| spiroxys hanzaki n. sp. (nematoda: gnathostomatidae) collected from the giant salamander, andrias japonicus (caudata: cryptobranchidae), in japan. | spiroxys hanzaki n. sp. (nematoda: gnathostomatidae) taken from the giant salamander, andrias japonicus (temminck, 1836) (caudata: cryptobranchidae) from hyogo prefecture, japan, is described. it closely resembles spiroxys allegheniensis walton, 1930, from the hellbender, cryptobranchus alleganiensis (daudin, 1803) (cryptobranchidae), of north america, in that it has minute dorsal and ventral lobes of the pseudolabium and a reduced gubernaculum but is readily distinguished by a pseudolabium with ... | 1998 | 9714220 |
| historic occurrence of the amphibian chytrid fungus batrachochytrium dendrobatidis in hellbender cryptobranchus alleganiensis populations from missouri. | the pathogenic fungus batrachochytrium dendrobatidis (bd) was recently detected in missouri hellbender cryptobranchus alleganiensis populations that have declined precipitously for unclear reasons. the objective of this study was to determine whether bd occurred historically in missouri hellbender populations or is a relatively novel occurrence. epidermal tissue was removed from 216 archived hellbenders collected from 7 missouri streams between 1896 and 1994. histological techniques and an immun ... | 2011 | 21991660 |
| evaluation of microorganisms cultured from injured and repressed tissue regeneration sites in endangered giant aquatic ozark hellbender salamanders. | investigation into the causes underlying the rapid, global amphibian decline provides critical insight into the effects of changing ecosystems. hypothesized and confirmed links between amphibian declines, disease, and environmental changes are increasingly represented in published literature. however, there are few long-term amphibian studies that include data on population size, abnormality/injury rates, disease, and habitat variables to adequately assess changes through time. we cultured and i ... | 2011 | 22205979 |
| health and habitat quality assessment for the eastern hellbender (cryptobranchus alleganiensis alleganiensis) in indiana, usa. | the eastern hellbender (cryptobranchus alleganiensis alleganiensis) has experienced precipitous population declines throughout its range. numerous factors are speculated to be involved, but no empirical evidence has been presented for any. we implemented a population-wide health assessment in indiana, usa, examining both the physical well-being of individuals and the quality of their habitat. physicochemical parameters were analyzed directly in the field and later in the laboratory, when appropr ... | 2011 | 22102654 |
| serum clinical biochemical and hematologic reference ranges of laboratory-reared and wild-caught xenopus laevis. | the south african clawed frogs xenopus laevis and x. tropicalis are fully aquatic amphibians and well-established animal models. because genetically engineered laboratory xenopus are now being produced, the establishment of normal reference ranges for serum biochemical and hematologic parameters is essential for phenotyping and as a diagnostic aide. we determined normal reference ranges for hematologic values from 3 populations of x. laevis: wild-caught frogs (n = 43) and frogs from 2 commercial ... | 2011 | 22330708 |
| cryptic impacts of temperature variability on amphibian immune function. | ectothermic species living in temperate regions can experience rapid and potentially stressful changes in body temperature driven by abrupt weather changes. yet, among amphibians, the physiological impacts of short-term temperature variation are largely unknown. using an ex situ population of cryptobranchus alleganiensis, an aquatic north american salamander, we tested the hypothesis that naturally occurring periods of temperature variation negatively impact amphibian health, either through dire ... | 2013 | 23948472 |
| what is your diagnosis? skin scraping from a hellbender. | | 2017 | 27870070 |
| prevalence of batrachochytrium dendrobatidis in eastern hellbender (cryptobranchus alleganiensis) populations in west virginia, usa. | the eastern hellbender (cryptobranchus alleganiensis alleganiensis) is a north american salamander species in decline throughout its range. efforts to identify the causes of decline have included surveillance for the chytrid fungus batrachochytrium dendrobatidis (bd), which has been associated with global amphibian population losses. we evaluated the prevalence of bd in 42 hellbenders at four sites in west virginia, us, from june to september 2013, using standard swab protocols and real-time pcr ... | 2016 | 27124331 |
| pathogenic chytrid fungus batrachochytrium dendrobatidis, but not b. salamandrivorans, detected on eastern hellbenders. | recent worldwide declines and extinctions of amphibian populations have been attributed to chytridiomycosis, a disease caused by the pathogenic fungus batrachochytrium dendrobatidis (bd). until recently, bd was thought to be the only batrachochytrium species that infects amphibians; however a newly described species, batrachochytrium salamandrivorans (bs), is linked to die-offs in european fire salamanders (salamandra salamandra). little is known about the distribution, host range, or origin of ... | 2015 | 25695636 |
| batrachochytrium dendrobatidis haplotypes on the hellbender cryptobranchus alleganiensis are identical to global strains. | to determine whether the chytrid fungus batrachochytrium dendrobatidis (bd) found on the hellbender cryptobranchus alleganiensis in the southern us is endemic or exotic, we identified the genetic type of this fungus using partial dna sequences of the internal transcribed spacer (its) region. we identified 3 genetic types, which are found on japanese amphibians other than the japanese giant salamander andrias japonicus, a species that belongs to the same family (cryptobranchidae) as hellbenders. ... | 2013 | 23446967 |
| prevalence of infection by batrachochytrium dendrobatidis and ranavirus in eastern hellbenders (cryptobranchus alleganiensis alleganiensis) in eastern tennessee. | hellbenders (n=97) were collected from the little and hiwassee rivers in eastern tennessee, usa, during 2009 and 2010. location and morphometrics for each animal were recorded, and nonlethal tissue samples were collected to estimate the prevalence of infection with batrachochytrium dendrobatidis (bd) and ranavirus in each watershed and year. real-time polymerase chain reaction was performed on skin swabs for bd and on tail clips for ranaviruses. overall prevalences of dna of bd, ranavirus, and c ... | 2012 | 22740521 |
| a new species of eimeria (apicomplexa: eimeriidae) from the marbled salamander, ambystoma opacum (caudata: ambystomatidae), from northern louisiana. | between december 2002 and june 2004, 10 marbled salamanders, ambystoma opacum, were examined for coccidian parasites. salamanders were collected in bradley (n = 2), little river (n = 1), miller (n = 1), and sevier (n = 1) counties, arkansas; webster parish, louisiana (n = 2); and bowie (n = 1) and nacogdoches (n = 2) counties, texas. two of 10 (20%) a. opacum from louisiana harbored an undescribed species of eimeria. oocysts of eimeria trauthi n. sp. were ellipsoidal, 36.6 x 33.1 (33-40 x 29-37) ... | 2008 | 18605797 |
| morphological variation of hypaxial musculature in salamanders (lissamphibia: caudata). | despite the acknowledged importance of the locomotory and respiratory functions associated with hypaxial musculature in salamanders, variation in gross morphology of this musculature has not been documented or evaluated within a phylogenetic or ecological context. in this study, we characterize and quantify the morphological variation of lateral hypaxial muscles using phylogenetically and ecologically diverse salamander species from eight families: ambystomatidae (ambystoma tigrinum), amphiumida ... | 1999 | 10420161 |
| comparative and phylogenetic perspectives of the cleavage process in tailed amphibians. | the order caudata includes about 660 species and displays a variety of important developmental traits such as cleavage pattern and egg size. however, the cleavage process of tailed amphibians has never been analyzed within a phylogenetic framework. we use published data on the embryos of 36 species concerning the character of the third cleavage furrow (latitudinal, longitudinal or variable) and the magnitude of synchronous cleavage period (up to 3-4 synchronous cell divisions in the animal hemis ... | 2015 | 25180466 |
| morphological and molecular characterization of a new species of leech (glossiphoniidae, hirudinida): implications for the health of its imperiled amphibian host (cryptobranchus alleganiensis). | the hellbender (cryptobranchus alleganiensis) is among the most intriguing and imperiled amphibians in north america. since the 1970s and 80s, western populations of the ozark and eastern subspecies in missouri have declined by nearly 80%. as a result of population declines, the ozark hellbender was recently federally protected as an endangered species, and the eastern subspecies was granted protection under cites. although habitat degradation is probably the biggest threat to hellbender populat ... | 2014 | 24574854 |
| cutaneous microbial community variation across populations of eastern hellbenders (cryptobranchus alleganiensis alleganiensis). | multicellular hosts maintain complex associations with microbial communities. while microbial communities often serve important functional roles for their hosts, our understanding of the local and regional processes that structure these communities remains limited. metacommunity analyses provide a promising tool for investigating mechanisms shaping microbiome heterogeneity, which is essential for predicting functional variation between hosts. using a metacommunity framework, we examined heteroge ... | 2017 | 28785252 |
| importance of demographic surveys and public lands for the conservation of eastern hellbenders cryptobranchus alleganiensis alleganiensis in southeast usa. | comparisons of recent and historic population demographic studies of eastern hellbenders cryptobranchus alleganiensis alleganiensis have identified significant population declines and extirpations associated with habitat degradation, poor water quality and disease, leading to nomination as a candidate for listing under the endangered species act. however, populations in the southern appalachian region of the range have received less attention despite relatively high levels of watershed protectio ... | 2017 | 28594881 |
| characterization of the cutaneous bacterial communities of two giant salamander subspecies. | pathogens currently threaten the existence of many amphibian species. in efforts to combat global declines, researchers have characterized the amphibian cutaneous microbiome as a resource for disease management. characterization of microbial communities has become useful in studying the links between organismal health and the host microbiome. hellbender salamanders (cryptobranchus alleganiensis) provide an ideal system to explore the cutaneous microbiome as this species requires extensive conser ... | 2017 | 27677893 |
| haematological and immunological characteristics of eastern hellbenders (cryptobranchus alleganiensis alleganiensis) infected and co-infected with endo- and ectoparasites. | disease is among the leading causes of the global decline in amphibian populations. in north america, parasites and pathogens are among the factors implicated in precipitous population declines of the giant hellbender salamander (cryptobranchus alleganiensis), but the incidence of infections and the responses of hellbenders to infections remain poorly studied. here, we document the prevalence of leech and trypanosome infections in a wild population of eastern hellbenders (cryptobranchus allegani ... | 2016 | 27293754 |
| genetic analysis reveals multiple parentage in captive reared eastern hellbender salamanders (cryptobranchus alleganiensis). | information on the parentage of captive reared clutches is vital for conservation head-starting programs. molecular methods, such as genotyping individuals with hyper-variable markers, can elucidate the genealogical contribution of captive-reared, reintroduced individuals to native populations. in this study, we used 12 polymorphic microsatellite loci to infer parentage of a clutch of 18 eastern hellbenders collected from a single nest from buffalo creek, west virginia, subsequently reared in ca ... | 2015 | 26301598 |
| evidence of ectoparasite-induced endocrine disruption in an imperiled giant salamander, the eastern hellbender (cryptobranchus alleganiensis). | parasitic leeches and trypanosomes release chemical signals into their hosts to evade immuno-detection, but it is unknown whether these compounds manipulate host behavior or endocrine physiology. we determined whether parasitic infections with leeches and/or trypanosomes affected the immune and stress response of an imperiled giant species of amphibian, the eastern hellbender (cryptobranchus alleganiensis daudin). we monitored corticosterone and white blood cell counts in response to restraint a ... | 2015 | 26034123 |
| climate change simulations predict altered biotic response in a thermally heterogeneous stream system. | climate change is predicted to increase water temperatures in many lotic systems, but little is known about how changes in air temperature affect lotic systems heavily influenced by groundwater. our objectives were to document spatial variation in temperature for spring-fed ozark streams in southern missouri usa, create a spatially explicit model of mean daily water temperature, and use downscaled climate models to predict the number of days meeting suitable stream temperature for three aquatic ... | 2014 | 25356982 |
| hellbender genome sequences shed light on genomic expansion at the base of crown salamanders. | among animals, genome sizes range from 20 mb to 130 gb, with 380-fold variation across vertebrates. most of the largest vertebrate genomes are found in salamanders, an amphibian clade of 660 species. thus, salamanders are an important system for studying causes and consequences of genomic gigantism. previously, we showed that plethodontid salamander genomes accumulate higher levels of long terminal repeat (ltr) retrotransposons than do other vertebrates, although the evolutionary origins of such ... | 2014 | 25115007 |
| population genetics of the eastern hellbender (cryptobranchus alleganiensis alleganiensis) across multiple spatial scales. | conservation genetics is a powerful tool to assess the population structure of species and provides a framework for informing management of freshwater ecosystems. as lotic habitats become fragmented, the need to assess gene flow for species of conservation management becomes a priority. the eastern hellbender (cryptobranchus alleganiensis alleganiensis) is a large, fully aquatic paedamorphic salamander. many populations are experiencing declines throughout their geographic range, yet the genetic ... | 2013 | 24204565 |
| redescription and molecular characterization of placobdella cryptobranchii (johnson & klemm, 1977) (glossiphoniidae, hirudinida). | placobdella cryptobranchii (johnson & klemm, 1977) was originally described from specimens collected from ozark hellbenders (cryptobranchus alleganiensis bishopi) from the north fork of the white river in missouri, u.s.a. leeches collected during august 2009 to august 2011 from five localities in missouri (including the type locality) facilitated a redescription and molecular characterization of placobdella cryptobranchii. placobdella cryptobranchii has a rusty, reddish-brown dorsum with 2 later ... | 2013 | 24146580 |
| a re-evaluation of a case-control model with contaminated controls for resource selection studies. | 1. a common sampling design in resource selection studies involves measuring resource attributes at sample units used by an animal and at sample units considered available for use. few models can estimate the absolute probability of using a sample unit from such data, but such approaches are generally preferred over statistical methods that estimate a relative probability of use. 2. the case-control model that allows for contaminated controls, proposed by lancaster & imbens (1996) and lele (2009 ... | 2013 | 23701233 |
| widespread trypanosome infections in a population of eastern hellbenders (cryptobranchus alleganiensis alleganiensis) in virginia, usa. | eastern hellbender salamanders (cryptobranchus alleganiensis alleganiensis) are declining in north america and because of this the health status of individuals in several populations is closely monitored by researchers. during a health survey of hellbenders from a stream in smyth county, va, usa, we examined giemsa-stained blood smears of 71 animals captured during 2011 for the presence of blood parasites. we discovered an unknown species of trypanosome that was apparently widespread within this ... | 2013 | 22926647 |
| predator-recognition training: a conservation strategy to increase postrelease survival of hellbenders in head-starting programs. | for species with declining populations, captive rearing with subsequent release into natural habitats ("head-starting") is often used as part of a conservation strategy. one challenge to head-starting programs is that head-started individuals can suffer high rates of postrelease predation. head-starting programs are currently being established for hellbenders (cryptobrancus alleganeinsis), large aquatic salamanders that are experiencing population declines throughout much of the species' range. ... | 2011 | 22147590 |
| innate immunity and stress physiology of eastern hellbenders (cryptobranchus alleganiensis) from two stream reaches with differing habitat quality. | in addition to depriving amphibians of physical habitat requirements (e.g., shelter, moisture, and food), habitat modification may also have subtle effects on the health of amphibians and potentially precipitate interactions with other deleterious factors such as pathogens, contaminants, and invasive species. the current study was designed to evaluate the physiological state of imperiled giant salamanders, the eastern hellbender (cryptobranchus alleganiensis), experiencing different surrounding ... | 2011 | 21872597 |
| microsatellite analysis supports mitochondrial phylogeography of the hellbender (cryptobranchus alleganiensis). | we investigated genetic diversity of the hellbender (cryptobranchus alleganiensis) throughout its range in the eastern us using nuclear markers and compared our results to a previously published mitochondrial analysis. a variety of nuclear markers, including protein-coding gene introns and microsatellites were tested but only microsatellites were variable enough for population level analysis. microsatellite loci showed moderate among population sharing of alleles, in contrast to the reciprocal m ... | 2011 | 21161568 |
| heavy metals, hematology, plasma chemistry, and parasites in adult hellbenders (cryptobranchus alleganiensis). | ozark (cryptobranchus alleganiensis bishopi) and eastern hellbenders (c. a. alleganiensis) from seven rivers in missouri, usa, were collected to investigate essential information on hematology, parasites, and plasma chemistry and levels of select heavy metals (hg, pb, cd, cr, and co) in the animals' blood. the body masses of ozark hellbenders were much smaller than those of eastern hellbenders. blood parasites were detected in ozark hellbenders, but not eastern hellbenders. the higher frequency ... | 2010 | 20821549 |
| occurrence of organic chemicals in two rivers inhabited by ozark hellbenders (cryptobranchus alleganiensis bishopi). | ozark hellbender (cryptobranchus alleganiensis bishopi) populations are in decrease throughout their native range with rare recruitment of young. increased estrogenic chemical levels and alterations of physicochemical properties in their habitat may play a significant role in this phenomenon. we report here the first systematic, comprehensive study of organic chemical concentrations and physical and nutrient parameters in two rivers containing ozark hellbender populations. water samples were col ... | 2007 | 17728992 |
| the ontogeny of feeding kinematics in a giant salamander cryptobranchus alleganiensis: does current function or phylogenetic relatedness predict the scaling patterns of movement? | studies of the scaling of feeding movements in vertebrates have included three species that display both near-geometric growth and isometry of kinematic variables. these scaling characteristics allow one to examine the "pure" relationship of growth and movement. despite similar growth patterns, the feeding movements of toads (bufo) slow down more with increasing body size than those of bass (micropterus), and sharks (ginglymostoma). this variation might be due to major differences in the mechani ... | 2005 | 16351963 |
| earliest known crown-group salamanders. | salamanders are a model system for studying the rates and patterns of the evolution of new anatomical structures. recent discoveries of abundant late jurassic and early cretaceous salamanders are helping to address these issues. here we report the discovery of well-preserved middle jurassic salamanders from china, which constitutes the earliest known record of crown-group urodeles (living salamanders and their closest relatives). the new specimens are from the volcanic deposits of the jiulongsha ... | 2003 | 12660782 |
| parsimony, molecular evolution, and biogeography: the case of the north american giant salamander. | to draw biogeographic conclusions about the central highlands region of the united states, we reconstructed the phylogeny of hellbender (cryptobranchus alleganiensis) populations from restriction-site variation in mtdna. we were unable to root the phylogeny using an outgroup and therefore could not weight restriction-site gains more heavily than site losses. as a result, maximum parsimony results in low phylogenetic resolution because of high levels of homoplasy in the data set. use of a recentl ... | 1994 | 28565155 |
| gas exchange and habitat selection in the aquatic salamanders necturus maculosus and cryptobranchus alleganiensis. | the standard metabolic rate (smr) and critical o(2) tension (p(c)) of water-breathing mudpuppies and hellbenders were determined at 20° c using open-system respirometry. both species are metabolic o(2) regulators, although the p(c) of hellbenders (90 mmhg) is much higher than that of mudpuppies (40 mmhg). the smr of the two species in water saturated with air was similar (19.5 and 20.0 μl o(2)/g·h for cryptobranchus and necturus, respectively) and not different from that of salamanders in genera ... | 1990 | 22160119 |
| respiratory, circulatory and acid-base adjustments to hypercapnia in a strictly aquatic and predominantly skin-breathing urodele, cryptobranchus alleganiensis. | upon initial exposure to increased ambient co2, cryptobranchus is titrated along an in vivo buffer line whose slope is considerably reduced from that observed when whole blood samples are equilibrated in vitro. during this time, there is no apparent reduction in the pco2 difference between arterial blood and inspired media (paco2 -pico2), despite an increase in auxiliary respiratory activities (lung and buccopharyngeal ventilation). the development of this non-compensated respiratory acidosis in ... | 1981 | 6801744 |
| respiratory properties of blood in a strictly aquatic and predominantly skin-breathing urodele, cryptobranchus alleganiensis. | the strictly aquatic urodele. cryptobranchus alleganiensis, is one of the largest gill-less vertebrates in which most of the respiratory gas exchanges occur across the skin. in this study we have examined some of the gas carrying relationships in blood to determine whether certain properties are particularly adaptive to the hellbender's well oxygenated habitat and predominantly cutaneous mode of respiration. the o2 dissociation curve is sigmoidal (n = 2.9) having a p50 of 23.6 mm hg (at pha and ... | 1981 | 6801743 |
| acid-base balance and temperature in a predominantly skin-breathing salamander, cryptobranchus alleganiensis. | blood gases and ph and plasma [na+], [k+], [cl-] and [lactate] were measured on arterial blood of the large predominantly skin-breathing salamander, the hellbender (cryptobranchus alleganiensis), at 5, 15 and 25 degrees c, both with and without access to air. access to air had no effect of any of the acid-base variables, but temperature had significant effects on both ph and pco2. blood ph decreased with temperature by about 0.016 unit/degrees c both in vivo and in vitro (over the range studied) ... | 1981 | 6787680 |
| the effects of enforced activity on ventilation, circulation and blood acid-base balance in the aquatic gill-less urodele, cryptobranchus alleganiensis; a comparison with the semi-terrestrial anuran, bufo marinus. | a combined respiratory and metabolic acidosis occurs in the arterial blood immediately following 30 min of strenuous activity in the predominantly skin-breathing urodele, cryptobranchus alleganiensis, and in the bimodal-breathing anuran, bufo marinus, at 25 degrees c. in bufo, the bulk of the post-exercise acidosis is metabolic in origin (principally lactic acid) and recovery is complete within 4-8 h. in the salamander, a lower magnitude, longer duration, metabolic acid component and a more pron ... | 1980 | 6767804 |
| aquatic respiration: an unusual strategy in the hellbender cryptobranchus alleganiensis alleganiensis (daudin). | separate and simultaneous determinations of aerial and aquatic gas exchange in the giant salamander, cryptobranchus alleganiensis alleganiensis (daudin) were made at 5 degrees , 15 degrees , and 25 degrees c. the aquatic respiration of this animal accounts for over 90 percent of the total volume of oxygen consumed and 97 percent of the total volume of carbon dioxide released at all temperatures. the lungs of these individuals are large transparent sacs which are poor respiratory organs; the lung ... | 1973 | 17811319 |
| influence of immunogenetics, sex and body condition on the cutaneous microbial communities of two giant salamanders. | the complex association between hosts and microbial symbionts requires the implementation of multiple approaches to evaluate variation in host physiology. within amphibians, heterogeneity in immunogenetic traits and cutaneous microbiota is associated with variation in disease resistance. ozark (cryptobranchus alleganiensis bishopi) and eastern hellbenders (c. a. alleganiensis) provide a model system to assess variation in host traits and microbial communities. ozark hellbenders have experienced ... | 2018 | 29411437 |
| prevalence of batrachochytrium dendrobatidis in immature eastern hellbenders cryptobranchus alleganiensis from north carolina, usa. | batrachochytrium dendrobatidis (bd) has been detected in wild hellbender cryptobranchus alleganiensis populations, with rare instances of chytridiomycosis and bd-induced mortality. to date, bd surveillance in hellbender populations has been disproportionately focused on adult age classes. a lingering question is whether bd might contribute to hellbender declines through disproportionate negative effects on immature age classes. the objective of this study was to quantify bd prevalence and load i ... | 2020 | 32672152 |
| geographic and individual determinants of important amphibian pathogens in hellbenders (cryptobranchus alleganiensis) in tennessee and arkansas, usa. | wildlife diseases are a major threat for species conservation and there is a growing need to implement disease surveillance programs to protect species of concern. globally, amphibian populations have suffered considerable losses from disease, particularly from chytrid fungi (batrachochytrium dendrobatidis [bd] and batrachochytrium salamandrivorans [bsal]) and ranavirus. hellbenders (cryptobranchus alleganiensis) are large riverine salamanders historically found throughout several watersheds of ... | 2020 | 32544028 |
| a novel bioaugmentation technique effectively increases the skin-associated microbial diversity of captive eastern hellbenders. | captive environments are maintained in hygienic ways that lack free-flowing microbes found in animals' natural environments. as a result, captive animals often have depauperate host-associated microbial communities compared to conspecifics in the wild and may have increased disease susceptibility and reduced immune function. eastern hellbenders (cryptobranchus alleganiensis alleganiensis) have suffered precipitous population declines over the past few decades. to bolster populations, eastern hel ... | 2020 | 32431814 |
| evaluation of severity and factors contributing to foot lesions in endangered ozark hellbenders, cryptobranchus alleganiensis bishopi. | arkansas populations of ozark hellbenders, cryptobranchus alleganiensis bishopi have declined precipitously over the past few decades and are now limited to a single river. biologists have also observed an increase of distal limb lesions with unidentified etiology and unknown role in morbidity and mortality of the species in this location. we documented lesions and collected associated individual size class data and pathogen samples in ozark hellbenders of arkansas (n = 73) from 2011 to 2014 wit ... | 2020 | 32118058 |
| a novel exophiala species associated with disseminated granulomatous inflammation in a captive eastern hellbender (cryptobranchus alleganiensis alleganiensis). | the genus exophiala is composed of ubiquitous, pigmented, saprotrophic fungi and includes both terrestrial and waterborne species. though exophiala species are generally considered opportunistic pathogens, exophialosis can be an important cause of morbidity and mortality in aquatic and semi-aquatic species. over a 6-year period, a captive 32-year-old male eastern hellbender (cryptobranchus alleganiensis alleganiensis), was treated for recurring, slow growing, ventral midline cutaneous masses. ex ... | 2020 | 32083105 |
| cortisol is the predominant glucocorticoid in the giant paedomorphic hellbender salamander (cryptobranchus alleganiensis). | corticosterone is widely regarded to be the predominant glucocorticoid produced in amphibians. however, we recently described unusually low baseline and stress-induced corticosterone profiles in eastern hellbenders (cryptobranchus alleganiensis alleganiensis), a giant, fully aquatic salamander. here, we hypothesized that hellbenders might also produce cortisol, the predominant glucocorticoid used by fishes and non-rodent mammals. to test our hypothesis, we collected plasma samples in two field e ... | 2020 | 31491375 |
| captivity-induced changes in the skin microbial communities of hellbenders (cryptobranchus alleganiensis). | variation in environmental conditions can result in disparate associations between hosts and microbial symbionts. as such, it is imperative to evaluate how environmental variables (e.g., habitat quality) can influence host-associated microbiome composition. within wildlife conservation programs, captive conditions can negatively influence the establishment and maintenance of "wild-type" microbiotas within a host. alternative microbial communities can result in the proliferation of disease among ... | 2019 | 30209587 |
| morphology and behavior of the feeding apparatus in cryptobranchus alleganiensis (amphibia: caudata). | cine and high-speed videographic analyses of feeding in cryptobranchus alleganiensis demonstrate that prey are captured by either inertial suction or a strike combined with suction. movements of cephalic elements during capture are generally similar to those of other suction-feeding vertebrates but more variable than those of most aquatic salamanders. following capture, prey frequently are manipulated and transported into and out of the buccal cavity across the teeth. specific features of the sk ... | 1994 | 29865388 |
| comparative anatomy and phylogeny of the cloacae of salamanders (amphibia: caudata). ii. cryptobranchidae, hynobiidae, and sirenidae. | cloacae were examined from salamanders representing the three families in which fertilization of eggs is known or inferred to occur externally. the cloacae of male and female sirenids are aglandular and lack cilia. sexual dimorphism in sirenid cloacae occurs only in the extent of epithelial stratification in the cloacal chamber in females (entire chamber) versus males (posterior angle of the vent). both male and female cryptobranchus alleganiensis possess ventral glands that secrete an acid muco ... | 1991 | 29865526 |