62 research outputs found

    Trade in wild anurans vectors the urodelan pathogen Batrachochytrium salamandrivorans into Europe

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    Pathogen pollution has caused dramatic losses of amphibian diversity on a global scale. The recently emerged chytrid fungus Batrachochytrium salamandrivorans (Bsal) has been hypothesized to have its origin in Asian urodelan populations, from which it may have been introduced to Europe through the trade in live urodelans. We here show that Bsal is present on wild small-webbed fire-bellied toads (Bombina microdeladigitora) from Vietnam and on representatives of the same species that have recently been imported in Germany. This finding suggests that the installment of measures to mitigate the Bsal threat through the amphibian trade should not be limited to urodeles, but should equally take anurans into account

    A New Species of Tylototriton from Northern Vietnam (Amphibia: Urodela: Salamandridae)

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    A new species of the salamandrid genus Tylototriton is described from Ha Giang and Cao Bang provinces, northern Vietnam, based on molecular and morphological data. The new species differs morphologically from all known congeners in the combination of blackish body coloration; medium-sized body; distinctly rough skin; tubercular vertebral ridge; knob-like rib nodules; large eye; and low, narrow tail. The distribution pattern of species of Tylototriton in Vietnam is briefly discussed

    A new species of Tritetrabdella (Hirudinida: Hirudiniformes: Haemadipsidae) from northern Indochina

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    A new species of the terrestrial haemadipsid genus Tritetrabdella, Tritetrabdella longiducta, from northern Indochina is described. The new species is distinguished from all congeners by the combination of triannulate somite VII, uniannulate somite XXV, three lobes of respiratory auricles in somites XXV–XXVII, 57 friction rays on caudal sucker, male gonopore (in somite XI b5/b6) and female gonopore (in somite XII b5) positions and slightly folded vaginal sac. Phylogenetic analyses using nuclear 18S rRNA and 28S rRNA, in addition to mitochondrial cytochrome c oxidase subunit I markers, confirmed that the new species forms a unique lineage among the known congeners. A key to all the species of Tritetrabdella is provided

    A giant crocodile skull from Can Tho, named “Dau Sau”, represents the largest known saltwater crocodile (Crocodylus porosus) ever reported from Vietnam

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    We report on a large crocodile skull recovered from a river bank in August 2010 near Đầu Sấu Bridge, in An Binh, Ninh Kieu District, Cần Thơ Province, in southern Vietnam. As the skull from Cần Thơ, named “Đầu Sấu“ herein, is now deposited in the Vietnam National Museum of Nature, Hanoi, we reinvestigated the circumstances surrounding its discovery and provide exact measurements. Skull length (dorsal mid-point) is 70.7 cm. The morphological features confirm it is from a Saltwater crocodile (Crocodylus porosus), and not a Siamese crocodile (C. siamensis), which historically also occurred throughout the Mekong Delta of Vietnam. Skull measurements are compared with those of other large C. porosus skulls for which reliable estimates of total length are available. We also provide measurements of the prepared skull of “Lolong” (69.8 cm), a 6.17 m long C. porosus captured in the Philippines in 2011. On the basis of known skull length:total length ratios the crocodile from Cần Thơ is estimated to be 6.3-6.8 m long. The skull of Đầu Sấu is likely to have been buried for at least 100 years. We discuss the origin of the local name Đầu Sấu, which has traditional and cultural significance, and provide historical reports of crocodiles in the area. Đầu Sấu is smaller than the largest known C. porosus skull (76 cm), but is the largest ever reported from Vietnam, and one of the largest C. porosus known.

    Batrachochytrium salamandrivorans is the predominant chytrid fungus in Vietnamese salamanders

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    The amphibian chytrid fungi, Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), pose a major threat to amphibian biodiversity. Recent evidence suggests Southeast Asia as a potential cradle for both fungi, which likely resulted in widespread host-pathogen co-existence. We sampled 583 salamanders from 8 species across Vietnam in 55 locations for Bsal and Bd, determined scaled mass index as a proxy for fitness and collected environmental data. Bsal was found within 14 of the 55 habitats (2 of which it was detected in 2013), in 5 salamandrid species, with a prevalence of 2.92%. The globalized pandemic lineage of Bd was found within one pond on one species with a prevalence of 0.69%. Combined with a complete lack of correlation between infection and individual body condition and absence of indication of associated disease, this suggests low level pathogen endemism and Bsal and Bd co-existence with Vietnamese salamandrid populations. Bsal was more widespread than Bd, and occurs at temperatures higher than tolerated by the type strain, suggesting a wider thermal niche than currently known. Therefore, this study provides support for the hypothesis that these chytrid fungi may be endemic to Asia and that species within this region may act as a disease reservoir

    Morphological and molecular characteristics of Panax sp. (Araliaceae) from Phu Xai lai leng mountain, Nghe An province, Vietnam

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    Seven sterile and young specimens of Panax sp. were collected in Phu Xai Lai Leng silicat mountain, the highest mountain  peak in central Vietnam. Morphologically, they resemble P. stipuleanatus and P. bipinnatifidus. However, they have stipules and leaflets that are not bipinnatifid. The ITS-DNA sequences of Panax sp. from Phu Xai Lai Leng are identical and exhibit a close relationship with P. stipuleanatus from Tam Duong district, Lai Chau province with strong bootstrap support (98%). Noticeably, these two taxa  are different by 2 nucleotides. A collection of standard specimens including inflorescence, infructescence, flowers and ripe fruits of Panax from Phu Xai Lai Leng is needed to determine its taxonomic status.

    The Three Pillars of Machine Programming

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    In this position paper, we describe our vision of the future of machine programming through a categorical examination of three pillars of research. Those pillars are:(i) intention,(ii) invention, and (iii) adaptation. Intention emphasizes advancements in the human-to-computer and computer-to-machine-learning interfaces. Invention emphasizes the creation or refinement of algorithms or core hardware and software building blocks through machine learning (ML). Adaptation emphasizes advances in the use of ML-based constructs to autonomously evolve software

    Dramatic Dietary Shift Maintains Sequestered Toxins in Chemically Defended Snakes

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    Unlike other snakes, most species of Rhabdophis possess glands in their dorsal skin, sometimes limited to the neck, known as nucho-dorsal and nuchal glands, respectively. Those glands contain powerful cardiotonic steroids known as bufadienolides, which can be deployed as a defense against predators. Bufadienolides otherwise occur only in toads (Bufonidae) and some fireflies (Lampyrinae), which are known or believed to synthesize the toxins. The ancestral diet of Rhabdophis consists of anuran amphibians, and we have shown previously that the bufadienolide toxins of frog-eating species are sequestered from toads consumed as prey. However, one derived clade, the Rhabdophis nuchalis Group, has shifted its primary diet from frogs to earthworms. Here we confirm that the worm-eating snakes possess bufadienolides in their nucho-dorsal glands, although the worms themselves lack such toxins. In addition, we show that the bufadienolides of R. nuchalis Group species are obtained primarily from fireflies. Although few snakes feed on insects, we document through feeding experiments, chemosensory preference tests, and gut contents that lampyrine firefly larvae are regularly consumed by these snakes. Furthermore, members of the R. nuchalis Group contain compounds that resemble the distinctive bufadienolides of fireflies, but not those of toads, in stereochemistry, glycosylation, acetylation, and molecular weight. Thus, the evolutionary shift in primary prey among members of the R. nuchalis Group has been accompanied by a dramatic shift in the source of the species’ sequestered defensive toxins
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