| effects of bombesin and bombesin-like peptides on gastrointestinal myoelectric activity. | gastrointestinal myoelectric activity was studied during intravenous infusion of bombesin and bombesin-like peptides in conscious dogs with electrodes chronically implanted at different levels between the stomach and the rectum. the peptides used were bombesin, the cooh-terminal hepta- octa-, and nonapeptide of bombesin, and litorin, a new natural peptide isolated from the skin of litoria aurea. bombesin significantly increased the frquency of pacesetter potentials (pp) in tha antrum, duodenum, ... | 1975 | 1126599 |
| a newly reported toxic australian frog (genus heleioporus). | attention is drawn to an indigenous poisonous frog which, preliminary toxicity experiments indicate, can cause pronounced distress to some species, including man. | 1975 | 1143146 |
| parallel bioassay of bombesin and litorin, a bombesin-like peptide from the skin of litoria aurea. | the spectrum of biological activity exhibited by litorin, a bombesin-like nonapeptide found in extracts of the skin of the australian leptodactylid frog litoria aurea was compared with that exhibited by the tetradecapeptide bombesin. 2 litorin proved to be more potent than bombesin on isolated smooth muscle preparations and on the urinary bladder in situ. however, it was less potent on dog systemic blood pressure and kidney vasculature activation of the renen-angiotensin system being slight or l ... | 1975 | 1201379 |
| electrophysiological effects of a neurotoxin extracted from the skin of the australian frog pseudophryne coriacea. | 1. the electrophysiological effects of a pumiliotoxin-b-like alkaloid extracted from the skin of the australian frog pseudophryne coriacea (psc) have been studied in rat superior cervical ganglia at 37 degrees c. 2. psc (50 mg/ml) elicits a broadening of the evoked compound action potential and, at rest, the appearance of spontaneous spike discharge at 10-20 hz. action potentials presumably originate far away from the soma, which is invaded in a typical is-sd sequence. 3. the toxin effect is not ... | 1992 | 1360386 |
| epileptogenic effects of skin extracts from the australian frog pseudophryne coriacea after intracerebral microinfusion in rats. | the behavioural and electrocortical (ecog) effects induced by a methanol extract of the skin of the australian frog pseudophryne coriacea, directly microinjected into several areas of the brain, were studied in freely moving rats. administration of the p. coriacea extract (5, 10, 15 and 20 micrograms) into the dorsal hippocampus produced a dose-dependent and reversible behavioural stimulation and ecog spikes lasting 20-140 min. similar but less intense effects were elicited in rats receiving inj ... | 1992 | 1557788 |
| electrophysiological effects of a pumiliotoxin-b-like alkaloid derived from the skin of the australian frog pseudophryne coriacea. | skin extracts of the australian frog pseudophryne coriacea (psc) potentiate and prolong the bioelectric activity of various excitable tissues. when studied by electrophysiological means in a preparation of mouse diaphragm, psc skin extracts did not affect the spontaneous acetylcholine (ach) release. however, the indirect stimulation of the preparation in the presence of psc skin extracts gave rise to a different profile of rhythmic activity showing afterpotentials and variable oscillatory activi ... | 1991 | 1659696 |
| six novel tachykinin- and bombesin-related peptides from the skin of the australian frog pseudophryne güntheri. | six novel peptides belonging to the tachykinin and bombesin families were isolated and sequenced from extracts of the skin of the australian myobatrachid frog pseudophryne güntheri. one of these peptides (pg-l) was of the bombesin family and may be considered an n-elongation of the litorin/ranatensin molecule, with which it shares an identical spectrum of activity on isolated smooth muscle preparations. the other five peptides were of the tachykinin family with two of these peptides (pg-spi and ... | 1990 | 2356157 |
| alkaloids from australian frogs (myobatrachidae): pseudophrynamines and pumiliotoxins. | australian frogs of the genus pseudophryne contain two distinct classes of alkaloids. the pseudophrynamine class (3a-prenyl pyrrolo[2,3-b]indoles) are unique to this genus of frogs of the family myobatrachidae, while the pumiliotoxin-a class (8-hydroxy-8-methyl-6-alkylidene-1-azabicyclo[4.3.0]nonanes) also occur in dendrobatid frogs of the genera dendrobates, epipedobates, and minyobates, in ranid frogs of the genus mantella, and in bufonid toads of the genus melanophryniscus. all seven species ... | 1990 | 2380714 |
| facilitation of [3h]acetylcholine and [3h]5-hydroxytryptamine release from rat cerebral cortex synaptosomes by a factor extracted from the skin of the australian frog pseudophryne coriacea. | a partly purified extract of the skin of the australian frog pseudophryne coriacea (psc) evoked the release of [3h]acetylcholine [( 3h]ach) and of [3h]5-hydroxytryptamine [( 3h]5-ht) from superfused rat cerebral cortex synaptosomes prelabeled with [3h]choline or [3h]5-ht, respectively. the psc-evoked release of both transmitters was sensitive to tetrodotoxin and was strictly ca2+-dependent. the release of [3h]5-ht caused by psc was unaffected by the 5-ht uptake inhibitor citalopram. activation o ... | 1989 | 2776843 |
| a potent factor in extracts of the skin of the australian frog, pseudophryne coriacea. apparent facilitation of transmitter release in isolated smooth muscle preparations. | extracts of the skin of the australian frog pseudophryne coriacea (psc) displayed potent stimulant effects on isolated smooth muscle preparations of intestine and similar effects on electrically-stimulated vas deferens preparations. these effects must be ascribed to an alkaloid, related in structure to the pumiliotoxins, a class of alkaloid compounds occurring in the skin of neotropical poison frogs. on the basis of results obtained with antagonists and blocking agents, it is suggested that the ... | 1985 | 2875414 |
| a potent factor in extracts of the skin of the australian frog, pseudophryne coriacea--iii. potentiation of contractions elicited in avian and mammalian isolated skeletal muscle preparations by direct and indirect electrical stimulation. | extracts of the skin of the australian frog pseudophryne coriacea displayed a striking potentiating effect on contractions evoked in isolated skeletal muscle preparations of mammals (phrenic nerve diaphragm) and birds (chick biventer cervicis and semispinalis muscles) by indirect and direct electrical stimulation. there was both a conspicuous increase in the amplitude of the twitch, up to 10-fold, and a remarkable prolongation of the duration of the twitch. the effect was dose- and frequency-dep ... | 1986 | 3022175 |
| intrarenal effects of [ala-pro-gly-(ile3-val5)] angiotensin ii in the conscious dog. | amphibian skin has functional characteristics of epithelium in the mammalian distal nephron and plays an important role in sodium and water metabolism in these animals. a peptide extracted from the skin of the australian frog crinia georgiana has been purified, has been determined to have the amino acid sequence of [ala-pro-gly-(ile3-val5)]angiotensin ii, and recently has been synthesized. we studied the renal effect of synthetic frog skin angiotensin ii (fsaii) infused via the renal artery in d ... | 1988 | 3275540 |
| occurrence of skin alkaloids in non-dendrobatid frogs from brazil (bufonidae), australia (myobatrachidae) and madagascar (mantellinae). | several taxa of small frogs from the southern hemisphere contain alkaloids similar or identical to compounds previously known only from neotropical poison frogs of the family dendrobatidae. skin of the brazilian toad melanophryniscus moreirae (family bufonidae) contains a new alkaloid 8-hydroxy-8-methyl-6-(5'-hydroxy-2'-methyl-hexylidene)-1-azabicycl o-[4.3.0] nonane (c16h29no2), which is designated pumiliotoxin 267c. such a structure is typical of the pumiliotoxin-a class of dendrobatid alkaloi ... | 1984 | 6523513 |
| synthesis of ala-pro-gly-[ile3, val5]angiotensin ii isolated from the skin of the australian frog crinia georgiana. | ala-pro-gly-[ile3, val5]angiotensin ii was synthesized by merrifield's solid-phase procedure. the peptide was purified by chromatography on successive columns of anion-exchange resin, sephadex g-25 and sp-sephadex c-25; its homogeneity was determined by degradation with alpha-chymotrypsin, ionophoresis, thin-layer chromatography, and high-pressure liquid chromatography (hplc). the dansyl derivative of this angiotensin has the same chromatographic behavior (tlc) as the dansyl undecapeptide, "crin ... | 1981 | 7277399 |
| in vitro and in vivo biological activities of pg-kii, a novel kassinin-like peptide from the skin of the australian frog, pseudophryne güntheri. | we compared the in vitro and in vivo biological activities of pg-kii (pglu-pro-asn-pro-asp-glu-phe-val-gly-leu-met-nh2), a new peptide belonging to the tachykinin family, related to kassinin, isolated and sequenced from extracts of the skin of the australian myobatrachid frog pseudophryne güntheri, with those of the well-known tachykinins [substance p (sp), neurokinin a (nka), neurokinin b (nkb), and kassinin (kass)] to study its pharmacological and receptor profile. pg-kii always proved inactiv ... | 1996 | 8899820 |
| further evidence that the tachykinin pg-kii is a potent agonist at central nk-3, but not nk-1, receptors. | intracerebroventricular (i.c.v.) injection of tachykinins (tks) inhibits ethanol intake and angiotensin ii-induced water intake; the effects are apparently mediated by nk-3 and nk-1 receptors, respectively. the present study evaluated the effect of the tk pg-kii, a novel kassinin-like peptide isolated from the skin of the australian frog pseudophryne güntheri, in these in vivo tests for central activity. pg-kii, given by i.c.v. injection, potently inhibited alcohol intake in genetically selected ... | 1997 | 9285931 |
| application of the fetax protocol to assess the developmental toxicity of nonylphenol ethoxylate to xenopus laevis and two australian frogs. | the frog embryo teratogenesis assay-xenopus (fetax) protocol has recently been adopted as a valuable tool for evaluating the embryotoxicity of environmental contaminants in amphibians. the bioassay utilises xenopus laevis as a test species, but there are few comparative studies to evaluate whether data collected in this species is applicable to other amphibians. in this study, the embryotoxicity of the nonionic surfactant, nonylphenol ethoxylate, was determined in x. laevis and the australian fr ... | 2000 | 10998496 |
| the acute toxicity of agricultural surfactants to the tadpoles of four australian and two exotic frogs. | nonionic surfactants are frequently incorporated into pesticide formulations, and are therefore a group of chemicals to which amphibians may be exposed in agricultural or urban landscapes. however, little is known about the effects of surfactant exposure in amphibians. feeding stage tadpoles of bufo marinus, xenopus laevis and four species of australian frogs (crinia insignifera, heleioporus eyrei, limnodynastes dorsalis and litoria moorei) were exposed to nonylphenol ethoxylate (npe) and alcoho ... | 2001 | 11504342 |
| testicular myxosporidiasis in anurans, with a description of myxobolus fallax n. sp. | during studies of amphibian sperm cryopreservation, a new species of myxosporidean parasite (myxozoa, myxosporae) was observed in the testes of the australian dwarf green tree frog litoria fallax (peters). myxosporidiasis was found to have no affect on l. fallax body condition or sperm numbers. myxobolus spores from l. fallax are morphologically distinct from myxobolus hylae spores (infecting the sympatric litoria aurea lesson) and the three previously named (exotic to australia) myxobolus speci ... | 2002 | 12075129 |
| microsatellite variation and population structure in a declining australian hylid litoria aurea. | the green and golden bell frog (litoria aurea) was once a common australian hylid. today, many populations are small and fragmented as a result of dramatic declines in distribution and abundance. we undertook a large-scale assessment of genetic structure and diversity in l. aurea using four species-specific microsatellite markers. twenty-one locations were sampled from throughout the species range covering 1000 km of the east coast of australia. levels of allelic diversity and heterozygosity wer ... | 2004 | 15189200 |
| effect of season and temperature on mortality in amphibians due to chytridiomycosis. | to investigate the distribution and incidence of chytridiomycosis in eastern australian frogs and to examine the effects of temperature on this disease. | 2004 | 15354853 |
| a new lineage of trypanosomes from australian vertebrates and terrestrial bloodsucking leeches (haemadipsidae). | little is known about the trypanosomes of indigenous australian vertebrates and their vectors. we surveyed a range of vertebrates and blood-feeding invertebrates for trypanosomes by parasitological and pcr-based methods using primers specific to the small subunit ribosomal rna (ssu rrna) gene of genus trypanosoma. trypanosome isolates were obtained in culture from two common wombats, one swamp wallaby and an australian bird (strepera sp.). by pcr, blood samples from three wombats, one brush-tail ... | 2005 | 15777919 |
| population trends associated with skin peptide defenses against chytridiomycosis in australian frogs. | many species of amphibians in the wet tropics of australia have experienced population declines linked with the emergence of a skin-invasive chytrid fungus, batrachochytrium dendrobatidis. an innate defense, antimicrobial peptides produced by granular glands in the skin, may protect some species from disease. here we present evidence that supports this hypothesis. we tested ten synthesized peptides produced by australian species, and natural peptide mixtures from five queensland rainforest speci ... | 2006 | 16205955 |
| alkaloids from amphibian skin: a tabulation of over eight-hundred compounds. | a diverse array of biologically active, lipid-soluble alkaloids have been discovered in amphibian skin. such alkaloids include the following: the steroidal samandarines from salamanders, the batrachotoxins, histrionicotoxins, gephyrotoxins, and epibatidine from neotropical poison frogs (dendrobatidae), the pumiliotoxins, allopumiliotoxins, homopumiliotoxins, and decahydroquinolines from certain genera of anurans from four families (dendrobatidae, mantellidae, bufonidae, and myobatrachidae), a va ... | 2005 | 16252926 |
| phylogenetics and evolution of bell frogs (litoria aurea species-group, anura: hylidae) based on mitochondrial nd4 sequences. | | 2006 | 16384717 |
| tadpoles of four common australian frogs are not effective predators of the common pest and vector mosquito culex annulirostris. | in a laboratory investigation of tadpoles of 4 australian frogs, limnodynastes peronii, limnodynastes tasmaniensis, litoria aurea, and litoria peronii, there was no evidence of active predation on larvae of culex annulirostris. the mortality of larvae was greatest when exposed to the tadpoles of litoria spp., which may have been the result of specific foraging behavior. results indicate that litoria spp. tadpoles may have a minor impact on mosquito populations, but they are unlikely to be useful ... | 2005 | 16506583 |
| nmr studies of aurein 1.2 analogs. | aurein 1.2 is an antimicrobial and anticancer peptide isolated from an australian frog. to improve our understanding of the mechanism of action, two series of peptides were designed. the first series includes the n-terminal membrane anchor of bacterial glucose-specific enzyme iia, aurein 1.2, and a newly identified aurein 1.2 analog from human ll-37 (llaa). the order of antibacterial activity is llaa>aurein 1.2>>the membrane anchor (inactive). the structure of llaa in detergent micelles was dete ... | 2006 | 16716252 |
| the marine biologist--bob endean. | bob endean was a dedicated marine biologist with an extensive knowledge of coral reef communities in the great barrier reef and fauna in subtropical queensland waters. he commenced a study of venomous and poisonous marine animals dangerous to man at a time when the field was new, employing a variety of techniques to investigate the venom apparatus, mode of delivery of venom or toxin, mode of toxic action on excitable tissues, and biochemistry of venom or toxin. determination of the pharmacologic ... | 2006 | 16952385 |
| characterization of the structure and membrane interaction of the antimicrobial peptides aurein 2.2 and 2.3 from australian southern bell frogs. | the structure and membrane interaction of the antimicrobial peptide aurein 2.2 (glfdivkkvvgalgsl-conh(2)), aurein 2.3 (glfdivkkvvgaigsl-conh(2)), both from litoria aurea, and a carboxy c-terminal analog of aurein 2.3 (glfdivkkvvgaigsl-cooh) were studied to determine which features of this class of peptides are key to activity. circular dichroism and solution-state nmr data indicate that all three peptides adopt an alpha-helical structure in the presence of trifluoroethanol or lipids such as 1,2- ... | 2007 | 17259271 |
| environmental deterioration increases tadpole vulnerability to predation. | human-induced environmental change is occurring at an unprecedented rate and scale. many freshwater habitats, in particular, have been degraded as a result of increased salinity. little is known about the effects of anthropogenic salinization on freshwater organisms, especially at sublethal concentrations, where subtle behavioural changes can have potentially drastic fitness consequences. using a species of australian frog (litoria ewingii), we experimentally examined the effects of salinization ... | 2008 | 18492650 |
| survey protocol for detecting chytridiomycosis in all australian frog populations. | spread of the amphibian chytrid fungus batrachochytrium dendrobatidis (bd) has caused the decline and extinction of frogs, but the distribution of bd is not completely known. this information is crucial to implementing appropriate quarantine strategies, preparing for outbreaks of chytridiomycosis due to introduction of bd, and for directing conservation actions towards affected species. this survey protocol provides a simple and standard method for sampling all frog populations in australia to m ... | 2008 | 18717061 |
| origin of the parasites of an invading species, the australian cane toad (bufo marinus): are the lungworms australian or american? | phylogeographical analyses that identify the geographical origin of parasites in invading species can clarify the parasites' potential for biological control of the invader and the risks posed by the parasite to native species. our data on nuclear and mitochondrial genetic sequences show that the nematode lungworms (rhabdias spp.) in invasive australian populations of cane toads (bufo marinus) are rhabdias pseudosphaerocephala, a south american species. we did not find this lungworm species in a ... | 2008 | 18803593 |
| frog glue enhances rotator cuff repair in a laboratory cadaveric model. | summary: rotator cuff tendons are typically reattached to the proximal humerus using transosseous sutures or suture anchors. their primary mode of failure is at the tendon-bone interface. we investigated the addition of a novel adhesive secreted from a species of australian frog (notaden bennetti) to different methods of rotator cuff repair. we hypothesized that the addition of frog glue would increase the strength of the repaired rotator cuff construct. three techniques were used to repair 42 f ... | 2009 | 19250843 |
| biocompatibility and modification of the protein-based adhesive secreted by the australian frog notaden bennetti. | when provoked, notaden bennetti frogs secrete a proteinaceous exudate, which rapidly forms a tacky and elastic glue. this material has potential in biomedical applications. cultured cells attached and proliferated well on glue-coated tissue culture polystyrene, but migrated somewhat slower than on uncoated surfaces. in organ culture, dissolved glue successfully adhered collagen-coated perfluoropolyether lenses to debrided bovine corneas and supported epithelial regrowth. small pellets of glue im ... | 2010 | 19569213 |
| inhibition of frog antimicrobial peptides by extracellular products of the bacterial pathogen aeromonas hydrophila. | to determine whether the extracellular products (ecps) from aeromonas hydrophila, a frog bacterial pathogen that is resistant to skin antimicrobial peptides of three different frog species xenopus laevis, litoria aurea and litoria raniformis, can modulate the activity of these peptides. | 2009 | 19728406 |
| severe sparganosis in australian tree frogs. | spargana of spirometra erinacei infect many vertebrate species, but severe disease from sparganosis has been reported from few host species. information on the effects of this common, introduced tapeworm of cats on australian frogs is lacking. our survey to detect significant diseases in free-ranging amphibians in eastern australia between 1993 and 2000 revealed that infection with spargana (plerocercoids) of s. erinacei occurred in 12/243 (4.9%) sick frogs. infections occurred in skeletal muscl ... | 2009 | 19901368 |
| museum material reveals a frog parasite emergence after the invasion of the cane toad in australia. | abstract: | 2010 | 20537137 |
| skin peptide and cdna profiling of australian anurans: genus and species identification and evolutionary trends. | host defense peptides of 35 species of australian frogs from the hylids cyclorana and litoria, and the myobatrachids crinia, limnodynastes and uperoleia have been identified. the biological activities of the majority of these peptides have been determined and include hormones, neuropeptides, opioids, immunomodulators, membrane active peptides [including antimicrobial, anticancer, antiviral (enveloped viruses like hiv and herpes) and antifungal peptides], neuronal nitric oxide synthase inhibitors ... | 2010 | 20932866 |
| infection dynamics of the lungworm rhabdias pseudosphaerocephala in its natural host, the cane toad (bufo marinus), and in novel hosts (native australian frogs). | host-parasite systems have often evolved over time, such that infection dynamics may become greatly modified from the time of initial contact of the host with the parasite. biological invasions may be useful to clarify processes in the initial contact of hosts with parasites, and allow us to compare parasite uptake between the ancestral (coevolved) host and novel (noncoevolved) hosts. cane toads (bufo marinus) are spreading rapidly through tropical australia, carrying with them a nematode lungwo ... | 2010 | 20966266 |
| the effects of experimentally infecting australian tree frogs with lungworms (rhabdias pseudosphaerocephala) from invasive cane toads. | invasive species may transmit novel pathogens to native taxa, and lacking a history of coevolutionary interactions with the pathogen, the new hosts may be severely affected. cane toads (bufo marinus) were introduced to australia in 1935, bringing with them a lungworm (rhabdias pseudosphaerocephala) not found in australian frogs. previous studies suggest that most frog species are unaffected by this parasite, but one tree-frog (litoria caerulea) can harbour high numbers of lungworm. more detailed ... | 2011 | 21624371 |
| antimicrobial peptides from the aurein family form ion-selective pores in bacillus subtilis. | the mechanism of action of aurein 2.2 and aurein 2.3, antimicrobial peptides from the frog litoria aurea, was investigated. proteomic profiling of the bacillus subtilis stress response indicates that the cell envelope is the main target for both aureins. upon treatment, the cytoplasmic membrane depolarizes and cellular atp levels decrease. global element analysis shows that intracellular concentrations of certain metal ions (potassium, magnesium, iron, and manganese) strongly decrease. selective ... | 2015 | 25821129 |
| high adult mortality in disease-challenged frog populations increases vulnerability to drought. | pathogen emergence can drive major changes in host population demography, with implications for population dynamics and sensitivity to environmental fluctuations. the amphibian disease chytridiomycosis, caused by infection with the fungal pathogen batrachochytrium dendrobatidis (bd), is implicated in the severe decline of over 200 amphibian species. in species that have declined but not become extinct, bd persists and can cause substantial ongoing mortality. high rates of mortality associated wi ... | 2016 | 27380945 |
| we made your bed, why won't you lie in it? food availability and disease may affect reproductive output of reintroduced frogs. | mitigation to offset the impacts of land development is becoming increasingly common, with reintroductions and created habitat programs used as key actions. however, numerous reviews cite high rates of poor success from these programs, and a need for improved monitoring and scientific testing to evaluate outcomes and improve management actions. we conducted extensive monitoring of a released population of endangered green and golden bell frogs, litoria aurea, within a created habitat, as well as ... | 2016 | 27463095 |
| low disease-causing threshold in a frog species susceptible to chytridiomycosis. | a simple diagnosis of the presence or absence of an infection is an uninformative metric when individuals differ considerably in their tolerance to different infection loads or resistance to rates of disease progression. models that incorporate the relationship between the progression of the infection with the potential alternate outcomes provide a far more powerful predictive tool than diagnosis alone. the global decline of amphibians has been amplified by batrachochytrium dendrobatidis, a path ... | 2016 | 27190153 |
| susceptibility to disease varies with ontogeny and immunocompetence in a threatened amphibian. | ontogenetic changes in disease susceptibility have been demonstrated in many vertebrate taxa, as immature immune systems and limited prior exposure to pathogens can place less developed juveniles at a greater disease risk. by causing the disease chytridiomycosis, batrachochytrium dendrobatidis (bd) infection has led to the decline of many amphibian species. despite increasing knowledge on how bd varies in its effects among species, little is known on the interaction between susceptibility and de ... | 2016 | 27021312 |
| effects of pond salinization on survival rate of amphibian hosts infected with the chytrid fungus. | the chytrid fungus batrachochytrium dendrobatidis has been implicated in the decline and extinction of amphibian populations worldwide, but management options are limited. recent studies show that sodium chloride (nacl) has fungicidal properties that reduce the mortality rates of infected hosts in captivity. we investigated whether similar results can be obtained by adding salt to water bodies in the field. we increased the salinity of 8 water bodies to 2 or 4 ppt and left an additional 4 water ... | 2015 | 25354647 |
| prevalence of batrachochytrium dendrobatidis infection is extremely low in direct-developing australian microhylids. | the emerging infectious disease chytridiomycosis has been implicated in declines and disappearances of amphibian populations around the world. however, susceptibility to infection and the extent of pathological effects of infection vary among hosts, and species with life histories that include parental care of direct-developing terrestrial eggs may tend to be less susceptible. we examined samples from a total of 595 individuals of 9 species of direct-developing australian frogs in the family mic ... | 2012 | 22968787 |
| pathology of a bohle-like virus infection in two australian frog species (litoria splendida and litoria caerulea). | gross and histopathological examination was performed on seven captive magnificent tree frogs (litoria splendida) and one green tree frog (litoria caerulea) that had died or been humanely destroyed while naturally infected with mahaffey road virus, a bohle iridovirus-like ranavirus. necropsy examination revealed skin lesions consisting of multiple small pale or haemorrhagic papules and ulcers in most frogs. other common gross findings were perineural haemorrhage affecting the spinal nerves, hydr ... | 2015 | 25678427 |
| host-parasite relationships during a biologic invasion: 75 years postinvasion, cane toads and sympatric australian frogs retain separate lungworm faunas. | invasive species may carry with them parasites from their native range, differing from parasite taxa found in the invaded range. host switching by parasites (either from the invader to native fauna or from native fauna to the invader) may have important consequences for the viability of either type of host (e.g., their survivorship, fecundity, dispersal ability, or geographic distribution). rhabdias pseudosphaerocephala (nematoda) is a common parasite of cane toads (rhinella marina) in the toad' ... | 2012 | 23060496 |
| knocking on heaven's door: are novel invaders necessarily facing naïve native species on islands? | the impact of alien predator species on insular native biota has often been attributed to island prey naïveté (i.e. lack of, or inefficient, anti-predator behavior). only rarely, however, has the concept of island prey naïveté been tested, and then only a posteriori (i.e. hundreds or thousands of years after alien species introduction). the presence of native or anciently introduced predators or competitors may be crucial for the recognition and development of adaptive behavior toward unknown pr ... | 2016 | 26978784 |
| a new species of australian frog (myobatrachidae: uperoleia) from the new south wales mid-north coast sandplains. | the discovery of new vertebrate species in developed countries is still occurring at surprising rates for some taxonomic groups, especially the amphibians and reptiles. while this most often occurs in under-explored areas, it occasionally still happens in well-inhabited regions. we report such a case with the discovery and description of u. mahonyi sp. nov., a new species of frog from a highly populated region of new south wales, australia. we provide details of its morphology, calls, embryos an ... | 2016 | 27811640 |
| new species of myxosporea from frogs and resurrection of the genus cystodiscus lutz, 1889 for species with myxospores in gallbladders of amphibians. | two new myxosporean species in the gallbladders of frogs have recently spread across eastern australia and cause disease. cystodiscus axonis sp. n. and cystodiscus australis sp. n. are species of myxosporea (myxozoa) identified from a range of australian frogs and tadpoles including the introduced cane toad (rhinella marina). the new species are defined by their distinct genetic lineage, myxospore morphology and ultrastructure of the pre-sporogonic development. spores of both species are produce ... | 2012 | 22260881 |
| disease-associated change in an amphibian life-history trait. | emerging pathogens can drive evolutionary shifts in host life-history traits, yet this process remains poorly documented in vertebrate hosts. amphibian chytridiomycosis, caused by infection with the fungal pathogen batrachochytrium dendrobatidis (bd), is the worst recorded wildlife disease and has caused the extinction of over 100 species across multiple continents. a similar number of additional species have experienced mass declines and bd remains a major source of mortality in many population ... | 2017 | 28707112 |
| skin sloughing in susceptible and resistant amphibians regulates infection with a fungal pathogen. | the fungal pathogen batrachochytrium dendrobatidis (bd) has been implicated in amphibian population declines globally. given that bd infection is limited to the skin in post-metamorphic amphibians, routine skin sloughing may regulate infection. skin sloughing has been shown to reduce the number of cultivatable microbes on amphibian skin, and bd infection increases skin sloughing rates at high loads. however, it is unclear whether species specific differences in skin sloughing patterns could regu ... | 2017 | 28615642 |
| novel dermaseptin, adenoregulin and caerin homologs from the central american red-eyed leaf frog, agalychnis callidryas, revealed by functional peptidomics of defensive skin secretion. | by integrating systematic peptidome and transcriptome studies of the defensive skin secretion of the central american red-eyed leaf frog, agalychnis callidryas, we have identified novel members of three previously described antimicrobial peptide families, a 27-mer dermaseptin-related peptide (designated drp-ac4), a 33-mer adenoregulin-related peptide (designated arp-ac1) and most unusually, a 27-mer caerin-related peptide (designated crp-ac1). while dermaseptin and adenoregulin were originally i ... | 2008 | 18555027 |
| investigating patterns in the spermiation response of eight australian frogs administered human chorionic gonadotropin (hcg) and luteinizing hormone-releasing hormone (lhrha). | exogenous lhrha and hcg are routinely employed to induce spermiation in vivo in anurans. to date, however, few studies have directly compared the efficacy of these two hormones. the aim of this study was threefold. first to quantify the spermiation response of eight australian anuran species (crinia glauerti, crinia georgiana, crinia pseudinsignifera, geocrinia rosea, heleioporus albopunctatus, heleioporuseyrei, neobatrachus pelobatoides and pseudophryne guentheri) administered lhrha and hcg. se ... | 2012 | 22909973 |
| impact of plio-pleistocene arid cycling on the population history of a southwestern australian frog. | southwestern australia is regarded as a global biodiversity hotspot. the region contains a high number of endemic species, ranging from gondwanan relicts to much more recently evolved plant and animal species. myobatrachid frogs are diverse in southwestern australia, and while we know they have speciated in situ in the southwest, we know little about the temporal and geographical patterning of speciation events. crinia georgiana is an ideal subject to test hypotheses concerning the effect of cli ... | 2007 | 17594447 |
| molecular phylogeny of the australian frog genera crinia, geocrinia, and allied taxa (anura: myobatrachidae). | we present a mitochondrial gene tree for representative species of all the genera in the subfamily myobatrachinae, with special emphasis on crinia and geocrinia. this group has been the subject of a number of long-standing taxonomic and phylogenetic debates. our phylogeny is based on data from approximately 780 bp of 12s rrna and 676 bp of nd2, and resolves a number of these problems. we confirm that the morphologically highly derived monotypic genera metacrinia, myobatrachus, and arenophryne ar ... | 2001 | 11697923 |
| influence of environmental oxygen on development and hatching of aquatic eggs of the australian frog, crinia georgiana. | the effect of oxygen partial pressure (po(2)) on development and hatching was investigated in aquatic embryos of the myobatrachid frog, crinia georgiana, in the field and in the laboratory. eggs from 29 field nests experienced widely variable po(2) but similar temperatures. mean po(2) in different nests ranged between 2.9 and 19.3 kpa (grand mean 12.9 kpa), and mean temperature ranged between 11.9 degrees and 16.8 degrees c (grand mean 13.7 degrees c). there was no detectable effect of po(2) or ... | 2013 | 11009404 |
| synchronous polyandry and multiple paternity in the frog crinia georgiana (anura: myobatrachidae). | multiple paternity has rarely been reported in anuran amphibians, with only three previous documented examples. for the australian frog crinia georgiana, we observed synchronous polyandry in an average of 44% of matings observed at four field sites. this suggests matings involving more than one male are common in this species. one to eight males were observed in amplectant groups with second males amplexed ventrally. genetic analyses, using allozyme electrophoresis, of offspring from two matings ... | 1999 | 10196064 |
| amino acid composition and sequence of crinia-angiotensin, an angiotensin ii-like endecapeptide from the skin of the australian frog crinia georgiana. | methanol extracts of the skin of the australian amphibian crinia georgiana contain large amounts of crinia-angiotensin ii, a new angiotensin ii-like peptide. this differs sharply from the conventional octapeptide angiotensins ii in having attached the tripeptide ala-pro-gly- to the n-terminus, and having an ile residue substituted for the val residue at position 6 from the c-terminus. small amounts of angiotensin-like peptides have been traced, by radioimmunoassay, in skin extracts of some other ... | 1979 | 488254 |
| interspecific variation in the phenology of advertisement calling in a temperate australian frog community. | spatial and temporal partitioning of resources underlies the coexistence of species with similar niches. in communities of frogs and toads, the phenology of advertisement calling provides insights into temporal partitioning of reproductive effort and its implications for community dynamics. this study assessed the phenology of advertisement calling in an anuran community from melbourne, in southern australia. we collated data from 1432 surveys of 253 sites and used logistic regression to quantif ... | 2015 | 26442760 |
| an immunomodulatory peptide related to frenatin 2 from skin secretions of the tyrrhenian painted frog discoglossus sardus (alytidae). | norepinephrine-stimulated skin secretions of the tyrrhenian painted frog discoglossus sardus tschudi, 1837 (alytidae) did not contain any peptide with antimicrobial or hemolytic activity. however, peptidomic analysis of the secretions revealed the presence of an abundant peptide with structural similarity to frenatin 2, previously isolated from the australian frog litoria infrafrenata (hylidae). the primary structure of the peptide, termed frenatin 2d, was established as dllgtlgnlplpfi.nh2 by au ... | 2013 | 23262358 |
| the energetics of endotrophic development in the frog geocrinia vitellina (anura: myobatrachinae). | the energetics of endotrophic development, where the nutrition required to complete metamorphosis is provided solely by yolk, has seldom been quantified. the energy cost of development to metamorphosis of the endotrophic australian frog geocrinia vitellina was measured using bomb calorimetry and closed-system respirometry. dry yolk had an energy density of 26.4 j x mg(-1), and an average 2.8-mm-diameter ovum contained 144 j. incubation at 15 degrees c produced a froglet of 5.8 mm snout-vent leng ... | 2006 | 11731974 |
| emerging myxosporean parasites of australian frogs take a ride with fresh fruit transport. | the spread of wildlife pathogens into new geographical ranges or populations is a conservation concern for endangered species. cystodiscus australis and cystodiscus axonis are two species of myxosporean parasites infecting australian frogs and tadpoles that have been recently recognised as important disease agents impacting amphibian conservation. yet despite their importance to wildlife health, the mechanism of emergence for these parasites is unknown. we hypothesise that these parasites are ca ... | 2012 | 23006438 |
| ontogenetic variation in the chemical defenses of cane toads (bufo marinus): toxin profiles and effects on predators. | we conducted a quantitative and qualitative chemical analysis of cane toad bufadienolides--the cardioactive steroids that are believed to be the principal cane toad toxins. we found complex shifts in toxin composition through toad ontogeny: (1) eggs contain at least 28 dominant bufadienolides, 17 of which are not detected in any other ontogenetic stage; (2) tadpoles present a simpler chemical profile with two to eight dominant bufadienolides; and (3) toxin diversity decreases during tadpole life ... | 2009 | 19263169 |
| the toxicity of glyphosate and several glyphosate formulations to four species of southwestern australian frogs. | the acute toxicity of technical-grade glyphosate acid, glyphosate isopropylamine, and three glyphosate formulations was determined for adults of one species and tadpoles of four species of southwestern australian frogs in 48-h static/renewal tests. the 48-h lc50 values for roundup(r) herbicide (mon 2139) tested against tadpoles of crinia insignifera, heleioporus eyrei, limnodynastes dorsalis, and litoria moorei ranged between 8.1 and 32.2 mg/l (2.9 and 11.6 mg/l glyphosate acid equivalent [ae]), ... | 1999 | 9888965 |
| selenium speciation influences bioaccumulation in limnodynastes peronii tadpoles. | despite being essential for animal health and fitness, se has a relatively narrow range between deficiency and toxicity, and excess se can cause a variety of adverse effects in aquatic organisms. amphibians are particularly vulnerable to contaminants during larval aquatic life stage, because they can accumulate toxic ions through various routes including skin, gills, lungs and digestive tract. few attempts have been made to understand the tissue-specific accumulation of trace elements, including ... | 2017 | 28343020 |
| short- and long-term consequences of developmental saline stress: impacts on anuran respiration and behaviour. | secondary salinization has been identified as a major stressor to amphibians. exposure to elevated salinity necessitates physiological adjustments and biochemical changes that may be energetically demanding. as such, exposure to non-lethal levels of salinity during development could potentially alter anuran metabolic rates and individual performance in both pre- and post-metamorphic life stages. we investigated the effects of non-lethal levels of salinity on metamorphic traits (time to reach met ... | 2016 | 26998337 |
| do invasive cane toads affect the parasite burdens of native australian frogs? | one of the most devastating impacts of an invasive species is the introduction of novel parasites or diseases to native fauna. invasive cane toads (rhinella marina) in australia contain several types of parasites, raising concern that the toads may increase rates of parasitism in local anuran species. we sampled cane toads and sympatric native frogs (limnodynastes peronii, litoria latopalmata, and litoria nasuta) at the southern invasion front of cane toads in north-eastern new south wales (nsw) ... | 2013 | 24533330 |
| larval tolerance to salinity in three species of australian anuran: an indication of saline specialisation in litoria aurea. | recent anthropogenic influences on freshwater habitats are forcing anuran populations to rapidly adapt to high magnitude changes in environmental conditions or face local extinction. we examined the effects of ecologically relevant elevated salinity levels on larval growth, metamorphosis and survival of three species of australian anuran; the spotted marsh frog (limnodynastes tasmaniensis), the painted burrowing frog (neobatrachus sudelli) and the green and golden bell frog (litoria aurea), in o ... | 2012 | 22916260 |
| adult frogs and tadpoles have different macroevolutionary patterns across the australian continent. | developmental changes through an animal's life are generally understood to contribute to the resulting adult morphology. possible exceptions are species with complex life cycles, where individuals pass through distinct ecological and morphological life stages during their ontogeny, ending with metamorphosis to the adult form. antagonistic selection is expected to drive low genetic correlations between life stages, theoretically permitting stages to evolve independently. here we describe, using a ... | 2017 | 29046549 |
| invasive cane toads are unique in shape but overlap in ecological niche compared to australian native frogs. | invasive species are an important issue worldwide but predicting invasiveness, and the underlying mechanisms that cause it, is difficult. there are several primary hypotheses to explain invasion success. two main hypothesis based on niche spaces stand out as alternative, although not exclusive. the empty niche hypothesis states that invaders occupy a vacant niche space in the recipient community, and the niche competition hypothesis states that invaders overlap with native species in niche space ... | 2017 | 29043018 |
| interaction of the antimicrobial peptide aurein 1.2 and charged lipid bilayer. | aurein 1.2 is a potent antimicrobial peptide secreted by frog litoria aurea. as a short membrane-active peptide with only 13 amino acids in sequence, it has been found to be residing on the surface of lipid bilayer and permeabilizing bacterial membranes at high concentration. however, the detail at the molecular level is largely unknown. in this study, we investigated the action of aurein 1.2 in charged lipid bilayers composed of dmpc/dmpg. oriented circular dichroism results showed that the pep ... | 2017 | 28623332 |
| myxozoan infections of caecilians demonstrate broad host specificity and indicate a link with human activity. | myxozoans are parasitic cnidarians that infect a wide variety of hosts. vertebrates typically serve as intermediate hosts whereas definitive hosts are invertebrates, including annelids and bryozoans. myxozoans are known to exploit species in two of the three extant amphibian orders (anura: frogs and toads; caudata: newts and salamanders). here we use museum collections to determine, to our knowledge for the first time, whether myxozoans also exploit the third amphibian order (gymnophiona: caecil ... | 2016 | 26945641 |
| predator presence and vegetation density affect capture rates and detectability of litoria aurea tadpoles: wide-ranging implications for a common survey technique. | trapping is a common sampling technique used to estimate fundamental population metrics of animal species such as abundance, survival and distribution. however, capture success for any trapping method can be heavily influenced by individuals' behavioural plasticity, which in turn affects the accuracy of any population estimates derived from the data. funnel trapping is one of the most common methods for sampling aquatic vertebrates, although, apart from fish studies, almost nothing is known abou ... | 2015 | 26605923 |
| controls and constrains of the membrane disrupting action of aurein 1.2. | aurein 1.2 is a 13 residue antimicrobial peptide secreted by the australian tree frog litoria aurea. it is a surface-acting membrane disrupting peptide that permeabilizes bacterial membranes via the carpet mechanism; the molecular details of this process are mostly unknown. here the mechanism of action of aurein 1.2 was investigated with an emphasis on the role of membrane charge and c-terminal amidation of the peptide. using quartz crystal microbalance (qcm) fingerprinting it was found that the ... | 2015 | 26574052 |
| convergent evolution across the australian continent: ecotype diversification drives morphological convergence in two distantly related clades of australian frogs. | animals from different clades but subject to similar environments often evolve similar body shapes and physiological adaptations due to convergent evolution, but this has been rarely tested at the transcontinental level and across entire classes of animal. australia's biome diversity, isolation and aridification history provide excellent opportunities for comparative analyses on broad-scale macroevolutionary patterns. we collected morphological and environmental data on eighty-four (98%) austral ... | 2015 | 26450269 |
| helpful invaders: can cane toads reduce the parasite burdens of native frogs? | many invading species have brought devastating parasites and diseases to their new homes, thereby imperiling native taxa. potentially, though, invaders might have the opposite effect. if they take up parasites that otherwise would infect native taxa, but those parasites fail to develop in the invader, the introduced species might reduce parasite burdens of the native fauna. similarly, earlier exposure to the other taxon's parasites might 'prime' an anuran's immune system such that it is then abl ... | 2015 | 26236630 |
| refugia and connectivity sustain amphibian metapopulations afflicted by disease. | metapopulation persistence in fragmented landscapes depends on habitat patches that can support resilient local populations and sufficient connectivity between patches. yet epidemiological theory for metapopulations has largely overlooked the capacity of particular patches to act as refuges from disease, and has suggested that connectivity can undermine persistence. here, we show that relatively warm and saline wetlands are environmental refuges from chytridiomycosis for an endangered australian ... | 2015 | 26108261 |
| evaluating monitoring methods to guide adaptive management of a threatened amphibian (litoria aurea). | prompt detection of declines in abundance or distribution of populations is critical when managing threatened species that have high population turnover. population monitoring programs provide the tools necessary to identify and detect decreases in abundance that will threaten the persistence of key populations and should occur in an adaptive management framework which designs monitoring to maximize detection and minimize effort. we monitored a population of litoria aurea at sydney olympic park ... | 2014 | 24834332 |
| comparison of reversible membrane destabilisation induced by antimicrobial peptides derived from australian frogs. | the membrane destabilising properties of the antimicrobial peptides (amp) aurein 1.2, citropin 1.1, maculatin 1.1 and caerin 1.1, have been studied by dual polarisation interferometry (dpi). the overall process of peptide induced membrane destabilisation was examined by the changes in bilayer order as a function of membrane-bound peptide mass per unit area and revealed three different modes of action. aurein 1.2 was the only peptide that significantly destabilised the neutral membrane (dmpc), wh ... | 2014 | 24593995 |
| myxosporean parasites in australian frogs: importance, implications and future directions. | myxosporean parasites have been identified in amphibians around the world yet very little is known about their diversity, biology and host impact. several species of australian frogs have recently been shown to be affected by myxosporidiosis caused by two new cystodiscus species. in this manuscript, we review what is known about the myxosporean parasites cystodiscus australis and cystodiscus axonis that produce myxospores in gallbladders of australian frogs and myxobolus fallax and myxobolus hyl ... | 2013 | 24533318 |
| spatio-temporal changes in the structure of an australian frog hybrid zone: a 40-year perspective. | spatio-temporal studies of hybrid zones provide an opportunity to test evolutionary hypotheses of hybrid zone maintenance and movement. we conducted a landscape genetics study on a classic hybrid zone of the south-eastern australian frogs, litoria ewingii and litoria paraewingi. this hybrid zone has been comprehensively studied since the 1960s, providing the unique opportunity to directly assess changes in hybrid zone structure across time. we compared both mtdna and male advertisement call data ... | 2013 | 24299399 |
| the effect of stress and stress hormones on dynamic colour-change in a sexually dichromatic australian frog. | rapid colour changes in vertebrates have fascinated biologists for centuries, herein we demonstrate dynamic colour change in an anuran amphibian, the stony creek frog (litoria wilcoxii), which turns from brown to bright (lemon) yellow during amplexus. we show this by comparing the colour of baseline (unpaired males) and amplecting (paired) males. we also investigate the possible role of stress and stress hormones on this colour change. frogs were subjected to four different levels of stressors ( ... | 2013 | 23507571 |
| making friends: social attraction in larval green and golden bell frogs, litoria aurea. | socio-ecological models combine environmental and social factors to explain the formation of animal groups. in anurans, tadpole aggregations have been reported in numerous species, but the factors driving this behaviour remain unclear. we conducted controlled choice experiments in the lab to determine whether green and golden bell frog (litoria aurea) tadpoles are directly attracted to conspecifics (social factors) in the absence of environmental cues. using repeated measures, we found that indi ... | 2013 | 23424662 |
| comparative pathology and ecological implications of two myxosporean parasites in native australian frogs and the invasive cane toad. | myxosporean parasites cystodiscus axonis and c. australis are pathogens of native and exotic australian frog species. the pathology and ecological outcomes of infection with these parasites were investigated in this study. gliosis was correlated to cystodiscus axonis plasmodia in the brains of (9/60) tadpoles and (3/9) adult endangered green and golden bell frogs using ordinal regression. severe host reactions to c. axonis (haemorrhage, necrosis, and vasulitis) were observed in the brains of thr ... | 2012 | 23056175 |
| a suspected parasite spill-back of two novel myxidium spp. (myxosporea) causing disease in australian endemic frogs found in the invasive cane toad. | infectious diseases are contributing to the decline of endangered amphibians. we identified myxosporean parasites, myxidium spp. (myxosporea: myxozoa), in the brain and liver of declining native frogs, the green and golden bell frog (litoria aurea) and the southern bell frog (litoria raniformis). we unequivocally identified two myxidium spp. (both generalist) affecting australian native frogs and the invasive cane toad (bufo marinus, syn. rhinella marina) and demonstrated their association with ... | 2011 | 21541340 |
| removing the rubbish: frogs eliminate foreign objects from the body cavity through the bladder. | during the course of a telemetry study on three species of australian frogs (litoria caerulea, litoria dahlii and cyclorana australis), we found that many of the surgically implanted transmitters had migrated into the bladder. we subsequently implanted small beads into l. caerulea and they were expelled from the body in 10-23 days. beads implanted into cane toads (rhinella marina) to document the process were either expelled or were enveloped into the bladder. this appears to be a unique pathway ... | 2011 | 21147830 |
| [volutionary reorganizations of ontogenesis in related frog species of the family myobatrachidae]. | literary data on the comparative embryology of australian endemic frogs of the family myobatrachidae have been considered. six main types of development have been recognized, the important criteria for which are egg size, the site of embryo and tadpole development (in water or on land), the character of larval nutrition (exotrophic or endotrophic), the occurrence of direct development, brooding, etc. an attention has been also paid to the character of the early cleavage process in the embryos of ... | 2010 | 20583624 |
| metabolic depression during aestivation does not involve remodelling of membrane fatty acids in two australian frogs. | changes in membrane lipid composition (membrane remodelling) have been associated with metabolic depression in some aestivating snails but has not been studied in aestivating frogs. this study examined the membrane phospholipid composition of two australian aestivating frog species cyclorana alboguttata and cyclorana australis. the results showed no major membrane remodelling of tissue in either frog species, or in mitochondria of c. alboguttata due to aestivation. mitochondrial membrane remodel ... | 2009 | 19466430 |
| association of coloration mode with population declines and endangerment in australian frogs. | successful protection of biodiversity requires increased understanding of the ecological characteristics that predispose some species to endangerment. theory posits that species with polymorphic or variable coloration should have larger distributions, use more diverse resources, and be less vulnerable to population declines and extinctions, compared with taxa that do not vary in color. we used information from literature on 194 species of australian frogs to search for associations of coloration ... | 2009 | 19459895 |
| membrane interactions of antimicrobial peptides from australian frogs. | the membrane interactions of four antimicrobial peptides, aurein 1.2, citropin 1.1, maculatin 1.1 and caerin 1.1, isolated from australian tree frogs, are reviewed. all four peptides are amphipathic alpha-helices with a net positive charge and range in length from 13 to 25 residues. despite several similar sequence characteristics, these peptides compromise the integrity of model membrane bilayers via different mechanisms; the shorter peptides exhibit a surface interaction mechanism while the lo ... | 2009 | 19013126 |
| impact of the invasive cane toad (bufo marinus) on an australian frog (opisthodon ornatus) depends on minor variation in reproductive timing. | invasive species are widely viewed as unmitigated ecological catastrophes, but the reality is more complex. theoretically, invasive species could have negligible or even positive effects if they sufficiently reduce the intensity of processes regulating native populations. understanding such mechanisms is crucial to predicting ultimate ecological impacts. we used a mesocosm experiment to quantify the impact of eggs and larvae of the introduced cane toad (bufo marinus) on fitness-related traits (n ... | 2009 | 18853191 |
| body temperature and resistance to evaporative water loss in tropical australian frogs. | although the skin of most amphibians measured to date offers no resistance to evaporative water loss (ewl), some species, primarily arboreal frogs, produce skin secretions that increase resistance to ewl. at high air temperatures, it may be advantageous for amphibians to increase ewl as a means to decrease body temperature. in australian hylid frogs, most species do not decrease their resistance at high air temperature, but some species with moderate resistance (at moderate air temperatures) gra ... | 2008 | 16829148 |
| water relations of the burrowing sandhill frog, arenophryne rotunda (myobatrachidae). | arenophryne rotunda is a small (2-8 g) terrestrial frog that inhabits the coastal sand dunes of central western australia. while sand burrowing is a strategy employed by many frog species inhabiting australia's semi-arid and arid zones, a. rotunda is unique among burrowing species because it lives independently of free water and can be found nocturnally active on the dune surface for relatively extended periods. consequently, we examined the physiological factors that enable this unique frog to ... | 2006 | 16315052 |
| characterization of a protein-based adhesive elastomer secreted by the australian frog notaden bennetti. | when provoked, notaden bennetti frogs secrete an exudate which rapidly forms a tacky elastic solid ("frog glue"). this protein-based material acts as a promiscuous pressure-sensitive adhesive that functions even in wet conditions. we conducted macroscopic tests in air to assess the tensile strength of moist glue (up to 78 +/- 8 kpa) and the shear strength of dry glue (1.7 +/- 0.3 mpa). we also performed nanomechanical measurements in water to determine the adhesion (1.9-7.2 nn or greater), resil ... | 2013 | 16283759 |
| patterns and fitness consequences of intraclutch variation in egg provisioning in tropical australian frogs. | intraclutch variation in offspring size should evolve when offspring encounter unpredictable environmental conditions. this form of bet-hedging should maximise the lifetime reproductive success of individuals that engage it. we documented the numbers of eggs and means and variances of yolk volume in 15 frog species that occur in tropical savanna woodland. we experimentally determined the effects of initial yolk volume on larval growth patterns in four species. intraclutch variation in yolk volum ... | 2005 | 16003504 |
| the structural organization of aurein precursor cdnas from the skin secretion of the australian green and golden bell frog, litoria aurea. | aureins are a family of peptides (13-25 residues), some of which possess potent antimicrobial and anti-cancer properties, which have been classified into 5 subgroups based upon primary structural similarities. they were originally isolated from the defensive skin secretions of the closely related australian bell frogs, litoria aurea and litoria raniformis, and of the 23 aurein peptides identified, 10 are common to both species. using a recently developed technique, we have constructed a cdna lib ... | 2005 | 15721491 |
| host-defence peptides of australian anurans: structure, mechanism of action and evolutionary significance. | host-defence peptides secreted from the skin glands of australian frogs and toads, are, with a few notable exceptions, different from those produced by anurans elsewhere. this review summarizes the current knowledge of the following classes of peptide isolated and characterized from australian anurans: neuropeptides (including smooth muscle active peptides, and peptides that inhibit the production of nitric oxide from neuronal nitric oxide synthase), antimicrobial and anticancer active peptides, ... | 2004 | 15203252 |