101 research outputs found

    Déclin précipité du Triton de Poiret Pleurodeles poireti Gervais, 1835 et autres changements du statut des amphibiens de Numidie, Algérie du Nord-Est

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    The worldwide erosion of biological diversity has not spared amphibians which are amongst the most affected taxa with numerous extinct or near-extinct species. Our knowledge of the status and ecology of amphibians of Algeria is still limited whereas local natural habitats are fast disappearing under a strong anthropogenic pressure. Eighty two localities were sampled between 1996 and 2010, to survey the amphibian community within Numidia, North-Eastern Algeria. Nine species, three Urodeles (Pleurodeles poireti, Pleurodeles nebulosus and Salamandra algira and six Anurans (Bufo bufo spinosus, Bufo mauritanicus, Bufo viridis, Discoglossus pictus, Hyla meridionalis and Pelophylax saharicus) were found within the region. Results suggest a marked, rapid and unexplained crash of the Algerian Newt Pleurodeles poireti, a species endemic to a small area in and around Djebel Edough (Annaba). Information on the status (abundance and distribution) of each recorded taxon is provided and conservation measures are discussed in the light of an apparent local decline of Anurans and the vulnerability of three species (S. algira, P. nebulosus and B. bufo spinosus)La crise aiguë que traverse la biodiversité à l'échelle planétaire n'a pas épargné les amphibiens qui figurent parmi les taxons les plus touchés, illustrés par le déclin prononcé ou la disparition de plusieurs espèces. Notre connaissance du statut et de l'écologie des amphibiens d'Algérie reste limitée alors que les milieux naturels locaux subissent une pression anthropique intense qui ne fait que s'accroître et qui risque de s'exacerber sous l'effet du réchauffement climatique. Dans le but d'inventorier et d'évaluer le statut du peuplement d'amphibiens du complexe de zones humides de la Numidie, «point chaud» pour de nombreux taxons aquatiques et poche relictuelle afrotropicale, nous avons échantillonné 82 sites entre 1996 et 2010. Un total de neuf espèces dont trois Urodèles (Pleurodeles poireti Gervais, 1835, Pleurodeles nebulosus (Guichenot, 1850) et Salamandra algira Bedriaga, 1883) et six Anoures (Bufo bufo spinosus, Bufo mauritanicus Schlegel, 1841, Bufo viridis Laurenti, 1768, Discoglossus picrus Otth, 1837, HYla meridionalis Boettger, 1874 et Pelophylax saharicus Boulanger in Hartert, 1913) ont été inventoriées. Un fait marquant est le déclin net, rapide et inexpliqué du Triton de Poiret Pleurodeles poireti, espèce endémique à une région limitée au Djebel Edough et ses environs, au cours des dernières années. Le statut de trois espèces (S. algira, P. nebulosus and B. bufo spinosus) semble préoccupant au vu des pressions anthropogéniques qui s'exercent sur la Numidie qui abrite 82% des amphibiens d'Algérie

    The origins and spread of domestic horses from the Western Eurasian steppes

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    This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: All collapsed and paired-end sequence data for samples sequenced in this study are available in compressed fastq format through the European Nucleotide Archive under accession number PRJEB44430, together with rescaled and trimmed bam sequence alignments against both the nuclear and mitochondrial horse reference genomes. Previously published ancient data used in this study are available under accession numbers PRJEB7537, PRJEB10098, PRJEB10854, PRJEB22390 and PRJEB31613, and detailed in Supplementary Table 1. The genomes of ten modern horses, publicly available, were also accessed as indicated in their corresponding original publications57,61,85-87.NOTE: see the published version available via the DOI in this record for the full list of authorsDomestication of horses fundamentally transformed long-range mobility and warfare. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling at Botai, Central Asia around 3500 BC. Other longstanding candidate regions for horse domestication, such as Iberia and Anatolia, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 BC, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 BC driving the spread of Indo-European languages. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium BC Sintashta culture

    Aquatic Hemiptera of northeastern Algeria: Distribution, phenology and conservation

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    A survey, involving the sampling of 83 sites, investigated the aquatic hemiptera of northeastern Algeria, a well known hotspot of aquatic biodiversity. The study recorded 35 species with data on distribution and phenology presented and discussed. Aspects of the life history of some species (Notonecta glauca and Notonecta obliqua) were inferred from their distribution and phenology and they were found to aestivate at high altitude refuges. Insect conservation in North Africa is still embryonic, relying mainly on protected areas to provide surrogate conservation to a rich and diverse group. This is inadequate in view of the current distribution of aquatic insects, often located in unprotected habitats (intermittent streams, temporary pools, dunary ponds) and the fact that diverse manifestations of global changes (loss of habitats due to water extraction and dam construction, invasive species, habitat fragmentation) are fast eroding the biodiversity of protected areas.Hémiptères aquatiques du nord-est de l’Algérie : distribution, phénologie et conservation. L’échantillonnage de 83 sites à travers le complexe de zones humides du nord-est Algérien, un point chaud de la biodiversité aquatique, a permis d’identifier 35 espèces d’hémiptères aquatiques. La répartition et la phénologie des espèces sont présentées et les histoires de vie de Notonecta glauca et Notonecta obliqua déduites. Ces deux espèces estivent dans des milieux refuges à hautes altitudes avant de redescendre se reproduire en plaine à l’automne. Diverses manifestations de changements globaux (pompage de l’eau, construction de barrages, introduction d’espèces exotiques et fragmentation des milieux) influencent négativement l’intégrité écologique des milieux de la région étudiée.Annani Fouzi, Alfarhan Ahmed, Samraoui Boudjéma. Aquatic Hemiptera of northeastern Algeria: Distribution, phenology and conservation. In: Revue d'Écologie (La Terre et La Vie), tome 67, n°4, 2012. pp. 423-435

    How recent innovations in gas chromatography-mass spectrometry have improved pesticide residue determination: An alternative technique to be in your radar

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    Recent advances in gas chromatography-mass spectrometry (GC-MS) (ionization sources at atmospheric pressure, fast GC, GCxGC, high resolution mass spectrometry, etc.) have significantly improved the capabilities of this technique, traditionally used to determine pesticides. Although liquid chromatography mass spectrometry (LC-MS/MS) is nowadays preferred, pyrethroids and organochlorine pesticides are more sensitive by GC-MS and a significant number of other pesticides work well by both techniques. Here, we critically review the development, instrumentation, approaches and applications of GC-MS, focusing on the analysis of pesticide residues published between 2000 and 2019 along with outstanding pioneer contributions, with special emphasis on those published after 2010. This review attempts to fill a void of information on the state-of-art of GC-MS for pesticide residue determination, describing the pros and cons of the different approaches, and the main applications.The financial support from the project number (RSP-2019/11) from King Saud University, Saudi Arabia is gratefully acknowledged.Peer reviewe
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