The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Philip C. Withers - One of the best experts on this subject based on the ideXlab platform.
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Pulmonary compliance and lung volume varies with ecomorphology in anuran amphibians: implications for ventilatory-assisted lymph flux
Journal of Experimental Biology, 2011Co-Authors: Michael S. Hedrick, Stanley S. Hillman, Robert C. Drewes, Philip C. WithersAbstract:SUMMARY Vertical movement of lymph from ventral regions to the dorsally located lymph hearts in anurans is accomplished by specialized skeletal muscles working in concert with lung ventilation. We hypothesize that more terrestrial species with greater lymph mobilization capacities and higher lymph flux rates will have larger lung volumes and higher pulmonary compliance than more semi-aquatic or aquatic species. We measured in situ mean and maximal compliance (Δvolume/Δpressure), distensibility (%Δvolume/Δpressure) and lung volume over a range of physiological pressures (1.0 to 4.0 cmH2O) for nine species of anurans representing three families (Bufonide, Ranidae and Pipidae) that span a range of body masses and habitats from terrestrial to aquatic. We further examined the relationship between these pulmonary variables and lymph flux for a semi-terrestrial bufonid (Rhinella marina), a semi-aquatic ranid (Lithobates catesbeianus) and an aquatic pipid (Xenopus laevis). Allometric scaling of pulmonary compliance and lung volume with body mass showed significant differences at the family level, with scaling exponents ranging from ∼0.75 in Bufonidae to ∼1.3 in Pipidae. Consistent with our hypothesis, the terrestrial Bufonidae species had significantly greater pulmonary compliance and greater lung volumes compared with semi-aquatic Ranidae and aquatic Pipidae species. Pulmonary distensibility ranged from ∼20 to 35% cmH2O–1 for the three families but did not correlate with ecomorphology. For the three species for which lymph flux data are available, R. marina had a significantly higher (P
Rick A Relyea - One of the best experts on this subject based on the ideXlab platform.
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very highly toxic effects of endosulfan across nine species of tadpoles lag effects and family level sensitivity
Environmental Toxicology and Chemistry, 2009Co-Authors: Devin K Jones, John I Hammond, Rick A RelyeaAbstract:Pesticides are commonly used for health and economic benefits worldwide, but increased use has led to increased contamination of aquatic habitats. To understand potential impacts on nontarget organisms in these habitats, toxicologists generally use short-term (4-d) toxicity tests on model organisms. For most pesticides, few amphibian tests have been conducted, but there is growing concern about the potential impact of pesticides to amphibian populations. For the insecticide endosulfan, previous studies have found that low concentrations can be very highly toxic to amphibians and have suggested that this mortality may exhibit important lag effects. To estimate the lethal concentration of endosulfan that would cause 50% mortality after 4 d (LC504-d) across a diversity of amphibians and the presence of lag effects, LC504-d experiments were conducted on nine species of tadpoles from three families (Bufonidae: Bufo americanus, B. boreas; Hylidae: Pseudacris crucifer, P. regilla, Hyla versicolor, and Ranidae: Rana pipiens, R. clamitans, R. cascadae, R. catesbeiana) and then held the animals for an additional 4 d in clean water. The LC504-d values for endosulfan ranged from 1.3 to 120 ppb, which classifies endosulfan as highly toxic to very highly toxic. Moreover, holding the animals for an additional 4 d in clean water revealed significant additional mortality in three of the nine species. Leopard frogs, for example, experienced no significant death during the initial 4-d exposure to 60 ppb but 97% death after an additional 4 d in clean water. A phylogenetic pattern also appears to exist among families, with Bufonidae being least susceptible, Hylidae being moderately susceptible, and Ranidae being most susceptible. Results from the present study provide valuable data to assess the impact of endosulfan on a globally declining group of vertebrates.
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VERY HIGHLY TOXIC EFFECTS OF ENDOSULFAN ACROSS NINE SPECIES OF TADPOLES: LAG EFFECTS AND FAMILY-LEVEL SENSITIVITY
2009Co-Authors: Devin K Jones, John I Hammond, Rick A RelyeaAbstract:Abstract—Pesticides are commonly used for health and economic benefits worldwide, but increased use has led to increased contamination of aquatic habitats. To understand potential impacts on nontarget organisms in these habitats, toxicologists generally use short-term (4-d) toxicity tests on model organisms. For most pesticides, few amphibian tests have been conducted, but there is growing concern about the potential impact of pesticides to amphibian populations. For the insecticide endosulfan, previous studies have found that low concentrations can be very highly toxic to amphibians and have suggested that this mortality may exhibit important lag effects. To estimate the lethal concentration of endosulfan that would cause 50 % mortality after 4 d (LC504-d) across a diversity of amphibians and the presence of lag effects, LC504-d experiments were conducted on nine species of tadpoles from three families (Bufonidae: Bufo americanus, B. boreas; Hylidae: Pseudacris crucifer, P. regilla, Hyla versicolor; and Ranidae: Rana pipiens, R. clamitans, R. cascadae, R. catesbeiana) and then held the animals for an additional 4 d in clean water. The LC504-d values for endosulfan ranged from 1.3 to 120 ppb, which classifies endosulfan as highly toxic to very highly toxic. Moreover, holding the animals for an additional 4 d in clean water revealed significant additional mortality in three of the nine species. Leopard frogs, for example, experienced no significant death during the initial 4-d exposure to 60 ppb but 97 % death after an additional 4 d in clean water. A phylogenetic pattern also appears to exist among families, with Bufonidae being least susceptible, Hylidae being moderately susceptible, and Ranidae being most susceptible. Results from the present study provide valuable data to assess the impact of endosulfan on a globally declining group of vertebrates. Keywords—Ecotoxicology Amphibian decline Nontarget Anuran Contaminan
Jennifer B Pramuk - One of the best experts on this subject based on the ideXlab platform.
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around the world in 10 million years biogeography of the nearly cosmopolitan true toads anura Bufonidae
Global Ecology and Biogeography, 2007Co-Authors: Jennifer B Pramuk, Tasia Robertson, Jack W Sites, Brice P NoonanAbstract:Aim The species-rich family of true toads (Anura: Bufonidae) has been the focus of several earlier studies investigating the biogeography of geographically widespread taxa. Herein, we employ newly developed Bayesian divergence estimate methods to investigate the biogeographical history of this group. Resulting age estimates are used to test several key temporal hypotheses including that the origin of the bufonid clade pre-dates Gondwanan vicariance (~105 million years ago, Ma). Area cladograms are also invoked to investigate the geographical origin of the family. Location Worldwide, except the Australia‐New Guinea plate, Madagascar and the Antarctic. Methods A phylogenetic hypothesis of the relationships among true toads was derived from analysis of 2521 bp of DNA data including fragments from three mitochondrial ( 12S , tRNA val , 16S ) and two nuclear ( RAG-1 , CXCR-4 ) genes. Analysis of multiple, unlinked loci with a Bayesian method for estimating divergence times allowed us to address the timing and biogeographical history of Bufonidae. Resulting divergence estimates permitted the investigation of alternative vicariance/dispersal scenarios that have been proposed for true toads. Results Our area cladogram resulting from phylogenetic analysis of DNA data supports a South American origin for Bufonidae. Divergence estimates indicate that the family originated earlier than had been suggested previously (78‐99 Ma). The age of the enigmatic Caribbean clade was dated to the late Palaeocene‐early Eocene. A return of bufonids to the New World in the Eocene was followed by rapid diversification and secondary expansion into South America by the early Oligocene (Rupelian). Main conclusions The South American origin of Bufonidae in the Upper Cretaceous was followed by relatively rapid expansion and radiation around the globe, ending with a return to the Americas via a Eurasian/North American land bridge in the Eocene. Though the exact route of this dispersal (Beringia or North Atlantic) remains unclear, an argument is made for the less frequently invoked North Atlantic connection. The origin of the enigmatic Caribbean lineage was found to be consistent with colonization following the bolide impact at the K/T boundary. These findings provide the first, firm foundation for understanding true toad divergence times and their truly remarkable and global radiation.
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phylogeny of south american bufo anura Bufonidae inferred from combined evidence
Zoological Journal of the Linnean Society, 2006Co-Authors: Jennifer B PramukAbstract:Despite the considerable research that has focused on the evolutionary relationships and biogeography of the genus Bufo, an evolutionary synthesis of the entire group has not yet emerged. In the present study, almost 4 kb of DNA sequence data from mitochondrial (12S, tRNAVal, and 16S) and nuclear (POMC; Rag-1) genes, and 83 characters from morphology were analysed to infer a phylogeny of South American toads. Phylogenies were reconstructed with parsimony and maximum likelihood and Bayesian model-based methods. The results of the analysis of morphological data support the hypothesis that within Bufo, some skull characters (e.g. frontoparietal width), correlated with the amount of cranial ossification, are prone to homoplasy. Unique and unreversed morphological synapomorphies are presented that can be used to diagnose recognized species groups of South American toads. The results of all phylogenetic analyses support the monophyly of most species groups of South American Bufo. In most DNA-only and combined analyses, the South American (minus the B. guttatus and part of the ‘B. spinulosus’ groups), North American, Central American, and African lineages form generally well-supported clades: ((((((((South America) (North America + Central America)) Eurasia) Africa) Eurasia) South America) West Indies) South America). This result confirms and extends prior studies recovering South American Bufo as polyphyletic. The biogeographical results indicate that: (1) The origin of Bufo predates the fragmentation of Gondwana; (2) Central and North American species compose the sister group to a large, ‘derived’ clade of South American Bufo; and (3) Eurasian species form the sister group to the New World clade. © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society, 2006, 146, 407–452.
Qurniawan, Tony Febri - One of the best experts on this subject based on the ideXlab platform.
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Amfibi dan Reptil Karst Gunung Sewu Zona Batur Agung, Gunung Kidul, Daerah Istimewa Yogyakarta
'Universitas Atma Jaya Yogyakarta', 2014Co-Authors: Qurniawan, Tony FebriAbstract:An inventory study of amphibians and reptiles from Karst Zone Batur Agung Gunung Kidul, Yogyakarta was carried out for first time. Exploration was conducted in July-August 2007, May-June 2008 and April 2009 at four districts of Patuk, Playen, Ngawen and Gedangsari. The results showed findings of 9 species of amphibians and 22 species of reptiles. Total of those amphibians and reptiles were recorded, the largest species of amphibian was Duttaphrynus melanostictus (Bufonidae) and Fejervarya limnocharis (Dicroglossidae). The largest species of reptile was Hemydactylus frenatus (Gekkonidae), Lygosoma bowringii (Scincidae), Ramphotyphlops braminus (Typhlopidae), Eutropis multifasciata (Scincidae) and Ahaetulla prasina (Colubridae). Keywords: Biodiversity, herpetofauna, Wanagama forest, Wonosadi forest, Bunder forestAbstrakStudi inventarisasi amfibi dan reptil telah dilakukan untuk permata kali di Zona Karst Batur Agung Gunung Kidul Yogyakarta. Penelitian berlangsung dari bulan Juli-Agustus 2007, Mei-Juni 2008 dan April 2009 di empat kecamatan, yaitu Patuk, Playen, Ngawen, dan Gedangsari. Hasil penelitian menunjukkan bahwa ditemukan 9 jenis amfibi dan 22 jenis reptil. Total keseluruhan jumlah jenis amfibi dan reptil tersebut, jenis amfibi yang melimpah yaitu Duttaphrynus melanostictus (Bufonidae) dan Fejervarya limnocharis (Dicroglossidae). Jenis reptil yang melimpah yaitu Hemydactylus frenatus (Gekkonidae), Lygosoma bowringii (Scincidae), Ramphotyphlops braminus (Typhlopidae), Eutropis multifasciata (Scincidae) dan Ahaetulla prasina (Colubridae). Kata kunci: Biodiversitas, herpetofauna, hutan Wanagama, hutan Wonosadi, hutan Bunde
Qurniawan T. F. - One of the best experts on this subject based on the ideXlab platform.
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Amfibi Dan Reptil Karst Gunung Sewu Zona Batur Agung, Gunung Kidul, Daerah Istimewa YOGYAKARTA
Atma Jaya University Yogyakarta, 2013Co-Authors: Qurniawan T. F.Abstract:An inventory study of amphibians and reptiles from Karst Zone Batur Agung Gunung Kidul, Yogyakarta was carried out for first time. Exploration was conducted in July-August 2007, May-June 2008 and April 2009 at four districts of Patuk, Playen, Ngawen and Gedangsari. The results showed findings of 9 species of amphibians and 22 species of reptiles. Total of those amphibians and reptiles were recorded, the largest species of amphibian was Duttaphrynus melanostictus (Bufonidae) and Fejervarya limnocharis (Dicroglossidae). The largest species of reptile was Hemydactylus frenatus (Gekkonidae), Lygosoma bowringii (Scincidae), Ramphotyphlops braminus (Typhlopidae), Eutropis multifasciata (Scincidae) and Ahaetulla prasina (Colubridae)
