Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
incubation temperature and satiety influence general locomotor and exploratory behaviors in the common snapping turtle (chelydra serpentina).temperature during embryogenesis determines sex and has been shown to influence other physiological traits in reptiles. the common snapping turtle (chelydra serpentina) is an ideal model for testing how temperature impacts behavior in species that display temperature-dependent sex determination. behavioral assays are crucial to understanding how a changing climate may affect whole organism function in the snapping turtle. currently, there are few behavioral assays for semi-aquatic vertebrates li ...202032194070
high prevalence of subclinical frog virus 3 infection in freshwater turtles of ontario, canada.ranaviruses have been associated with chelonian mortality. in canada, the first two cases of ranavirus were detected in turtles in 2018 in ontario, although a subsequent survey of its prevalence failed to detect additional positive cases. to confirm the prevalence of ranavirus in turtles in ontario, we used a more sensitive method to investigate if lower level persistent infection was present in the population. here we report results via a combination of qpcr, pcr, sanger sequencing and genome s ...202032174301
further characterisation of haemocystidium chelodinae-like haemoproteidae isolated from the bellinger river snapping turtle (myuchelys georgesi).the bellinger river snapping turtle (myuchelys georgesi) is endemic to australia and is confined to a highly restricted distribution in the bellinger river in new south wales. routine veterinary health examinations of 17 healthy turtles were undertaken, along with the collection and analysis of blood samples, during conservation efforts to save the species following a catastrophic population decline. microscopy analysis of blood films detected haemoproteidae parasites that morphologically resemb ...202031754857
wait and snap: eastern snapping turtles (chelydra serpentina) prey on migratory fish at road-stream crossing culverts.there is growing evidence that culverts at road-stream crossings can increase fish density by reducing stream width and fish movement rates, making these passageways ideal predator ambush locations. in this study, we used a combination of videography and δ13c stable isotope analyses to investigate predator-prey interactions at a road-stream crossing culvert. eastern snapping turtles (chelydra serpentina) were found to regularly reside within the culvert to ambush migratory river herring (alosa s ...202032961086
morphometric data for five freshwater turtles in south, central, and west texas.from 2008 to 2013, we sampled freshwater turtle populations at 66 sites in south, central, and west texas, usa. sampling sites included ponds, lakes, resacas (oxbow lakes), canals, and rivers. we sampled turtle populations using baited hoop nets (66 sites) and basking traps (3 sites), and captured turtles by hand opportunistically in terrestrial habitat. we measured carapace length and width, plastron length and width, body depth, and weight of captured turtles. excluding recaptures, we measured ...202032195296
draft genome of the common snapping turtle, chelydra serpentina, a model for phenotypic plasticity in reptiles.turtles are iconic reptiles that inhabit a range of ecosystems from oceans to deserts and climates from the tropics to northern temperate regions. yet, we have little understanding of the genetic adaptations that allow turtles to survive and reproduce in such diverse environments. common snapping turtles, chelydra serpentina, are an ideal model species for studying adaptation to climate because they are widely distributed from tropical to northern temperate zones in north america. they are also ...202032998935
surgical anatomy of celiotomy approaches to the stomach in the common snapping turtle (chelydra serpentina).entanglement in or ingestion of fishing gear is a common cause of morbidity and mortality in chelonians. commercial and recreational fishing activities exert bycatch pressures sufficient to cause population declines in the common snapping turtle (chelydra serpentina) and the alligator snapping turtle (macrochelys spp.). gastrotomy for the removal of fish hook foreign bodies from the stomach of freshwater turtles typically requires a plastron osteotomy but in sea turtles has been successfully acc ...201931120665
role for androgens in determination of ovarian fate in the common snapping turtle, chelydra serpentina.sex steroids are involved in sex determination in almost all vertebrates, including species with temperature-dependent sex determination (tsd). it is well established that aromatase and estrogens are involved in ovary determination in tsd species. in contrast, the role of non-aromatizable androgens in tsd is less clear. in this study, we used dihydrotestosterone (dht) and an antagonist of the mammalian androgen receptor (flutamide) to examine the impact of androgens on sex determination in the s ...201931059691
measurement and modelling of primary sex ratios for species with temperature-dependent sex determination.for many oviparous animals, incubation temperature influences sex through temperature-dependent sex determination (tsd). although climate change may skew sex ratios in species with tsd, few available methods predict sex under natural conditions, fewer still are based on mechanistic hypotheses of development, and field tests of existing methods are rare. we propose a new approach that calculates the probability of masculinization (pm) in natural nests. this approach subsumes the mechanistic hypot ...201930352829
antibacterial activities of plasma from the common (chelydra serpentina) and alligator snapping turtle (macrochelys temminckii).innate immunity provides a fast-acting and nonspecific defense against microbial infection, and appears to have particular importance in the immune response of ectothermic vertebrates. chelonians are a globally distributed and diverse group, yet little is known about their basic immune function. the chelonian family chelydridae is made up of two genera (chelydra and macrochelys), represented in our study by the widespread common snapping turtle ( chelydra serpentina; cst) and the southeast usa e ...201930273972
positive or negative? the shell alters the relationship among behavioral defense strategy, energy metabolic levels and antioxidant capacity in freshwater turtles.the relationships among energy metabolic levels, behavioral and other physiological traits help to determine the trade-off of energy allocation between different traits and the evolution of life-history driven by natural selection. however, these relationships may be distinctive in selected animal taxa because of their unique traits. in the present study, the relationships among energy metabolic levels, behavioral defense strategies, and antioxidant capacity were explored in three freshwater tur ...201930809267
regulation of blood flow in the pulmonary and systemic circuits during submerged swimming in common snapping turtle (chelydra serpentina).blood flow patterns and heart rate have rarely been investigated in freely swimming turtles and their regulation during swimming is unknown. in this study, we investigated the blood flow patterns and heart rate in surfacing and during graded, submerged swimming activity in common snapping turtles. we further investigated the effects of beta-adrenergic and cholinergic receptor blockade on blood flow and heart rate during these activities. our findings illustrate that surfacing is accompanied by a ...201931331940
correction: different mechanisms of serum complement activation in the plasma of common (chelydra serpentina) and alligator (macrochelys temminckii) snapping turtles.[this corrects the article doi: 10.1371/journal.pone.0217626.].201931291346
developmental plasticity of cardiac anoxia-tolerance in juvenile common snapping turtles ( chelydra serpentina).for some species of ectothermic vertebrates, early exposure to hypoxia during embryonic development improves hypoxia-tolerance later in life. however, the cellular mechanisms underlying this phenomenon are largely unknown. given that hypoxic survival is critically dependent on the maintenance of cardiac function, we tested the hypothesis that developmental hypoxia alters cardiomyocyte physiology in a manner that protects the heart from hypoxic stress. to test this hypothesis, we studied the comm ...201931238852
long term effects of chronic prenatal exposure to hypercarbia on organ growth and cardiovascular responses to adrenaline and hypoxia in common snapping turtles.reptilian embryos often face challenging environmental gas compositions during incubation, which may inflict long-lasting effects in the individuals' physiological responses. these conditions can have a lasting effect on the animal into juvenile life as chronic prenatal exposure to hypercarbia results in enlarged hatchling organ size, higher growth rate and resting metabolic rate, although relatively smaller increment in metabolic scope during digestion. therefore, we wanted to verify whether pr ...201931004807
anthropogenic nest sites provide warmer incubation environments than natural nest sites in a population of oviparous reptiles near their northern range limit.oviposition site choice affects a host of offspring phenotypes and directly impacts maternal fitness. recent evidence suggests that oviparous reptiles often select nest sites where the landscape has been altered by anthropogenic activity, whereas natural nest sites are less often used. we leverage a long-term study of snapping turtle (chelydra serpentina) to identify natural nest sites and anthropogenic nest sites and to compare habitat variables among nest site types. natural and anthropogenic ...201930953168
phylogenetic origins for severe acetaminophen toxicity in snake species compared to other vertebrate taxa.while it has been known for a while that some snake species are extremely sensitive to acetaminophen, the underlying mechanism for this toxicity has not been reported. to investigate if essential detoxification enzymes are missing in snake species that are responsible for biotransformation of acetaminophen in other vertebrate species, livers were collected from a variety of snake species, together with samples from alligator, snapping turtle, cat, rat, and cattle. subcellular fractions were anal ...201930268769
health assessment of free-ranging chelonians in an urban section of the bronx river, new york, usa.the bronx river in bronx, new york, us spans an area of significant human development and has been subject to historic and ongoing industrial contamination. we evaluated the health of freeranging native common snapping turtles ( chelydra serpentina) and nonnative invasive red-eared sliders ( trachemys scripta) in a segment of the bronx river between may and july 2012. in 18 snapping turtles and nine sliders, complete physical examinations were performed, ectoparasites collected, and blood was an ...201930226800
first report of ranavirus mortality in a common snapping turtle chelydra serpentina.an adult male snapping turtle with marked palpebral edema and multifocal skin ulceration was found alive in a marsh in southern ontario in summer 2017. the turtle was transported to a rehabilitation facility and died 4 d after arrival. the carcass was submitted to the canadian wildlife health cooperative for post-mortem examination. gross lesions included ulcerative conjunctivitis, necrotizing stomatitis, and splenomegaly. microscopically, this corresponded to multisystemic fibrinonecrotizing va ...201931188138
different mechanisms of serum complement activation in the plasma of common (chelydra serpentina) and alligator (macrochelys temminckii) snapping turtles.reptiles are declining worldwide yet our understanding of their immune function lags far behind other taxa. the innate immune system is the primary mode of defense in reptiles, and the serum complement cascade is its major component. we assessed serum complement activity of plasma in two closely related aquatic turtle species, the common snapping turtle (cst; chelydra serpentina) and alligator snapping turtle (ast; macrochelys temminckii). we used a sheep red blood cell (srbc) hemolysis assay to ...201931170203
detecting trends in body size: empirical and statistical requirements for intraspecific analyses.attributing biological explanations to observed ecogeographical and ecological patterns require eliminating potential statistical and sampling artifacts as alternative explanations of the observed patterns. here, we assess the role of sample size, statistical power, and geographic inclusivity on the general validity and statistical significance of relationships between body size and latitude for 3 well-studied species of turtles. we extend those analyses to emphasize the importance of using stat ...201931616479
blood flow distribution in embryonic common snapping turtles chelydra serpentina (reptilia; chelonia) during acute hypoxia and α-adrenergic regulation.embryonic turtles have four distinct vascular beds that separately perfuse the developing embryo's body and the extra-embryonic yolk sac, amnion and chorioallantoic membrane (cam). the mechanisms enabling differential regulation of blood flow through these separate beds, in order to meet the varying demands of the embryo during development, is of current interest. the present investigation followed the changes in blood flow distribution during an acute exposure to hypoxia and after α-adrenergic ...201931505219
substituted diphenylamine antioxidants and benzotriazole uv stabilizers in blood plasma of fish, turtles, birds and dolphins from north america.substituted diphenylamine antioxidants (sdpas) and benzotriazole uv stabilizers (bzt-uvs) are additives used in industrial and commercial applications to prevent degradation by oxidation and are contaminants of emerging environmental concern. little is known about the fate of these contaminants in wildlife, particularly in reptiles, birds and marine mammals. nine sdpas and six bzt-uvs were measured in blood plasma of seven fish species, snapping turtles (chelydra serpentina), double-crested corm ...201930081360
identification of a novel nidovirus as a potential cause of large scale mortalities in the endangered bellinger river snapping turtle (myuchelys georgesi).in mid-february 2015, a large number of deaths were observed in the sole extant population of an endangered species of freshwater snapping turtle, myuchelys georgesi, in a coastal river in new south wales, australia. mortalities continued for approximately 7 weeks and affected mostly adult animals. more than 400 dead or dying animals were observed and population surveys conducted after the outbreak had ceased indicated that only a very small proportion of the population had survived, severely th ...201830356240
agricultural land use creates evolutionary traps for nesting turtles and is exacerbated by mercury pollution.the rate of anthropogenic habitat conversion often exceeds the rate of natural ecological and evolutionary processes, which sometimes creates mismatches between environmental cues and adaptive behaviors. in numerous species of aquatic turtles, nest site selection is primarily based on cues related to high solar exposure, which leads females to select sites where humans have disturbed habitat. these disturbed sites are often contaminated by pollutants, such as mercury. despite the fact that anthr ...201829962084
colonization and usage of an artificial urban wetland complex by freshwater turtles.conservation authorities invest heavily in the restoration and/or creation of wetlands to counteract the destruction of habitat caused by urbanization. monitoring the colonization of these new wetlands is critical to an adaptive management process. we conducted a turtle mark-recapture survey in a 250 ha artificially created wetland complex in a large north american city (toronto, ontario). we found that two of ontario's eight native turtle species (snapping turtle (sn), chelydra serpentina, and ...201830123718
using non-destructive techniques to measure mercury (hg) concentrations in gravid blanding's turtles (emydoidea blandingii) in northeastern illinois.aquatic turtles are suitable biomonitors of wetland ecosystem health because they are long-lived and occupy elevated trophic positions in wetland food webs. this study aimed to determine hg exposure in adult blanding's turtles (emydoidea blandingii), an imperiled prairie-wetland species endemic to the northern u.s. and southern canada. claw samples were collected from gravid females from four wetland sites in northeast illinois. claw hg concentrations ranged from 654 to 3132 ng/g and we found no ...201830073403
comparison of alligator snapping turtle ( macrochelys temminckii) plasma biochemical profiles from two clinical analyzers.the interpretation of plasma biochemical profiles can be confounded by the methodologies by which samples are analyzed. the goal of this study was to compare agreement between two biochemical analyzers for plasma samples from alligator snapping turtles ( macrochelys temminckii). blood was obtained from the dorsal coccygeal vein of captive-reared, juvenile turtles ( n = 34), stored in lithium heparin tubes, and centrifuged to separate plasma from whole blood. plasma samples were stored at 5°c pri ...201830592915
comparative cranial morphology of the late cretaceous protostegid sea turtle desmatochelys lowii.the phylogenetic placement of cretaceous marine turtles, especially protostegidae, is still under debate among paleontologists. whereas protostegids were traditionally thought to be situated within the clade of recent marine turtles (chelonioidea), some recent morphological and molecular studies suggest placement along the stem of cryptodira. the main reason why the evolution of marine turtles is still poorly understood, is in part due to a lack of insights into the cranial anatomy of protostegi ...201830568851
convective oxygen transport during development in embryos of the snapping turtle chelydra serpentina.this study investigated the maturation of convective oxygen transport in embryos of the snapping turtle (chelydra serpentina). measurements included: mass, oxygen consumption (v̇o2 ), heart rate, blood oxygen content and affinity and blood flow distribution at 50%, 70% and 90% of the incubation period. body mass increased exponentially, paralleled by increased cardiac mass and metabolic rate. heart rate was constant from 50% to 70% incubation but was significantly reduced at 90% incubation. hema ...201830065037
a new method of estimating thermal performance of embryonic development rate yields accurate prediction of embryonic age in wild reptile nests.temperature has a strong effect on ectotherm development rate. it is therefore possible to construct predictive models of development that rely solely on temperature, which have applications in a range of biological fields. here, we leverage a reference series of development stages for embryos of the turtle chelydra serpentina, which was described at a constant temperature of 20 °c. the reference series acts to map each distinct developmental stage onto embryonic age (in days) at 20 °c. by exten ...201829801626
assessment of blood lead, zinc, and mercury concentrations and cholinesterase activity in captive-reared alligator snapping turtles ( macrochelys temminckii) in louisiana, usa.the alligator snapping turtle ( macrochelys temminckii) is a freshwater apex predator that has experienced severe population declines throughout its range due to historical overharvesting and habitat degradation. because of its long lifespan, high trophic level, and limited home range, it is a suitable sentinel species for monitoring environmental contaminants. in louisiana, us a pilot program aims to augment free-ranging populations by releasing captive-reared individuals. baseline values of po ...201829697311
repeatability and sources of variation of the bacteria-killing assay in the common snapping turtle.research on reptile ecoimmunology lags behind that on other vertebrates, despite the importance of such studies for conservation and evolution. because the innate immune system is highly conserved across vertebrate lineages, assessments of its performance may be particularly useful in reptiles. the bacteria-killing assay requires a single, small blood sample and quantifies an individual's ability to kill microorganisms. the assay's construct validity and interpretability make it an attractive me ...201729356460
pulmonary anatomy and a case of unilateral aplasia in a common snapping turtle (chelydra serpentina): developmental perspectives on cryptodiran lungs.the common snapping turtle (chelydra serpentina) is a well studied and broadly distributed member of testudines; however, very little is known concerning developmental anomalies and soft tissue pathologies of turtles and other reptiles. here, we present an unusual case of unilateral pulmonary aplasia, asymmetrical carapacial kyphosis, and mild scoliosis in a live adult c. serpentina. the detailed three-dimensional (3d) anatomy of the respiratory system in both the pathological and normal adult c ...201729063595
characterization of the foxl2 proximal promoter and coding sequence from the common snapping turtle (chelydra serpentina).sex is determined by temperature during embryogenesis in snapping turtles, chelydra serpentina. previous studies in this species show that dihydrotestosterone (dht) induces ovarian development at temperatures that normally produce males or mixed sex ratios. the feminizing effect of dht is associated with increased expression of foxl2, suggesting that androgens regulate transcription of foxl2. to test this hypothesis, we cloned the proximal promoter (1.6kb) and coding sequence for snapping turtle ...201728711355
high levels of maternally transferred mercury disrupt magnetic responses of snapping turtle hatchlings (chelydra serpentina).the earth's magnetic field is involved in spatial behaviours ranging from long-distance migration to non-goal directed behaviours, such as spontaneous magnetic alignment (sma). mercury is a harmful pollutant most often generated from anthropogenic sources that can bio-accumulate in animal tissue over a lifetime. we compared sma of hatchling snapping turtles from mothers captured at reference (i.e., low mercury) and mercury contaminated sites. reference turtles showed radio frequency-dependent sm ...201728501632
embryonic hypoxia programmes postprandial cardiovascular function in adult common snapping turtles (chelydra serpentina).reduced oxygen availability (hypoxia) is a potent stressor during embryonic development, altering the trajectory of trait maturation and organismal phenotype. we previously documented that chronic embryonic hypoxia has a lasting impact on the metabolic response to feeding in juvenile snapping turtles (chelydra serpentina). turtles exposed to hypoxia as embryos [10% o2 (h10)] exhibited an earlier and increased peak postprandial oxygen consumption rate, compared with control turtles [21% o2 (n21)] ...201728495871
phenotypic plasticity of nest timing in a post-glacial landscape: how do reptiles adapt to seasonal time constraints?life histories evolve in response to constraints on the time available for growth and development. nesting date and its plasticity in response to spring temperature may therefore be important components of fitness in oviparous ectotherms near their northern range limit, as reproducing early provides more time for embryos to complete development before winter. we used data collected over several decades to compare air temperature and nest date plasticity in populations of painted turtles and snap ...201727870008
metabolic rates are elevated and influenced by maternal identity during the early, yolk-dependent, post-hatching period in an estuarine turtle, the diamondback terrapin (malaclemys terrapin).non-genetic maternal effects, operating through a female's physiology or behavior, can influence offspring traits and performance. here we examined potential maternal influences on metabolic rates (mr) of offspring in an estuarine turtle, the diamondback terrapin (malaclemys terrapin). females and their eggs were collected from the field and the eggs incubated in the laboratory for subsequent measurement of mr of females, late-stage embryos, newly-hatched individuals that were nutritionally depe ...201727894885
developmental cardiovascular physiology of the olive ridley sea turtle (lepidochelys olivacea).our understanding of reptilian cardiovascular development and regulation has increased substantially for two species the american alligator (alligator mississippiensis) and the common snapping turtle (chelydra serpentina) during the past two decades. however, what we know about cardiovascular maturation in many other species remains poorly understood or unknown. embryonic sea turtles have been studied to understand the maturation of metabolic function, but these studies have not addressed the ca ...201728642099
effects of life-history requirements on the distribution of a threatened reptile.survival and reproduction are the two primary life-history traits essential for species' persistence; however, the environmental conditions that support each of these traits may not be the same. despite this, reproductive requirements are seldom considered when estimating species' potential distributions. we sought to examine potentially limiting environmental factors influencing the distribution of an oviparous reptile of conservation concern with respect to the species' survival and reproducti ...201727488734
determination of linear and cyclic volatile methylsiloxanes in blood of turtles, cormorants, and seals from canada.we measured the concentrations of linear and cyclic volatile methylsiloxanes (vms) concentrations in the blood plasma of turtles, cormorants, and seals collected from canadian freshwater and marine ecosystems. a modified quick, easy, cheap, effective, rugged, and safe (quechers) method was developed to quantify the levels of linear and cyclic vms in the plasma samples. the cyclic vms of hexamethylcyclotrisiloxane (d3), octamethylcyclotetrasiloxane (d4), decamethylcyclopentasiloxane (d5), and dod ...201727663360
morbidity and mortality of wild turtles at a north carolina wildlife clinic: a 10-year retrospective.the medical records from 1,847 wild turtle patients seen between 2005 and 2014 by the turtle rescue team at the north carolina state university college of veterinary medicine were analyzed. eastern box turtles (terrapene carolina carolina; n = 947), yellow-bellied sliders (trachemys scripta scripta; n = 301), cooters ( pseudemys spp.; n = 235), common snapping turtles (chelydra serpentina; n = 165), and eastern painted turtles (chrysemys picta; n = 93) made up 94.3% of all patients. patient admi ...201728920820
an unusual mortality event in johnstone river snapping turtles elseya irwini (johnstone) in far north queensland, australia.an unusual mortality event in johnstone river snapping turtles (elseya irwini) in far north queensland, australia, occurred during the summer months of december 2014 and january 2015. we report the data collected during the mortality event, including counts of sick and dead animals, clinical appearance and one necropsy.201728948624
molecular and morphological characterization of a haemogregarine in the alligator snapping turtle, macrochelys temminckii (testudines: chelydridae).a severely underweight alligator snapping turtle macrochelys temminckii troost in harlan, 1835, was found near tyler, texas, and taken to the caldwell zoo. blood films were submitted to texas a&m university, college station, texas, for morphological and molecular identification of haemogregarine-like inclusions in the red blood cells. intraerythrocytic haemogregarina sp. forms were found on microscopic examination at a parasitemia of <1 %. the morphology and morphometric data for the forms indic ...201727807618
an immunohistochemical approach to identify the sex of young marine turtles.marine turtles exhibit temperature-dependent sex determination (tsd). during critical periods of embryonic development, the nest's thermal environment directs whether an embryo will develop as a male or female. at warmer sand temperatures, nests tend to produce female-biased sex ratios. the rapid increase of global temperature highlights the need for a clear assessment of its effects on sea turtle sex ratios. however, estimating hatchling sex ratios at rookeries remains imprecise due to the lack ...201728296279
diatoms on the carapace of common snapping turtles: luticola spp. dominate despite spatial variation in assemblages.filamentous algae are often visible on the carapaces of freshwater turtles and these algae are dominated by a few species with varying geographic distributions. compared to filamentous algae, little is known about the much more speciose microalgae on turtles. our objectives were to compare the diatom flora on a single turtle species (the common snapping turtle, chelydra serpentina) across part of its range to examine spatial patterns and determine whether specific diatom taxa were consistently a ...201728192469
genetic effects of landscape, habitat preference and demography on three co-occurring turtle species.expanding the scope of landscape genetics beyond the level of single species can help to reveal how species traits influence responses to environmental change. multispecies studies are particularly valuable in highly threatened taxa, such as turtles, in which the impacts of anthropogenic change are strongly influenced by interspecific differences in life history strategies, habitat preferences and mobility. we sampled approximately 1500 individuals of three co-occurring turtle species across a g ...201727997082
ontogenetic shifts in the diet of plains hog-nosed snakes (heterodon nasicus) revealed by stable isotope analysis.wild snake diets are difficult to study using traditional methods, but stable isotopes offer several advantages, including integrating dietary information over time, providing data from individuals that have not fed recently, and avoiding bias towards slowly-digesting prey items. we used stable isotope signatures of carbon and nitrogen from scale tissue, red blood cells, and blood plasma to assess the diet of wild plains hog-nosed snakes (heterodon nasicus) in illinois. we developed bayesian mix ...201727692795
atrazine alters expression of reproductive and stress genes in the developing hypothalamus of the snapping turtle, chelydra serpentina.atrazine is an herbicide used to control broadleaf grasses and a suspected endocrine disrupting chemical. snapping turtles lay eggs between late may and early june, which could lead to atrazine exposure via field runoff. our goal was to determine whether a single exposure to 2ppb or 40ppb atrazine during embryogenesis could induce short- and long-term changes in gene expression within the hypothalamus of snapping turtles. we treated eggs with atrazine following sex determination and measured gen ...201627495953
epinephrine or gv-26 electrical stimulation reduces inhalant anesthestic recovery time in common snapping turtles (chelydra serpentina).prolonged anesthetic recovery times are a common clinical problem in reptiles following inhalant anesthesia. diving reptiles have numerous adaptations that allow them to submerge and remain apneic for extended periods. an ability to shunt blood away from pulmonary circulation, possibly due to changes in adrenergic tone, may contribute to their unpredictable inhalant anesthetic recovery times. therefore, the use of epinephrine could antagonize this response and reduce recovery time. gv-26, an acu ...201627468022
reptile embryos lack the opportunity to thermoregulate by moving within the egg.historically, egg-bound reptile embryos were thought to passively thermoconform to the nest environment. however, recent observations of thermal taxis by embryos of multiple reptile species have led to the widely discussed hypothesis that embryos behaviorally thermoregulate. because temperature affects development, such thermoregulation could allow embryos to control their fate far more than historically assumed. we assessed the opportunity for embryos to behaviorally thermoregulate in nature by ...201627322129
embryonic common snapping turtles (chelydra serpentina) preferentially regulate intracellular tissue ph during acid-base challenges.the nests of embryonic turtles naturally experience elevated co2 (hypercarbia), which leads to increased blood pco2  and a respiratory acidosis, resulting in reduced blood ph [extracellular ph (phe)]. some fishes preferentially regulate tissue ph [intracellular ph (phi)] against changes in phe; this has been proposed to be associated with exceptional co2 tolerance and has never been identified in amniotes. as embryonic turtles may be co2 tolerant based on nesting strategy, we hypothesized that t ...201627091863
morphological study on the olfactory systems of the snapping turtle, chelydra serpentina.in this study, the olfactory system of a semi-aquatic turtle, the snapping turtle, has been morphologically investigated by electron microscopy, immunohistochemistry, and lectin histochemistry. the nasal cavity of snapping turtle was divided into the upper and lower chambers, lined by the sensory epithelium containing ciliated and non-ciliated olfactory receptor neurons, respectively. each neuron expressed both gαolf, the α-subunit of g-proteins coupling to the odorant receptors, and gαo, the α- ...201627059760
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 ...201615887082
a novel candidate gene for temperature-dependent sex determination in the common snapping turtle.temperature-dependent sex determination (tsd) was described nearly 50 years ago. researchers have since identified many genes that display differential expression at male- vs. female-producing temperatures. yet, it is unclear whether these genes (1) are involved in sex determination per se, (2) are downstream effectors involved in differentiation of ovaries and testes, or (3) are thermo-sensitive but unrelated to gonad development. here we present multiple lines of evidence linking cirbp to sex ...201626936926
body burdens of heavy metals in lake michigan wetland turtles.tissue heavy metal concentrations in painted (chrysemys picta) and snapping (chelydra serpentina) turtles from lake michigan coastal wetlands were analyzed to determine (1) whether turtles accumulated heavy metals, (2) if tissue metal concentrations were related to environmental metal concentrations, and (3) the potential for non-lethal sampling techniques to be used for monitoring heavy metal body burdens in freshwater turtles. muscle, liver, shell, and claw samples were collected from painted ...201626832725
phenotypic plasticity in the common snapping turtle (chelydra serpentina): long-term physiological effects of chronic hypoxia during embryonic development.studies of embryonic and hatchling reptiles have revealed marked plasticity in morphology, metabolism, and cardiovascular function following chronic hypoxic incubation. however, the long-term effects of chronic hypoxia have not yet been investigated in these animals. the aim of this study was to determine growth and postprandial o2 consumption (v̇o2), heart rate (fh), and mean arterial pressure (pm, in kpa) of common snapping turtles (chelydra serpentina) that were incubated as embryos in chroni ...201626608655
skin allograft and xenograft rejection in the snapping turtle, chelydra serpentina. 20164893940
post-hatching development of mitochondrial function, organ mass and metabolic rate in two ectotherms, the american alligator (alligator mississippiensis) and the common snapping turtle (chelydra serpentina).the ontogeny of endothermy in birds is associated with disproportionate growth of thermogenic organs and increased mitochondrial oxidative capacity. however, no similar study has been made of the development of these traits in ectotherms. for comparison, we therefore investigated the metabolism, growth and muscle mitochondrial function in hatchlings of a turtle and a crocodilian, two ectotherms that never develop endothermy. metabolic rate did not increase substantially in either species by 30 d ...201626962048
blood flukes of asiatic softshell turtles: revision of coeuritrema mehra, 1933 (digenea: schistosomatoidea) and a new species infecting chinese softshell turtles, pelodiscus sinensis (trionychidae), from vietnam.coeuritrema mehra, 1933, previously regarded as a junior subjective synonym of hapalorhynchus stunkard, 1922, herein is revised to include coeuritrema lyssimus mehra, 1933 (type species), coeuritrema rugatus (brooks et sullivan, 1981) comb. n., and coeuritrema platti roberts et bullard sp. n. these genera are morphologically similar by having a ventral sucker, non-fused caeca, two testes, a pre-testicular cirrus sac, an intertesticular ovary, and a common genital pore that opens dorsally and in ...201627827338
comparative analysis of glucagonergic cells, glia, and the circumferential marginal zone in the reptilian retina.retinal progenitors in the circumferential marginal zone (cmz) and müller glia-derived progenitors have been well described for the eyes of fish, amphibians, and birds. however, there is no information regarding a cmz and the nature of retinal glia in species phylogenetically bridging amphibians and birds. the purpose of this study was to examine the retinal glia and investigate whether a cmz is present in the eyes of reptilian species. we used immunohistochemical analyses to study retinal glia, ...201626053997
traumatic amputation of finger from an alligator snapping turtle bite.legend states that the alligator snapping turtle (macrochelys temminckii) should be handled with extreme caution as it has jaw strength powerful enough to bite a wooden broomstick in half. tales of bite injuries from what is the largest freshwater turtle in north america exist anecdotally, yet there are few descriptions of medical encounters for such. the risk of infection from reptilian bites to the hand in an aquatic environment warrants thorough antibiotic treatment in conjunction with hand s ...201627116923
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 ...201612529844
preferential intracellular ph regulation: hypotheses and perspectives.the regulation of vertebrate acid-base balance during acute episodes of elevated internal pco2  is typically characterized by extracellular ph (phe) regulation. changes in phe are associated with qualitatively similar changes in intracellular tissue ph (phi) as the two are typically coupled, referred to as 'coupled ph regulation'. however, not all vertebrates rely on coupled ph regulation; instead, some preferentially regulate phi against severe and maintained reductions in phe preferential phi ...201627489212
high levels, partitioning and fish consumption based water guidelines of perfluoroalkyl acids downstream of a former firefighting training facility in canada.high levels of perfluoroalkyl acids (pfaas), especially perfluorooctane sulfonic acid (pfos), have been observed at locations in/around/downstream of the sites where pfos-based firefighting foam was used repeatedly for a prolonged period. in this study, we conducted a detailed investigation of pfaa contamination in the lake niapenco area in ontario, canada, where among the highest ever reported levels of pfos were recently measured in amphipods, fish and snapping turtle plasma. levels and distri ...201627302846
photoreceptor coupling in turtle retina.photoreceptors in the isolated turtle retina of two species of turtle, chelydra serpentina and pseudemus scripta elegans, were penetrated with double-barrel electrodes. physiological responses were recorded through one barrel and neurobiotin tracer was injected from the other. intracellular injection of neurobiotin revealed patterns of tracer-coupled photoreceptors. both the patterns of tracer coupling and the electrophysiology suggest a high degree of specificity of connections. rods seem to be ...20159682876
a risk assessment approach to manage inundation of elseya albagula nests in impounded waters: a win-win situation?a risk assessment process was used to trial the impact of potential new operating rules on the frequency of nest inundation for the white-throated snapping turtle, elseya albagula, in the impounded waters of the burnett river, queensland, australia. the proposed operating rules would increase the barrage storage level during the turtle nesting season (may-july) and then would be allowed to reduce to a lower level for incubation for the rest of the year. these proposed operating rules reduce rate ...201525432451
deaths in bellinger river snapping turtles. 201526211039
spontaneous magnetic alignment by yearling snapping turtles: rapid association of radio frequency dependent pattern of magnetic input with novel surroundings.we investigated spontaneous magnetic alignment (sma) by juvenile snapping turtles using exposure to low-level radio frequency (rf) fields at the larmor frequency to help characterize the underlying sensory mechanism. turtles, first introduced to the testing environment without the presence of rf aligned consistently towards magnetic north when subsequent magnetic testing conditions were also free of rf ('rf off → rf off'), but were disoriented when subsequently exposed to rf ('rf off → rf on'). ...201525978736
evaluating recent taxonomic changes for alligator snapping turtles (testudines: chelydridae).the alligator snapping turtle (macrochelys temminckii troost in harlan 1835, sensu lato) has been historically treated as a single, wide-ranging species, until a recently published paper by thomas et al. (2014; hereafter thomas et al.) analyzed variation in morphology and mitochondrial dna sequence data to describe two new species of macrochelys: the apalachicola alligator snapping turtle (macrochelys apalachicolae thomas, granatosky, bourque, krysko, moler, gamble, suarez, leone & roman 2014) a ...201525947748
a mycoplasma species of emydidae turtles in the northeastern usa.mycoplasma infections can cause significant morbidity and mortality in captive and wild chelonians. as part of a health assessment of endangered bog turtles (glyptemys muhlenbergii) in the northeastern us, choanal and cloacal swabs from these and other sympatric species, including spotted turtles (clemmys guttata), eastern box turtles (terrapene carolina carolina), wood turtles (glyptemys insculpta), and common snapping turtles (chelydra serpentina) from 10 sampling sites in the states (us) of d ...201525574806
snapping turtles (chelydra serpentina) from canadian areas of concern across the southern laurentian great lakes: chlorinated and brominated hydrocarbon contaminants and metabolites in relation to circulating concentrations of thyroxine and vitamin a.the metabolites of polychlorinated biphenyls (pcbs) and polybrominated diphenyl ethers (pbdes), as well as other halogenated phenolic contaminants (hpcs) have been shown to have endocrine-disrupting properties, and have been reported with increasing frequency in the blood of wildlife, and mainly in mammals and birds. however, little is known about the persistence, accumulation and distribution of these contaminants in long-lived freshwater reptiles. in the present study, in addition to a large s ...201526519832
an appraisal of the use of an infrared digital monitoring system for long-term measurement of heart rate in reptilian embryos.measurement of heart rate (fh) in embryonic reptiles has previously imposed some degree of invasive treatment on the developing embryo. recently a non-invasive technique of fh detection from intact eggs was developed for commercial avian breeders and has since been used in biological research. this device uses infrared light, enabling it to detect heartbeats in very early embryos. however, infrared light is a source of heat and extended enclosure of an egg in the device is likely to affect tempe ...201526086361
critical windows of cardiovascular susceptibility to developmental hypoxia in common snapping turtle (chelydra serpentina) embryos.environmental conditions fluctuate dramatically in some reptilian nests. however, critical windows of environmental sensitivity for cardiovascular development have not been identified. continuous developmental hypoxia has been shown to alter cardiovascular form and function in embryonic snapping turtles (chelydra serpentina), and we used this species to identify critical periods during which hypoxia modifies the cardiovascular phenotype. we hypothesized that incubation in 10% o2 during specific ...201525730266
atrazine and glyphosate dynamics in a lotic ecosystem: the common snapping turtle as a sentinel species.atrazine and glyphosate are two of the most common pesticides used in the us midwest that impact water quality via runoff, and the common snapping turtle (chelydra serpentina) is an excellent indicator species to monitor these pesticides especially in lotic systems. the goals of this study were to (1) quantify atrazine, the atrazine metabolite diaminochlorotriazine (dact), and glyphosate burdens in common snapping turtle tissue from individuals collected within the embarras river in illinois; (2 ...201525678354
molecular and morphological differentiation of testes and ovaries in relation to the thermosensitive period of gonad development in the snapping turtle, chelydra serpentina.ambient temperatures during embryonic development determine gonadal sex in many reptiles. the temperature sensitive period for sex determination has been defined by shifting eggs between female- and male-producing temperatures in a few species. this phase spans 20-35% of embryogenesis in most species, which makes it difficult to define the mechanisms that transduce temperature into a signal for ovarian versus testicular development. we present an extensive set of studies that define a brief peri ...201525662229
toxicity of pesticides associated with potato production, including soil fumigants, to snapping turtle eggs (chelydra serpentina).turtles frequently oviposit in soils associated with agriculture and, thus, may be exposed to pesticides or fertilizers. the toxicity of a pesticide regime that is used for potato production in ontario on the survivorship of snapping turtle (chelydra serpentina) eggs was evaluated. the following treatments were applied to clean soil: 1) a mixture of the pesticides chlorothalonil, s-metolachlor, metribuzin, and chlorpyrifos, and 2) the soil fumigant metam sodium. turtle eggs were incubated in soi ...201424105794
dietary exposure of bde-47 and bde-99 and effects on behavior, bioenergetics, and thyroid function in juvenile red-eared sliders (trachemys scripta elegans) and common snapping turtles (chelydra serpentina).juvenile red-eared sliders (trachemys scripta elegans) and snapping turtles (chelydra serpentina) were fed food dosed with brominated diphenyl ether-47 (bde-47) or bde-99 for 6 mo beginning approximately 9 mo posthatch. during the exposure period, measurements of growth, bioenergetics, and behavior were made; thyroid function and accumulation were quantified postexposure. whole-body concentrations of both congeners were lower in red-eared sliders compared with snapping turtles after 6 mo of expo ...201425210006
adjustments in cholinergic, adrenergic and purinergic control of cardiovascular function in snapping turtle embryos (chelydra serpentina) incubated in chronic hypoxia.adenosine is an endogenous nucleoside that acts via g-protein coupled receptors. in vertebrates, arterial or venous adenosine injection causes a rapid and large bradycardia through atrioventricular node block, a response mediated by adenosine receptors that inhibit adenylate cyclase and decrease cyclic amp concentration. chronic developmental hypoxia has been shown to alter cardioregulatory mechanisms in reptile embryos, but adenosine's role in mediating these responses is not known. we incubate ...201425106687
substrate color-induced melanization in eight turtle species from four chelonian groups.background color convergence of prey occurring through local adaptation or phenotypically plastic responses can reduce predation rates by visual predators. we assessed the capacity for substrate color-induced melanization in eight turtle species within the groups chelydridae, emydidae, kinosternidae, and trionychidae by rearing individuals on black or white substrates for 160 days. in all aquatic turtle species, integuments of the head and carapace of the individuals that were reared on a black ...201424993507
exogenous application of estradiol to eggs unexpectedly induces male development in two turtle species with temperature-dependent sex determination.steroid hormones affect sex determination in a variety of vertebrates. the feminizing effects of exposure to estradiol and the masculinizing effects of aromatase inhibition during development are well established in a broad range of vertebrate taxa, but paradoxical findings are occasionally reported. four independent experiments were conducted on two turtle species with temperature-dependent sex determination (chrysemys picta and chelydra serpentina) to quantify the effects of egg incubation tem ...201424954686
thermoregulatory behavior is widespread in the embryos of reptiles and birds.recent studies have demonstrated that thermoregulatory behavior occurs not only in posthatching turtles but also in turtles prior to hatching. does thermoregulatory behavior also occur in the embryos of other reptile and bird species? our experiments show that such behavior is widespread but not universal in reptile and bird embryos. we recorded repositioning within the egg, in response to thermal gradients, in the embryos of three species of snakes (xenochrophis piscator, elaphe bimaculata, and ...201424561606
taxonomic assessment of alligator snapping turtles (chelydridae: macrochelys), with the description of two new species from the southeastern united states.the alligator snapping turtle, macrochelys temminckii, is a large, aquatic turtle limited to river systems that drain into the gulf of mexico. previous molecular analyses using both mitochondrial and nuclear dna suggested that macrochelys exhibits significant genetic variation across its range that includes three distinct genetic assemblages (western, central, and eastern = suwannee). however, no taxonomic revision or morphological analyses have been conducted previously. in this study, we test ...201424869532
high levels of perfluoroalkyl acids in sport fish species downstream of a firefighting training facility at hamilton international airport, ontario, canada.a recent study reported elevated concentrations of perfluorooctane sulfonic acid (pfos) and other perfluoroalkyl acids (pfaas) in surface water, snapping turtles, and amphipods in lake niapenco, downstream of hamilton international airport, ontario, canada. here, our goals were to 1) determine the extent of pfaa contamination in sport fish species collected downstream of the airport, 2) explore if the airport could be a potential source, and 3) compare fish pfos concentrations to consumption adv ...201424632327
integrative demographic modeling reveals population level impacts of pcb toxicity to juvenile snapping turtles.a significant challenge in ecotoxicology and risk assessment lies in placing observed contaminant effects in a meaningful ecological context. polychlorinated biphenyls (pcbs) have been shown to affect juvenile snapping turtle survival and growth but the ecological significance of these effects is difficult to discern without a formal, population-level assessment. we used a demographic matrix model to explore the potential population-level effects of pcbs on turtles. our model showed that effects ...201424047552
separation of two distinct gonadotropins from the pituitary gland of the snapping turtle (chelydra serpentina). 20134544465
reproductive physiology in eastern snapping turtles (chelydra serpentina) exposed to runoff from a concentrated animal feeding operation.the eastern snapping turtle (chelydra serpentina) is widely distributed throughout the eastern and central us and is a useful model organism to study land-use impacts on water quality. we compared the reproductive condition of turtles from a pond impacted by runoff from land applied with animal manure from a concentrated animal feeding operation (cafo) relative to animals from a control pond. turtles from the cafo site were heavier and had higher plasma concentrations of vitellogenin (vtg, mean ...201324502728
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 ...201323125337
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 ...201323147837
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 ...201323010870
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 ...201322972700
halogenated phenolic compound determination in plasma and serum by solid phase extraction, dansylation derivatization and liquid chromatography-positive electrospray ionization-tandem quadrupole mass spectrometry.a robust, sensitive and accurate method was developed for the simultaneous determination in plasma and serum of suite a halogenated phenolic compounds (hpcs) for which several are known to persist in the environment and analytically pure standards are available. namely, 14 congeners of hydroxylated polybrominated diphenyl ethers (oh-pbdes), six congeners of hydroxylated polychlorinated biphenyls (oh-pcbs), pentachlorophenol, pentabromophenol and the flame retardant tetrabromobisphenol a (tbbpa). ...201324210890
non-destructive techniques for biomonitoring of spatial, temporal, and demographic patterns of mercury bioaccumulation and maternal transfer in turtles.mercury (hg) is a globally ubiquitous pollutant that has received much attention due to its toxicity to humans and wildlife. the development of non-destructive sampling techniques is a critical step for sustainable monitoring of hg accumulation. we evaluated the efficacy of non-destructive sampling techniques and assessed spatial, temporal, and demographic factors that influence hg bioaccumulation in turtles. we collected muscle, blood, nail, and eggs from snapping turtles (chelydra serpentina) ...201323500054
mercury exposure is associated with negative effects on turtle reproduction.mercury (hg), a ubiquitous and highly toxic bioaccumulative contaminant, can maternally transfer and elicit deleterious effects on adult reproduction and offspring phenotype in fish, amphibians, and birds. however, the effects of hg on reproduction remain largely unstudied in reptiles. we evaluated the consequences of maternally transferred hg on a long-lived aquatic omnivore, the common snapping turtle (chelydra serpentina). we collected eggs and tissues from gravid female turtles along a broad ...201323360167
plasticity of cardiovascular function in snapping turtle embryos (chelydra serpentina): chronic hypoxia alters autonomic regulation and gene expression.reptile embryos tolerate large decreases in the concentration of ambient oxygen. however, we do not fully understand the mechanisms that underlie embryonic cardiovascular short- or long-term responses to hypoxia in most species. we therefore measured cardiac growth and function in snapping turtle embryos incubated under normoxic (n21; 21% o₂) or chronic hypoxic conditions (h10; 10% o₂). we determined heart rate (fh) and mean arterial pressure (pm) in acute normoxic (21% o₂) and acute hypoxic (10 ...201323552497
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 ...201222541670
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 ...201222871607
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 ...201222578330
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 ...201222208739
Refresh
firstprev
1234
nextlast
Displaying items 1 - 100 of 336