Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| experimental exposure of eggs to polybrominated diphenyl ethers bde-47 and bde-99 in red-eared sliders (trachemys scripta elegans) and snapping turtles (chelydra serpentina) and possible species-specific differences in debromination. | polybrominated diphenyl ethers (pbdes) are a bioaccumulative, persistent, and toxic class of flame retardants that can potentially impact turtles in natural habitats via exposure through maternal transfer. to simulate maternal transfer in the present study, pbde congeners bde-47 and bde-99 were topically applied to the eggshell and were allowed to diffuse into the egg contents of the red-eared slider (trachemys scripta elegans) and snapping turtle (chelydra serpentina). eggs were topically dosed ... | 2013 | 23147837 |
| temperature-dependent sex determination modulates cardiovascular maturation in embryonic snapping turtles chelydra serpentina. | we investigated sex differences in cardiovascular maturation in embryos of the snapping turtle chelydra serpentina, a species with temperature-dependent sex determination. one group of eggs was incubated at 26.5°c to produce males. another group of eggs was incubated at 26.5°c until embryos reached stage 17; eggs were then shifted to 31°c for 6 days to produce females, and returned to 26.5°c for the rest of embryogenesis. thus, males and females were at the same temperature when autonomic tone w ... | 2013 | 23125337 |
| nondestructive indices of mercury exposure in three species of turtles occupying different trophic niches downstream from a former chloralkali facility. | turtles are useful for studying bioaccumulative pollutants such as mercury (hg) because they have long life spans and feed at trophic levels that result in high exposure to anthropogenic chemicals. we compared total hg concentrations in blood and toenails of three species of turtles (chelydra serpentina, sternotherus odoratus, and graptemys geographica) with different feeding ecologies from locations up- and downstream of a superfund site in virginia, usa. mercury concentrations in turtle tissue ... | 2013 | 23010870 |
| anatomy of the fully formed chondrocranium of emydura subglobosa (chelidae): a pleurodiran turtle. | the chondrocranium is a cartilaginous structure that forms around and protects the brain and sensory organs of the head. through ontogeny, this skeletal structure may become more elaborate, remodeled and reabsorbed, and/or ossified. though considerable attention has been given to the formation of the chondrocranium and a great amount of data has been gathered on the development of this structure among many craniates, the anatomy of this structure in turtles often is neglected. we describe the ma ... | 2013 | 22972700 |
| species specific differences in the in vitro metabolism of the flame retardant mixture, firemaster® bz-54. | firemaster(®) bz-54 is a flame retardant additive and consists of a brominated benzoate (2-ethylhexyl 2,3,4,5-tetrabromobenzoate; tbb) and a brominated phthalate (bis (2-ethylhexyl) 2,3,4,5-tetrabromophthalate; tbph). previous research has shown that fathead minnows exposed in vivo to firemaster(®) bz-54 accumulate tbb and tbph. this study examined the in vitro biotransformation potential of tbb and tbph in hepatic subcellular fractions (i.e., s9, microsomes and cytosol) in the fathead minnow, c ... | 2012 | 22889877 |
| comparative effects of in ovo exposure to sodium perchlorate on development, growth, metabolism, and thyroid function in the common snapping turtle (chelydra serpentina) and red-eared slider (trachemys scripta elegans). | perchlorate is a surface and groundwater contaminant found in areas associated with munitions and rocket manufacturing and use. it is a thyroid-inhibiting compound, preventing uptake of iodide by the thyroid gland, ultimately reducing thyroid hormone production. as thyroid hormones influence metabolism, growth, and development, perchlorate exposure during the embryonic period may impact embryonic traits that ultimately influence hatchling performance. we topically exposed eggs of red-eared slide ... | 2012 | 22871607 |
| cutaneous fibroma in a captive common snapping turtle (chelydra serpentina). | an adult female common snapping turtle (chelydra serpentina) had a mass on the plantar surface of the right forelimb that was removed surgically. microscopical examination revealed many spindle cells with mild anisocytosis and anisokaryosis and a surrounding collagenous stroma. there were no mitoses. immunohistochemistry showed that the spindle cells expressed vimentin, but not desmin. a diagnosis of cutaneous fibroma was made. tumours are reported uncommonly in chelonian species. cutaneous fibr ... | 2012 | 22578330 |
| widespread reproductive variation in north american turtles: temperature, egg size and optimality. | theory predicts the existence of an optimal offspring size that balances the trade-off between offspring fitness and offspring number. however, in wild populations of many species, egg size can still vary from year to year for unknown reasons. here, we hypothesize that among-year variation in population mean egg size of freshwater turtles is partly a consequence of their gonadal sensitivity to seasonal temperatures, a physiological mechanism which principally functions to synchronize reproductio ... | 2012 | 22541670 |
| highly elevated levels of perfluorooctane sulfonate and other perfluorinated acids found in biota and surface water downstream of an international airport, hamilton, ontario, canada. | per- and poly-fluorinated compounds (pfcs), which include perfluorinated carboxylates (pfcas) and sulfonates (pfsas) and various precursors, are used in a wide variety of industrial, commercial and domestic products. this includes aqueous film forming foam (afff), which is used by military and commercial airports as fire suppressants. in a preliminary assessment prior to this study, very high concentrations (>1 ppm wet weight) of the pfsa, perfluorooctane sulfonate (pfos), were discovered in the ... | 2012 | 22208739 |
| Incidental nest predation in freshwater turtles: inter- and intraspecific differences in vulnerability are explained by relative crypsis. | There has long been interest in the influence of predators on prey populations, although most predator-prey studies have focused on prey species that are targets of directed predator searching. Conversely, few have addressed depredation that occurs after incidental encounters with predators. We tested two predictions stemming from the hypothesis that nest predation on two sympatric freshwater turtle species whose nests are differentially prone to opportunistic detection-painted turtles (Chrysemy ... | 2011 | 22009341 |
| absorption of current use pesticides by snapping turtle (chelydra serpentina) eggs in treated soil. | reptiles often breed within agricultural and urban environments that receive frequent pesticide use. consequently, their eggs and thus developing embryos may be exposed to pesticides. our objectives were to determine (i) if turtle eggs are capable of absorbing pesticides from treated soil, and (ii) if pesticide absorption rates can be predicted by their chemical and physical properties. snapping turtle (chelydra serpentina) eggs were incubated in soil that was treated with 10 pesticides (atrazin ... | 2011 | 21862099 |
| toxicity of pesticide and fertilizer mixtures simulating corn production to eggs of snapping turtles (chelydra serpentina). | many reptiles oviposit in soils associated with agricultural landscapes. we evaluated the toxicity of a pesticide and fertilizer regime similar to those used in corn production in ontario on the survivorship of exposed snapping turtle (chelydra serpentina) eggs. the herbicides atrazine, dimethenamid, and glyphosate, the pyrethroid insecticide tefluthrin, and the fertilizer ammonia, were applied to clean soil, both as partial mixtures within chemical classes, as well as complete mixtures. eggs we ... | 2011 | 21831407 |
| replication and persistence of vhsv ivb in freshwater turtles. | with the emergence of viral hemorrhagic septicemia virus (vhsv) strain ivb in the great lakes of north america, hatchery managers have become concerned that this important pathogen could be transmitted by animals other than fish. turtles are likely candidates because they are poikilotherms that feed on dead fish, but there are very few reports of rhabdovirus infections in reptiles and no reports of the fish rhabdoviruses in animals other than teleosts. we injected common snapping turtles chelydr ... | 2011 | 21790064 |
| multi-scale hierarchy of chelydra serpentina: microstructure and mechanical properties of turtle shell. | carapace, the protective shell of a freshwater snapping turtle, chelydra serpentina, shields them from ferocious attacks of their predators while maintaining light-weight and agility for a swim. the microstructure and mechanical properties of the turtle shell are very appealing to materials scientists and engineers for bio-mimicking, to obtain a multi-functional surface. in this study, we have elucidated the complex microstructure of a dry chelydra serpentina's shell which is very similar to a m ... | 2011 | 21783154 |
| mercury concentrations in snapping turtles (chelydra serpentina) correlate with environmental and landscape characteristics. | mercury (hg) deposited onto the landscape can be transformed into methylmercury (mehg), a neurotoxin that bioaccumulates up the aquatic food chain. here, we report on hg concentrations in snapping turtles (chelydra serpentina) across new york state, usa. the objectives of this study were to: (1) test which landscape, water, and biometric characteristics correlate with total hg (thg) concentrations in snapping turtles; and (2) determine whether soft tissue thg concentrations correlate with scute ... | 2011 | 21688194 |
| an egg injection technique to evaluate the effect of polychlorinated biphenyls on the hatching success of the snapping turtle (chelydra serpentina serpentina). | embryos of oviparous organisms are exposed to contaminants by two pathways: contaminant uptake from the surrounding environment, and the transfer from female to offspring (maternal transfer). the initial source of contaminant exposure for most embryos is likely to be maternal transfer; therefore, maternal transfer studies are critical in determining the effects of contaminants on future populations. injection of contaminants directly into eggs is one route of experimental contaminant exposure th ... | 2011 | 21191884 |
| temperature effects on snapping performance in the common snapper chelydra serpentina (reptilia, testudines). | studies on the effect of temperature on whole-animal performance traits other than locomotion are rare. here we investigate the effects of temperature on the performance of the turtle feeding apparatus in a defensive context. we measured bite force and the kinematics of snapping in the common snapping turtle (chelydra serpentina) over a wide range of body temperatures. bite force performance was thermally insensitive over the broad range of temperatures typically experienced by these turtles in ... | 2011 | 21137093 |
| structure of the newly found green turtle egg-white ribonuclease. | marine green turtle (chelonia mydas) egg-white ribonuclease (gtrnase) was crystallized from 1.1 m ammonium sulfate ph 5.5 and 30% glycerol using the sitting-drop vapour-diffusion method. the structure of gtrnase has been solved at 1.60 a resolution by the molecular-replacement technique using a model based on the structure of rnase 5 (murine angiogenin) from mus musculus (46% identity). the crystal belonged to the monoclinic space group c2, with unit-cell parameters a = 86.271, b = 34.174, c = 3 ... | 2010 | 20606267 |
| physiology of hibernation under the ice by turtles and frogs. | successful overwintering under ice by an air-breathing vertebrate requires either effective aquatic respiration if dissolved o(2) is available or the capacity for prolonged anaerobic metabolism if o(2) supplies are limiting. frogs can remain aerobic for many weeks when submerged at low temperature, even at water po(2) as low as 30 mmhg, but are unable to survive even 1 week in anoxic water. fuel reserves of hibernating frogs limit aerobic submergence, whereas acidosis may limit anoxic submergenc ... | 2010 | 20535765 |
| fourteen nuclear genes provide phylogenetic resolution for difficult nodes in the turtle tree of life. | advances in molecular biology have expanded our understanding of patterns of evolution and our ability to infer phylogenetic relationships. despite many applications of molecular methods in attempts at resolving the evolutionary relationships among the major clades of turtles, some nodes in the tree have proved to be extremely problematic and have remained unresolved. in this study, we use 14 nuclear loci to provide an in depth look at several of these troublesome nodes and infer the systematic ... | 2010 | 19913628 |
| parent-offspring conflict and selection on egg size in turtles. | the trade-off between offspring size and number can present a conflict between parents and their offspring. because egg size is constrained by clutch size, the optimal egg size for offspring fitness may not always be equivalent to that which maximizes parental fitness. we evaluated selection on egg size in three turtle species (apalone mutica, chelydra serpentina and chrysemys picta) to determine if optimal egg sizes differ between offspring and their mothers. although hatching success was gener ... | 2009 | 19796084 |
| latent mortality of juvenile snapping turtles from the upper hudson river, new york, exposed maternally and via the diet to polychlorinated biphenyls (pcbs). | we conducted a factorial experiment to compare sublethal and lethal responses of juvenile snapping turtles exposed maternally and/or through the diet to polychlorinated biphenyls (pcbs) over 14 months posthatching. maternal exposure did not affect embryonic development or hatching success. thyrosomatic indices were not influenced by treatments, although hepatosomatic indices were lower in animals having been exposed to pcbs maternally relative to those having been exposed both maternally and via ... | 2009 | 19731717 |
| helminth infracommunities of the common snapping turtle (chelydra serpentina serpentina) from westhampton lake, virginia. | patterns of infracommunity similarity were examined for 27 male and 6 female common snapping turtles, chelydra serpentina serpentina, collected from westhampton lake on the campus of the university of richmond in richmond, virginia, during the summer months of 1979 and 1980. patterns of infracommunity similarity based on parasite abundance emphasized differences between years and between host sexes. patterns of similarity based on parasite presence or absence emphasized differences among the mon ... | 2009 | 19658450 |
| lack of biological effects of water accommodated fractions of chemically- and physically-dispersed oil on molecular, physiological, and behavioral traits of juvenile snapping turtles following embryonic exposure. | snapping turtle (chelydra serpentina) eggs were exposed to two concentrations of chemically- or physically-dispersed water accommodated fractions of weathered arabian light crude oil (low=0.5 and high=10 g oil/l water). solutions were passed through nest substrate to simulate alterations in composition during percolation to egg depth. hatchlings were raised for 13 months during which numerous endpoints were measured. prior to percolation, total pah ("tpah"; the sum of 52 pahs measured) in physic ... | 2009 | 19631965 |
| the platelet-derived growth factor signaling system in snapping turtle embryos, chelydra serpentina: potential role in temperature-dependent sex determination and testis development. | the platelet-derived growth factor (pdgf) signaling system is known to play a significant role during embryonic and postnatal development of testes in mammals and birds. in contrast, genes that comprise the pdgf system in reptiles have never been cloned or studied in any tissue, let alone developing gonads. to explore the potential role of pdgf ligands and their receptors during embryogenesis, we cloned cdna fragments of pdgf-a, pdgf-b, and receptors pdgfr-alpha and pdgfr-beta in the snapping tu ... | 2009 | 19523392 |
| lipid metabolism during embryonic development of the common snapping turtle, chelydra serpentina. | the metabolism of lipids and fatty acids during embryonic development of chelydra serpentina (common snapping turtle) was investigated. substantial changes in lipid class and fatty acid composition occurred as lipids were transferred from the yolk to the yolk sac membrane (ysm) and then to the brain, eyes, heart, and lungs of the hatchling. lipids were hydrolyzed in the yolk prior to transport to the ysm, shown by a large increase in free fatty acids (ffas) during the second half of development. ... | 2009 | 19416694 |
| cross-reactivity of a polyclonal antibody against chinemys reevesii vitellogenin with the vitellogenins of other turtle species: chelydra serpentina , macrochelys temminckii , and pelodiscus sinensis. | vitellogenin (vtg), a yolk-precursor protein in oviparous vertebrates, is a useful biomarker for reproductive physiology and environmental estrogenic pollution. to examine interspecific applicability of an enzyme-linked immunosorbent assay (elisa) for quantifying chinemys reevesii vtg, we observed cross-reactivity between a polyclonal antibody against chinemys reevesii vtg and the vtgs from other turtle species: chelydra serpentina (chelydridae), macrochelys temminckii (chelydridae), and pelodis ... | 2008 | 19267600 |
| a new haemogregarina species of the alligator snapping turtle, macrochelys temminckii (testudines: chelydridae), in georgia and florida that produces macromeronts in circulating erythrocytes. | haemogregarina macrochelysi n. sp. (apicomplexa: haemogregarinidae) of the alligator snapping turtle, macrochelys temminckii, is characterized by slender, recurved gamonts 29-35 x 3-4.5 microm, in which the anterior limb comprises 48-54% of the total length. the gamont nucleus, 5-7.5 x 2-5 microm, is situated at approximately midbody of the gamont. meronts typical of haemogregarina occupying erythrocytes have 3-8 small, compact nuclei and are 13-17 x 4.5-9 microm. erythrocytic meronts that conta ... | 2009 | 19245282 |
| accumulation and maternal transfer of polychlorinated biphenyls in snapping turtles of the upper hudson river, new york, usa. | we conducted field studies over three years to assess body burdens and maternal transfer of polychlorinated biphenyls (pcbs) as well as indices of sexual dimorphism in snapping turtles (chelydra serpentina) of the upper hudson river (ny, usa.) we collected adult turtles in areas known to be contaminated with pcbs and in nearby reference areas for measurement of body size, precloacal length, and penis size. we analyzed pcb concentrations in eggs collected over three years and in whole blood from ... | 2008 | 18699700 |
| health assessment of free-ranging alligator snapping turtles (macrochelys temminckii) in georgia and florida. | the alligator snapping turtle (macrochelys temminckii) is a large freshwater turtle endemic to river systems that drain into the gulf of mexico. turtle populations were sharply reduced by commercial harvest in the 1970s and 1980s; however, the species has yet to be protected under the endangered species act. while anthropogenic stressors such as habitat fragmentation and degradation and illegal capture continue to threaten populations, the degree to which disease may be contributing to any decli ... | 2008 | 18689653 |
| an outbreak of salmonella food poisoning at a snapping turtle restaurant. | 2008 | 18653984 | |
| carbon dioxide (co2) laser treatment of cutaneous papillomas in a common snapping turtle, chelydra serpentina. | carbon dioxide (co2) laser was used to treat multiple cutaneous papillomas on an adult female common snapping turtle, chelydra serpentina serpentina. a combination of excisional and ablative techniques provided excellent intraoperative visibility and postoperative results due to the laser's unique ability to incise and vaporize soft tissue. | 2008 | 18634218 |
| formation and ossification of limb elements in trachemys scripta and a discussion of autopodial elements in turtles. | though sequences of formation and ossification of bony elements have been described for many taxa, controversy surrounds the formation of limb elements in turtles. three hypotheses for patterns of formation of autopodial elements have been proposed, differing primarily in the origin of distal carpal/tarsal 3, the digital arch, and centrale 4. patterns of formation and ossification of limb elements are described for trachemys scripta. these patterns are compared to similar data for representative ... | 2008 | 18624573 |
| detection of salmonellae in different turtle species within a headwater spring ecosystem. | sediments and water from the slough arm of spring lake, the headwaters of the san marcos river, texas, usa, as well as swabs from biofilms on carapaces and from the cloacae of 18 common musk turtles (sternotherus odoratus), 21 red-eared sliders (trachemys scripta elegans), nine texas river cooters (pseudemys texana), one snapping turtle (chelydra serpentina serpentina), and three guadalupe spiny soft-shell turtles (apalone spinifera guadalupensis), caught at the same site, were analyzed for salm ... | 2008 | 18436690 |
| expression of putative sex-determining genes during the thermosensitive period of gonad development in the snapping turtle, chelydra serpentina. | modes of sex determination are quite variable in vertebrates. the developmental decision to form a testis or an ovary can be influenced by one gene, several genes, environmental variables, or a combination of these factors. nevertheless, certain morphogenetic aspects of sex determination appear to be conserved in amniotes. here we clone fragments of nine candidate sex-determining genes from the snapping turtle chelydra serpentina, a species with temperature-dependent sex determination (tsd). we ... | 2007 | 18391536 |
| the effects of electrolytes and sugars on the erythrocytes of the turtle, chelydra serpentina. | 1949 | 18108892 | |
| snapping turtles (chelydra serpentina) as bioindicators in canadian areas of concern in the great lakes basin. 1. polybrominated diphenyl ethers, polychlorinated biphenyls, and organochlorine pesticides in eggs. | we examined the concentrations and spatial patterns of congeners of pbdes, pcbs, and organochlorine pesticides in snapping turtle (chelydra serpentina) eggs from areas of concern (aocs) on the canadian shores of lake ontario, st. lawrence river, and connecting channels. eggs from lyons creek (niagara river aoc) reflected a local pcb source over a range of 7.5 km (3.2-10.8) from the welland canal. pcb contamination in eggs declined with increasing distance from the welland canal, whereas the rela ... | 2007 | 18044496 |
| snapping turtles (chelydra serpentina) as bioindicators in canadian areas of concern in the great lakes basin. ii. changes in hatching success and hatchling deformities in relation to persistent organic pollutants. | hatching success and deformities in snapping turtle hatchlings (chelydra serpentina) were evaluated using eggs collected from 14 sites in the canadian lower great lakes, including areas of concern (aoc), between 2001 and 2004. eggs were analyzed for pcbs, pbdes, and pesticides. between 2002 and 2004, hatchling deformity rates were highest in two aocs (18.3-28.3%) compared to the reference sites (5.3-11.3%). hatching success was poorest in three aocs (71.3-73.1%) compared to the reference sites ( ... | 2008 | 18039552 |
| the survival of beat in the removed heart of the snapping turtle. | 1916 | 17840076 | |
| on chelydra serpentina. | 1893 | 17832441 | |
| snapping turtle plea. | 1973 | 17816278 | |
| possible adaptive value of water exchanges in flexible-shelled eggs of turtles. | use of energy reserves by embryos of common snapping turtles (chelydra serpentina) is related to the hydric conditions to which eggs are exposed during incubation and to the net exchanges of water through the eggshells. embryos developing inside eggs with a relatively favorable water balance use more of their energy reserves metabolically and grow larger before hatching than embryos inside eggs with less favorable water exchanges. | 1981 | 17760193 |
| toxicity of nitrogenous fertilizers to eggs of snapping turtles (chelydra serpentina) in field and laboratory exposures. | many reptiles oviposit in soil of agricultural landscapes. we evaluated the toxicity of two commonly used nitrogenous fertilizers, urea and ammonium nitrate, on the survivorship of exposed snapping turtle (chelydra serpentina) eggs. eggs were incubated in a community garden plot in which urea was applied to the soil at realistic rates of up to 200 kg/ha in 2004, and ammonium nitrate was applied at rates of up to 2,000 kg/ha in 2005. otherwise, the eggs were unmanipulated and were subject to ambi ... | 2007 | 17702542 |
| influence of feeding ecology on blood mercury concentrations in four species of turtles. | mercury is a relatively well-studied pollutant because of its global distribution, toxicity, and ability to bioaccumulate and biomagnify in food webs: however, little is known about bioaccumulation and toxicity of hg in turtles. total hg (thg) concentrations in blood were determined for 552 turtles representing four different species (chelydra serpentina, sternotherus odoratus, chrysemys picta, and pseudemys rubriventris) from a hg-contaminated site on the south river (va, usa) and upstream refe ... | 2007 | 17702349 |
| can natural phenotypic variances be estimated reliably under homogeneous laboratory conditions? | the phenotypic variance is assumed to be greater in a more heterogeneous environment. the validity of this assumption is important for microevolutionists to extrapolate results from the laboratory to field environments. we subjected clutches of eggs from common snapping turtles (chelydra serpentina) to a split-family design to evaluate the variability in incubation time and four size traits of neonates from eggs incubated in the laboratory and those left in situ. mean size measurements were simi ... | 2007 | 17584235 |
| shell bone histology indicates terrestrial palaeoecology of basal turtles. | the palaeoecology of basal turtles from the late triassic was classically viewed as being semi-aquatic, similar to the lifestyle of modern snapping turtles. lately, this view was questioned based on limb bone proportions, and a terrestrial palaeoecology was suggested for the turtle stem. here, we present independent shell bone microstructural evidence for a terrestrial habitat of the oldest and basal most well-known turtles, i.e. the upper triassic proterochersis robusta and proganochelys quenst ... | 2007 | 17519193 |
| high-resolution analysis of salmonellae from turtles within a headwater spring ecosystem. | sediments and water from the pristine headwaters of the san marcos river, texas, usa, as well as swabs from biofilms on the carapace and from the cloacae of 17 musk turtles (sternotherus odoratus) and one snapping turtle (chelydra serpentina serpentina) caught at the same site, were analysed for salmonellae by culture and molecular techniques. whereas enrichment cultures from sediment and water samples were negative for salmonellae in pcr- and in situ hybridization-based analyses, both technique ... | 2007 | 17250751 |
| comparative shell buffering properties correlate with anoxia tolerance in freshwater turtles. | freshwater turtles as a group are more resistant to anoxia than other vertebrates, but some species, such as painted turtles, for reasons not fully understood, can remain anoxic at winter temperatures far longer than others. because buffering of lactic acid by the shell of the painted turtle is crucial to its long-term anoxic survival, we have tested the hypothesis that previously described differences in anoxia tolerance of five species of north american freshwater turtles may be explained at l ... | 2007 | 17008457 |
| physiological responses to freezing in hatchlings of freeze-tolerant and -intolerant turtles. | freeze tolerance is a complex cold-hardiness adaptation that has independently evolved in a diverse group of organisms, including several ectothermic vertebrates. because little is known about the mechanistic basis for freeze tolerance in reptiles, we compared responses to experimental freezing in winter-acclimatized hatchlings representing nine taxa of temperate north american turtles, including ones that tolerated freezing and others that did not. viability rates of hatchlings frozen to -3 deg ... | 2006 | 16758216 |
| polychlorinated biphenyl concentrations, congener profiles, and ratios in the fat tissue, eggs, and plasma of snapping turtles (chelydra s. serpentina) from the ohio basin of lake erie, usa. | concentrations and profiles of polychlorinated biphenyls (pcbs) were determined in three tissues of adult snapping turtles (chelydra serpentina serpentina) from six locations in the ohio basin of lake erie to characterize tissue variation and geographic trends. the locations included the ohio areas of concern, i.e., the ashtabula, black, and maumee rivers; the ottawa river near toledo; and two reference sites. mean total pcbs were greatest in turtles from the ottawa river followed by the maumee, ... | 2006 | 16583258 |
| effects of environmentally relevant concentrations of atrazine on gonadal development of snapping turtles (chelydra serpentina). | the herbicide atrazine has been suspected of affecting sexual development by inducing aromatase, resulting in the increased conversion of androgens to estrogens. we used snapping turtles (chelydra serpentina), a species in which sex is dependent on the production of estrogen through aromatase activity in a temperature-dependent manner, to investigate if environmentally relevant exposures to atrazine affected gonadal development. eggs were incubated in soil to which atrazine was applied at a typi ... | 2006 | 16519315 |
| the complete mitochondrial genome of the enigmatic bigheaded turtle (platysternon): description of unusual genomic features and the reconciliation of phylogenetic hypotheses based on mitochondrial and nuclear dna. | the big-headed turtle (platysternon megacephalum) from east asia is the sole living representative of a poorly-studied turtle lineage (platysternidae). it has no close living relatives, and its phylogenetic position within turtles is one of the outstanding controversies in turtle systematics. platysternon was traditionally considered to be close to snapping turtles (chelydridae) based on some studies of its morphology and mitochondrial (mt) dna, however, other studies of morphology and nuclear ( ... | 2006 | 16464263 |
| oviductal morphology in relation to hormonal levels in the snapping turtle, chelydra serpentina. | microscopic and in situ visual observations were used to relate circulating hormone levels to morphological changes in the oviduct of the snapping turtle chelydra serpentina throughout the ovarian cycle. increase in levels of progesterone (p), estradiol (e2) and testosterone (t) levels coincide with an increase in number and growth of endometrial glands, luminal epithelial cells and secretory droplets throughout the oviduct. testosterone and estradiol levels rose significantly (p < 0.05) after t ... | 2006 | 16384588 |
| intramembranous ossification of scleral ossicles in chelydra serpentina. | scleral ossicles are present in many reptiles, including turtles and birds. in both groups the sclerotic ring situated in the eye is composed of a number of imbricating scleral ossicles or plates. despite this gross morphological similarity, andrews (1996. an endochondral rather than a dermal origin for scleral ossicles in cryptodiran turtles. j. herpetol. 30, 257-260) reported that the scleral ossicles of turtles develop endochondrally unlike those in birds, which develop intramembranously afte ... | 2006 | 16377163 |
| high incidence of deformity in aquatic turtles in the john heinz national wildlife refuge. | the john heinz national wildlife refuge is subject to pollution from multiple sources. we studied development of snapping turtle (chelydra serpentina) and painted turtle (chrysemys picta) embryos from the refuge from 2000 through 2003. mean annual deformity rate of pooled painted turtle clutches over four years ranged from 45 to 71%, while that of snapping turtle clutches ranged from 13 to 19%. lethal deformities were more common than minor or moderate deformities in embryos of both species. adu ... | 2006 | 16360253 |
| polycyclic aromatic hydrocarbons affect survival and development of common snapping turtle (chelydra serpentina) embryos and hatchlings. | polycyclic aromatic hydrocarbons (pahs) are toxic compounds found in the john heinz national wildlife refuge in philadelphia, pennsylvania. we assessed the impact of pahs and crude oil on snapping turtle development and behavior by exposing snapping turtle eggs from the refuge and from three clean reference sites to individual pahs or a crude oil mixture at stage 9 of embryonic development. exposure to pahs had a significant effect on survival rates in embryos from one clean reference site, but ... | 2006 | 16360251 |
| a high standard metabolic rate constrains juvenile growth. | the allocation of energy to various components of an individual's energy budget is often viewed as a competitive process. as such, a tradeoff may exist between production (growth) and maintenance metabolism. one view of a potential tradeoff, termed "the principle of allocation", suggests that individuals with lower maintenance metabolic expenditures may have higher growth rates. to determine whether such a tradeoff exists, i analyzed the relationship between growth rate and maintenance metabolis ... | 2002 | 16351863 |
| characterization of a ribonuclease gene and encoded protein from the reptile, iguana iguana. | in this work we identify an intronless open reading frame encoding an rnase a ribonuclease from genomic dna from the iguana iguana igh2 cell line. the iguana rnase is expressed primarily in pancreas, and represents the majority of the specific enzymatic activity in this tissue. the encoded sequence shares many features with its better-known mammalian counterparts including the crucial his12, lys40 and his114 catalytic residues and efficient hydrolytic activity against yeast trna substrate (k(cat ... | 2005 | 15893436 |
| survival and physiological responses of hatchling blanding's turtles (emydoidea blandingii) to submergence in normoxic and hypoxic water under simulated winter conditions. | overwintering habits of hatchling blanding's turtles (emydoidea blandingii) are unknown. to determine whether these turtles are able to survive winter in aquatic habitats, we submerged hatchlings in normoxic (155 mmhg po2) and hypoxic (6 mmhg po2) water at 4 degrees c, recording survival times and measuring changes in key physiological variables. for comparison, we simultaneously studied hatchling softshell (apalone spinifera) and snapping (chelydra serpentina) turtles, which are known to overwi ... | 2016 | 15887082 |
| perfluorinated compounds in aquatic organisms at various trophic levels in a great lakes food chain. | trophic transfer of perfluorooctanesulfonate (pfos) and other related perfluorinated compounds was examined in a great lakes benthic foodweb including water-algae-zebra mussel-round goby-smallmouth bass. in addition, perfluorinated compounds were measured in livers and eggs of chinook salmon and lake whitefish, in muscle tissue of carp, and in eggs of brown trout collected from michigan. similarly, green frog livers, snapping turtle plasma, mink livers, and bald eagle tissues were analyzed to de ... | 2005 | 15883668 |
| anoxia tolerance and freeze tolerance in hatchling turtles. | freezing survival in hatchling turtles may be limited by ischemic anoxia in frozen tissues and the associated accumulation of lactate and reactive oxygen species (ros). to determine whether mechanisms for coping with anoxia are also important in freeze tolerance, we examined the association between capacities for freezing survival and anoxia tolerance in hatchlings of seven species of turtles. tolerance to freezing (-2.5 degrees c) was high in emydoidea blandingii, chrysemys picta, terrapene orn ... | 2005 | 15739066 |
| absence of detectable salmonella cloacal shedding in free-living reptiles on admission to the wildlife center of virginia. | salmonellosis is an important reptile-associated zoonotic infection in the united states. cloacal swabs were collected from reptiles admitted to the wildlife center of virginia, waynesboro, virginia, cultured for salmonella using hektoen and xylose lysine deoxycholate agars, and inoculated in selenite broth. all three were incubated at 37 degrees c for 18-24 hr. seventy-five animals were included in the study, representing eight species, 34 eastern box turtles (terrapene carolina carolina), 14 e ... | 2004 | 15732603 |
| redescription of dracunculus globocephalus mackin, 1927 (nematoda: dracunculidae), a parasite of the snapping turtle, chelydra serpentina. | dracunculus globocephalus mackin, 1927 (nematoda: dracunculoidea) is redescribed from specimens collected from the mesentery of the snapping turtle, chelydra serpentina (l.), in louisiana, usa. the use of scanning electron microscopy, applied for the first time in this species, made it possible to study details in the structure of the cephalic end and the arrangement of male caudal papillae that are difficult to observe under the light microscope. this species markedly differs from all other spe ... | 2004 | 15729947 |
| secretory proteins in the reproductive tract of the snapping turtle, chelhydra serpentina. | sds-polyacrylamide gel electrophoresis was used to separate the secretory proteins produced by the epithelial and endometrial glands of the uterine tube and uterus in the snapping turtle chelydra serpentina. the proteins were analyzed throughout the phases of the reproductive cycle from may to august, including preovulatory, ovulatory, postovulatory or luteal, and vitellogenic phases. the pattern of secretory proteins is quite uniform along the length of the uterine tube, and the same is true of ... | 2004 | 15596394 |
| observations on the leech placobdella ornata feeding from bony tissues of turtles. | the leech placobdella ornata was observed feeding from the blood sinuses of the plastron and carapace bones of chelydra serpentina and chrysemys picta. evidence of successful feeding included blood upwelling from the point of attachment and gastric ceca of the leeches freshly filled with blood after removal. there was an apparent preference for the sulci between scales of the shell. | 2004 | 15562628 |
| skeletal development of macrochelys temminckii (reptilia: testudines: chelydridae). | few descriptions of the development and sequence of chondrification and ossification of the entire skeleton of turtles exist, particularly compared to other groups of reptiles. in this study, the embryonic skeleton and its ontogenesis are described for the alligator snapping turtle, macrochelys temminckii (chelydridae). morphological descriptions utilize cleared and double-stained embryonic specimens and form the basis of comparison of the ontogenesis of the skeleton between this species and its ... | 2005 | 15536645 |
| contaminant residues in snapping turtle (chelydra s. serpentina) eggs from the great lakes-st. lawrence river basin (1999 to 2000). | to determine temporal and geographic variations of environmentally persistent pollutants, the concentrations of several contaminants were measured in snapping turtle eggs in 1999 and 2000. contaminants included polychlorinated biphenyls (pcbs), non- ortho pcbs, polychlorinated dibenzodioxins and furans, organochlorine pesticides, and total mercury. egg collection sites within the st. lawrence area of concern (aoc) and the territory of akwesasne included turtle creek, snye marsh, and raquette riv ... | 2004 | 15386150 |
| diagnosis of skeletal injuries in chelonians using computed tomography. | computed tomography (ct) was used to diagnose the cause of lameness in a radiated tortoise (geochelone radiata) and to determine the extent of shell and skeletal trauma in two snapping turtles (chelydra serpentina). the radiated tortoise's lameness was ultimately attributed to luxation of the right-shoulder joint that was not detected during plain film radiography. axial and appendicular fractures were identified in one of the snapping turtles that were not detected during plain film radiography ... | 2004 | 15305520 |
| characterization of contaminants in snapping turtles (chelydra serpentina) from canadian lake erie areas of concern: st. clair river, detroit river, and wheatley harbour. | pcbs, organochlorine pesticides and dioxins/furans in snapping turtle eggs and plasma (chelydra serpentina) were evaluated at three areas of concern (aocs) on lake erie and its connecting channels (st. clair river, detroit river, and wheatley harbour), as well as two inland reference sites (algonquin provincial park and tiny marsh) in 2001-2002. eggs from the detroit river and wheatley harbour aocs had the highest levels of p,p'-dde (24.4 and 57.9 ng/g) and sum pcbs (928.6 and 491.0 ng/g) wet we ... | 2004 | 15276278 |
| lactate accumulation, glycogen depletion, and shell composition of hatchling turtles during simulated aquatic hibernation. | we submerged hatchling western painted turtles chrysemys picta schneider, snapping turtles chelydra serpentina l. and map turtles graptemys geographica le sueur in normoxic and anoxic water at 3 degrees c. periodically, turtles were removed and whole-body [lactate] and [glycogen] were measured along with relative shell mass, shell water, and shell ash. we analyzed the shell for [na+], [k+], total calcium, total magnesium, pi and total co2. all three species were able to tolerate long-term submer ... | 2004 | 15235017 |
| environmental contamination and developmental abnormalities in eggs and hatchlings of the common snapping turtle (chelydra serpentina serpentina) from the great lakes-st lawrence river basin (1989-1991). | during 1989-1991, we assessed developmental abnormalities in embryos and hatchlings from eggs of the common snapping turtle (chelydra serpentina serpentina). eggs were collected and artificially incubated from eight sites in ontario, canada and akwesasne/new york, usa. in eggs from the same clutches we measured 20 organochlorine pesticides, 48 polychlorinated biphenyl (pcbs) congeners including 6 non-ortho pcbs, 8 polychlorinated dibenzodioxins (pcdds), 14 polychlorinated dibenzofurans (pcdfs) a ... | 1998 | 15093107 |
| lymphoid aggregates in gonads of embryos, hatchlings, and young of turtles with temperature-dependent sex determination. | cellular infiltrations forming lymphoid-like aggregates were previously observed in gonads of two turtle species exhibiting temperature-dependent sex determination (tsd): at hatching in chelydra serpentina; at and after hatching in emys orbicularis. we show here that such aggregates are also present in gonads of testudo graeca by the end of embryonic development, suggesting that their occurrence is general in turtles. since in c. serpentina, infiltrations were observed mainly in testes exhibitin ... | 2004 | 14743515 |
| an experimental approach to the development of ear capsule in the turtle, chelydra serpentina. | 1965 | 14329484 | |
| hypoxia: effects on heart rate and respiration in the snapping turtle. | in response to atmospheres containing decreasing amounts of oxygen, snapping turtles (chelydra serpentina) maintained a fairly constant oxygen uptake. their heart rate increased and the period of apnea between breathing cycles decreased. small animals had a slightly greater mean uptake per gram than those five to ten times as large. | 1963 | 14014707 |
| a new species of auridistomum (trematoda: auridistomidae) from snapping turtles of georgia. | 1959 | 13802130 | |
| analysis of vagal and cholinesterase effects on the heart of chelydra serpentina. | 1958 | 13606222 | |
| use of intravascular carbon dioxide gas to demonstrate interatrial septal defects. | 1958 | 13606221 | |
| circulation and blood pressure in the great vessels and heart of the turtle (chelydra serpentina). | 1957 | 13458464 | |
| survival and behavior of freshwater turtles after rehabilitation from an oil spill. | an oil spill in february 2000 at the john heinz national wildlife refuge in southeastern pennsylvania affected four species of freshwater turtles including painted turtles (chrysemys picta), snapping turtles (chelydra serpentina), red-eared slider turtles (trachemys scripta), and red-bellied turtles (pseudemys rubriventris). in the summer and fall of 2000, there were no differences in survival, home range, and temperature preference of 16 oil exposed/rehabilitated (oer) turtles, 18 possibly expo ... | 2003 | 12927492 |
| yolk steroid hormones and sex determination in reptiles with tsd. | in reptiles with temperature-dependent sex determination (tsd), the temperature at which the eggs are incubated determines the sex of the offspring. the molecular switch responsible for determining sex in these species has not yet been elucidated. we have examined the dynamics of yolk steroid hormones during embryonic development in the snapping turtle, chelydra serpentina, and the alligator, alligator mississippiensis, and have found that yolk estradiol (e(2)) responds differentially to incubat ... | 2003 | 12849957 |
| [requirements for the keeping of dangerous exotic animals]. | the problem of dangerous dogs receives a lot of public attention. however, there is another group of animals that can threaten public security--the group of dangerous exotic animals. in daily routine mainly venomous snakes, spiders and scorpions or crocodiles, giant snakes and snapping turtles are of practical importance. the paper gives hints how to keep these animals according to animal protection and public safety rules. | 2003 | 12822263 |
| acanthostomum macroclemidis n. sp. (digenea: cryptogonimidae: acanthostominae) from the alligator snapping turtle, macroclemys temmincki. | acanthostomum macroclemidis n. sp. is described from specimens found in the intestine of an alligator snapping turtle macroclemys temmincki from southern mississippi. the most important diagnostic features of the new species are the general shape and proportions of the body, the position of the pharynx (relative length of the prepharynx and esophagus), the egg size, the relative length and position of the vitelline fields, and the number, shape, and size of the circumoral spines. the new species ... | 2003 | 12659321 |
| osteology and skeletal development of apalone spinifera (reptilia: testudines: trionychidae). | despite considerable attention that other groups of reptiles have received, few descriptions of the development and sequences of chondrification and ossification of the entire skeleton of turtles exist. herein, the adult skeleton of the spiny softshell turtle, apalone spinifera (testudines: trionychidae), is described; this description forms a basis of comparison for the embryonic skeleton and its ontogenesis. descriptions are made on the basis of cleared and double-stained embryos and dry skele ... | 2003 | 12616574 |
| the physiology of overwintering in a turtle that occupies multiple habitats, the common snapping turtle (chelydra serpentina). | common snapping turtles, chelydra serpentina (linnaeus), were submerged in anoxic and normoxic water at 3 degrees c. periodic blood samples were taken, and po(2), pco(2), ph, [na(+)], [k(+)], [cl(-)], total ca, total mg, [lactate], [glucose], hematocrit, and osmolality were measured; weight gain was determined; and plasma [hco(3)(-)] was calculated. submergence in normoxic water caused a decrease in pco(2) from 10.8 to 6.9 mmhg after 125 d, partially compensating a slight increase in lactate and ... | 2016 | 12529844 |
| morbidity and mortality of reptiles admitted to the wildlife center of virginia, 1991 to 2000. | medical records from 694 reptiles admitted to the wildlife center of virginia (wcv; waynesboro, virginia, usa) from 1991 to 2000 were reviewed to determine causes of morbidity and mortality. eighteen species were represented but the majority of cases were four species; eastern box turtle (terrapene carolina) (66%), eastern painted turtle (chrysemys picta) (11%), common snapping turtle (chelydra serpentina) (10%), and rat snake (elaphe sp.) (6%). there was a significant increase in reptile cases ... | 2002 | 12528435 |
| ranking terrestrial vertebrate species for utility in biomonitoring and vulnerability to environmental contaminants. | the measurement of contaminant tissue concentrations or exposure-related effects in biota has been used extensively to monitor pollution and environmental health. terrestrial vertebrates have historically been an important group of species in such evaluations, not only because many are excellent sentinels of environmental contamination, but also because they are valued natural resources in their own right that may be adversely affected by toxicant exposure. selection of appropriate vertebrates f ... | 2003 | 12442504 |
| comparative patterns of postcranial ontogeny in therian mammals: an analysis of relative timing of ossification events. | data on the relative sequence of ossification of postcranial elements for eight therian mammals (myotis lucifugus, homo sapiens, rattus norvegicus, mus musculus, mesocricetus auratus, cavia porcellus, didelphis albiventris, and sminthopsis macroura) and three outgroups (chelydra serpentina, alligator mississippiensis, and lacerta vivipara) were taken from the literature. for each species, a matrix was constructed in which the relative timing of the onset of ossification in 24 elements was summar ... | 2002 | 12362432 |
| dynamics of yolk steroid hormones during development in a reptile with temperature-dependent sex determination. | many oviparous reptiles exhibit temperature-dependent sex determination (tsd); i.e., the temperature at which the egg is incubated determines the sex of the offspring. in tsd reptiles, yolk steroids not only may influence sex determination, but also may mediate hormonal effects on subsequent growth and behavior, as in some avian species. we investigated changes in the levels of estradiol (e(2)) and testosterone (t) during development in yolks of snapping turtle eggs, examined how incubation temp ... | 2002 | 12161199 |
| yolk hormone levels in the eggs of snapping turtles and painted turtles. | although yolk steroids appear to play important roles in the development, growth, and behavior of some birds, their effects in oviparous reptiles are largely unknown. these investigations were initiated to determine initial levels of steroid hormones in the yolks of eggs from two turtle species. clutches of snapping turtle (chelydra serpentina) and of painted turtle (chrysemys picta) eggs were collected and individual egg yolks were analyzed for estradiol-17beta (e(2)) and testosterone (t) using ... | 2002 | 12161198 |
| wetness of the nest environment influences cardiac development in pre- and post-natal snapping turtles (chelydra serpentina). | we dissected hearts from near-term embryos and hatchlings of common snapping turtles (chelydridae: chelydra serpentina) whose eggs had incubated on wet or dry substrates, and then dried and individually weighed the heart and yolk-free carcass from each animal. hearts and carcasses of prenatal and neonatal animals grew at different rates, and the patterns of growth by both heart and carcass differed between wet and dry environments. hearts grew faster, both in actual mass and in mass adjusted for ... | 2002 | 12095870 |
| sexually dimorphic morphology of hatchling snapping turtles (chelydra serpentina) from contaminated and reference sites in the great lakes and st. lawrence river basin, north america. | some organochlorine pesticides and industrial chemicals may alter sexually dimorphic traits through endocrine disruption. therefore, we examined a sexually dimorphic trait, precloacal length, of hatchling snapping turtles (chelydra serpentina) incubated from 31 clutches from a heavily contaminated site (hamilton harbour, on, canada; n = 14), a moderately contaminated site (akwesasne mohawk territory; n = 3), and from a reference site (algonquin provincial park, on, canada; n = 14). the mean sum ... | 2002 | 12013138 |
| octylphenol (op) alters the expression of members of the amyloid protein family in the hypothalamus of the snapping turtle, chelydra serpentina serpentina. | the gonadal estrogen estradiol-17beta (e(2)) is important for developing and regulating hypothalamic function and many aspects of reproduction in vertebrates. pollutants such as octylphenol (op) that mimic the actions of estrogens are therefore candidate endocrine-disrupting chemicals. we used a differential display strategy (rna-arbitrarily primed polymerase chain reaction) to isolate partial cdna sequences of neurotransmitter, developmental, and disease-related genes that may be regulated by o ... | 2002 | 11882478 |
| the pulmonary surfactant system matures upon pipping in the freshwater turtle chelydra serpentina. | pulmonary surfactant (ps), a mixture of phospholipids (pl), neutral lipids and surfactant proteins (sp), lowers surface tension within the lung, which increases lung compliance and improves the removal of fluid at birth. here, we have examined the expression of thyroid transcription factor-1 (ttf-1) and the surfactant protein sp-b, and also the composition of pulmonary surfactant lipids in the developing lung of the turtle chelydra serpentina. lavage and lung tissue were collected from late embr ... | 2002 | 11854378 |
| functional conservation of the promoter regions of vertebrate tyrosinase genes. | tyrosinase is the key enzyme for synthesizing melanin pigments, which primarily determine mammalian skin coloration. considering the important roles of pigments in the evolution and the adaptation of vertebrates, phylogenetic changes in the coding and flanking regulatory sequences of the tyrosinase gene are particularly intriguing. we have now cloned cdna encoding tyrosinase from japanese quail and snapping turtle. these nonmammalian cdna are highly homologous to those of the mouse and human tyr ... | 2001 | 11764277 |
| expression of p450(arom) in malaclemys terrapin and chelydra serpentina: a tale of two sites. | the formation of estrogens from androgens in all vertebrates is catalyzed by the "aromatase" complex, which consists of a membrane bound p(450) enzyme, p(450) aromatase (which binds the androgen substrate and inserts an oxygen into the molecule), and a flavoprotein (nadph-cytochrome p450 reductase). among vertebrates, the two major sites of aromatase expression are the brain and gonads. given the importance of estrogen in reptile sex determination, we set out to examine whether p450arom was invo ... | 2001 | 11748616 |
| wildlife as sentinels of human health effects in the great lakes--st. lawrence basin. | there is no existing formal, long-term program for gathering evidence of the incidence and severity of the health effects of toxic substances in wildlife. however, research-based studies of bald eagles, herring gulls, night herons, tree swallows, snapping turtles, mink, and beluga over the past 30 years have revealed a broad spectrum of health effects in the great lakes-st. lawrence basin including thyroid and other endocrine disorders, metabolic diseases, altered immune function, reproductive i ... | 2001 | 11744503 |
| transmission of haemogregarina balli from painted turtles to snapping turtles through the leech placobdella ornata. | six leeches (placobdella ornata) were allowed to feed on a painted turtle (chrysemys picta marginata) infected with haemogregarina balli and subjected to a period of diapause before being allowed to feed on 2 laboratory-reared snapping turtles (chelydra serpentina). weekly examination of thin blood films revealed infections of the turtles at 130 days postfeeding. these observations provide support for broad host specificity of hemogregarine parasites of chelonians. | 2001 | 11695407 |
| snapping turtles (chelydra serpentina) as monitors for mercury contamination of aquatic environments. | we assessed the distribution of mercury in snapping turtles (chelydra serpentina) by analyzing front shoulder muscle, back leg muscle, tail muscle, blood, liver, and marginal carapacial scute (shell) of 26 adult turtles from five small lakes. total mercury concentration in muscle ranged from 50 to 500 ng g(-1) wet weight and was highly correlated among the three tissue locations. there was no relationship between muscle mercury concentration and body size. mercury concentration in blood was simi ... | 2001 | 11683228 |
| cross-species investigations of prenatal experience, hatching behavior, and postnatal behavioral laterality. | turning biases have been reported in some mammalian species, but less is known about such biases in nonmammalians. this study investigated turning biases in domestic chicks, bobwhite and japanese quail, leopard geckos, and snapping turtles. domestic chicks (white leghorn and bantam) and bobwhite quail demonstrate strong group laterality. japanese quail chicks, snapping turtles, and leopard geckos demonstrate no significant group bias. results are discussed with regard to differences in embryonic ... | 2001 | 11568878 |
| organochlorine pesticides, pcbs, dibenzodioxin, and furan concentrations in common snapping turtle eggs (chelydra serpentina serpentina) in akwesasne, mohawk territory, ontario, canada. | subsamples of eight clutches of common snapping turtle eggs (chelydra serpentina serpentina) were collected from four sites from the territory of the mohawk nation, akwesasne, on the shore of the st. lawrence river. egg contents were analyzed for organochlorine pesticides, polychlorinated biphenyls (pcbs), dibenzodioxins, and furans. the sites were 2 to 13 km downstream from pcb-contaminated landfill sites. maximum concentrations of total pcbs in snapping turtle clutches were extremely high, and ... | 2001 | 11443374 |