| a projection from the mesencephalic tegmentum to the nucleus isthmi in the frogs, rana pipiens and acris crepitans. | the nucleus isthmi is a prominent part of the frog's visual system. each nucleus isthmi receives input from the ipsilateral tectum and sends output to both tecta. until now, no non-tectal inputs to the nucleus isthmi of amphibians have been demonstrated. anterograde and retrograde tracing with horseradish peroxidase in rana pipiens and acris crepitans now reveal that a diffuse group of cells in the mesencephalic tegmentum projects to the caudal region of the contralateral nucleus isthmi. these c ... | 1987 | 3497362 |
| convergent morphological evolution detected by studying proteins of tree frogs in the hyla eximia species group. | protein studies have uncovered an apparent case of convergent evolution among north american tree frogs. the species hyla eximia and hyla regilla are so similar in external morphology that the "wrightorum" subspecies is assigned by some authorities to h. eximia and by others to h. regilla. yet microcomplement fixation experiments show that "wrightorum" albumin, though virtually indistinguishable from authentic h. eximia albumin, differs as much from h. regilla albumin as from albumins of species ... | 1974 | 4134390 |
| a forty-three year museum study of northern cricket frog (acris crepitans) abnormalities in arkansas: upward trends and distributions. | the northern cricket frog (acris crepitans) is a resident of streams, rivers, and wetlands of eastern north america. we documented abnormalities in a. crepitans housed in the arkansas state university museum of zoology herpetology collection. abnormality frequency increased from 1957 to 2000 (chi 2 = 43.76, df = 3, p < 0.001). from 1957 through 1979 only 3.33% of specimens were unusual. this rate was 6.87% during the 1990s, and in 2000 it was 8.48%. high frequencies of abnormalities were identif ... | 2003 | 14567212 |
| physiological effects and bioconcentration of triclosan on amphibian larvae. | we examined the acute effects of triclosan (tcs) exposure, a common antimicrobial found as a contaminant in the field, on survival and physiology of amphibian larvae. lc50 values were determined after 96h for north american larval species: acris crepitans blanchardii, bufo woodhousii woodhousii, rana sphenocephala, and for a developmental model: xenopus laevis. amphibian larvae were most sensitive to tcs exposure during early development based upon 96-h lc50 values. heart rates for x. laevis and ... | 2010 | 20417311 |
| tadpole size, cholinesterase activity, and swim speed in four frog species after exposure to sub-lethal concentrations of chlorpyrifos. | while physiological biomarkers exist to verify exposure of amphibians in natural populations to agricultural chemicals, the ecological relevance of changes in these parameters is often difficult to determine. we compare the relationship between tadpole cholinesterase (che; a common enzymatic biomarker of exposure to op pesticides) and measures of size and swim speed in four native north american species of anurans (hyla chrysoscelis, rana sphenocephala, acris crepitans, and gastrophryne olivacea ... | 2008 | 18448174 |
| skeletal morphology and postmetamorphic ontogeny of acris crepitans (anura: hylidae): a case of miniaturization in frogs. | acris crepitans is a small, semiaquatic member of the treefrog family hylidae. much recent attention has been paid to this species because of reports of population declines and malformations, yet few works have considered the skeletal anatomy of this common north american frog. herein, we provide a detailed description of the morphology and adult ontogeny of the skeleton of a. crepitans, and discuss novel morphologies, interesting postmetamorphic developmental patterns, and intraspecific skeleta ... | 2007 | 17278133 |
| species limits and phylogeography of north american cricket frogs (acris: hylidae). | cricket frogs are widely distributed across the eastern united states and two species, the northern cricket frog (acris crepitans) and the southern cricket frog (a. gryllus) are currently recognized. we generated a phylogenetic hypothesis for acris using fragments of nuclear and mitochondrial genes in separate and combined phylogenetic analyses. we also used distance methods and fixation indices to evaluate species limits within the genus and the validity of currently recognized subspecies of a. ... | 2008 | 18462953 |
| skeletal morphogenesis of the vertebral column of the miniature hylid frog acris crepitans, with comments on anomalies. | although the vertebral columns of anurans have received much study in the last 150 years, few detailed descriptions exist of the skeletal morphogenesis of this anatomical unit. herein, the ontogeny of the vertebral skeleton of the hylid frog acris crepitans is described based on cleared and double-stained specimens, radiographs, and 3d reconstructions generated from synchrotron microct scans. the adult axial formula is 1-7-1-1, and the vertebral centra are epichordal and procoelous. the neural a ... | 2009 | 18946872 |
| wildlife toxicology: biomarkers of genotoxic exposures at a hazardous waste site. | a large number of hazardous waste sites in the united states have undergone the initial stages of remediation or containment. at many of the remaining sites, the potential for exposure to ecological receptors is a primary concern. this manuscript reports on studies to investigate the impact on ecological receptors exposed to complex mixtures at a former creosote facility. currently there are isolated areas on-site that were not addressed in the initial removal action that appear to be releasing ... | 2009 | 19533345 |
| blind location and separation of callers in a natural chorus using a microphone array. | male frogs and toads call in dense choruses to attract females. determining the vocal interactions and spatial distribution of the callers is important for understanding acoustic communication in such assemblies. it has so far proved difficult to simultaneously locate and recover the vocalizations of individual callers. here a microphone-array technique is developed for blindly locating callers using arrival-time delays at the microphones, estimating their steering-vectors, and recovering the ca ... | 2009 | 19640054 |
| elevated temperature as a treatment for batrachochytrium dendrobatidis infection in captive frogs. | the amphibian chytrid fungus batrachochytrium dendrobatidis (bd) has been implicated in amphibian declines worldwide. in vitro laboratory studies and those done on wild populations indicate that bd grows best at cool temperatures between 17 and 25 degrees c. in the present study, we tested whether moderately elevating the ambient temperature to 30 degrees c could be an effective treatment for frogs infected with bd. we acquired 35 bullfrogs rana catesbeiana from breeding facilities and 36 northe ... | 2011 | 21790070 |
| why do animals repeat displays? | both agonistic and sexual animal displays often involve more than one performance of some specific display action. since repetition is energetically costly there must be good reasons why a signaller should carry out such repetitive actions, rather than simply displaying once. we briefly review three different 'reasons' which arise from three different receiver assessment rules: when assessment is based on the average magnitude of all display actions so far, the reason for the repetition is to im ... | 1997 | 9268441 |
| latitudinal effects on metabolic rates in the cricket frog, acris crepitans: acutely measured rates in summer frogs. | | 1972 | 4637906 |
| latitudinal effects on metabolic rates in the frog, acris crepitans: seasonal comparisons. | | 1973 | 4732533 |
| parathion accumulation in cricket frogs and its effect on american kestrels. | adult cricket frogs (acris crepitans) were held individually for 96 h in static systems containing initial concentrations of either 0, 0.1, 1.0, or 10 ppm parathion in 10 ml water. mortality of cricket frogs was directly related to the parathion concentration in the water. frogs from the 1.0- and 10-ppm groups accumulated 0.08 and 4.6 ppm parathion, respectively. one of four american kestrels (falco sparverius) fed frogs from the 10-ppm group died from organophosphate poisoning less than 3 h aft ... | 1982 | 7161839 |
| a comparison of energy substrates and reproductive patterns of two anurans. acris crepitans and bufo woodhousei. | the seasonal pattern of carcass, liver and ovary lipid and liver non-lipid mass was examined in the cricket frog, acris crepitans, and woodhouse's toad, bufo woodhousei. reproductive patterns were also studied. the over-winter reduction of body lipid and liver non-lipid material was attributed to metabolism in acris crepitans. male, but not female, bufo woodhousei exhibited seasonal variation in lipid stores that was attributable to metabolism. females, but not males, showed seasonal variation i ... | 1987 | 2886261 |
| call patterns and basilar papilla tuning in cricket frogs. i. differences among populations and between sexes. | male cricket frogs (acris crepitans) produce a broad-band, high frequency advertisement call with a single spectral peak (the dominant frequency). we measured the dominant frequencies of male calls from six populations in central texas and one from indiana and compared them to the tuning of basilar papilla afferents in males and females. averaging over all populations, mean call dominant frequency was 3.69 khz, mean male basilar papilla tuning was 3.63 khz, and mean female basilar papilla tuning ... | 1992 | 1633554 |
| call patterns and basilar papilla tuning in cricket frogs. ii. intrapopulation variation and allometry. | we determined the influence of body size on the male advertisement call's dominant frequency and basilar papilla's (bp) tuning in male and female cricket frogs (acris crepitans) in two texas populations (wimberley and stengel ranch). in both populations, call and tuning characters correlated negatively with body size; females were larger than males and their bps were tuned to a lower frequency. analysis of covariance showed that neither the sex difference in tuning nor the population differences ... | 1992 | 1633555 |
| new host records for myxidium serotinum (protozoa: myxosporea) from north american amphibians. | three hundred twenty-five amphibians (80 salamanders, 245 frogs and toads) from arkansas and texas, representing 28 species within 9 families (ambystomatidae, plethodontidae, salamandridae, sirenidae, bufonidae, hylidae, leptodacytlidae, microhylidae, ranidae) were examined for gall bladder myxosporeans. of these, 32 (10%) were found to harbor myxidium serotinum kudo and sprague, 1940, including 3 (4%) of the salamanders and 29 (12%) of the frogs and toads. this report documents 6 new host recor ... | 1995 | 7776139 |
| arginine vasotocin injection increases probability of calling in cricket frogs, but causes call changes characteristic of less aggressive males. | male cricket frogs, acris crepitans communicate to males and females using advertisement calls, which are arranged into call groups. calls at the middle and end, but not beginning of the call group, are modified in response to male-male aggressive interactions. we found in this field study of male cricket frogs in natural breeding choruses that the peptide hormone arginine vasotocin (avt) not only increased the probability that males called after injections, but also caused modifications in midd ... | 1995 | 8748513 |
| correlations between call characteristics and morphology in male cricket frogs (acris crepitans). | we investigated the relationships among spectral and temporal advertisement-call characteristics and the sizes of the laryngeal and ear components thought to underlie the generation and reception of species-specific vocalizations in male cricket frogs (acris crepitans). we tested the predictions that the volumes of the structural elements necessary for acoustic communication would be correlated with various parameters of the vocalizations. the anatomy of laryngeal and ear structures was reconstr ... | 1996 | 8831143 |
| intraspecific variation in laryngeal and ear morphology in male cricket frogs (acris crepitans) | in a previous report, the authors found significant population variation in the calls of cricket frogs (acris crepitans) that could not be explained by geographic variation in body size alone. here we extend that work by investigating intraspecific population variation in the morphological characteristics underlying acoustic communication in male cricket frogs from several sites in texas. we measured the volumes of laryngeal and auditory components responsible for the generation or reception of ... | 1998 | 9480730 |
| forms and prevalence of intersexuality and effects of environmental contaminants on sexuality in cricket frogs (acris crepitans). | cricket frogs (acris crepitans) from several different sites in illinois were collected to assess the effects of environmental contamination on the prevalence of intersex gonads. of 341 frogs collected in 1993, 1994, and 1995, 2.7% were intersex individuals. there was no statistically significant relationship between the chemical compounds detected and cricket frog intersexuality. however, there was an association approaching significance (p = 0.07) between the detection of atrazine and intersex ... | 1998 | 9647894 |
| the effects of arginine vasotocin on the calling behavior of male cricket frogs in changing social contexts. | we investigated the effects of the neurohypophysial peptide, arginine vasotocin (avt), on the calling behavior of male acris crepitans during and immediately following a simulated acoustic agonistic encounter. avt did not block the aggressive response to agonistic calls, as the changes in temporal call characteristics in response to the encounter were similar to those of saline-treated males. however, avt caused males to begin calling sooner during the agonistic encounter and to call significant ... | 1998 | 9878274 |
| temporal call changes and prior experience affect graded signalling in the cricket frog. | we investigated how male cricket frogs acris crepitans, alter their advertisement calls in response to broadcasts of synthetic calls that were either 'attractive' or 'aggressive'. the stimulus calls differed in temporal but not spectral characteristics. male cricket frogs produced a more aggressive call when presented with the aggressive stimulus, indicating that they perceived the temporal differences between the two call categories. the direction and degree of temporal and spectral changes dep ... | 1999 | 10196050 |
| forebrain arginine vasotocin correlates of alternative mating strategies in cricket frogs. | in cricket frogs, acris crepitans, sexually active males can switch between calling and noncalling (satellite) mating strategies and injections of the neuropeptide arginine vasotocin (avt) stimulate calling behavior. we report here that this behavioral variation of animals under field conditions is associated with variations in avt-immunoreactive (avt-ir) staining in distinct brain nuclei. in both calling and satellite males, one avt-ir brain region was found in a continuous string of cells betw ... | 1999 | 10433886 |
| observations on the life history and descriptions of coccidia (apicomplexa) from the western chorus frog, pseudacris triseriata triseriata, from eastern nebraska. | two hundred and twenty-four anurans of 6 species (47 adults and 16 tadpoles of rana blairi, 35 r. catesbeiana, 31 hyla chrysoscelis, 30 adults and 46 tadpoles of pseudacris triseriata triseriata, 11 bufo woodhousii, and 8 acris crepitans) from pawnee lake, lancaster county, nebraska, were surveyed for coccidian parasites during march 2001 to may 2002. of these, 23 of 30 (77%) adults and 4 of 46 (9%) tadpoles of p. t. triseriata shed oocysts of isospora cogginsi n. sp. oocysts of i. cogginsi were ... | 2003 | 12880252 |
| cricket frogs maintain body hydration and temperature near levels allowing maximum jump performance. | one goal of this study was to determine the combination of hydration and temperature in the northern cricket frog acris crepitans that allowed maximum jump distance in the laboratory. second, environmental variables in the field were measured to determine the best predictor(s) of mean body temperature and hydration and to determine whether frogs maintain levels of temperature and hydration yielding maximum jump distance. laboratory data revealed that hydration and the hydration-temperature inter ... | 2006 | 14988797 |
| intersexuality and the cricket frog decline: historic and geographic trends. | exposure to anthropogenic endocrine disruptors has been listed as one of several potential causes of amphibian declines in recent years. we examined gonads of 814 cricket frogs (acris crepitans) collected in illinois and deposited in museum collections to elucidate relationships between the decline of this species in illinois and the spatial and temporal distribution of individuals with intersex gonads. compared with the preorganochlorine era studied (1852-1929), the percentage of intersex crick ... | 2005 | 15743712 |
| thyroid endocrine disruption in stonerollers and cricket frogs from perchlorate-contaminated streams in east-central texas. | in october 2001 and march 2002, a field survey of central stonerollers (campostoma anomalum) from perchlorate-contaminated streams in central texas was conducted to assess thyroid endocrine disruption. a survey of adult male and female cricket frogs (acris crepitans) was performed at the same site between 2001 and 2003. perchlorate is an oxidizer primarily used in solid-fuel rockets, and many sites that processed or used perchlorate are now contaminated. histological analysis revealed that the f ... | 2006 | 16341611 |
| a new species of myxidium (myxosporea: myxidiidae), from the western chorus frog, pseudacris triseriata triseriata, and blanchard's cricket frog, acris crepitans blanchardi (hylidae), from eastern nebraska: morphology, phylogeny, and critical comments on amphibian myxidium taxonomy. | during march 2001-april 2004, 164 adult anurans of 6 species (47 rana blairi, 35 rana catesbeiana, 31 hyla chrysoscelis, 31 pseudacris triseriata triseriata, 11 bufo woodhousii, and 9 acris crepitans blanchardi) from pawnee lake, lancaster county, nebraska, were surveyed for myxozoan parasites. of these, 20 of 31 (65%) p. triseriata triseriata and 1 of 9 (11%) a. crepitans blanchardi were infected with a new species of myxidium. myxidium melleni n. sp. (myxosporea) is described from the gallblad ... | 2006 | 16884007 |
| influence of temperature and duration of acclimation, time of day, sex and body weight on metabolic rates in the hylid frog, acris crepitans. | | 1969 | 5367353 |
| geographic variation of lactate dehydrogenase in the cricket frog, acris crepitans. | | 1969 | 5365509 |
| sun compass orientation of the northern cricket frog, acris crepitans. | | 1967 | 6031109 |
| the influence of temperature on chytridiomycosis in vivo. | chytridiomycosis, an amphibian disease caused by the fungal pathogen batrachochytrium dendrobatidis (bd), is an ideal system for studying the influence of temperature on host-pathogen relationships because both host and pathogen are ectothermic. studies of bd in culture suggest that optimal growth occurs between 17 and 23°c, and death of the fungus occurs above 29 or below 0°c. amphibian immune systems, however, are also temperature dependent and often more effective at higher temperatures. we t ... | 2017 | 28879516 |
| metal concentrations of tadpoles in experimental ponds. | anuran tadpoles are found in a variety of habitats, many of which are acidified or have high ambient concentrations of metals from anthropogenic sources. a few studies that have been conducted on metals in tadpoles demonstrate that they can contain high concentrations of some metals but have not demonstrated clear relationships between ambient conditions and metal concentrations. this study examines the influence of soil, water treatment, amphibian species, and body portion analyzed on metal con ... | 1996 | 15091435 |
| the role of environmental selection in intraspecific divergence of mate recognition signals in the cricket frog, acris crepitans. | | 1990 | 28567808 |
| does sexual dimorphism vary by population? laryngeal and ear anatomy in cricket frogs. | acoustic communication in many anuran species can show the effects of both natural and sexual selection. this is reflected in the sexually dimorphic anatomy of the larynx and ear structures, as well as the allometric relationship of these morphological traits to head or body size. in this study, we examined laryngeal and ear structures of cricket frogs acris crepitans not only as sexually dimorphic characteristics, but also as they differ across populations in environmentally different habitats. ... | 2019 | 31263493 |
| fungal infection has sublethal effects in a lowland subtropical amphibian population. | the amphibian chytrid fungus, batrachochytrium dendrobatidis (bd), has been implicated as a primary cause of decline in many species around the globe. however, there are some species and populations that are known to become infected in the wild, yet declines have not been observed. here we conducted a yearlong capture-mark-recapture study and a 2-year long disease monitoring study of northern cricket frogs, acris crepitans, in the lowland subtropical forests of louisiana. | 2018 | 30217158 |
| temperature-dependent effects of cutaneous bacteria on a frog's tolerance of fungal infection. | defense against pathogens is one of many benefits that bacteria provide to animal hosts. a clearer understanding of how changes in the environment affect the interactions between animals and their microbial benefactors is needed in order to predict the impact and dynamics of emerging animal diseases. due to its dramatic effects on the physiology of animals and their pathogens, temperature may be a key variable modulating the level of protection that beneficial bacteria provide to their animal ho ... | 2018 | 29563909 |
| responses of male cricket frogs (acris crepitans) to attenuated and degraded advertisement calls. | we examined the vocal and non-vocal responses of male cricket frogs (acris crepitans) to conspecific advertisement calls that had been attenuated or degraded by reducing the depth of amplitude modulation (am). both are characteristic of changes to the call as it is transmitted through natural habitats. as stimulus calls became more intense or less degraded, male cricket frogs gradually decreased their call rate and increased the number of call groups and pulse groups in their calls, changes indi ... | 2017 | 28966421 |