| nest placement of the giant amazon river turtle, podocnemis expansa, in the araguaia river, goiás state, brazil. | the giant amazon river turtle (podocnemis expansa) nests on extensive sand bars on the margins and interior of the channel during the dry season. the high concentration of nests in specific points of certain beaches indicates that the selection of nest placement is not random but is related to some geological aspects, such as bar margin inclination and presence of a high, sandy platform. the presence of access channels to high platform points or ramp morphology are decisive factors in the choice ... | 2005 | 16042279 |
| use and commercialization of podocnemis expansa (schweiger 1812) (testudines: podocnemididae) for medicinal purposes in two communities in north of brazil. | throughout brazil a large number of people seek out reptiles for their meat, leather, ornamental value and supposed medicinal importance. however, there is a dearth of information on the use of reptiles in folk medicine. in north brazil, the freshwater turtle, podocnemis expansa, is one of the most frequently used species in traditional medicines. many products derived from p. expansa are utilized in rural areas and also commercialized in outdoor markets as a cure or treatment for different dise ... | 2008 | 18208597 |
| development of a polymerase chain reaction test for entamoeba invadens. | entamoeba invadens is a protozoal parasite of reptiles that causes colitis, abscesses of liver and other organs, and sometimes acute death. it is generally considered a commensal of chelonians but has also been implicated as a cause of colitis, diarrhea, and death in gopher (gopherus polyphemus) and leopard (geochelone pardalis) tortoises. diagnosis of e. invadens is currently by detection of trophozoites and/or cysts upon direct fecal examination. however, definitive diagnosis of e. invadens ha ... | 2008 | 18634210 |
| the use of rocuronium in giant amazon turtle podocnemis expansa (schweigger, 1812) (testudines, podocnemididae). | to determine whether rocuronium would provide safe, short-term immobilization in podocnemis expansa. | 2009 | 19705031 |
| enterobacteriaceae associated with eggs of podocnemis expansa and podocnemis unifilis (testudines:chelonia) in nonpolluted sites of national park of araguaia plains, brazil. | fertile eggs of podocnemis expansa and podocnemis unifilis were investigated for the presence of enterobacteria, as these two endangered species have the potential for conservation measures that include egg transfer. knowledge of normal microflora associated with turtles and turtle eggs would help effectively manage the transfer of these eggs among institutions. thirty eggs of each species were collected, aseptically transferred, cracked inside plastic bags containing tetrathionate broth, and sp ... | 2010 | 21370647 |
| enterobacteriaceae in mouth and cloaca of podocnemis expansa and p. unifilis (testudines: chelonia) populations of national park of araguaia plains, brazil. | shigella flexnerii and escherichia coli were the most frequent gram-negative bacteria found in the mouth cavity and cloacae of the turtles podocnemis expansa and p. unifilis on beaches in the national park of araguaia, brazil. reptiles are known as salmonella carriers, despite rarely isolated in these turtles. | 2011 | 24031664 |
| an evaluation of the use of reptile dermal scutes as a non-invasive method to monitor mercury concentrations in the environment. | reptiles are ideal organisms for the non-invasive monitoring of mercury (hg) contamination. we have investigated hg bioaccumulation in tissue layers of reptile dermis as a basis for establishing a standardized collection method for hg analysis. tissue samples from freshwater turtle species podocnemis unifilis and podocnemis expansa and caiman species melanosuchus niger and caiman crocodilus, all from the amazonian region, were analysed in this study. we first tested the relationships between hg ... | 2015 | 24974226 |
| haematological values of post-laying arrau turtle (podocnemis expansa) in the orinoco river, venezuela. | the arrau turtle (podocnemis expansa) is an endangered species, as a result of long-lasting, unsustainable exploitation. to obtain reference haematological values from the wild podocnemis expansa during post-laying, 20 turtles were captured in the orinoco river. blood was obtained from the dorsal cervical sinus in lithium heparin tubes. red blood cells (rbc), white blood cells (wbc), thrombocytes (tc), packed cell volume (pcv), plasmatic protein (pp), haemoglobin (hgb), mean corpuscular volume ( ... | 2012 | 21122881 |
| gonadotrophic, prolactin, corticosterone, and gonadal hormones levels over 15 months in giant amazon river turtles - podocnemis expansa (schweigger, 1812) (testudines: podocnemididae), in captive conditions. | in order to achieve successful captive breeding the podocnemis expansa, it is necessary to study their reproductive endocrinology. the purpose of this research was to evaluate and characterize plasma concentrations in gonadotrophic, gonadic, corticosterone and prolactin hormones from giant amazon turtles under captive conditions. blood samples were collected over a 15 month period. the samples were assayed by the use of radioimmunoassay, prolactin, corticosterone, lh, fsh, testosterone, 17β-estr ... | 2017 | 28492802 |
| on clutch size and hatching success of the south american turtles podocnemis expansa (schweigger, 1812) and p. unifilis troschel, 1848 (testudines, podocnemididae). | data on clutch size and hatching success of p. expansa were gathered for seven beaches traditionally used by the species and re-analyzed statistically by means of regression analysis, of the number of eggs on the number of females (or nests) and of the number of young on the number of eggs. all regressions were linear, passed through the origin and had excellent fits. average clutch size varied from 75 to 123, and presented geographic differentiation: (i) rio orinoco, (ii) rio trombetas + rio br ... | 2003 | 14605677 |
| prevalence and parasitemia of haemogregarina sp. in podocnemis expansa (testudines: podocnemididae) from the brazilian amazon. | seventy-five turtles podocnemis expansa in the brazilian amazon were examined for the presence of ectoparasites and hemoparasites. samplings were performed in three study areas in the state of tocantins, brazil. twenty-five specimens were sampled per study area (a commercial breeding facility, an indigenous subsistence breeding facility and a wild population of the javaés river). hemoparasites of the genus haemogregarina were found in 66% (50/75) of the turtle specimens, and the infections were ... | 2015 | 26154958 |
| parasitization by sauroplasma sp. (apicomplexa: haemohormidiidae) in chelonian podocnemis expansa (testudines: podocnemididae) in the brazilian amazon. | the prevalence and parasitemia of the piroplasm sauroplasma sp. were evaluated in the amazon chelonian podocnemis expansa in brazil. samples were collected from 75 chelonians from 3 locations, including a commercial breeding facility, an indigenous subsistence breeding facility, and a wild population. sauroplasma were found in 72% (54/75) of the chelonians, and the prevalence varied among the sampling sites. no significant correlations were found between the prevalence and the sex and body condi ... | 2016 | 26561340 |
| effects of the exposure to atrazine on bone development of podocnemis expansa (testudines, podocnemididae). | the use of pesticides is a widely spread practice in brazilian agriculture, and dispersion of these substances is an important factor for the fauna and flora. atrazine is an endocrine disruptor in the xenoestrogen class that is used worldwide in agricultural practices. in brazil, its use is permitted in several crops. podocnemis expansa is a representative of the testudines order that is the largest freshwater reptile of south america. its distribution enables it to get in contact with molecules ... | 2016 | 26850621 |
| new insights of karyoevolution in the amazonian turtles podocnemis expansa and podocnemis unifilis (testudines, podocnemidae). | cytogenetic studies were conducted in the brazilian amazon turtles, podocnemis expansa schweigger, 1912 (pex) and podocnemis unifilis troschel, 1848 (pun) to understand their karyoevolution. their chromosomal complements were compared using banding techniques (c, g-, ag-nor and chromomycin a3) and fluorescence in situ hybridization (fish), and efforts were made to establish evolutionary chromosomal relationships within the podocnemidae family. | 2016 | 27708713 |
| morphology and molecular phylogeny of a new myxidium species (cnidaria: myxosporea) infecting the farmed turtle podocnemis expansa (testudines: podocnemididae) in the brazilian amazon. | this study reports, for the first time, a myxosporan species of the genus myxidium in a neotropical turtle. myxidium turturibus n. sp., was found in the gall bladder of podocnemis expansa (testudines: podocnemididae) farmed in brazilian amazon. numerous disporic pseudoplasmodia in different developmental stages, and mature spores were free in the bile. mature myxospores were fusiform, slightly arcuate in valval view, measuring 13.6±0.4 (13.1-15.1) μm in length and 4.1±0.3 (3.4-4.6) μm in width. ... | 2017 | 27693559 |
| metabolism of testosterone in vitro by brain and pituitary slices of a seawater turtle (chelonia mydas mydas) and freshwater turtle (podocnemis expansa). | | 1981 | 7265967 |
| occurrence of hydroxysteroid oxidoreductases in liver of turtles. | 1. hydroxysteroid oxidoreductases have been partially purified from the cytosol fraction (105,000 g supernatant) of liver from a fresh-water turtle (podocnemis expansa) and a sea-water turtle (chelonia mydas mydas) by precipitation with ammonium sulphate (as, 10-80% saturation). 2. the following enzymes were detected (substrates in brackets): 3 alpha-hydroxysteroid oxidoreductase (androsterone), 3 beta-hydroxysteroid oxidoreductase (dhea) and 17 beta-hydroxysteroid oxidoreductase (testosterone, ... | 1987 | 2827953 |
| serum biochemistry of the arrau turtle (podocnemis expansa): frozen analyte stability and the effects of long-term storage. | turtles are a major source of protein for riverside human populations in brazil. the encouragement of commercial breeding meets conservation efforts for these animals, and it is, therefore, crucial to understand the physiologic and behavioral aspects of semi-aquatic species in captive conditions. serum biochemical tests are ancillary diagnostic tools, and sample storage is a main problem since clinical laboratories are not always available near the habitats of these species. | 2020 | 32141118 |
| first report on the mutagenicity and cytotoxicity of zno nanoparticles in reptiles. | understanding how human activities affect animal biodiversity is essential to investigations about the biological effects of several pollutants and contaminants dispersed in the environment. this is the case of zinc oxide nanoparticles (zno nps), which are emerging pollutants whose effect on reptiles' health is completely unknown. thus, the objective of the present study is to evaluate the possible damages induced by these nps in podocnemis expansa juveniles (amazon turtle) by using morphologica ... | 2019 | 31276868 |
| yeasts occurring in surface and mouth cavity of two chelonian species, podocnemis expansa schweigger and p. unifilis troschel (reptilia: chelonia: pelomedusidae), in the javaés river border of araguaia national park in brazil. | thirty-eight specimens of free-ranging podocnemis expansa (amazon turtle) and 22 of p. unifilis (tracajá) were screened for yeast isolation from surface (plastron, skin, and nails), eye, and mouth cavity. a hundred and eighteen yeast isolates belonging to 39 species were obtained. debaryomyces hansenii, candida galli, c. sake, and rhodotorula mucilaginosa were the most frequent species isolated from these chelonians. species diversity measured by shannon's index was shown to be low and a degree ... | 2010 | 20936145 |
| nesting ecology of podocnemis expansa (schweigger, 1812) and podocnemis unifilis (troschel, 1848) (testudines, podocnemididae) in the javaés river, brazil. | nest site has influence on incubation duration and hatching success of two neotropical turtles, the giant amazon river turtle (podocnemis expansa) and yellow-spotted side-neck turtle (podocnemis unifilis--'tracajá'). the 2000 and 2001 nesting seasons have been monitored at the javaés river in bananal island, brazil. although they nest on the same beaches, there is a separation of the nesting areas of p unifilis and p. expansa nests on the upper parts of the beach. the incubation duration for p. ... | 2010 | 20231963 |
| mercury levels in muscle of six species of turtles eaten by people along the rio negro of the amazon basin. | mercury levels in the amazon river are generally high, but there are no published studies on hg levels in turtles from the region. in this study, levels of hg were examined in the muscle of six species of turtles in the rio negro in the amazon basin of brazil, including podocnemis unifilis, podocnemis expansa, podocnemis erythrocephala, podocnemis sextuberculata, peltocephalus dumerilianus, and chelus fimbriatus. it is important to analyze hg levels in chelonians in this region because of the po ... | 2010 | 19621205 |
| chondrogenesis of the limbs and mesopodial ossification of podocnemis expansa schweigger, 1812 (testudines: podocnemidae). | we address the chondrogenic formation of the limbs and the mesopodial ossification pattern of the pleurodira podocnemis expansa, to resolve the homology of these elements as well as the pattern of connection of the autopodial elements and the origin of the digital arch. embryos and juveniles of p. expansa were cleared and stained for cartilage and bone. the fore- and hind-limbs were also studied histologically. we describe the development of the stylopodium and zeugopodium originating from a y-s ... | 2011 | 21290416 |
| a new genus and a new species of cladorchiidae (digenea: dadayiinae) from podocnemis expansa (chelonia) of the neotropical region, state of pará, brazil. | a new species of amphistome digenean from the stomach and intestine of podocnemis expansa (pelomedusidae), of the tropical rain forest, from the state of pará, brazil, is described and allocated to a new genus ( oriximinatrema noronhae ). the new species is characterized by the presence of an esophageal bulb, an esophageal extension uncovered by an extension of the pharyngeal sacs, a well-developed cirrus sac, post-bifurcal genital sucker, a ventro-terminal acetabulum with an anterior lip, and m ... | 2012 | 22088092 |
| association of midazolam with ketamine in giant amazon river turtles podocnemis expansa breed in captivity. | evaluate the effects of two anesthetic associations in giant amazon river turtles (p. expansa). | 2012 | 22378369 |
| reproductive indices in natural nests of giant amazon river turtles podocnemis expansa (schweigger, 1812) (testudines, podocnemididae) in the environmental protection area meanders of the araguaia river. | a count was made of unhatched eggs and hatchling live and dead podocnemis expansa turtles in 327 natural nests located on the beaches of the environmental protection area (epa) meanders of the araguaia river, to determine the percentage of hatching (94.63%), non-hatching (5.37%), survival (94.24%) and hatchling mortality (5.76%), and the average percentage of dead hatchlings during the 15 days in the nursery (0.97%). the mean number of hatchlings per nest was determined from the sum of the numbe ... | 2012 | 22437402 |
| conservation genetics of harvested river turtles, podocnemis expansa and podocnemis unifilis, in the peruvian amazon: all roads lead to iquitos. | we present a mtdna analysis of podocnemis expansa (n = 81) and podocnemis unifilis (n = 228) turtles traded in peru to evaluate the potential origin of these animals. in particular, we were interested in the relationship between samples reported in the iquitos markets (ims) and a pacaya samiria natural reserve (psnr) where illegal hunting is presumed. our mtdna data showed that, for both species, all haplotypes found within the psnr were observed in the im, and that these markets also displayed ... | 2012 | 22651234 |
| association of acepromazine with propofol in giant amazon turtles podocnemis expansa reared in captivity. | to evaluate the effects of different concentrations of an anesthetic association in giant amazon turtles (podocnemis expansa). | 2012 | 22850706 |
| turtle vocalizations as the first evidence of posthatching parental care in chelonians. | until recently, freshwater turtles were thought to be silent reptiles, neither vocalizing nor hearing very well. we recorded individuals in nature, captivity, and during interactions between adults and hatchlings and show that hatchlings and adult turtles, podocnemis expansa, produce sounds in and out of the water. sounds were emitted by hatchlings inside the egg, in open nests, in the river, and in captive conditions. adult females were recorded producing sounds in the river, while basking, whi ... | 2013 | 23088649 |
| cytogenetic comparison of podocnemis expansa and podocnemis unifilis: a case of inversion and duplication involving constitutive heterochromatin. | podocnemis expansa and p. unifilis present 2n = 28 chromosomes, a diploid number similar to those observed in other species of the genus. the aim of this study was to characterize these two species using conventional staining and differential cbg-, gtg and ag-nor banding. we analyzed specimens of p. expansa and p. unifilis from the state of tocantins (brazil), in which we found a 2n = 28 and karyotypes differing in the morphology of the 13(th) pair, which was submetacentric in p. expansa and tel ... | 2013 | 24130442 |
| effects of exposure to methyl parathion on egg hatchability and eggshell chemical composition in podocnemis expansa (testudines, podocnemididae). | eggshell evaluation may serve as an indicator of the effect of substances released in the environment, which may change eggshell shape, size, structure, and/or chemical composition. additionally, exposure may interfere with hatching rates in contaminated eggs. the objective of this study was to better understand how exposure to the insecticide methyl parathion interferes with chemical changes in eggshells of podocnemis expansa throughout their artificial incubation, as well as with egg hatchabil ... | 2015 | 25826061 |
| relationship between multiple paternity and reproductive parameters for podocnemis sextuberculata (testudines: podocnemididae) in the trombetas river, brazil. | genetic studies of multiple paternity are a valuable tool to gain information on the reproductive biology of turtles. we analyzed paternity type in podocnemis sextuberculata and related number of fathers per nest to nesting period (beginning, middle, or end of nesting season); clutch size (number of eggs); female size; and hatchling success. females were captured and maximum linear carapace lengths measured during the 60 days that encompass the nesting season at rio trombetas biological reserve ... | 2016 | 26909934 |
| polyandrous behavior in an overexploited giant south american turtle (podocnemis expansa) population in central amazon, brazil. | the aim of the present study was to investigate the reproductive behavior of the giant amazon river turtle (podocnemis expansa) in the amazon. this was carried out by estimating the degree of polymorphism in five dna microsatellites in a sample of 359 hatchlings from 12 nests in the mamirauá sustainable development reserve in the municipality of tefé, state of amazonas, brazil. an analysis of allele frequency and variation in the five microsatellite loci allowed for determination of multiple pat ... | 2017 | 28218789 |
| enzymes of energy metabolism in hatchlings of amazonian freshwater turtles (testudines, podocnemididae). | the metabolic profiles of selected tissues were analyzed in hatchlings of the amazonian freshwater turtles podocnemis expansa, p. unifilis and p. sextuberculata. metabolic design in these species was judged based on the key enzymes of energy metabolism, with special emphasis on carbohydrate, lipid, amino acid and ketone body metabolism. all species showed a high glycolytic potential in all sampled tissues. based on low levels of hexokinase, glycogen may be an important fuel for these species. th ... | 2009 | 19675933 |
| mercury concentrations in different tissues of turtle and caiman species from the rio purus, amazonas, brazil. | total mercury (hg) concentrations of muscle, liver, blood, and epidermal keratin were measured in typically consumed, economically and culturally important species of turtle (podocnemis unifilis and podocnemis expansa) and caiman (melanosuchus niger and caiman crocodilus) from the rio purus in the amazon basin, brazil. methylmercury (mehg) concentrations were also measured in muscle tissue, representing the first analysis of mehg concentrations in amazonian reptile species. in muscle tissues hg ... | 2015 | 26387493 |
| biochemical and hematological reference ranges for amazon freshwater turtle, podocnemis expansa (reptilia: pelomedusidae), with morphologic assessment of blood cells. | blood parameters are useful to measure physiological disturbances in chelonians. thus they can provide important information for the diagnosis and prognosis of diseases. the aim of this paper was to determine the reference range of plasma glucose, total protein, triglycerides, cholesterol and urea levels, as well as hematocrit, hemoglobin, red blood cell, thrombocyte and white blood cell counts for healthy podocnemis expansa (schweigger, 1812), bred in a turtle farm in the amazonas state, brazil ... | 2009 | 18617203 |
| pharmacological restraint of captivity giant amazonian turtle podocnemis expansa (testudines, podocnemididae) with xylazine and propofol. | identify a technique to induce brief sedation and hypnosis in podocnemis expansa. | 2016 | 18552999 |
| estimating population structure under nonequilibrium conditions in a conservation context: continent-wide population genetics of the giant amazon river turtle, podocnemis expansa (chelonia; podocnemididae). | giant amazon river turtles, podocnemis expansa, are indigenous to the amazon, orinoco, and essequibo river basins, and are distributed across nearly the entire width of the south american continent. although once common, their large size, high fecundity, and gregarious nesting, made p. expansa especially vulnerable to over-harvesting for eggs and meat. populations have been severely reduced or extirpated in many areas throughout its range, and the species is now regulated under appendix ii of th ... | 2006 | 16599962 |
| multiple paternity in side-neck turtles podocnemis expansa: evidence from microsatellite dna data. | multiple paternity was found in two clutches of podocnemis expansa using eight microsatellite loci. when loci were analysed separately a minimum of two males was estimated for nest n23, and three for nest c17. when all loci were combined, three patrilines were detected in n23, and six in c17. the distribution of full-sib cluster sizes indicated a disproportionate contribution of one male to clutch c17, consistent with possible sperm competition, or the mixing of leftover and newly acquired sperm ... | 2000 | 10652079 |
| [morphologic study of the embryonic development of the amazonian turtle podocnemis expansa, pelomedusidae]. | two egg groups from four clutches of the amazon turtle, podocnemis expansa, were incubated at 32-34 degrees c and 35-38 degrees c, respectively. the incubation of the first group lasted approximately 47 days and the second 43 days. to standardize the stages, a series of 25 stages was recorded, based on observation of morphological evolution related to incubation duration and its respective temperatures. | 1990 | 2098852 |
| molecular detection of hemogregarines and haemosporidians in brazilian free-living testudines. | morphological and molecular techniques were used to investigate the presence of hemogregarines and haemosporidians in biological samples of free-living geoffroy's side-necked turtles (phrynops geoffroanus) and giant amazon turtles (podocnemis expansa) from brazil. no evolutionary form of haemosporidians or hemogregarines were observed in the blood smears of 83 p. geoffroanus samples, and there were no meronts in the histological sections of 31 necropsied p. geoffroanus samples. all dna samples e ... | 2018 | 30050752 |
| mutagenic, genotoxic and morphotoxic potential of different pesticides in the erythrocytes of podocnemis expansa neonates. | despite the damaging effects of pesticides glyphosate (gly), atrazine (atra) and fipronil (fip) on different organisms, the mutagenic, genotoxic and morphotoxic potential of testudine erythrocytes in freshwater remains unknown. thus, the aim of the present study is to assess the toxicological potential of these compounds in podocnemis expansa (amazonian turtles) neonates from eggs artificially incubated in substrate at different concentrations of herbicides gly and atra and insecticide fip. micr ... | 2020 | 32783869 |
| evolutionary insights in amazonian turtles (testudines, podocnemididae): co-location of 5s rdna and u2 snrna and wide distribution of tc1/mariner. | eukaryotic genomes exhibit substantial accumulation of repetitive dna sequences. these sequences can participate in chromosomal reorganization events and undergo molecular cooption to interfere with the function and evolution of genomes. in turtles, repetitive dna sequences appear to be accumulated at probable break points and may participate in events such as non-homologous recombination and chromosomal rearrangements. in this study, repeated sequences of 5s rdna, u2 snrna and tc1/mariner trans ... | 2020 | 32229487 |
| osteodensitometry and tomographic findings in four captive giant south american turtles (podocnemis expansa) with metabolic bone disease. | giant south american turtles (podocnemis expansa) are at a risk of extinction because of the rapid decline in their population over the last few decades. metabolic bone disease (mbd) is common in captive testudines, but is often not diagnosed until a later stage. the authors present the cases of four captive giant south american turtles with carapace deformity secondary to mbd that underwent computed tomography (ct) scans of the carapace bones and vertebral column. findings indicative of changes ... | 2019 | 31260212 |
| development of scleral ossicles in podocnemis expansa (testudines: podocnemididae) embryos exposed to atrazine. | understanding the effects of atrazine exposure on embryo development in oviparous animals may provide important data regarding the impacts of agrochemical use on wildlife and the ecosystem. this study set out to determine the effects of embryonic atrazine exposure on the development of osseous and cartilaginous components of scleral ossicles in podocnemis expansa. eggs were collected at the environmental protection area meandros do rio araguaia, brazil, and artificially incubated in sand treated ... | 2019 | 31195844 |
| do amazon turtles exposed to environmental concentrations of the antineoplastic drug cyclophosphamide present mutagenic damages? if so, would such damages be reversible? | antineoplastic drugs (ad) have been increasingly used, but the disposal of their wastes in the environment via hospital effluent and domestic sewage has emerged as an environmental issue. the current risks posed to these animals and effects of pollutants on the reptiles' population level remain unknown due to lack of studies on the topic. the aim of the present study was to evaluate the mutagenicity of neonate podocnemis expansa exposed to environmental concentrations (ec) of cyclophosphamide (c ... | 2019 | 30637546 |