236 research outputs found

    Karyotype of a Ranid Frog, Platymantis pelewensis, from Belau, Micronesia, with Comments on Its Systematic Implications

    Get PDF
    The karyotype of Platymantis pelewensis Peters, 1867, the only native, endemic amphibian in Belau, extremely isolated from other congeners, consisted of 2n = 22 homologous chromosomes largely forming a graded series. Of these, chromosomes of pairs 1, 5, 6, 8, 10, and 11 were metacentric; the remainder were submetacentric. Secondary constrictions were evident on shorter arms of pair 7. This karyotype is nearly identical with that of P. papuensis Meyer from New Guinea, but is distinct from two Philippine congeners hitherto karyotyped both in chromosome number and morphology. This suggests that the ancestral form of P. pelewensis dispersed from New Guinea or other Melanesian islands

    A checklist of chromosome numbers of South Asian reptiles

    Get PDF
    The chromosome numbers of 119 species of reptiles that occur in the south Asian region are listed. The inventory includes three crocodiles, 13 turtles, 54 lizards and 49 snakes. This represents about a fourth of the known species of the subcontinent. Cytogenetic information in many cases offers clues to the detection of cryptic species overlooked by morphological taxonomists

    Finding Euroscaptor mizura (Mammalia : Insectivora) and Its Nest from under Hebeloma radicosum (Fungi : Agaricales) in Ashiu, Kyoto, with Data of Possible Contiguous Occurrences of Three Talpine Species in This Region

    Get PDF
    We examined nests and other traces of moles in Ashiu, Kyoto, beneath fruit bodies of a mushroom species, Hebeloma radicosum, which grows on the underground latrines of small mammals. We also attempted to catch animals at nesting sites which were detected through the fungal fruiting. As a result, an adult specimen of a talpine mole species, Euroscaptor mizura, was collected together with its nest. This is the first record of E. mizura from Ashiu region. Also, this is the first report of the nest of E. mizura, of the mushroom-mole nest association in H. radicosum and E. mizura, and of the capture of a mole at the nesting site under indication of the fungus. Morphological features of the animal and structure of the nest are described. This finding further revealed a contiguousness in the distribution of three talpine species, E. mizura, Mogera wogura and Mogera kobeae in Ashiu

    A snail-eating snake recognizes prey handedness

    Get PDF
    Specialized predator-prey interactions can be a driving force for their coevolution. Southeast Asian snail-eating snakes (Pareas) have more teeth on the right mandible and specialize in predation on the clockwise-coiled (dextral) majority in shelled snails by soft-body extraction. Snails have countered the snakes’ dextral-predation by recurrent coil reversal, which generates diverse counterclockwise-coiled (sinistral) prey where Pareas snakes live. However, whether the snake predator in turn evolves any response to prey reversal is unknown. We show that Pareas carinatus living with abundant sinistrals avoids approaching or striking at a sinistral that is more difficult and costly to handle than a dextral. Whenever it strikes, however, the snake succeeds in predation by handling dextral and sinistral prey in reverse. In contrast, P. iwasakii with little access to sinistrals on small peripheral islands attempts and frequently misses capturing a given sinistral. Prey-handedness recognition should be advantageous for right-handed snail-eating snakes where frequently encountering sinistrals. Under dextral-predation by Pareas snakes, adaptive fixation of a prey population for a reversal gene instantaneously generates a sinistral species because interchiral mating is rarely possible. The novel warning, instead of sheltering, effect of sinistrality benefitting both predators and prey could further accelerate single-gene ecological speciation by left-right reversal.ArticleScientific Reports.6:23832(2016)journal articl

    The herpetofauna of the Babuyan Islands, Northern Philippines

    Get PDF
    We document 52 species of amphibians and reptiles from the Babuyan Islands in the northern Philippines. Among these records, 12 species are endemic to the Babuyan Islands and another 18 are endemic to the Philippines. Prevalence of endemic forms in the island group is high, with 1–3 island-endemic species present in each of the major islands. The present-day assemblage of herpetofauna in the island group is attributed to dispersal from Luzon and subsequent diversification. No evidence of successful southward colonization of species from Taiwan is found. Based on data from our own surveys, and to enable future work, we provide an updated list of the species from the Babuyan and Batanes Island groups. Molecular phylogenetic studies are recommended to gain more insights into the evolutionary history of the island-endemic forms and the biogeography of the small islands between Luzon and Taiwan

    Phylogenetic Relationships of Eublepharid Geckos (Reptilia: Squamata): A Molecular Approach

    Get PDF
    Phylogenetic analyses were carried out for representatives of all eublepharid genera and afew other gekkonoid taxa using sequence data for 879 base pairs of mitochondrial 12S and 16S ribosomalRNA genes. Neighbor-joining (NJ) distance analysis of the data suggested independent great divergencesof Coleonyx and Aeluroscalabotes, and monophyly of the remainder within Eublepharidae (bootstrap proportion[BP]=76%). Of the latter, the two African genera, Hemitheconyx and Holodactylus, were almost certainlymonophyletic altogether (BP=99%), whereas their sister-group relationship with Eublepharis received a weaker,but still substantial support (BP=68%). Within Goniurosaurus kuroiwae, G. k. splendens first diverged fromthe remainder (BP=100%), followed by G. k. kuroiwae from the northern part of Okinawajima (BP=100%): G.k. kuroiwae from the southern part of Okinawajima and G. k. orientalis, differing from each other at onlyseven bases, diverged finally (BP=99%). Parsimony analysis yielded results consistent with those of NJanalysis with respect to the monophyly of the two African genera and relationships within G. kuroiwae, butretained the other relationships within Eublepharidae unresolved. Our results, while showing no seriousdiscrepancies with the relationships among eublepharid genera hypothesized from morphological data, casta serious doubt to the currently accepted population systematics within G. kuroiwae. Furthermore, results ofboth analyses suggested a closer affinity of Diplodactylinae (as represented by Rhacodactylus trachyrhynchus)with Eublepharidae, rather than with Gekkoninae. Our study lends a robust support to the Laurasian origin ofthe family Eublepharidae

    Influence of Deposition Condition on Y 2

    Get PDF
    Y2O3 nanoparticle suspension aqueous solution was prepared using citric acid. Then, Y2O3 film was deposited using this solution with pulsed electrophoretic deposition (EPD). A dense Y2O3 film of 25.7 μm thickness was obtained with deposition conditions of 0.5 wt% Y2O3 concentration, bias voltage of 0.5 V, and bias frequency of 1 kHz. The respective resistivities of the as-deposited film and films heat-treated at 200°C and 400°C were 2.84 × 103 Ω·cm, 5.36 × 104 Ω·cm, and 2.05 × 106 Ω·cm. A 59.8 μm thick dense Y2O3 film was obtained using two-step deposition with change of the bias voltage: a first step of 0.5 V and a second step of 2.0 V
    corecore