Search results for "amphibian"

Phylogeny and classification of poison frogs (Amphibia: dendrobatidae), based on mitochondrial 16S and 12S ribosomal RNA gene sequences.

2000

An analysis of partial sequences of the 16S ribosomal rRNA gene (582 bp) of 20 poison frog species (Dendrobatidae) confirmed their phylogenetic relationships to bufonid and leptodactylid frogs. Representatives of the ranoid families and subfamilies Raninae, Mantellinae, Petropedetinae, Cacosterninae, Arthroleptidae, Astylosternidae, and Microhylidae did not cluster as sister group of the Dendrobatidae. Similar results were obtained in an analysis using a partial sequence of the 12S gene (350 bp) in a reduced set of taxa and in a combined analysis. Within the Dendrobatidae, our data supported monophyly of the genus Phyllobates but indicated paraphyly of Epipedobates and Colostethus. Minyobat…

Cracking the nut: Geographical adjacency of sister taxa supports vicariance in a polytomic salamander clade in the absence of node support

2008

The urodelan genus Lyciasalamandra, which inhabits a relatively small area along the southern Turkish coast and some Aegean islands, provides an outstanding example of a diverse but phylogenetically unresolved taxon. Molecular trees contain a single basal polytomy that could be either soft or hard. We here use the information of nuclear (allozymes) and mitochondrial (fractions of the 16S rRNA and ATPase genes) datasets in combination with area relationships of lineages to resolve the phylogenetic relationships among Lyciasalamandra species in the absence of sufficient node support. We can show that neither random processes nor introgressive hybridization can be invoked to explain that the m…

Cytotoxicity and antimitotic activity of Rhinella schneideri and Rhinella marina venoms.

2019

Abstract Ethnopharmacological relevance Rhinella schneideri and Rhinella marina are toad venoms distributed in different parts of the world, including Brazil, Columbia and amazon. Venoms extracted from different species have many clinical applications such as antimicrobial cardiotonics and treatment of cancer. Aim of the study; In this study, we aim to investigate the effect of venoms extracted from R. schneideri and R. marina on cancer cells and verify possible mechanism of action. Material and method Cytotoxicity analyses was performed using the resazurin reduction assay, where different concentrations of venoms were tested against sensitive CCRF-CEM and P-gp overexpressing ADR/CEM5000 le…

Indagine su due popolazioni di rana verde (Pelophylax synklepton hispanicus) della Sicilia occidentale

2008

Contribution to the knowledge of Tunisian amphibians: notes on distribution, habitat features and breeding phenology

2009

In order to improve the knowledge on amphibian fauna in Tunisia, about 300 water bodies belonging to different habitat typologies were sampled during the period 2004-2008. At the sites where amphibians were observed, we recorded the UTM coordinates, the altitude, and the following environmental features: habitat typology, hydroperiod, electric conductivity, temperature, water turbidity, and macrophyte coverage. The presence of the seven species currently known with certainty for Tunisia has been confirmed: Pleurodeles nebulosus, Discoglossus pictus, Bufo bufo, B. mauritanicus, B. boulengeri, Hyla meridionalis and Pelophylax saharicus. Conversely, no evidence on the occurrence of Salamandra …

Contribute to the knowledge of Tunisian amphibians: Notes on distribution, habitat features and phenology

2007

The evolutionary course of vertebrate foot, from fish to man

2009

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…

Molecular markers and species delimitation: examples from the European batrachofauna

1996

AbstractMolecular techniques have revolutionised zoological systematics since the beginning of the seventies. Within the last twenty years numerous new amphibian species have been described in Europe almost solely on the basis of molecular data. This paper focuses on the use of molecular character state and genetic distance data for the delimitation of species. Case studies of European anurans (Discoglossus, water frogs of the genus Rana) are discussed in the framework of concurring species concepts to illustrate problems of assigning species status to divergent populations on the basis of molecular data.

Ornamentation of dermal bones of

2017

Background Amphibians are animals strongly dependent on environmental conditions, like temperature, water accessibility, and the trophic state of the reservoirs. Thus, they can be used in modern palaeoenvironmental analysis, reflecting ecological condition of the biotope. Methods To analyse the observed diversity in the temnospondyl Metoposaurus krasiejowensis from Late Triassic deposits in Krasiejów (Opole Voivodeship, Poland), the characteristics of the ornamentation (such as grooves, ridges, tubercules) of 25 clavicles and 13 skulls were observed on macro- and microscales, including the use of a scanning electron microscope for high magnification. The different ornamentation patterns fou…