decreases ammonia transport through the gills, impairing nitrogenous waste. the consequent toxicity is usually drastic to most fishes. a few species are able to synthesize urea as a way to detoxify plasma ammonia. we studied three teleosts of the family erythrinidae living in distinct environments, and assumed the biochemical behaviors would be different in spite of their being closely related species. adult fish collected in the wild were submitted to alkaline water a ... | 2004 | 15462300 |
| biochemical responses of two erythrinidae fish to environmental ammonia. | the non-ionized form of ammonia is very toxic to many aquatic species. it is especially important in several aspects of fish biology. a large range of organismal strategies for coping with environmental stressors is usually observed in living organisms. among those, the responses for managing chemical stressors are well studied. the present work compares biochemical responses of two evolutionarily close species, hoplias malabaricus and hoplerythrinus unitaeniatus, exposed to environmental ammoni ... | 2004 | 15195368 |
| erythrocyte senescence and haematological changes induced by starvation in the neotropical fish traíra, hoplias malabaricus (characiformes, erythrinidae). | adult specimens of traira (hoplias malabaricus bloch) were subjected to long-term starvation (30 to 240 days) and re-fed for 30 days after 90 and 240 days of food deprivation. counting of immature erythrocytes in peripheral blood showed that erythropoiesis decreased significantly during the first 30 days of food deprivation. the results suggest that a process of senescence takes place in the pre-existent red blood cells and that the cells are not replaced during starvation. after 240 days of sta ... | 2005 | 15792593 |
| spatial synchrony of a highly endemic fish assemblage (segredo reservoir, iguaçu river, paraná state, brazil). | in this study, patterns of spatial synchrony in population fluctuations (cross-correlation) of an endemic fish assemblage of a neotropical reservoir (segredo reservoir, iguaçu river, paraná state, brazil) were reported. first, the level of population synchrony for 20 species was estimated. second, population synchrony was correlated, using the mantel test, with geographical distances among sites (n = 11) and also environmental synchrony (temperature). nine species presented significant correlati ... | 2005 | 16341422 |
| [parasitism of hoplias malabaricus (bloch, 1794) (characiformes, erythrinidae) by quadrigyrus machadoi fábio, 1983 (eoacanthocephala, quadrigyridae) at a pond, aguaí, state of são paulo, brazil]. | the parasitism of trahira, hoplias malabaricus, by the acanthocephalan quadrigyrus machadoi was studied. fish were collected at a pond located on palmeiras farm (21 degrees 59'19''s, 47 degrees 12'04''w), municipal district of aguaí, são paulo, brazil, during the period of january, 2002 to may, 2003. among the 64 specimens analyzed, 56 (prevalence=87.5%) were infected with three to 573 specimens of quadrigyrus machadoi (mean intensity=119.0+/- 120.6 and mean abundance=104.1+/-119.4). most of the ... | 2005 | 16445871 |
| mercury and selenium concentrations in fish samples from cachoeira do piriámunicipality, parástate, brazil. | mercury is a major public health concern because of its widespread occurrence in the environment and its toxic effects on humans, mainly through fish ingestion. on the other hand, selenium is known by its antioxidant effect. for this reason, the knowledge of the correlation between mercury and selenium concentrations in fish samples can bring important information allowing a better understanding of mercury equilibrium in the inhabitants of the amazon region. in this paper, total mercury and sele ... | 2005 | 15589232 |
| mutagenic effects of mercury pollution as revealed by micronucleus test on three amazonian fish species. | genotoxic effect of mercury pollution over amazonian fish species was evaluated by using the micronucleus test (mnt). distinct mean frequencies of micronuclei (mn) were observed in three trophically distinct characin fish species collected in two riverine environments in the amazon basin: the madeira (polluted area) and the solimões (unpolluted area) rivers. mean frequencies of mn observed in prochilodus nigricans (detritivore), mylossoma duriventris (omnivore), and hoplias malabaricus (piscivor ... | 2005 | 15589237 |
| the effects of different predator species on antipredator behavior in the trinidadian guppy, poecilia reticulata. | different types of predators often elicit different antipredator responses in a common type of prey. alternatively, some prey species may adopt a general response, which provides limited protection from many different types of predator. the trinidadian guppy, poecilia reticulata, is faced with a wide range of different predators throughout its range and is known to display varying levels of antipredator behavior depending on the predator assemblage. pike cichlids, crenicichla frenata, are regard ... | 2006 | 16896976 |
| spawning and parental care in hoplias malabaricus (teleostei, characiformes, erythrinidae) in the southern pantanal, brazil. | herein we describe spawning and egg guarding in the erythrinid fish hoplias malabaricus observed in the southern pantanal (19 degrees 34' s and 57 degrees 00' w), state of mato grosso do sul, brazil. nests were depressions built on sandy soil in flooded areas, and contained a mean of 8,197 +/- 2,204 eggs (n = 4); the mean diameter of eggs was 1.44 +/- 0.09 mm (n = 400). among 11 nests observed, eight were guarded by males and three by the pair. one male remained in the nest for six days, and two ... | 2006 | 16906301 |
| losses of immunoreactive parvalbumin amacrine and immunoreactive alphaprotein kinase c bipolar cells caused by methylmercury chloride intoxication in the retina of the tropical fish hoplias malabaricus. | to quantify the effects of methylmercury (mehg) on amacrine and on on-bipolar cells in the retina, experiments were performed in mehg-exposed groups of adult trahiras (hoplias malabaricus) at two dose levels (2 and 6 microg/g, ip). the retinas of test and control groups were processed by mouse anti-parvalbumin and rabbit anti-alphaprotein kinase c (alphapkc) immunocytochemistry. morphology and soma location in the inner nuclear layer were used to identify immunoreactive parvalbumin (pv-ir) and a ... | 2006 | 16501820 |
| contracaecum sp. infection in hoplias malabaricus (moncholo) from rivers and marshes of colombia. | nematode infection indices were recorded in hoplias malabaricus captured in six different rivers and a marsh belonging to the north coast basin of colombia, and from the amazon river, during february 2003-december 2004. preliminary morphological analysis of nematodes indicated the presence of contracaecum sp. parasites were mostly found in the intestinal mesenteries and a very low percentage in muscle. parasite prevalence in all sampling locations at the north of colombia was 100%, whereas in th ... | 2006 | 16650597 |
| factors controlling hg levels in two predatory fish species in the negro river basin, brazilian amazon. | a number of environmental factors have been shown to influence the dynamics of hg in aquatic ecosystems. here we investigate the influence of fish size, ph, dissolved organic carbon (doc), and the availability of potential methylation sites (floodplain forests and hydromorphic soils) on the concentration of total hg in two carnivorous fishes: cichla spp. and hoplias malabaricus in the negro river, brazil. fish and water samples for chemical analysis were collected from 33 sites in the negro basi ... | 2006 | 16690103 |
| the piscine micronucleus test to assess the impact of pollution on the japaratuba river in brazil. | in situ investigations of the effects of mutagenic pollutants (environmental monitoring) have increasingly used bioindicators, and fish often have been used in these studies as sentinel organisms. in the present study, we have used the piscine micronucleus test (mnt) as an in situ biological indicator of chemical contamination in two fresh water fish species (astyanax bimaculatus and hoplias malabaricus). the fish were collected from two sites (sites 1 and 2) in the japaratuba river (sergipe, br ... | 2006 | 16388529 |
| fish mercury bioaccumulation as a function of feeding behavior and hydrological cycles of the rio negro, amazon. | the acidic black waters of the rio negro are unimpacted by anthropogenic sources and yet, are characterized by fish containing relatively high hg concentrations. regular annual flooding alters the aquatic environment, thereby affecting fish feeding strategies. we studied the impact of annual flooding on fish-hg bioaccumulation. tucunarés (cychla spp, carnivorous), peixe-cachorro (hydrolycus scomberoides, carnivorous), traíra (hoplias malabaricus, carnivorous), piranha-branca (serrasalmus aff. ei ... | 2006 | 16443397 |
| cardiac function of two ecologically distinct neotropical freshwater fish: curimbata, prochilodus lineatus (teleostei, prochilodontidae), and trahira, hoplias malabaricus (teleostei, erythrinidae). | an isometric muscle preparation was used to investigate the importance of the ventricular sarcoplasmic reticulum (sr) and extracellular ca(2+) (2.5 up to 10.5 mm) to force generation at 25 degrees c (acclimation temperature) in two ecologically distinct neotropical teleost fish: curimbata (active species), and trahira (sedentary species). the post-rest force was studied with and without 10 mum ryanodine in the medium. the positive inotropism observed for both species in response to increases on ... | 2006 | 16931079 |
| effects of mercury intoxication on the response of horizontal cells of the retina of thraira fish (hoplias malabaricus). | methyl mercury (mehg) is highly neurotoxic, affecting visual function in addition to other central nervous system functions. the effect of mercury intoxication on the amplitude of horizontal cell responses to light was studied in the retina of the fish hoplias malabaricus. intracellular responses were recorded from horizontal cells of fish previously intoxicated with mehg by intraperitoneal injection (ip group) or by trophic exposure (t group). only one retina per fish was used. the doses of meh ... | 2006 | 16862290 |
| a tandemly repetitive centromeric dna sequence of the fish hoplias malabaricus (characiformes: erythrinidae) is derived from 5s rdna. | a substantial fraction of the eukaryotic genome consists of repetitive dna sequences that include satellites, minisatellites, microsatellites, and transposable elements. although extensively studied for the past three decades, the molecular forces that generate, propagate and maintain repetitive dnas in the genomes are still discussed. to further understand the dynamics and the mechanisms of evolution of repetitive dnas in vertebrate genome, we searched for repetitive sequences in the genome of ... | 2006 | 16850219 |
| hematological findings in neotropical fish hoplias malabaricus exposed to subchronic and dietary doses of methylmercury, inorganic lead, and tributyltin chloride. | hematological indices are gaining general acceptance as valuable tools in monitoring various aspects the health of fish exposed to contaminants. in this work some effects of methyl mercury (mehg), inorganic lead (pb2+), and tributyltin (tbt) in a tropical fish species were evaluated by hematological methods after a trophic exposition at a subchronic level. forty-two mature individuals of the freshwater top predator fish hoplias malabaricus were exposed to trophic doses (each 5 days) of mehg (0.0 ... | 2006 | 16388797 |
| mast cell heterogeneity between two different species of hoplias sp. (characiformes: erythrinidae): response to fixatives, anatomical distribution, histochemical contents and ultrastructural features. | mast cells from two erythrinid species: hoplias malabaricus and hoplias lacerdae, were studied in several tissues throughout the body using light and electron microscopy. mast cells were found in all organs studied, but were especially abundant in the gastrointestinal tract, and were always in association with connective tissue. these cells showed different characteristics between the two species studied, like varied morphology, anatomical distribution, density, basophilic/eosinophilic staining ... | 2007 | 16824768 |
| comparative chromosome mapping of 5s rdna and 5shindiii repetitive sequences in erythrinidae fishes (characiformes) with emphasis on the hoplias malabaricus 'species complex'. | chromosomal localization of 5s rdna and 5shindiii repetitive sequences was carried out in several representatives of the erythrinidae family, namely in karyomorphs a, d, and f of hoplias malabaricus, and in h. lacerdae, hoplerythrinusunitaeniatus and erythrinus erythrinus. the 5s rdna mapped interstitially in two chromosome pairs in karyomorph a and in one chromosome pair in karyomorphs d and f and in h. lacerdae. the 5shindiii repetitive dna mapped to the centromeric region of several chromosom ... | 2007 | 17901704 |
| voronoi analysis uncovers relationship between mosaics of normally placed and displaced amacrine cells in the thraira retina. | although neuronal dynamics is to a high extent a function of synapse strength, the spatial distribution of neurons is also known to play an important role, which is evidenced by the topographical organization of the main stations of the visual system: retina, lateral geniculate nucleus, and cortex. the coexisting systems of normally placed and displaced amacrine cells in the vertebrate retina provide interesting examples of retinotopic spatial organization. however, it is not clear whether these ... | 2007 | 17426353 |
| enzymatic inhibition and morphological changes in hoplias malabaricus from dietary exposure to lead(ii) or methylmercury. | neotropical fish traíra (hoplias malabaricus) were used to investigate the effects of dietary doses of metals through individual exposures to either inorganic lead(ii) or methylmercury, respectively, 21 microg pb2+g(-1) w.w. and 75 ng h(3)c-hg+g(-1) w.w., every 5 days, for 70 days (14 doses). the erythrocyte delta-aminolevulinic acid dehydratase (alad) activity was inhibited after 14 doses of pb2+ and h(3)c-hg+. the muscle cholinesterase (che) activity was inhibited after 14 doses of h(3)c-hg+. ... | 2007 | 16757027 |
| effects of dietary methylmercury on liver and kidney histology in the neotropical fish hoplias malabaricus. | methylmercury is a potent toxic present in amazonian fish species due to gold mining activities. in the present work, we investigated the morphological effects of methylmercury in liver and kidney of hoplias malabaricus feeding contaminated prey fish over 70 days. two groups of nine mature fish (tested and control) were acclimatized for four weeks to laboratory conditions and then the tested group fed prey fish previously contaminated at an additional level of 0.075 microg mehg g(-1) at 5-day in ... | 2007 | 17296226 |
| annual flooding and fish-mercury bioaccumulation in the environmentally impacted rio madeira (amazon). | regular annual flooding of the amazonian rivers changes the aquatic environment affecting fish feeding strategies. the rio madeira has been greatly impacted by deforestation for agricultural projects, damming for a hydroelectric power plant, and alluvial gold extraction. we studied fish-hg concentrations within defined weight ranges of representative species at the top of the food web, comparing high and low water seasons. selected piscivorous species (cichla spp, hoplias malabaricus, pinirampus ... | 2007 | 17356898 |
| anthropogenic impact of mercury accumulation in fish from the rio madeira and rio negro rivers (amazonia). | fish is an important concentrator of mono-methyl mercury and the main route to human contamination. we compared fish hg bioaccumulation (within similar weight ranges) in two amazonian river habitats during high-water seasons. the rio madeira has been greatly impacted by agriculture, alluvial gold extraction, and a hydroelectric reservoir, whereas the rio negro is much less affected by these human activities. the species at the top of the food web, hoplias malabaricus (piscivorous; 80-668 ng hg/g ... | 2007 | 17625245 |
| [metazoan parasites of six fishes species from lajes reservoir in the state of rio de janeiro, brazil]. | from april 2002 to july 2003, 231 freshwater fishes from lajes reservoir in the state of rio de janeiro, brazil (22 degrees 42' - 22 degrees 50's, 43 degrees 53' - 44 degrees 05'w) were necropsied to study their community metazoan parasites: 39 astyanax bimaculatus (linnaeus, 1758), 79 a. fasciatus (cuvier, 1819), 23 hypostomus affinis (steindachner, 1877), 26 hoplias malabaricus (bloch, 1794), 30 loricariichthys castaneus (castelnau, 1855) and 34 trachelyopterus striatulus (steindachner, 1876). ... | 2007 | 18078597 |
| evolutionary cytogenetics of the hoplias lacerdae, miranda ribeiro, 1908 group. a particular pathway concerning the other erythrinidae fish. | the taxonomy/systematics of the erythrinidae fish is still imprecise, with several doubts on their relationships. karyotypes and chromosomal characteristics of some species of the hoplias lacerdae group (erythrinidae), from different brazilian hydrographic basins and pisciculture stations, were analyzed in the present study, using conventional giemsa staining, c-banding, silver staining, mithramycin and distamycin/dapi fluorochromes, and fluorescent in situ hybridization (fish). a diploid chromo ... | 2007 | 18278357 |
| toxic effects of ddt and methyl mercury on the hepatocytes from hoplias malabaricus. | here, we examined the impact of dichlorodiphenyltrichloroethane (ddt) and monomethyl mercury (mehg) on the redox milieu and survival of hepatocytes from hoplias malabaricus (traíra). after isolation and attachment of cells, we established one control and four treatments: ddt (50nm of ddt), mehg i (0.25microm of mehg), mehg ii (2.5microm of mehg) and ddt * mehg i (combination of 50nm of ddt and 0.25microm of mehg). after four days the exposed hepatocytes presented significantly increased damage i ... | 2008 | 18675336 |
| distribution of mercury in several environmental compartments in an aquatic ecosystem impacted by gold mining in northern colombia. | mercury (hg) used in gold amalgamation is a major source of contamination in developing countries. water, sediments, plankton, fish, and human samples from grande marsh, a hg-polluted marsh located in the south of bolívar, municipality of montecristo, colombia, were collected during both the rainy and the dry seasons (2003-2006), at three different sampling sites, and analyzed for total hg (t-hg) content. water, sediment, seston, phytoplankton, and zooplankton t-hg concentrations were 0.33 +/- 0 ... | 2008 | 18250950 |
| a comparative analysis of putative oxygen-sensing cells in the fish gill. | we investigated the distribution of serotonin (5-ht)-containing neuroepithelial cells (necs), the putative o(2) sensing cells, in the gills of four species of fish: trout (oncorhynchus mykiss), goldfish (carassius auratus), trairão (hoplias lacerdae) and traira (hoplias malabaricus) using immunohistochemical markers for 5-ht, synaptic vesicles and neural innervation. we found that all fish had a cluster of innervated, serotonergic necs at the filament tips, but there were species-specific distri ... | 2008 | 18375847 |
| profile of micronucleus frequencies and dna damage in different species of fish in a eutrophic tropical lake. | lake paranoá is a tropical reservoir for the city of brasilia, which became eutrophic due to inadequate sewage treatment associated with intensive population growth. at present, two wastewater treatment plants are capable of processing up to 95% of the domestic sewage, thereby successfully reducing eutrophization. we evaluated both genotoxic and cytotoxic parameters in several fish species (geophagus brasiliensis, cichla temensis, hoplias malabaricus, astyanax bimaculatus lacustres, oreochromis ... | 2009 | 21637659 |
| comparative chromosome mapping of repetitive sequences. implications for genomic evolution in the fish, hoplias malabaricus. | seven karyomorphs of the fish, hoplias malabaricus (a-g) were previously included in two major groups, group i (a, b, c, d) and group ii (e, f, g), based on their similar karyotype structure. in this paper, karyomorphs from group i were analyzed by means of distinct chromosomal markers, including silver-stained nucleolar organizer regions (ag-nors) and chromosomal location of repetitive sequences (18s and 5s rdna, and satellite 5shindiii-dna), through fluorescence in situ hybridization (fish), i ... | 2009 | 19583858 |
| genotoxic evaluation of different doses of inorganic lead (pbii) in hoplias malabaricus. | different genetic biomarkers have been used to evaluate the pollution effects of mutagenic agents such as metals and also a great variety of chemicals delivered on the environment by human activities. this way, the aim of the present report was to evaluate the effects of inorganic lead in fishes through the frequency of piscine micronuclei and nuclear morphological alterations in peripheral cells, chromosomal aberration frequency and comet assays in blood and kidney cells. specimens of hoplias m ... | 2009 | 18843540 |
| influence of ecological factors and of land use on mercury levels in fish in the tapajós river basin, amazon. | mercury (hg) contamination of riparian communities and of environmental compartments of the amazon can be directly related to the occupation of the territory. the objective of this study was to identify the characteristics of aquatic environments that are associated with high levels of hg in ichthyofauna. our research aimed at determining the influence of variables related to fish ecology, types of aquatic environment, fishing activities by local riparian populations, and watershed use on the le ... | 2009 | 19356749 |
| chromosomal variability among allopatric populations of erythrinidae fish hoplias malabaricus: mapping of three classes of repetitive dnas. | karyotype and chromosomal characteristics from 3 allopatric populations of hoplias malabaricus, cytogenetically the most studied erythrinidae taxon, were investigated using different staining techniques (c-, ag-, and cma(3) banding) as well as fluorescent in situ hybridization (fish) to detect 18s rdna, 5s rdna, and 5shindiii satellite dna sites. the isolation, cloning and characterization of an 18s rdna probe from h. malabaricus genome were also performed for the first time in order to develop ... | 2009 | 19729917 |
| in vitro larvicidal activity of geraniol and citronellal against contracaecum sp (nematoda: anisakidae). | human infection with fish parasites can result from the ingestion of incompletely cooked or raw fish, giving origin to parasitic diseases such as anisakiasis, caused by parasites of the anisakidae family. the present study assessed the in vitro larvicidal effect of two monoterpene compounds, geraniol and citronellal, against contracaecum sp (nematoda: anisakidae). four hundred live larvae of contracaecum sp obtained from 'traíra' fish (hoplias malabaricus, bloch, 1974) were analyzed on 40 petri ... | 2009 | 19787148 |
| differentiation of y chromosome in the x(1)x(1)x(2)x(2)/x(1)x(2)y sex chromosome system of hoplias malabaricus (characiformes, erythrinidae). | six populations of hoplias malabaricus from the lower paranapanema river were studied and showed 2n = 40 with metacentric/submetacentric chromosomes for females and 2n = 39 with m/sm chromosomes for males, thereby revealing a multiple sex chromosome system of the x(1)x(1)x(2)x(2)/x(1)x(2)y type. the y chromosome was the largest metacentric chromosome in all karyotypes. the heterochromatic blocks were located in a pericentromeric region of all pairs and in telomeric regions in some other pairs. a ... | 2009 | 20016139 |
| differentiation of the xy sex chromosomes in the fish hoplias malabaricus (characiformes, erythrinidae): unusual accumulation of repetitive sequences on the x chromosome. | the wolf fish hoplias malabaricus (erythrinidae) presents a high karyotypic diversity, with 7 karyomorphs identified. karyomorph a is characterized by 2n = 42 chromosomes, without morphologically differentiated sex chromosomes. karyomorph b also has 2n = 42 chromosomes for both sexes, but differs by a distinct heteromorphic xx/xy sex chromosome system. the cytogenetic mapping of 5 classes of repetitive dna indicated similarities between both karyomorphs and the probable derivation of the xy chro ... | 2010 | 20502069 |
| development of microsatellite markers for hoplias malabaricus (erythrinidae). | we identified 14 microsatellite loci for the wolf fish, hoplias malabaricus (erythrinidae), from a genomic shotgun library. twenty-five primers were designed, and 48 individuals of h. malabaricus from four localities of northwest goiás, in central brazil, were genotyped to characterize the polymorphism at each locus. fourteen primers amplified clearly interpretable products using a single pcr protocol; six loci were polymorphic, but with a low number of alleles per locus (2 or 3). expected heter ... | 2010 | 20690083 |
| performance of human immunostimulating agents in the improvement of fish cytogenetic preparations. | inoculation with bacterial or fungal antigens that stimulate cell proliferation has been widely used to obtain metaphases for cytogenetic studies of fish. we evaluated the potential of new pharmaceutical compounds as mitogenic agents in fish, testing the efficacy of aminovac (mixed antigens and epsilon-acetamidocaproic acid), broncho-vaxom (bacterial lysate) and estimoral (bacterial lysate) to increase the mitotic index in fingerlings of the neotropical fish prochilodus brevis (prochilodontidae) ... | 2010 | 20845306 |
| first report about saxitoxins in freshwater fish hoplias malabaricus through trophic exposure. | cyanobacterial waterblooms, such as the saxitoxin (stx) producer cylindrospermopsis raciborskii, have been a worldwide concern in environmental health. however, the bioaccumulation of this neurotoxin in the trophic chain is not completely known. the aim of the present work was to evaluate stx bioaccumulation through chemical analyses and the toxic and trophic effects using biomarkers in the tropical freshwater fish hoplias malabaricus. they were fed once every five days with astyanax sp. before ... | 2010 | 21073887 |
| the chromosomal distribution of microsatellite repeats in the genome of the wolf fish hoplias malabaricus, focusing on the sex chromosomes. | distribution of 12 mono-, di- and tri-nucleotide microsatellites on the chromosomes of 2 karyomorphs with 2 distinct sex chromosome systems (a simple xx/xy - karyomorph b and a multiple x(1)x(1)x(2)x(2)/x(1)x(2)y - karyomorph d) in hoplias malabaricus, commonly referred to as wolf fish, was studied using their physical mapping with fluorescence in situ hybridization (fish). the distribution patterns of different microsatellites along the chromosomes varied considerably. strong hybridization sign ... | 2010 | 21099206 |
| evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish. | fungal infections in human skin, such as sporotrichosis, can occur after fish induced trauma. this work aimed to identify fungi in freshwater fish that are pathogenic to humans. | 2011 | 21468475 |
| Whole chromosome painting reveals independent origin of sex chromosomes in closely related forms of a fish species. | The wolf fish Hoplias malabaricus includes well differentiated sex systems (XY and X(1)X(2)Y in karyomorphs B and D, respectively), a nascent XY pair (karyomorph C) and not recognized sex chromosomes (karyomorph A). We performed the evolutionary analysis of these sex chromosomes, using two X chromosome-specific probes derived by microdissection from the XY and X(1)X(2)Y sex systems. A putative-sex pair in karyomorph A was identified, from which the differentiated XY system was evolved, as well a ... | 2011 | 21927842 |
| new and previously described species of urocleidoides (monogenoidea: dactylogyridae) infecting the gills and nasal cavities of hoplias malabaricus (characiformes: erythrinidae) from brazil. | during an investigation of the biodiversity and structure of parasite communities among native populations of the erythrinid fish hoplias malabaricus (characiformes) from 7 rivers in brazil, the following monogenoidean (dactylogyridae) species were found: urocleidoides malabaricusi n. sp., urocleidoides naris n. sp., urocleidoides cuiabai n. sp., urocleidoides brasiliensis n. sp., and urocleidoides eremitus kritsky, thatcher, and boeger, 1986. specimens considered as a new genus of dactylogyrida ... | 2011 | 21506767 |
| genotoxic evaluation of different doses of methylmercury (ch₃hg⁺) in hoplias malabaricus. | the survey of the effects of toxic metals and its organic compounds are of critical importance because these compounds tend to accumulate in aquatic environments. in the present work, the genotoxic potential of methylmercury, an organomercurial compound with high toxicity and present in large amounts in fish of the amazon due to the mining process, was evaluated using the piscine micronucleus test and comet assay in fish. specimens of hoplias malabaricus (popularly known as traira), a neotropica ... | 2012 | 22682032 |
| morphological evidence of neurotoxicity in retina after methylmercury exposure. | the visual system is particularly sensitive to methylmercury (mehg) exposure and, therefore, provides a useful model for investigating the fundamental mechanisms that direct toxic effects. during a period of 70 days, adult of a freshwater fish species hoplias malabaricus were fed with fish prey previously labeled with two different doses of methylmercury (0.075 and 0.75 μgg(-1)) to determine the mercury distribution and morphological changes in the retina. mercury deposits were found in the phot ... | 2012 | 22531226 |
| comparative parasitism of the fish plagioscion squamosissimus in native and invaded river basins. | biological invasions are considered a major threat to biodiversity around the world, but the role of parasites in this process is still little investigated. here, we compared parasite infections of a host species in the areas where it originated and where it was introduced, and in native and introduced species in the same environment, using the endoparasites of the fish plagioscion squamosissimus (sciaenidae) in 3 brazilian basins. samples were taken in 2 rivers where the species is native, i.e. ... | 2012 | 22468610 |
| dna barcoding neotropical fishes: recent advances from the pampa plain, argentina. | the fish fauna of the pampa plain, the southernmost distribution range of many neotropical species, was barcoded in this study. coi sequences were analysed by means of distance (k2p/nj) and character-based (ml) models, as well as the barcode index number (bin). k2p/nj analysis was able to discriminate among all previously identified species while also revealing the likely occurrence of two cryptic species that were further supported by bin and ml analyses. on the other hand, both bin and ml were ... | 2012 | 22984883 |
| tooth morphology, implantation and replacement system of hoplias malabaricus (teleostei, characiformes, erythrinidae). | the oropharyngeal cavity of hoplias malabaricus, an ichthyophagous freshwater fish, is anatomically adapted to predation. macroscopic and microscopic analyses were conducted in order to study the morphology and system of implantation and replacement of teeth. the results showed that this teleost has conical and caniniform teeth, with an orthodentin crown covered by an enameloid cap and a vascularised orthodentin in the root. with regard to the implantation system, there is a junction between the ... | 2013 | 24789394 |
| hematological alterations caused by high intensity of l3 larvae of contracaecum sp railliet & henry, 1912 (nematoda, anisakidae) in the stomach of hoplias malabaricus in lakes in pirassununga, são paulo. | the objective of the present study was to discover the hematological indices of hoplias malabaricus infected by larvae of contracaecum sp. a total of 105 fish were collected from two lakes located in the municipal district of pirassununga, são paulo, brazil, of which 95.2% were infested by l3 larvae of contracaecum sp., with an average intensity of 348.7 ± 231.55 helminths/fish. a total of 76 fish were analyzed to establish hematological parameters. following analysis, it was found that there wa ... | 2013 | 23666228 |
| nematode and mercury content in freshwater fish belonging to different trophic levels. | fish are a protein source for many people in colombia. however, environmental pollution of some aquatic ecosystems may pose health risks to humans. the aim of this study was to assess the levels of total mercury (t-hg) in muscle and their relationship with nematode infections in fish from dique channel, a freshwater ecosystem located northern colombia. eight hundred ninety fish specimens belonging to 13 different species were collected. t-hg concentration was measured using atomic absorption spe ... | 2013 | 23494159 |
| hematologic and hepatic responses of the freshwater fish hoplias malabaricus after saxitoxin exposure. | the bioaccumulation of saxitoxins (stx) in the trophic chain, mainly in freshwater, are not completely known. this work aimed to elucidate the effects of stx on hoplias malabaricus through trophic bioassay. the fish were fed once every five days with astyanax sp. before being subjected to an intraperitoneal inoculation with the lysate of cylindrospermopsis raciborskii culture containing 97% stx and 3% by neosaxitoxin and gonyautoxin during 20 days. the animal's liver was assessed using biomarker ... | 2013 | 23402841 |
| parasites of the fish cichla piquiti (cichlidae) in native and invaded brazilian basins: release not from the enemy, but from its effects. | the enemy release hypothesis is frequently used to explain the success of invaders, postulating that introduced species have escaped from their native enemies, including parasites. here, we tested this hypothesis for the tucunaré (cichla piquiti), a predatory cichlid, and its endoparasites. first, the parasites and their influence on the condition of the hosts in the native environment, the tocantins river (to), were compared to an environment where the fish was introduced, the paraná river (pr) ... | 2013 | 23052767 |
| nematodes in hoplerytrinus unitaeniatus, hoplias malabaricus and pygocentrus nattereri (pisces characiformes) in marajó island, brazil. | the aim of this study was to evaluate the tegument, musculature and mesentery of 102 specimens of hoplerytrinus unitaeniatus, 104 of hoplias malabaricus and 101 of pygocentrus nattereri, from arari lake, marajó island, state of pará, brazil. were identified the nematodes contracaecum sp., eustrongylides sp. and procamallanus sp. contracaecum sp. was the most prevalent, with rates of 84.31% (h. unitaeniatus), 95.19% (h. malabaricus), and 89.11% (p. nattereri). the highest prevalences of eustrongy ... | 2013 | 22832760 |
| hematological parameters of hoplias malabaricus (characiformes: erythrinidae) parasitized by monogenea in lagoons in pirassununga, brazil. | hematology is an important pathological and diagnostic tool. this paper describes the hematological parameters of 76 specimens of hoplias malabaricus infested with monogenean parasites, which were collected from two lagoons. the hematological parameters included: erythrocyte count (er), microhematocrit (hct), hemoglobin (hb), mean corpuscular volume (mcv), mean corpuscular hemoglobin (mch) and mean corpuscular hemoglobin concentration (mchc). the blood parameters showed no significant changes as ... | 2014 | 24473868 |
| behavioral changes caused by austrodiplostomum spp. in hoplias malabaricus from the são francisco river, brazil. | traira (hoplias malabaricus) is a neotropical fish that is widely distributed in freshwater environments in south america. in the present study, we documented the occurrence of metacercariae of austrodiplostomum spp. (diplostomidae) in the eyes and cranial cavity of h. malabaricus and described parasite-induced behavioral changes in the host. the fish were collected from the upper são francisco river, in the serra da canastra mountain range, minas gerais, transported alive to the laboratory, obs ... | 2014 | 24248631 |
| mercury distribution in target organs and biochemical responses after subchronic and trophic exposure to neotropical fish hoplias malabaricus. | in the present study, we investigated the mercury distribution, mercury bioaccumulation, and oxidative parameters in the neotropical fish hoplias malabaricus after trophic exposure. forty-three individuals were distributed into three groups (two exposed and one control) and trophically exposed to fourteen doses of methylmercury each 5 days, totalizing the doses of 1.05 μg g⁻¹ (m1.05) and 10.5 μg g⁻¹ (m10.5 group). autometallography technique revealed the presence of mercury in the intestinal epi ... | 2014 | 23925892 |
| genetic differentiation among distinct karyomorphs of the wolf fish hoplias malabaricus species complex (characiformes, erythrinidae) and report of unusual hybridization with natural triploidy. | in this study, genetic differentiation between karyomorphs a (2n = 42) and d (2n = 39/40) of the wolf fish hoplias malabaricus, which is comprised of several cryptic species that present a wide variety of diploid chromosome numbers and sex chromosome systems, resulting in the identification of seven distinct karyomorphs (a-g), was investigated using a combination of molecular and cytogenetic tools. deep sequence divergences for both karyomorphs were observed and indicate a long period of reprodu ... | 2014 | 25263542 |
| morphological aspects of clinostomidae metacercariae (trematoda: digenea) in hoplerytrinus unitaeniatus and hoplias malabaricus (pisces: erythrinidae) of the neotropical region, brazil. | species of fish of marajó island, state of pará, brazil, were examined to identify the trematodes parasitizing 102 hoplerytrinus unitaeniatus (gold wolf fish) and 104 hoplias malabaricus (thraira). metacercariae of two species of trematodes, 170 specimens of clinostomatopsis sorbens and 10 ithyoclinostomum dimorphum were found and identified. the parasitary indices of c. sorbens from h. unitaeniatus and h. malabaricus, were 43.14% and 30.77% for prevalence, 2.52 and 1.84 for mean intensity, 1.09 ... | 2014 | 24838543 |
| digenea of hoplias intermedius and hoplias malabaricus (actinopterygii, erythrinidae) from upper são francisco river, brazil. | a total of 103 specimens of hoplias intermedius (günther, 1864) and 86 specimens of h. malabaricus (bloch, 1794) from the upper são francisco river, state of minas gerais were collected between april 2011 and august 2013, and their parasitic fauna were investigated. four species of digenea were found: metacercariae of austrodiplostomum sp., and ithyoclinostomum sp.; and adult specimens of phyllodistomum spatula odhner, 1902, and pseudosellacotyla lutzi (freitas, 1941) yamaguti, 1954. the prevale ... | 2015 | 26154953 |
| effects of trophic exposure to dexamethasone and diclofenac in freshwater fish. | steroidal and non-steroidalanti-inflammatories are pharmaceutical prescribed in human medicine and have the potential to contaminate water and sediments via inputs from sewage treatment plants. their impacts on humans and ecosystems are emerging issues in environmental health. the aim of the present work was to evaluate the effects of diclofenac and dexamethasone in male fish hoplias malabaricus after trophic exposure. fish were fed twice every week with astyanax sp. submitted to intraperitoneal ... | 2015 | 25645142 |
| the role of ovarian steroids in reproductive plasticity in hoplias malabaricus (teleostei: characiformes: erythrinidae) in tropical reservoirs with different degrees of pollution. | chemicals in aquatic environments may lead to impairment of fish reproduction, but some species display plasticity levels to survive and reproduce in such localities. we investigated the reproductive cycle in a teleost species, hoplias malabaricus, which inhabits a variety of environments with different degrees of pollution. adult females were sampled at two locations in são paulo state (brazil), the reference ponte nova (pn) reservoir and the polluted billings (bil) reservoir. metabolic and end ... | 2015 | 25449659 |
| structure of the parasites communities in two erythrinidae fish from amazon river system (brazil). | this study compared the parasite communities of hoplias malabaricus and hoplerythrinus unitaeniatus from amazon river system. hoplias malabaricus were infected by ichthyophthirius multifiliis, piscinoodinium pillulare, tetrahymena sp., urocleidoides eremitus, braga patagonica, metacercariae of clinostomum marginatum, procamallanus (spirocamallanus) inopinatus, larvae of contracaecum sp. and larvae of nomimoscolex matogrossensis. hoplerythrinus unitaeniatus were also infected by these same specie ... | 2015 | 26083690 |
| genotoxic and mutagenic evaluation of water samples from a river under the influence of different anthropogenic activities. | pollution of aquatic ecosystems is associated with the discharge of mostly industrial and urban effluents, which may cause loss of biodiversity and damage to public health. this study aims to evaluate the toxicity and mutagenicity of water samples collected in the corrente river, a major waterway in the river basin district of pedro ii, piauí (brazil). this river is exposed to intense anthropogenic influence from urban, automotive mechanical and family farm waste, and it is used as the main sour ... | 2016 | 27588572 |
| seasonal pattern in parasite infracommunities of hoplerythrinus unitaeniatus and hoplias malabaricus (actinopterygii: erythrinidae) from the brazilian amazon. | the present study investigated the effects of seasonal variation in parasites infracommunities of hoplerythrinus unitaeniatus and hoplias malabaricus from a tributary of amazon river. for h. unitaeniatus and h. malabaricus, 11 parasite species were similar, and greatest parasite richness occurred during the rainy season. ichthyophthirius multifiliis was the dominant parasite species for both hosts. in h. unitaeniatus, infection by whittingtonocotyle caetei, whittingtonocotyle jeju, urocleidoides ... | 2016 | 26751882 |
| electrocardiographic characterization of myocardial function in normoxic and hypoxic teleosts. | electrocardiography was applied to analyze cardiac function of four teleost species (piaractus mesopotamicus, hoplias malabaricus, hoplias lacerdae and cyprinus carpio) during normoxia and graded hypoxia. in these species, hypoxic bradycardia consistently occurred during severe hypoxia (below the critical oxygen tension--pco2) and was accompanied by alterations in the ecg recordings. three basic ecg alterations were demonstrable: 1) increase in the t wave area and amplitude, being more positive ... | 2016 | 8728858 |
| fatty acid composition of tropical fish depends on reservoir trophic status and fish feeding habit. | eutrophication results in a deficiency of n-3 lc-pufa (long-chain polyunsaturated fatty acids) in aquatic food chains, affecting fish nutrition and physiology. the trophic transfer of fa (fatty acids) to fish species of different feeding habits was investigated in two reservoirs in southeast brazil-the mesotrophic ponte nova reservoir (pn) and the hypereutrophic billings reservoir (bil). total fa profile of stomach contents and adipose tissue, triacylglycerols (tag), and phospholipids (pl) from ... | 2016 | 27631676 |
| effects of trophic exposure to diclofenac and dexamethasone on hematological parameters and immune response in freshwater fish. | the aim of the present study was to evaluate the effects of diclofenac and dexamethasone on hematological parameters and immune response in the fish species hoplias malabaricus after trophic exposure. fish were fed twice every week with astyanax sp., which were given an intraperitoneal inoculation with diclofenac (0 μg/kg, 0.2 μg/kg, 2.0 μg/kg, or 20.0 μg/kg) or dexamethasone (0.03 μg/kg, 0.3 μg/kg, or 3.0 μg/kg). after 12 doses, the hematological parameters and lipopolysaccharide-induced nitric ... | 2016 | 27003719 |
| hepatotoxicity and metabolic effects of cellular extract of cyanobacterium radiocystis fernandoi containing microcystins rr and yr on neotropical fish (hoplias malabaricus). | the toxicological effect of cellular extract of cyanobacterium radiocystis fernandoi strain r28 containing rr and yr microcystins was analyzed in the fish hoplias malabaricus with emphasis on the liver structure and energetic metabolism, after short-term exposure. fish were intraperitoneally (i.p.) injected with 100 μg of equivalent mc-lr kg(-1) body mass containing in the cellular extract of r. fernandoi strain r28. twelve and 96 h post-injection, the plasma, liver and white muscle were sampled ... | 2017 | 28242458 |