Search results for "Amphibian"
showing 10 items of 61 documents
Indagine su due popolazioni di rana verde (Pelophylax synklepton hispanicus) della Sicilia occidentale
2008
Molecular phylogenetics and historical biogeography of the west-palearctic common toads (Bufo bufo species complex)
2012
In most pan-Eurasiatic species complexes, two phenomena have been traditionally considered key processes of their cladogenesis and biogeography. First, it is hypothesized that the origin and development of the Central Asian Deserts generated a biogeographic barrier that fragmented past continuous distributions in Eastern and Western domains. Second, Pleistocene glaciations have been proposed as the main process driving the regional diversification within each of these domains. The European common toad and its closest relatives provide an interesting opportunity to examine the relative contributions of these paleogeographic and paleoclimatic events to the phylogeny and biogeography of a wide…
2020
While many morphological, physiological, and ecological characteristics of organisms scale with body size, some do not change under size transformation. They are called invariant. A recent study recommended five criteria for identifying invariant traits. These are based on that a trait exhibits a unimodal central tendency and varies over a limited range with body mass (type I), or that it does not vary systematically with body mass (type II). We methodologically improved these criteria and then applied them to life history traits of amphibians, Anura, Caudata (eleven traits), and reptiles (eight traits). The numbers of invariant traits identified by criteria differed across amphibian orders…
Pentadactyl manus of the Metoposaurus krasiejowensis from the Late Triassic of Poland, the first record of pentadactyly among Temnospondyli
2020
Abstract Temnospondyli are commonly believed to have possessed four digits in the manus and five in the pes. However, actual finds of articulated autopodia are extremely rare. Therefore, an articulated, slightly incomplete forelimb skeleton with preserved manus of Metoposaurus krasiejowensis from the Late Triassic of Poland is important in providing new details about the structure and ossification sequence in the temnospondyl limb. The most important observation is the presence of five metacarpals in this specimen. This allows reconstructing the manus as pentadactyl. The number of phalanges and the distribution of distal articulation facets allow reconstruction of the digit formula as (2?)‐…
Influenza del dimorfismo comportamentale nella stima della grandezza di popolazione. Il caso di Bufo viridis.
2007
Can the introduction of Xenopus laevis affect native amphibian populations? Reduction of reproductive occurrence in presence of the invasive species
2010
Biological invasions are regarded as a form of global change and potential cause of biodiversity loss. Xenopus laevis is an anuran amphibian native to sub-Saharan Africa with strong invasive capacity, especially in geographic regions with a Mediterranean climate. In spite of the worldwide diffusion of X. laevis, the effective impact on local ecosystems and native amphibian populations is poorly quantified. A large population of X. laevis occurs in Sicily and our main aim of this work was to assess the consequences of introduction of this alien species on local amphibian populations. In this study we compare the occurrence of reproduction of native amphibians in ponds with and without X. lae…
Blood Anticoagulant Activity of Sulphated Ovular Mucins of Amphibians
1957
THE mucin constituting the gelatinous layer which envelops the eggs of Bufo bufo, if digested with papain and then sulphated, shows a marked anticoagulant activity on the fibrinogen and the whole blood plasma1. A similar anticoagulant activity has now been shown by the ovular mucins of other species of amphibians, sulphated without any previous proteolysis.
Amphibians of the Kayan Mentarang National Park (East Kalimantan, Indonesia): estimating overall and local species richness
2004
On the basis of surveys since 1997 and an intensive survey at the World Wildlife Fund field station at Lalut Birai in 2001, we assessed the importance of the Kayan Mentarang National Park in East Kalimantan for the conservation of Borneo's amphibian fauna. Sixty-five frog species and one Caecilian species are currently known to occur in this region. We report their occurrence in 16 subareas. Most of the species were recorded at Upper Bahau (41) and at the Lalut Birai field station (33). Based on the results of opportunistic searches and transect censuses at Lalut Birai, we argue that the amphibian diversity of the national park is still greatly underestimated.