| chromosome banding in amphibia. xxi. inversion polymorphism and multiple nucleolus organizer regions in agalychnis callidryas (anura, hylidae). | cytogenetic analyses were performed on several populations of the central american tree frog agalychnis callidryas, using conventional methods and banding techniques. the karyotype of this species is distinguished by an inversion polymorphism in chromosome 9, which is either submetacentric or telocentric. the populations examined are in hardy-weinberg equilibrium with respect to the two alternative morphs of chromosome 9. this is the first report of the occurrence of an intrapopulational chromos ... | 1995 | 7835080 |
| tachykinins and other biologically active peptides from the skin of the costa rican phyllomedusid frog agalychnis callidryas. | peptides present in a methanol extract prepared from skin of the costa rican frog agalychnis callidryas of the phyllomedusinae subfamily were studied by sequence analysis and pharmacological tests. members of five different peptide families-tachykinins, bradykinins, caerulein, opioid peptides and sauvagine-were found. in particular, the extract contained a number of tachykinins with the following sequences: gly-pro-pro-asp-pro-asn-lys-phe-ile-gly-leu-met-nh2, gly-pro-pro-asp-pro-asp-arg(lys)-phe ... | 1997 | 9145422 |
| discordant patterns of evolutionary differentiation in two neotropical treefrogs. | comparative studies of codistributed taxa test the degree to which historical processes have shaped contemporary population structure. discordant patterns of lineage divergence among taxa indicate that species differ in their response to common historical processes. the complex geologic landscape of the isthmus of central america provides an ideal setting to test the effects of vicariance and other biogeographic factors on population history. we compared divergence patterns between two codistrib ... | 2009 | 19368645 |
| genetic diversification, vicariance, and selection in a polytypic frog. | spatial patterns of heritable phenotypic diversity reflect the relative roles of gene flow and selection in determining geographic variation within a species. we quantified color differentiation and genetic divergence among 20 populations of the red-eyed tree frog (agalychnis callidryas) in lower central america. phylogenetic analyses revealed 5 well-supported mitochondrial dna clades, and we infer from our phylogeny that geographic barriers have played a large role in structuring populations. t ... | 2009 | 19589848 |
| the shape of things to come: linking developmental plasticity to post-metamorphic morphology in anurans. | development consists of growth and differentiation, which can be partially decoupled and can be affected by environmental factors to different extents. in amphibians, variation in the larval environment influences development and causes changes in post-metamorphic shape. we examined post-metamorphic consequences, both morphological and locomotory, of alterations in growth and development. we reared tadpoles of two phylogenetically and ecologically distant frog species (the red-eyed treefrog agal ... | 2010 | 20492091 |
| larval epidermis of the red eye tree frog agalychnis callidryas (anura, hylidae): ultrastructural investigation on the kugelzellen, specialized forms of the constitutive skein cell line. | an ultrastructural study was carried out on the epidermis of agalychnis callidryas tadpoles during limb development. larval epidermis consisted of four cell layers: basal, lower intermediate, upper intermediate, and surface or apical layers. basal cells represented the stem compartment of intermediate cells: both belong to the skein cell (sc) lineage, described in several anuran species, on account of the conspicuous intracytoplasmic tonofilament bundles. apical cells were secretory in nature an ... | 2011 | 21809457 |
| ex situ diet influences the bacterial community associated with the skin of red-eyed tree frogs (agalychnis callidryas). | amphibians support symbiotic bacterial communities on their skin that protect against a range of infectious pathogens, including the amphibian chytrid fungus. the conditions under which amphibians are maintained in captivity (e.g. diet, substrate, enrichment) in ex situ conservation programmes may affect the composition of the bacterial community. in addition, ex situ amphibian populations may support different bacterial communities in comparison to in situ populations of the same species. this ... | 2014 | 24416427 |
| effects of visible implanted elastomer marking on physiological traits of frogs. | amphibians possess innate immune defences, including antimicrobial peptides and symbiotic bacterial communities, that can protect them from infectious diseases, including chytridiomycosis. on-going research is attempting to use amphibian symbiotic bacteria to develop probiotic treatments that can protect hosts from the causative agent of chytridiomycosis, the fungal pathogen batrachochytrium dendrobatidis. events that cause disruption of symbiotic bacterial communities or deplete peptide stores ... | 2014 | 27293663 |
| efficacy of treatment and long-term follow-up of batrachochytrium dendrobatidis pcr-positive anurans following itraconazole bath treatment. | all anuran specimens in the wildlife conservation society's collections testing positive for batrachochytrium dendrobatidis (bd) were treated with itraconazole and then studied after treatment to assess the long-term effects of itraconazole and the drug's effectiveness in eliminating bd carriers. twenty-four individuals and eight colonies of 11 different species (75 total specimens) tested positive for bd via polymerase chain reaction (pcr) on multicollection survey. all positive individuals and ... | 2013 | 23805558 |
| act-2: a novel myotropic and antimicrobial type 2 tryptophyllin from the skin secretion of the central american red-eyed leaf frog, agalychnis callidryas. | tryptophyllins are a diverse family of amphibian peptides originally found in extracts of phyllomedusine frog skin by chemical means. their biological activities remain obscure. here we describe the isolation and preliminary pharmacological characterization of a novel type 2 tryptophyllin, named act-2, from the skin secretion of the red-eyed leaf frog, agalychnis callidryas. the peptide was initially identified during smooth muscle pharmacological screening of skin secretion hplc fractions and t ... | 2014 | 24693226 |
| medusins: a new class of antimicrobial peptides from the skin secretions of phyllomedusine frogs. | natural drug discovery represents an area of research with vast potential. the investigation into the use of naturally-occurring peptides as potential therapeutic agents provides a new "chemical space" for the procurement of drug leads. intensive and systematic studies on the broad-spectrum antimicrobial peptides found in amphibian skin secretions are of particular interest in the quest for new antibiotics to treat multiple drug-resistant bacterial infections. here we report the molecular clonin ... | 2013 | 23415652 |
| a new red-eyed treefrog of agalychnis (anura: hylidae: phyllomedusinae) from middle magdalena river valley of colombia with comments on its phylogenetic position. | we describe a new species of the charismatic red-eyed treefrogs (genus agalychnis) from middle magdalena river valley of colombia (05°50'8.04"n, 74°50'16.55"w, 380 m a.s.l.). the new species is readily distinguished from all species members of the group by having orange flanks with small white warts. phylogenetic analysis of dna sequences of 16s rrna gene recovered the new species as a member of the agalychnis callidryas group. the presence of a red hue in the iris and a golden reticulated palpe ... | 2013 | 26042285 |
| colouration in amphibians as a reflection of nutritional status: the case of tree frogs in costa rica. | colouration has been considered a cue for mating success in many species; ornaments in males often are related to carotenoid mobilization towards feathers and/or skin and can signal general health and nutrition status. however, there are several factors that can also link with status, such as physiological blood parameters and body condition, but there is not substantial evidence which supports the existence of these relationships and interactions in anurans. this study evaluated how body score ... | 2017 | 28837604 |
| the hatching process and mechanisms of adaptive hatching acceleration in hourglass treefrogs, dendropsophus ebraccatus. | environmentally cued hatching is well documented in anurans, enabling embryos to escape diverse threats. however, knowledge of anuran hatching mechanisms is limited and based largely on aquatic-breeding species without known plasticity in hatching timing. generally, hatching gland cells produce a hatching enzyme that degrades the vitelline membrane. we investigated hatching and its regulation in terrestrial embryos of hourglass treefrogs, dendropsophus ebraccatus, which accelerate hatching to es ... | 2017 | 29056480 |
| egg clutch dehydration induces early hatching in red-eyed treefrogs, agalychnis callidryas. | terrestrial eggs have evolved repeatedly in tropical anurans exposing embryos to the new threat of dehydration. red-eyed treefrogs, agalychnis callidryas, lay eggs on plants over water. maternally provided water allows shaded eggs in humid sites to develop to hatching without rainfall, but unshaded eggs and those in less humid sites can die from dehydration. hatching responses of amphibian eggs to dry conditions are known from two lineages with independent origins of terrestrial eggs. here, we e ... | 2017 | 28717595 |
| variation in male spermiation response to exogenous hormones among divergent populations of red-eyed treefrogs. | the non-lethal collection of sperm from live males is an important component for multiple captive-breeding techniques, including assisted reproductive technology (art) protocols, sperm cryopreservation and in vitro fertilization. however, in amphibians, the type and amount of hormone necessary to induce spermiation can be highly variable, even among closely related species. we are unaware of any studies that have examined the spermiation response to exogenous hormones across highly differentiate ... | 2016 | 27919288 |
| skin of the red eye tree frog agalychnis callidryas (hylidae, phyllomedusinae) contains lipid glands of the type described in the genus phyllomedusa. | several anuran species of the genus phyllomedusa are known to possess specialized cutaneous glands producing lipids and exhibit a peculiar wiping behavior. this behavior is a stereotyped repertory of fore and hind limb movements distributing hydrophobic molecules onto the body surface and reducing evaporative water loss. no reports are presently available on the occurrence of lipid glands in other phyllomedusine genera, and data on the structure of the secretory units specialized for the product ... | 2017 | 27741569 |
| acute, chronic and biochemical effects of chlorothalonil on agalychnis callidryas, isthmohyla pseudopuma and smilisca baudinii tadpoles. | declines of amphibian populations have been a worldwide issue of concern for the scientific community during the last several decades. efforts are being carried out to elucidate factors related to this phenomenon. among these factors, pathogens, climate change, and environmental pollution have been suggested as possible causes. regarding environmental pollutants, some pesticides are persistent in the environment and capable of being transported long distances from their release point. in costa r ... | 2016 | 27495920 |
| how embryos escape from danger: the mechanism of rapid, plastic hatching in red-eyed treefrogs. | environmentally cued hatching allows embryos to escape dangers and exploit new opportunities. such adaptive responses require a flexibly regulated hatching mechanism sufficiently fast to meet relevant challenges. anurans show widespread, diverse cued hatching responses, but their described hatching mechanisms are slow, and regulation of timing is unknown. arboreal embryos of red-eyed treefrogs, agalychnis callidryas, escape from snake attacks and other threats by very rapid premature hatching. w ... | 2016 | 27307544 |
| additive effects of mean temperature, temperature variability, and chlorothalonil to red-eyed treefrog (agalychnis callidryas) larvae. | amphibian populations are declining globally, and multiple anthropogenic stressors, including contamination by pesticides and shifting climates, are driving these declines. climate change may increase average temperatures or increase temperature variability, either of which may affect the susceptibility of nontarget organisms to contaminants. eight-day ecotoxicological assays were conducted with red-eyed treefrog (agalychnis callidryas) larvae to test for additive and interactive effects of expo ... | 2016 | 27163793 |
| putting μ/g in a new light: plasticity in life history switch points reflects fine-scale adaptive responses. | life history theory predicts that organisms with complex life cycles should transition between life stages when the ratio of growth rate (g) to risk of mortality (µ) in the current stage falls below that in the subsequent stage. empirical support for this idea has been mixed. implicit in both theory and empirical work is that the risk of mortality in the subsequent stage is unknown. however, some embryos and larvae of both vertebrates and invertebrates assess cues of post-transition predation ri ... | 2015 | 26405744 |
| the scotopic and photopic visual sensitivity in the nocturnal tree frog agalychnis callidryas. | the red-eyed tree frog (agalychnis callidryas) is endemic to the rainforests of central america. during the night, it hunts for insects in the treetops whereas at daytime, the frogs rest under leaves. in the present study we determined the relative visual sensitivity spectrum of this nocturnal frog species by erg recordings in both the dark- and light-adapted state. in both the scotopic- and photopic-sensitivity curve, we found only minor individual variations among the tested individuals. the s ... | 2015 | 26184717 |
| identification and functional analysis of a novel tryptophyllin peptide from the skin of the red-eye leaf frog, agalychnis callidryas. | amphibian skin has proved repeatedly to be a largely untapped source of bioactive peptides and this is especially true of members of the phyllomedusinae subfamily of frogs native to south and central america. tryptophyllins are a group of peptides mainly found in the skin of members of this genus. in this study, a novel tryptophyllin (tph) type 3 peptide, named act-3, has been isolated and structurally-characterised from the skin secretion and lyophilised skin extract of the red-eye leaf frog, a ... | 2015 | 25561903 |
| plastic hatching timing by red-eyed treefrog embryos interacts with larval predator identity and sublethal predation to affect prey morphology but not performance. | many animals respond to predation risk by altering their morphology, behavior, or life-history. we know a great deal about the cues prey respond to and the changes to prey that can be induced by predation risk, but less is known about how plastic responses to predators may be affected by separate plastic responses occurring earlier in life, particularly during the embryonic period. embryos of a broad array of taxa can respond to egg- or larval-stage risks by altering hatching timing, which may a ... | 2014 | 24967896 |
| acute toxicity tests and meta-analysis identify gaps in tropical ecotoxicology for amphibians. | amphibian populations are declining worldwide, particularly in tropical regions where amphibian diversity is highest. pollutants, including agricultural pesticides, have been identified as a potential contributor to decline, yet toxicological studies of tropical amphibians are very rare. the present study assesses toxic effects on amphibians of 10 commonly used commercial pesticides in tropical agriculture using 2 approaches. first, the authors conducted 8-d toxicity assays with formulations of ... | 2014 | 24934557 |
| maternally derived chemical defences are an effective deterrent against some predators of poison frog tadpoles (oophaga pumilio). | parents defend their young in many ways, including provisioning chemical defences. recent work in a poison frog system offers the first example of an animal that provisions its young with alkaloids after hatching or birth rather than before. but it is not yet known whether maternally derived alkaloids are an effective defence against offspring predators. we identified the predators of oophaga pumilio tadpoles and conducted laboratory and field choice tests to determine whether predators are dete ... | 2014 | 24850895 |
| consequences of induced hatching plasticity depend on predator community. | many prey species face trade-offs in the timing of life history switch points like hatching and metamorphosis. costs associated with transitioning early depend on the biotic and abiotic conditions found in the subsequent life stage. the red-eyed treefrog, agalychnis callidryas, faces risks from predators in multiple, successive life stages, and can hatch early in response to mortality threats at the egg stage. here we tested how the consequences of life history plasticity, specifically early hat ... | 2014 | 24844644 |
| impact of plant cover on fitness and behavioural traits of captive red-eyed tree frogs (agalychnis callidryas). | despite the importance of ex situ conservation programmes as highlighted in the amphibian conservation action plan, there are few empirical studies that examine the influence of captive conditions on the fitness of amphibians, even for basic components of enclosure design such as cover provision. maintaining the fitness of captive amphibian populations is essential to the success of ex situ conservation projects. here we examined the impact of plant cover on measures of fitness and behaviour in ... | 2014 | 24740289 |
| bradykinin-related peptides (brps) from skin secretions of three genera of phyllomedusine leaf frogs and their comparative pharmacological effects on mammalian smooth muscles. | while bradykinin has been identified in the skin secretions from several species of amphibian, bradykinin-related peptides (brps) are more common constituents. these peptides display a plethora of primary structural variations from the type peptide which include single or multiple amino acid substitutions, n- and/or c-terminal extensions and post-translational modifications such as proline hydroxylation and tyrosine sulfation. such modified peptides have been reported in species from many famili ... | 2014 | 24394432 |
| non-invasive measurement of frog skin reflectivity in high spatial resolution using a dual hyperspectral approach. | most spectral data for the amphibian integument are limited to the visible spectrum of light and have been collected using point measurements with low spatial resolution. in the present study a dual camera setup consisting of two push broom hyperspectral imaging systems was employed, which produces reflectance images between 400 and 2500 nm with high spectral and spatial resolution and a high dynamic range. | 2013 | 24058464 |
| behavioral plasticity mitigates risk across environments and predators during anuran metamorphosis. | most animals metamorphose, changing morphology, physiology, behavior and ecological interactions. size- and habitat-dependent mortality risk is thought to affect the evolution and plastic expression of metamorphic timing, and high predation during the morphological transition is posited as a critical selective force shaping complex life cycles. nonetheless, empirical data on how risk changes across metamorphosis and stage-specific habitats, or how that varies with size, are rare. we examined pre ... | 2013 | 23824140 |
| interactive effects of pesticide mixtures, predators, and environmental regimes on the toxicity of two pesticides to red-eyed tree frog larvae. | global amphibian declines have many corroborative causes, and the use of pesticides in agriculture is a likely contributor. in places with high pesticide usage, such as costa rica, agrochemical pesticides may interact with other factors to contribute to rapid species losses. classical ecotoxicological studies rarely address the effects of a pesticide in combination with other stressors. the present study investigated the synergistic roles of 2 pesticides (chlorothalonil and endosulfan), predator ... | 2013 | 23804394 |
| prey subsidy or predator cue? direct and indirect effects of caged predators on aquatic consumers and resources. | the non-consumptive effects of predators on prey can affect prey phenotypes, potentially having important consequences for communities due to trait-mediated indirect interactions. predicting non-consumptive effects and their impacts on communities can be difficult because predators can affect resources directly through nutrient cycling and indirectly by altering prey resource use, which can lead to complex interactions among resources and consumers. in this study we examined the effects of caged ... | 2013 | 23771817 |
| risk-induced hatching timing shows low heritability and evolves independently of spontaneous hatching in red-eyed treefrogs. | plasticity in the timing of transitions between stages of complex life cycles allows organisms to adjust their growth and development to local environmental conditions. genetic variation in such plasticity is common, but the evolution of context-dependent transition timing may be constrained by information reliability, lag-time and developmental constraints. we studied the genetic architecture of hatching plasticity in embryos of the red-eyed treefrog (agalychnis callidryas) in response to simul ... | 2013 | 23621370 |
| prey responses to predator chemical cues: disentangling the importance of the number and biomass of prey consumed. | to effectively balance investment in predator defenses versus other traits, organisms must accurately assess predation risk. chemical cues caused by predation events are indicators of risk for prey in a wide variety of systems, but the relationship between how prey perceive risk in relation to the amount of prey consumed by predators is poorly understood. while per capita predation rate is often used as the metric of relative risk, studies aimed at quantifying predator-induced defenses commonly ... | 2012 | 23082171 |
| clutch identity and predator-induced hatching affect behavior and development in a leaf-breeding treefrog. | for species with complex life cycles, transitions between life stages result in niche shifts that are often associated with evolutionary trade-offs. when conditions across life stages are unpredictable, plasticity in niche shift timing may be adaptive; however, factors associated with clutch identity (e.g., genetic or maternal) may influence the effects of such plasticity. the red-eyed treefrog (agalychnis callidryas) is an ideal organism for investigating the effects of genetics and life stage ... | 2013 | 23011848 |
| effects of size and size structure on predation and inter-cohort competition in red-eyed treefrog tadpoles. | individual and relative body size are key determinants of ecological performance, shaping the strength and types of interactions within and among species. size-dependent performance is particularly important for iteroparous species with overlapping cohorts, determining the ability of new cohorts to invade habitats with older, larger conspecifics. we conducted two mesocosm experiments to examine the role of size and size structure in shaping growth and survival in tadpoles of the red-eyed treefro ... | 2012 | 22565492 |
| a novel kazal-type trypsin inhibitor from the skin secretion of the central american red-eyed leaf frog, agalychnis callidryas. | the chemical complexity of the defensive skin secretion of the red-eyed leaf frog, (agalychnis callidryas), has not been elucidated in detail. during a systematic study of the skin secretion peptidomes of phyllomedusine frogs, we discovered a novel kazal-type protein with potent trypsin inhibitory activity (ki = 1.9 nm) that displays the highest degree of structural similarity with kazal proteins from bony fishes. the protein was located in reverse-phase hplc fractions following a screen of such ... | 2012 | 22464955 |
| wasp predation drives the assembly of fungal and fly communities on frog egg masses. | community ecology aims to understand how species interactions shape species diversity and abundance. although less studied than predatory or competitive interactions, facilitative interactions can be important in communities associated with ephemeral microhabitats. successful recruitment from these habitats requires species to rapidly colonize, develop, and disperse during brief periods of habitat suitability. interactions between organisms, including processing chain interactions whereby initia ... | 2012 | 22011841 |
| carry-over effects of the larval environment on post-metamorphic performance in two hylid frogs. | life history theory and empirical studies suggest that large size or earlier metamorphosis are suitable proxies for increased lifetime fitness. thus, across a gradient of larval habitat quality, individuals with similar phenotypes for these traits should exhibit similar post-metamorphic performance. here we examine this paradigm by testing for differences in post-metamorphic growth and survival independent of metamorphic size in a temperate (spring peeper, pseudacris crucifer) and tropical (red- ... | 2010 | 20658150 |
| vibrational signaling in the agonistic interactions of red-eyed treefrogs. | sensitivity to substrate-borne vibrations is widespread in animals and evolutionarily precedes hearing but, compared with other sensory modalities, we know little about vibrational communication, particularly in vertebrates. for plant-dwelling arthropods, vibrations are likely as important as sound. arboreal vertebrates excite plant vibrations with most movements, but the behavioral relevance of these vibrations has not been tested experimentally. in playback experiments using a robotic model fr ... | 2010 | 20493702 |
| 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 |
| to hatch and hatch not: similar selective trade-offs but different responses to egg predators in two closely related, syntopic treefrogs. | risk-sensitive hatching is adaptive for species facing a trade-off between egg-stage and post-hatching risks, and environmental variation in one or both stages. such plasticity has been found in amphibians, fishes, reptiles and spiders, with red-eyed treefrogs (agalychnis callidryas) being the best-studied case. we assessed hatching plasticity and egg- and larval-stage risks in a closely related, syntopic species, the gliding leaf-frog (agalychnis spurrelli). we found a lower hatching response t ... | 2007 | 17375328 |
| opposite shifts in size at metamorphosis in response to larval and metamorph predators. | predation risk can cause organisms to alter the timing of life history switch points. theory suggests that increased risk in an early life stage should select for switching earlier and smaller, while increased risk in the subsequent stage should select for switching later and larger. this framework has frequently been applied to metamorphosis in amphibians, with mixed results. few studies examining the effect of larval predation risk on metamorphosis have observed the predicted pattern, and no s ... | 2006 | 16602285 |
| temporal pattern cues in vibrational risk assessment by embryos of the red-eyed treefrog, agalychnis callidryas. | the embryos of red-eyed treefrogs, agalychnis callidryas, use vibrations transmitted through their arboreal egg clutch to cue escape hatching behavior when attacked by egg-eating snakes. hatching early increases the risk of predation in the water, so embryos should avoid it unless they are in danger. we exposed egg clutches to intermittent vibrations with different combinations of vibration duration and spacing to examine the role of simple temporal pattern cues in the escape hatching response. ... | 2006 | 16574797 |
| development, surface exposure, and embryo behavior affect oxygen levels in eggs of the red-eyed treefrog, agalychnis callidryas. | oxygen stress can slow development, induce hatching, and kill eggs. terrestrial anamniote embryos face a potential conflict between oxygen uptake and water loss. we measured oxygen levels within eggs to characterize the respiratory environment for embryos of the red-eyed treefrog, agalychnis callidryas, a neotropical frog with arboreal egg masses and plastic hatching timing. perivitelline oxygen partial pressure (po2) was extremely variable both within and among eggs. po2 increased with air-expo ... | 2013 | 16228935 |
| hatching timing, oxygen availability, and external gill regression in the tree frog, agalychnis callidryas. | the physiological role of the embryonic external gills in anurans is equivocal. in some species, diffusion alone is clearly sufficient to supply oxygen throughout the embryonic period. in others, morphological elaboration and environmental regulation of the external gills suggest functional importance. since oxygen stress is a common trigger of hatching, i examined the relationships among hatching timing, oxygen stress, and external gill loss. i worked with the red-eyed tree frog, agalychnis cal ... | 2016 | 12024291 |
| do prostaglandins regulate external gill regression in anurans? | although the endocrinological mechanism controlling regression of the internal, larval gills of anurans (frogs and toads) is well understood, the mechanism regulating loss of the external, embryonic gills is not known. based on the homology of the mammalian ductus arteriosus with a portion of the amphibian branchial arches, and the regulation of blood flow in the mammalian ductus by prostaglandins of the e family (pges), we hypothesized that anuran external gill loss is also regulated by pges. t ... | 2001 | 11351324 |
| environmental and developmental effects on external gill loss in the red-eyed tree frog, agalychnis callidryas. | i examined the effects of development, hatching, and oxygen availability on external gill loss in red-eyed tree frogs, agalychnis callidryas. under natural conditions, the arboreal embryos maintained large external gills until hatching, which occurred from 5-8 d after oviposition. at hatching, when tadpoles entered the water, external gills began to regress. in older hatchlings this process was extremely rapid. gill circulation was lost on average within 16 min and sometimes within 5 min. gills ... | 2013 | 11073790 |
| wasp predation and wasp-induced hatching of red-eyed treefrog eggs. | eggs often suffer high levels of predation and, compared with older animals, embryos have few options available for antipredator defence. none the less, hatchlings can escape from many predators to which eggs are vulnerable. i studied early hatching as an antipredator defence of red-eyed treefrog embryos, agalychnis callidryas, in response to egg predation by social wasps (polybia rejecta). red-eyed treefrogs attach their eggs to vegetation overhanging water, where they are exposed to arboreal a ... | 2000 | 11032653 |
| multiple paternity in the red-eyed treefrog agalychnis callidryas (cope). | dna fingerprinting of tadpoles from two different 'one female-two male' matings of the red-eyed treefrog, agalychnis callidryas, revealed multiple paternity of offspring. offspring were assigned paternity based on bands shared with the putative father, but not shared between putative fathers or with the mother. paternity was split approximately 44/56% and 36/64% in two matings. these results do not support a hypothesis of sperm priority in access to unfertilized eggs by primary males. multiple p ... | 1995 | 8574447 |
| adaptive plasticity in hatching age: a response to predation risk trade-offs. | the life histories of many animals are characterized by niche shifts, the timing of which can strongly affect fitness. in the tree frog agalychnis callidryas, which has arboreal eggs, there is a trade-off between predation risks before and after hatching. when eggs are attacked by snakes, tadpoles escape by hatching rapidly and falling into the water below. eggs not attacked by snakes hatch later, when newly emerged tadpoles are less vulnerable to aquatic predators. plasticity in hatching allows ... | 1995 | 11607529 |
| patterns of reproduction and habitat use in an assemblage of neotropical hylid frogs. | we censused pond-breeding hylid frogs in northeastern costa rica weekly for 15 months to deseribe patterns of reproduction, habitat use, and to establish baseline data on relative abundance for members of the assemblage. reproduction in the costa rican assemblage was seasonal and occurred only during wet months. some species called, but none reproduced, during the dry season. three species (agalychnis callidryas, hyla ebraccata, and scinax elaeochroa) accounted for more than 75% of the observati ... | 1994 | 28313905 |
| identification and rational design of a novel antibacterial peptide dermaseptin-ac from the skin secretion of the red-eyed tree frog agalychnis callidryas. | antibiotic resistance represents a tremendous contemporary clinical challenge. given this challenge, antimicrobial peptides (amps) are regarded as one of the most promising new options for next-generation lead antibiotics. here, we describe the antibacterial activities of a cationic peptide named drp-ac4, obtained from frog skin secretion using shotgun cloning. two modified peptides were derived by substituting the sequence of amino acids to complete the hydrophobic face (drp-ac4b) and increase ... | 2020 | 32397600 |
| skin bacterial communities of neotropical treefrogs vary with local environmental conditions at the time of sampling. | the amphibian skin microbiome has been the focus of recent studies aiming to better understand the role of these microbial symbionts in host defense against disease. however, host-associated microbial communities are complex and dynamic, and changes in their composition and structure can influence their function. understanding temporal variation of bacterial communities on amphibian skin is critical for establishing baselines from which to improve the development of mitigation techniques based o ... | 2019 | 31275740 |
| genetic and phenotypic evidence of a contact zone between divergent colour morphs of the iconic red-eyed treefrog. | hybrid zones act as natural laboratories where divergent genomes interact, providing powerful systems for examining the evolutionary processes underlying biological diversity. in this study, we characterized patterns of genomic and phenotypic variation resulting from hybridization between divergent intraspecific lineages of the neotropical red-eyed treefrog (agalychnis callidryas). we found genetic evidence of a newly discovered contact zone and phenotypic novelty in leg colour-a trait suspected ... | 2020 | 32945036 |
| how do red-eyed treefrog embryos sense motion in predator attacks? assessing the role of vestibular mechanoreception. | the widespread ability to alter timing of hatching in response to environmental cues can serve as a defense against threats to eggs. arboreal embryos of red-eyed treefrogs, agalychnis callidryas, can hatch up to 30% prematurely to escape predation. this escape-hatching response is cued by physical disturbance of eggs during attacks, including vibrations or motion, and thus depends critically on mechanosensory ability. predator-induced hatching appears later in development than flooding-induced, ... | 2019 | 31586019 |
| when and where to hatch? red-eyed treefrog embryos use light cues in two contexts. | hatching timing is under strong selection and environmentally cued in many species. embryos use multiple sensory modalities to inform hatching timing and many have spontaneous hatching patterns adaptively synchronized to natural cycles. embryos can also adaptively shift their hatching timing in response to environmental cues indicating immediate threats or opportunities. such cued shifts in hatching are widespread among amphibians; however, we know little about what, if anything, regulates their ... | 2018 | 30533307 |
| genetic variation and selection of mhc class i loci differ in two congeneric frogs. | major histocompatibility complex (mhc) genes encode proteins in the acquired immune response pathway that often show distinctive selection-driven patterns in wild vertebrate populations. we examined genetic variation and signatures of selection in the mhc class i alpha 1 (a1)- and alpha 2 (a2)-domain encoding exons of two frog congeners [agalychnis callidryas (n = 20) and a. lemur (n = 20)] from a single locality in panama. we also investigated how historical demographic processes may have impac ... | 2018 | 29450668 |